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Purpose: To compare the parameters and indices of a novel swept-source optical coherence tomography device (SS-OCT, ANTERION) with those of a rotating Scheimpflug camera (RSC)-based tomograph (Pentacam) in normal and keratoconic (KC) eyes., Methods: This prospective, monocentric, cross-sectional study included individuals with unoperated normal and KC eyes, selecting one eye per subject. Ectasia-specific parameters analysed with the SS-OCT were difference in mean keratometry (K mean ) in the inferior and superior meridians, maximum keratometry value (K max ), elevation of the posterior surface at the thinnest point, screening corneal objective risk of ectasia (SCORE) and thinnest point thickness. With the RSC, parameters determined were Belin/Ambrosio total deviation value (BAD-D), index of height decentration and index of vertical asymmetry. KC classification with the SS-OCT was based on the anterior and posterior radii of curvature and thinnest point thickness according to the ABCD classification of the RSC system., Results: This study included 117 individuals with healthy eyes and 335 eyes with KC. The indices with the highest diagnostic discriminatory ability between the two cohorts were SCORE, difference of K mean in the inferior and superior meridians and posterior elevation of the thinnest point (SS-OCT), as well as the index of height decentration, index of vertical asymmetry and BAD-D (RSC). The classifications using SS-OCT defined mild-stage KC as K max , posterior elevation of the thinnest point and thinnest point thickness as ≤50.9 D, ≤30 and ≥472 μm, respectively. Moderate stage values were 51-55.9 D, 31-69 and 471-438 μm, respectively, while respective advanced stage were ≥56 D, ≥70 and ≤437 μm., Conclusion: The diagnostic capabilities for both devices were found to be comparable. KC classification using SS-OCT can be independently based on the anterior surface, posterior surface and corneal thickness., (© 2024 The Author(s). Ophthalmic and Physiological Optics published by John Wiley & Sons Ltd on behalf of College of Optometrists.)

Introduction: This study aimed to compare the consistency of pupil offset measurements obtained using the Pentacam, Keratron Scout, and Sirius devices., Methods: This retrospective cross-sectional study included 146 young myopic individuals (292 eyes) scheduled for refractive surgery at Dalian Third People's Hospital between January 2023 and December 2023. Three devices were utilized to measure the chord mu of the pupil deviation along with the Cartesian distances of the X and Y coordinates (Px, Py) associated with the pupil offset. Repeated-measures analysis of variance was used to compare differences in pupil offset acquisition across various devices. Additionally, the intraclass correlation coefficient (ICC) and Bland-Altman plot were utilized to assess the consistency among the three devices., Results: Chord mu, measured using the Pentacam, Keratron Scout, and Sirius devices, were 0.18 ± 0.10, 0.21 ± 0.11, and 0.18 ± 0.11, respectively. The Px values were 0.00 ± 0.14, -0.02 ± 0.16, and -0.01 ± 0.13, respectively, while the Py values were 0.09 ± 0.13, 0.10 ± 0.15, and 0.10 ± 0.13. The ICCs for the three device measurements, chord mu, Px, and Py, were 0.817, 0.900, and 0.855, respectively. When comparing the three devices, the 95% limits of agreement (LoA) for mu and Px measured using the Sirius and Keratron Scout were the narrowest, ranging from -0.15 to 0.08 and -0.11 to 0.13, respectively. Additionally, the 95% LoA for Py measured using the Sirius and Pentacam was the narrowest, ranging from -0.13 to 0.15. The pupil centers in both eyes were predominantly located above the apex of the cornea., Conclusion: Sirius, Keratron Scout, and Pentacam have good consistency in pupil shift measurement in young myopic patients, and the three devices can be used as references in clinical practice., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Ning and Zhang.)

Purpose: The aim is to assess for any lasting changes in corneal densitometry (CD) in patients who underwent small incision lenticule extraction (SMILE) and developed early transient postoperative corneal haze., Methods: This retrospective chart review analyzed 98 eyes from 49 patients who underwent SMILE at the Hoopes Vision Clinic and had one-year postoperative Pentacam CD (Oculus Optikgeräte GmbH, Wetzlar, Germany). These were compared to 78 eyes from 42 unoperated myopic control patients with documented CD measurements. The preoperative CD, measured in grayscale units (GSU), was compared between SMILE patients who developed early transient haze ("transient haze group"), SMILE patients who did not build haze ("non-haze group"), and patients who did not undergo any refractive surgery ("controls"). The postoperative CD was compared between the transient haze and non-haze groups. Then, the postoperative CD was compared to the preoperative CD for the non-haze group and transient haze group, respectively., Results: The only significant difference in preoperative CD was in the central layer of the cornea at the 6-10 mm annulus between the non-haze group and controls (17.31 ±3.77 vs. 16.18 ±3.92 GSU; p=0.04). Postoperatively, there were no differences in CD between the non-haze group and the transient haze group (p<0.05). Comparing postoperative CD to preoperative CD, the non-haze group had increased CD in the 2-6 mm annulus of the anterior (1.54 ±0.45 GSU; p=0.001), posterior (0.65 ±2.28 GSU; p=0.032), and full thickness (0.72 ±0.29 GSU; p=0.006) layers of the cornea in addition to an increased CD in the 6-10 mm annulus of the posterior corneal layer (1.19 ±0.55 GSU; p=0.049). The transient haze group had an increased CD in the 2-6 mm annulus of the anterior (2.61 ±1.09 GSU; p=0.021) and full thickness (1.44 ±0.68 GSU; p=0.039) layers of the cornea., Conclusion: There is no lasting difference in CD between patients who develop postoperative transient haze and those who do not after undergoing SMILE., Competing Interests: Human subjects: Consent was obtained or waived by all participants in this study. Biomedical Research Alliance of New York (BRANY) issued approval A20-12-547-823. Animal subjects: All authors have confirmed that this study did not involve animal subjects or tissue. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work., (Copyright © 2024, Pandya et al.)

Objectives: To investigate the diagnostic value of iTrace visual function analyzer, Pentacam 3D anterior segment analysis system and Lens Opacities Classification System III (LOCS III) in assessing lens opacity in patients with age-related cataract (ARC)., Methods: A total of 129 patients with ARC admitted to Anonymized from May 2019 to April 2021 were selected as the research objects. The degree of lens opacity was evaluated by LOCS III classification, iTrace and anterior segment analysis., Results: The Pentacam nucleus staging (PNS) grade was strongly correlated with nuclear color (NC) ( r  = 0.537, p <  0.05) and moderately correlated with nuclear opalescence (NO) ( r  = 0.473, p <  0.05). The integrated density (IntDen) in 3-mm nuclear region was strongly correlated with NC ( r  = 0.548, p <  0.05) and NO ( r  = 0.539, p <  0.05). The dysfunctional lens index (DLI) in 3-mm area was negatively correlated with NC ( r =-0.252, p <  0.05), NO ( r =-0.239, p <  0.05) and posterior subcapsular cataract ( r =-0.271, p <  0.05). PNS was weakly negatively correlated with the DLI in 3-mm area ( r =-0.219, p <  0.05), and IntDen in 3-mm core area was weakly negatively correlated with the DLI in 3-mm area ( r =-0.291, p <  0.05)., Conclusion: A combination of iTrace, anterior segment analysis and LOCS III may be beneficial in objectively assessing the opacity of different regions of the lens.

Purpose: The purpose of this study was to evaluate the correlations and consistency among the central corneal thickness (CCT) of healthy myopic patients measured with three different anterior segment analysis systems., Design: This was a retrospective study. The study included myopia patients who had undergone preoperative examinations in the refractive surgery department of our hospital between January 2021 and December 2023. The CCT was measured separately using Pentacam, Sirius, and IOLMaster 700., Methods: Statistical analysis was conducted using SPSS software. Correlations among the three groups of measured values were assessed using the Pearson method, and a simple scatter plot and fitting line were drawn. Bland‒Altman scatter plots and 95 % limits of agreement (LoAs) were used to evaluate consistency in the data among the systems., Results: A total of 269 patients participated in the study, including 134 males (49.8 %) and 135 females (50.2 %). The CCT measurements by Pentacam, Sirius, and IOLMaster 700 instruments were found to be 541.63 ± 31.67 μm, 541.74 ± 33.36 μm, and 548.90 ± 34.19 μm respectively; significant differences were observed among these measurements (p < 0.05). Significant differences were also observed in CCT between Pentacam and IOLMaster 700 as well as between Sirius and IOLMaster 700 (p < 0.05). The CCT measurements by all three devices showed high positive correlation with all p values less than 0.001: Pentacam and Sirius, r = 0.972; Pentacam and IOLMaster 700, r = 0.966; and Sirius and IOLMaster 700, r = 0.962. The respective 95 % LoAs were -0.18∼0.18; -1.51∼-1.11; and -1.52∼-1., Conclusion: The results indicate that there is a high correlation in measuring CCT for healthy myopic eyes using three different anterior segment analysis systems. However, the differences in the values measured by the three devices were statistically significant. Therefore, in actual clinical practice, it is suggested that the same device should be used to measure and evaluate the CCT across visits., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

Purpose: This study aimed to compare the differences between the Zeiss IOL Master and Oculus Pentacam in keratometry and central anterior chamber depth (ACD) measurements in patients with high myopia and cataracts., Methods: Between January 2019 and December 2020, 89 patients (103 eyes) with cataracts and high myopia who underwent preoperative cataract evaluation at Nanchang First Hospital were selected for retrospective analysis. Keratometry (K1, K2) and ACD were measured with the IOL Master and Pentacam. Paired t-tests were performed to compare the differences, while the Bland-Altman method was used to evaluate the agreement., Results: The K1 value was (43.15±2.44) D for the IOL Master and (42.98±2.47) D for the Pentacam, and the difference between the two instruments was statistically significant (P<0.01). The K2 value was (44.55±2.63) D for the IOL Master and (44.32±2.55) D for the Pentacam. The ACD was (3.44±0.33)mm for the IOL Master and (3.39±0.36)mm for the Pentacam. There were statistically significant differences between the two instruments in both keratometry and ACD (P<0.01). The absolute values of the maximum difference between the two instruments for K1 and K2 were 1.1 and 1.07; thus, the consistency of the two instruments with respect to this measurement was poor. However, the absolute value of the maximum difference between the two instruments for ACD was 0.34, so the consistency of the two instruments in relation to this measurement was good., Conclusions: Both the IOL Master and the Pentacam can be used in the measurement of keratometry and ACD in patients with high myopia and cataracts, but the keratometry measurements should be compared in clinical application., (Copyright © 2024 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)

Purpose: To determine if Scheimpflug tomography pachymetry map and posterior elevation map patterns can predict the occurrence of corneal edema following uneventful phacoemulsification surgery in Fuchs endothelial corneal dystrophy (FECD)., Design: Observational prospective case-control study., Participants: Fifty FECD eyes (50 patients) with visually significant cataract: 25 with subclinical corneal edema (SCE) versus 25 without SCE., Methods: Preoperatively, FECD was clinically assessed, and only patients devoid of clinical corneal edema were enrolled. Utilizing the Mayo Clinic classification for subclinical corneal edema (SCE), eligible FECD eyes were stratified based on Scheimpflug imaging pachymetry map and posterior elevation map characteristics, including loss of regular isopachs, displacement of the cornea's thinnest point, and the presence of posterior surface depression, into two groups: Group A representing FECD with SCE, and Group B: FECD without SCE. One week postoperatively, clinical and tomographic evaluation was performed. Regression analysis was conducted to evaluate predictors of corneal edema after uneventful phacoemulsification surgery in both groups., Results: All patients were successfully imaged before and 1 week after surgery. Visual acuity was significantly improved in both groups (P < 0.001). No postoperative clinical edema was observed in Group B, while 23 (92%) had mild edema and 2 (8%) had moderate edema in Group A. Both groups showed a significant increase in postoperative central corneal thickness (CCT) and thinnest corneal thickness (TCT) (both P < 0.001). Compared to Group B, Group A showed a significant central flattening of the anterior corneal surface (P = 0.007 and P = 0.04 for K1 and K2 respectively), and a significant increase in the postoperative posterior surface depression. Multivariate analysis showed that 94% of postoperative corneal edema could be predicted by the presence of preoperative posterior surface depression (P = 0.04, ARR = 5.8 (1.89-35.7))., Conclusion: Scheimpflug tomography pachymetry map and posterior elevation map patterns can predict corneal edema after uneventful phacoemulsification surgery in FECD with subclinical corneal edema., Competing Interests: The authors report no conflicts of interest in this work., (© 2024 Eleiwa et al.)

Background: Accurate prediction of postoperative vault in implantable collamer lens (ICL) implantation is crucial; however, current formulas often fail to account for individual anatomical variations, leading to suboptimal visual outcomes and necessitating improved predictive models. We aimed to verify the prediction accuracy of our new predictive model for vaulting based on anterior and posterior chamber structural parameters., Methods: This retrospective observational study included 137 patients (240 eyes) who previously underwent ICL surgery. Patients were randomly divided into the model establishment (192 eyes) or validation (48 eyes) groups. Preoperative measurements of the anterior and posterior chamber structures were obtained using Pentacam, CASIA2 anterior segment optical coherence tomography (AS-OCT), ultrasound biomicroscopy, and other devices. Stepwise multiple linear regression analysis was used to evaluate the relationship between the vault and each variable (WL formula). The Friedman test was performed for the vaulting prediction results of the WL, NK (Ver. 3), and KS formulas (Ver. 4) in CASIA2 AS-OCT, as well as the Zhu formula and vault measurements. The proportions of prediction error within ± 250 μm per formula were compared., Results: The predicted vault values of the WL, NK, KS, and Zhu formulas and vault measurements were 668.74 ± 162.12, 650.85 ± 248.47, 546.56 ± 128.99, 486.56 ± 210.76, and 716.06 ± 233.84 μm, respectively, with a significant difference (χ 2  = 69.883, P = 0.000). Significant differences were also found between the measured vault value and Zhu formula, measured vault value and KS formula, WL formula and Zhu formula, WL formula and KS formula, NK formula and KS formula, and NK formula and Zhu formula (P < 0.001) but not between other groups. The proportions of prediction error within ± 250 μm per formula were as follows: WL formula (81.3%) > NK formula (70.8%) > KS formula (66.7%) > Zhu formula (54.2%)., Conclusions: The WL formula, which considers the complexity of the anterior and posterior chamber structures, demonstrates greater calculation accuracy, compared with the KS (Ver. 4) and Zhu formulas. The proportion of absolute prediction error ≤ 250 μm is higher with the WL formula than with the NK formula (ver. 3). This enhanced predictive capability can improve ICL sizing decisions, thereby increasing the safety and efficacy of ICL implantation surgeries., (© 2024. The Author(s).)

Purpose: To evaluate the effect of night shifts on the biomechanical properties of the cornea using Scheimpflug camera-based imaging (Corvis and Pentacam)., Methods: Thirty-four participants from the medical staff who had at least six night shifts per month as a case group and fifty-two participants as a control group participated in the study. The biomechanical characteristics of the cornea using the Corvis device and the topographical characteristics of the cornea using the Pentacam device were investigated in the participants., Results: The main indices of corneal biomechanics including Corvis Biomechanical Index (0.17 ± 0.18 vs. 0.15 ± 0.14; P = 0.66 [adjusted] and 0.66 [unadjusted]) and Tomographic and Biomechanical Index (0.16 ± 0.19 vs. 0.14 ± 0.19; P = 0.78 [adjusted] and 0.63 [unadjusted]) were not significantly different between case and control groups., Conclusion: Our study showed that night shifts do not independently affect corneal biomechanical indices., Competing Interests: There are no conflicts of interest., (Copyright: © 2024 Journal of Current Ophthalmology.)

Aim: This study aimed to differentiate moderate to high myopic astigmatism from forme fruste keratoconus using Pentacam parameters and develop a predictive model for early keratoconus detection., Methods: We retrospectively analysed 196 eyes from 105 patients and compared Pentacam variables between myopic astigmatism (156 eyes) and forme fruste keratoconus (40 eyes) groups. Receiver operating characteristic curve analysis was used to determine the optimal cut-off values, and a logistic regression model was used to refine the diagnostic accuracy., Results: Statistically significant differences were observed in most Pentacam variables between the groups (p < 0.05). Parameters such as the Index of Surface Variance (ISV), Keratoconus Index (KI), Belin/Ambrosio Deviation Display (BAD&#95;D) and Back Elevation of the Thinnest Corneal Locale (B.Ele.Th) demonstrated promising discriminatory abilities, with BAD&#95;D exhibiting the highest Area under the Curve. The logistic regression model achieved high sensitivity (92.5%), specificity (96.8%), accuracy (95.9%), and positive predictive value (88.1%)., Conclusion: The simultaneous evaluation of BAD&#95;D, ISV, B.Ele.Th, and KI aids in identifying forme fruste keratoconus cases. Optimal cut-off points demonstrate acceptable sensitivity and specificity, emphasizing their clinical utility pending further refinement and validation across diverse demographics., (© 2024. The Author(s).)

Purpose: To investigate the effect of the near visual task of movie-watching in the straight gaze position on corneal topographic parameters., Methods: Thirty myopic young adults with an average age of 25.10 ± 4.13 years were recruited for the study. The designed near visual task consisted of watching a movie in the straight gaze position at a distance of 40 cm for 30 minutes. Corneal topography was performed using Oculus Keratograph 4 (OCULUS, Wetzlar, Germany) before and immediately after watching the movie, as well as at 10, 20, and 30 minutes intervals after completing this near visual task. Zernike coefficients, asphericity indices, refractive parameters, and diagnostic indices of keratoconus were recorded for statistical analysis., Results: Movie-watching at a close distance solely using the straight gaze position had no effect on Zernike coefficients ( P > 0.130). Also, watching the movie had no effect on other corneal topography parameters including irregularities ( P = 0.208), spherical eccentricity ( P = 0.270), maximum decentration ( P = 0.553), axis of maximum decentration ( P = 0.186), peripheral astigmatism ( P = 0.179), and average asphericity of the quadrants at 10 to 30º ( P > 0.163)., Conclusion: The results of the present study showed that watching movies in the straight gaze position had no effect on corneal topographic parameters and did not cause errors in corneal topographic measurements., Competing Interests: None., (Copyright © 2024 Tanhaye Shamsabady et al.)

Objective The objective of this study was to compare K1, K2, Kmax, and pachymetry values from Pentacam and Galilei scans of corneal topography in order to assess their correlation and interchangeability in clinical practice. Methodology A total of 34 patients (68 eyes) were enrolled in the study. Corneal topography was performed using Pentacam and Galilei devices on the same day. K1, K2, Kmax, and pachymetry readings were obtained from the scans and analyzed using paired t-tests and Bland-Altman plots. Results There were minimal differences in clinical settings between Pentacam and Galilei for K1, K2, Kmax (>0.75 D), and pachymetry values (>15 um). However, there was a statistically significant difference found between Kmax and pachymetry, making their interchangeability questionable. Conclusion Pentacam and Galilei demonstrate a good correlation between corneal keratometric values (K1, K2, and Kmax) and pachymetry values in clinical settings, and they should be used interchangeably with caution., Competing Interests: Human subjects: Consent was obtained or waived by all participants in this study. Ethical Review Committee, Armed Forces Institute of Ophthalmology issued approval 308/ERC/AFIO. The research project titled "Comparative Analysis of Keratometric and Pachymetry Values From Corneal Topography Scans: A Comparison Between Pentacam and Galilei" has not been previously conducted at the Armed Forces Institute of Ophthalmology. It is further explained that ethical issues regarding the topic have been discussed, and the hospital's local ethical committee did not find anything objectionable in the study. Animal subjects: All authors have confirmed that this study did not involve animal subjects or tissue. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work., (Copyright © 2024, Tariq et al.)

Purpose: To assess the differences and similarities in the corneal curvature obtained by two swept-source optical coherence tomography (SS-OCT) devices, Scheimpflug imaging system and one ray tracing aberrometer in patients with cataracts. Moreover, this study aimed to compare the differences in posterior corneal (PK), total corneal (TK) and true net power (TNP) measurements among the IOLMaster 700, CASIA2, and Pentacam., Methods: A total of 200 eyes of 200 patients (116 female, 58%) were enrolled in this study, with a mean age of 65.9 ± 9.5 years. The flattest (Kf), steepest (Ks), and mean cornal powers (Km), J 0 , and J 45 were obtained using two SS-OCT-based biometric devices, one rotating camera system and one ray-tracing aberrometer. The PK, TK and TNP values were also measured using these devices. To evaluate the differences and similarities between the devicves, the Friedman test, Pearson correlation coefficient (r), intraclass coefficient correlation (ICC) and Bland‒Altman plots with 95% limits of agreement (LoA) were used, and boxplots and stacked histograms were generated to describe the distributions of the data., Results: There were no significant differences between the IOLMaster 700 and Pentacam for any of the keratometry values. Additionally, there were no significant differences between the IOLMaster 700 and iTrace in evaluating J 0 and J 45 . Bland‒Altman plots revealed relatively wide LoA widths, almost larger than 1 diopter for the keratometry values and almost larger than 0.5 diopter for J 0 and J 45 values among the four devices. In terms of PK and TK values, significant differences and low ICCs were found among the three devices., Conclusions: Although strong correlations and good agreement were found among the IOLMaster700, CASIA2, Pentacam and iTrace for Kf, Ks, Km and J 0 , J 45 , it seems that the measurements should not be used interchangeably because of the wide LoA widths and the presence of significant differences among the devices. Similarly, due to significant differences and low ICCs, the PK, TK and TNP values obtained by IOLMaster 700, CASIA2, and Pentacam should not be used interchangeably., (© 2023. The Author(s).)

Introduction: Evaluation of anterior segment parameters is crucial in ophthalmic procedures such as intraocular surgeries and contact lens fitting. However, the use of tropicamide in diabetic patients presents challenges due to its potential impact on biometric measurements. This study aims to investigate and compare the effects of 0.5% and 1% tropicamide on anterior segment parameters in diabetic patients., Methods: This double-masked randomized clinical trial enrolled 98 patients with diabetes mellitus. Participants were randomly assigned to receive either 0.5% or 1% tropicamide. Anterior segment parameters were measured using Pentacam HR (Oculus Optikgeräte GmbH, Wetzlar, Germany) before and 30 minutes after tropicamide administration. Parameters included anterior chamber depth (ACD), anterior chamber volume (ACV), anterior chamber angle (ACA), keratometry, central corneal thickness (CCT), white-to-white distance (WTW), and pupillary diameter (PD)., Results: Both concentrations of 0.5% and 1% tropicamide induced significant changes in anterior segment parameters. There was a notable increase in PD (2.99 ± 0.62, 3.11 ± 0.55, respectively, both P-values < 0.001), ACD (both 0.10 ± 0.05, both P-values < 0.001), ACV (16.69 ± 9.56, 17.51 ± 9.26, respectively, both P-values < 0.001), and WTW (0.06 ± 0.14, 0.03 ± 0.30, respectively, both P-values < 0.001), along with a decrease in ACA (-3.50 ± 10.65, -3.30 ± 6.87, P-value < 0.001 and P-value=0.001, respectively), and CCT (-6.10 ± 8.06, -6.39 ± 9.97, respectively, both P-values < 0.001) post-dilation. However, no significant changes were observed in keratometry (front Km (-0.03 ± 0.19, -0.04 ± 0.21, respectively), back Km (0.01 ± 0.05, 0.004 ± 0.05, respectively), P-values> 0.05)., Conclusion: Both concentrations of tropicamide exhibited comparable effects on anterior segment parameters in diabetic patients. These post-dilation changes should be considered for accurate intraocular lens power calculation and decision-making for cataract, phakic intraocular lens, and refractive surgeries., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2024, Elmi Sadr et al.)

Purpose: To evaluate the use of the Pentacam to analyse the presence or absence of fluid pockets under the anterior capsule and their significance in terms of surgical management and prevention of complications., Settings: Abant İzzet Baysal University Hospital, Bolu, Turkey DESIGN: Randomized, masked, prospective design METHODS: 60 patients with mature cataracts underwent standard phacoemulsification (Phaco) and intraocular lens (IOL) implantation. Patients were divided into 3 groups. Group 1 underwent Phaco+IOL implantation without imaging by Pentacam. Group 2 had fluid detected in Pentacam imaging before the operation and underwent Phaco+IOL implantation with Brazilian method. Group 3 had no fluid detected in Pentacam imaging before the operation and underwent standart Phaco+IOL implantation operation., Results: When the complication rates of 3 different groups were examined separately, they were found to be 15 % in group 1; 5 % in group 2 and 5 % in group 3, respectively. When compared in pairs as Group 1-2, 1-3, and 2-3, respectively (p < 0.01), (p < 0.01), (p > 0.05). The nuclear density of Group 2 and Group 3 was measured, resulting in 30.2 % and 29.6 %, respectively (P = 0.614). Lens thickness, patients with fluid (+) had a thickness of 5.35 mm, while patients with fluid (-) had a thickness of 3.96 mm (p < 0.05)., Conclusion: Patients who are not imaged with pentacam before surgery experience more complications than other groups because the presence of fluid is unknown. Central lens thickness was higher in patients with fluid, and there was no significant difference in nuclear density between the groups with and without fluid. Pentacam can show the presence of supcapsular fluid and we recommend that imaging tools be more widely used in cataract surgery. We think that this will enable surgeons to make a more accurate surgical planning and reduce the risk of complications., Competing Interests: Declaration of competing interest The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper., (Copyright © 2024. Published by Elsevier B.V.)

Keratoconus (KC) is the most common corneal ectasia. Optical coherence tomography angiography (OCT-A) is a relatively new non-invasive imaging technique that allows the visualization and quantification of retinal and choriocapillary blood vessels. The aim of this study is to assess retinal and choriocapillary vessel density (VD) differences between KC patients and healthy controls and to investigate correlations between VD and KC severity. Fifty-two eyes were included in this exploratory study: twenty-six eyes from 26 KC patients and twenty-six eyes from 26 age- and gender-matched healthy controls. All patients underwent Scheimpflug corneal topography with Pentacam, axis lengths measurement and optical coherence tomography angiography (OCT-A). The thinnest spot in corneal pachymetry, maximum K (Kmax) and KC severity indices from the Belin/Ambrósio enhanced ectasia display (BAD) were also assessed. There was a distinct reduction particularly in the retinal VD of the superficial capillary plexus (SCP). Correlation analyses showed strong and moderate negative correlations between the VD in the macular SCP and BAD KC scores and between the SCP VD and Kmax. There was no difference in retinal thickness between the KC and healthy controls. With this study, further evidence for altered VD measurements by OCT-A in KC patients is given. For the first time, we demonstrated negative correlations between BAD KC scores and retinal blood vessel alterations. A major limitation of the study is the relatively small sample size. Since an artefactual reduction of the quantitative OCT-A measurements due to irregular corneal topography in KC must be assumed, it remains to be investigated whether there are also actual changes in the retinal microcirculation in KC.

Pupil diameter is a key parameter for corneal and multifocal intraocular lens surgery. Many devices are dedicated to measure the pupil size, but do not specify the illumination during capture. The aim of this study was to present illumination levels in routinely used ophthalmic devices which present pupil sizes. To obtain measurements, the lux meter was placed in the chin rest in the corneal plane and the room was completely dimmed. Ten measurements were taken for each device. The illumination levels for white and red Placido disk corneal topographers were 1253.1 ± 0.2 and 329.0 ± 0.2 lux, respectively (both photopic conditions). Scheimpflug corneal tomography should be considered as a mesopic measurement (14.5 ± 0.1 lux). Optical coherence tomography and autorefractometry are scotopic measurements (0.4-0.6 lux). We postulate that producers should provide illumination levels of their devices measuring pupil size. Moreover, when mentioning a pupil size, one should consider presenting to what lighting conditions it refers to., (© 2023. The Author(s).)

Purpose: To assess the feasibility and reliability of biometric measurements taken with the Eyestar 900 device in keratoconus eyes in comparison with those taken with the Pentacam HR and IOLMaster 700., Methods: Seventy-five eyes of 75 patients with keratoconus were included. The central corneal thickness (CCT), thinnest point of corneal thickness (TCT), axial length (AL), flat (K1) and steep (K2) anterior and posterior (Kp1, Kp2) keratometry, maximal keratometry (KMax) and anterior chamber depth (ACD) were compared between the Eyestar 900, Pentacam HR and IOLMaster 700. Reliability parameters such as the coefficient of variation (CoV) and intraclass correlation coefficient (ICC) were calculated. Pearson's r was determined to assess the correlation between devices., Results: A high repeatability (CoV < 1%) and intraclass correlation (ICC > 0.9) was found for all devices, led by AL, TCT, K1 and K2 (CoV 0.01-0.36%; ICC 0.994-1.00). The largest correlation between devices was found for AL (Eyestar vs. IOLMaster, r = 1.0), K1 (Eyestar vs. IOLMaster, r = 0.997) and ACD (Eyestar vs. IOLMaster, r = 0.995; Pentacam vs. IOLMaster, r = 0.987; Eyestar vs. Pentacam, r = 0.983), but there were significant differences in measured values between devices (p < 0.001), whereas the correlation was only slightly lower (r = 0.947 to 0.994) for KMax, CCT, TCT, K2, Kp1 and Kp2., Conclusion: Keratometric and axial length measurements with the Eyestar 900 were feasible and revealed a high repeatability and a good correlation to the other devices in eyes with keratoconus., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Purpose: We assess the relationship between preoperative myopic sphere, astigmatism, and spherical equivalent and effective optical zone (EOZ) size, shape, and decentration within individual populations of post-LASIK, PRK, and SMILE patients., Patients and Methods: A retrospective chart review was conducted with 118 LASIK, 144 PRK, and 41 SMILE eyes from 179 total patients that underwent compound myopic ablation. One-year postoperative Pentacam tangential difference maps were used for EOZ data measurements. Correlational analysis between compound myopic measures [sphere, cylinder, manifest refractive spherical equivalent (MRSE)] and EOZ parameters was performed, and differences between groups of myopic sphere and cylinder within each surgery type were assessed., Results: An increase in absolute myopic sphere (and subsequent MRSE) is associated with a smaller EOZ area in SMILE (r=0.454, p=0.003) and a more circular EOZ shape in LASIK (r=0.396, p<0.001) and PRK (r=0.563, p<0.001). An increase in absolute myopic cylinder is associated with an increased EOZ area in all three surgery types [LASIK (r=-0.459, p<0.001), PRK (r=-0.716, p<0.001), SMILE (r=-0.429, p=0.005)] and a more elliptical EOZ in LASIK (r=-0.491, p<0.001) and PRK (r=-0.538, p<0.001)., Conclusion: While astigmatism may be correlated to EOZ size within all three refractive surgery types, myopic sphere alone is insufficient to estimate EOZ size differences for procedures with a large blend zone of ablation like LASIK or PRK. Shape is just as important a factor as size to consider when examining corneal EOZ differences; reported correlative findings likely result from inherent differences in surgical technique and abruptness of planned surgical ablation borders., Competing Interests: The authors report no conflicts of interest in this work., (© 2024 Moshirfar et al.)

Background: Comparison of OPD-Scan III and Pentacam measurements of relevant parameters guiding the selection of multifocal intraocular lenses in cataract patients., Methods: A retrospective study included 120 patients (120 eyes) with cataract. Their chord kappa, chord alpha, corneal spherical aberration, and pupil size were measured by OPD-Scan Ⅲ and Pentacam. Pairwise t-tests, Pearson tests, and Bland-Altman analyses were used, respectively, to assess the difference, correlation, and agreement between the devices., Results: There was no significant difference in photopic chord kappa and corneal spherical aberration between the two instruments (P = 0.054, P = 0.065). Chord alpha and pupil size varied significantly between the two instruments (P < 0.001). OPD-Scan III results revealed a significant association between photopic chord kappa and mesopic chord kappa (r = 0.823, P < 0.001). There was a significant positive correlation between photopic and mesopic chord kappa measured by OPD-Scan Ⅲ and chord kappa measured by Pentacam (r = 0.840, r  = 0.757, P < 0.001). The chord alpha evaluated by the two tools had a moderate correlation (r = 0.442, P < 0.001) between them. Bland-Altman analysis showed that there was excellent agreement between the two instruments in measuring chord kappa and corneal spherical aberration, while the chord alpha and pupil size were not consistent., Conclusions: The chord kappa and corneal spherical aberration measured by OPD-Scan III and Pentacam were consistent in the preoperative decision making of multifocal intraocular lens implantation in cataract patients, both of which have clinical guiding significance. In addition, OPD-Scan III provides more comprehensive day and night chord kappa and pupil diameters, which improves clinical advice for patients with complicated ocular diseases and high demands for nocturnal vision., Competing Interests: Declaration of Competing Interest The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Purpose: To compare the consistency of Pentacam Scheimpflug system (Pentacam® HR), ray-tracing aberrometry (iTrace), and swept source optical coherence tomography (IOLMaster 700) measurements for Angle Kappa and angle Alpha., Methods: A prospective randomized cohort study. 86 individuals (86 eyes) aged 19-45 years with best corrected vision of 4.9 or better were randomly selected from January 2022 to December 2022 in a tertiary-level hospital. Angle Kappa and angle Alpha were measured or calculated using Pentacam, iTrace, and IOLMaster 700, respectively., Results: The mean difference of angle Kappa between any two instruments was not statistically significant, but the mean difference of angle Alpha between both Pentacam and iTrace, Pentacam and IOLMaster 700, and iTrace and IOLMaster 700 was statistically significant (p value <0.001, 0.003, <0.001). The highest consistency of angle Kappa and the narrowest 95% LoA (-0.20 to 0.21) were found between Pentacam and iTrace according to Bland Altman plots, but between Pentacam and IOLMaster 700 according to Mountain plots. Both Bland Altman plots and Mountain plots showed the highest consistency of angle Alpha and the narrowest 95% LoA (-0.14 to 0.24) between Pentacam and iTrace., Conclusion: The mean angle Kappa among Pentacam® HR, iTrace, and IOLMaster 700 had good agreement, and the value of angle Kappa could be output directly, making it more convenient for clinical application. The measured or calculated angle Alpha had poor agreement, and ophthalmologists could refer to measurements from multiple instruments., (Copyright © 2023. Published by Elsevier B.V.)

The aim of the thesis is to present the case of a patient in whom bilateral calcification of the hydrophilic intraocular lens (IOL) Lentis M+ LS-313 MF30 (Oculentis) has developed. Due to the negative effect on visual functions, explantation and replacement of the artificial lens was necessary in both eyes. Case Report: An overview of the available literature summarized the diagnostics, current examination methods and possibilities of the surgical solution of calcification of the bifocal hydrophilic lens Lentis M+ LS-313 MF30 (Oculentis). The specific solution is described in a case report of a patient in whom calcification of both lenses developed 6 years after implantation of the IOL. In 2015, the patient underwent uncomplicated cataract surgery of both eyes with the implantation of an artificial intraocular lens into the capsule. In September 2021, an 82-year-old man was examined at our outpatient clinic for deterioration of visual acuity and changes in the material of the artificial IOL which were perceptible during a clinical examination, on the recommendation of a local ophthalmologist. Blurred vision predominated. A diagnosis of intraocular lens opacification was confirmed and documented using a Scheimpflug camera (OCULUS Pentacam HR) and anterior OCT (Avanti RTVue XR Optovue,). The patient was indicated for explantation and replacement of the opacified intraocular lens in the left and subsequently in the right eye- The same type of IOL was used for reimplantation with good functional results. Conclusion: Since 2010, multifocal lens implantation has been on an upward trend worldwide. This type of MF IOL has also been used in thousands of implantations. A number of other explantations can be expected in the coming years. The optimal solution is the correct replacement of the calcified IOL with the same construction made of safer hydrophobic material.

Pterygium is a common inflammatory-proliferative disease characterized by the invasion of degeneratively altered fibrovascular tissue into the cornea. This literature review analyzes the etiological factors and pathogenetic concepts of its development, describes modern methods of diagnostics and surgical treatment of pterygium, and pays particular attention to the assessment of structural and functional changes in the cornea occurring during the growth of pterygium and after its excision.

Clinical Relevance: Assessing the consistency of pupil offset measurements between the Pentacam and Keratron Scout is essential for the refractive surgery design of young myopic patients., Background: Accurate preoperative measurement of pupil offset is critical to achieving a better quality of vision after refractive surgery. The Pentacam and Keratron Scout are commonly used in hospitals, and evaluating their consistency is essential for accurate measurement of pupil offset., Methods: Six hundred eyes (600 subjects) were included in this study. Pupil offset and its X, Y-component were measured by Pentacam and Keratron Scout, respectively. Agreement and repeatability between the two devices were identified by intraclass correlation coefficient and Bland-Altman plots with 95% limits of agreement. Paired t-tests and Pearson analysis were used to compare the differences and correlations between the two devices., Results: The mean age of all subjects was 23 ± 5 years. The mean pupil offset magnitude obtained from Pentacam and Keratron Scout was 0.16 ± 0.08 mm and 0.15 ± 0.07 mm. The 95% limits of agreement (-0.11-0.13, -0.09-0.11, and -0.11-0.12) and intraclass correlation coefficient (0.82, 0.84, and 0.81) demonstrated good agreement and repeatability of the two devices in measuring pupil offset and its X, Y-component. A significant correlation between the two devices was found ( r  = 0.71, 0.73, and 0.70). The direction of pupil offset measured by the devices was both predominately towards the superonasal quadrant., Conclusion: Pentacam and Keratron Scout showed good agreement in measuring pupil offset and its X, Y-component, which can be used interchangeably in clinical practice.

Background: Proper correction of spherical aberration using intraocular lenses requires precise selection of the sphericity of intraocular lens surfaces based on individual biometric data and corneal asphericity coefficient (Q value). This study aimed to determine and analyze the corneal Q value and its related factors among Saudi participants., Methods: In this cross-sectional study, normal right eyes of healthy Saudi participants aged 17 - 58 years who visited Al-Kahhal Medical Complex, Dammam, Saudi Arabia, were included. The Pentacam rotating Scheimpflug camera was used to determine the average Q value at 6-mm diameter. Q values were obtained from each quadrant (superior, nasal, inferior, and temporal) and two meridians (horizontal and vertical). Mean Q values of the anterior and posterior corneal surfaces were also obtained. Other factors including age, sex, refractive error, and central corneal radius were documented., Results: Five hundred right eyes from 500 participants were included. The mean (standard deviation [SD]) (range) age was 27.2 (7.1) (18 - 58) years. The mean (SD) (range) Q value of 500 eyes was - 0.24 (0.10) (- 0.71 to + 0.09) anteriorly and - 0.16 (0.14) (- 0.70 to + 0.23) posteriorly, being significantly more prolate anteriorly ( P  < 0.05). The corneas were significantly more prolate in the nasal than in the temporal quadrant, in the superior than in the inferior quadrant, and in the horizontal than in the vertical meridian (all P  < 0.05). There were statistically significant differences in anterior, nasal, temporal, inferior, horizontal, and vertical Q values among age groups (all P  < 0.05) but not in the superior or posterior Q values (both P  > 0.05). The corneas became less prolate with increasing age ( P  < 0.05). However, Q values were comparable between the sexes (all P  > 0.05). There was no significant correlation between anterior (r = + 0.08; P  = 0.095) or posterior (r = - 0.08; P  = 0.092) Q value and spherical equivalent, but a significant trend was detected toward more prolate shape with increasing myopia in the temporal and inferior quadrants (r = + 0.19; P  < 0.001, r = + 0.10; P  = 0.022, respectively). There was a significant negligible correlation between the posterior Q value and central corneal radius (r = - 0.18; P  < 0.001) but no significant correlation between the anterior Q value and central corneal radius (r = + 0.02; P  = 0.673)., Conclusions: Most corneas in this Saudi population were prolate in contour. Anterior corneal asphericity was positively correlated with age and was not significantly related to sex, refractive error, or central corneal radius. Further studies are needed to verify our preliminary findings., Competing Interests: None., (© Author(s).)

Purpose: To quantify the effects of Descemet stripping automated endothelial keratoplasty (DSAEK) on corneal clarity and densitometry of patients with long-standing pseudophakic bullous keratopathy (PBK) complicated with subepithelial fibrosis., Methods: Thirty-four eyes with PBK complicated with corneal edema for more than 6 months and subepithelial fibrosis were enrolled. All subjects underwent complete ophthalmic examination and corneal densitometry module of Pentacam HR, before and 1, 3, and 6 months after DSAEK., Results: Thirteen patients were excluded due to postoperative complications or missed to follow-up visits. Finally, twenty-one patients' data were analyzed. Corneal densitometry measures significantly decreased in all three layers (anterior, central, and posterior) 3 and 6 months after surgery compared to preoperative values; however, the differences did not reach statistical significance in the 1 st month. Moreover, densitometry measurements were significantly lower at month 6 compared to month 1, but not at month 3 compared to month 1. Corneal densitometry of the anterior layer was significantly higher than central and posterior layers in 2 mm and 6 mm zones preoperatively and at all postoperative visits. Corneal light backscatter of each three layers was not statistically different between 0-2 mm and 2-6 mm in all pre- and postoperative visits., Conclusions: Corneal densitometry in cases of PBK begins to improve after DSAEK in different layers in a slow and continued trend which takes up to 6 months for an effect to be seen. Interestingly, this improvement is possible even in complicated corneas with long-standing edema. Hence, corneal densitometry can be used as an objective method for quantification of the outcome of DSAEK in complicated cases of PBK., Competing Interests: There are no conflicts of interest., (Copyright: © 2023 Journal of Current Ophthalmology.)

Objectives: To retest the performance of Pentacam parameters in the detection of eyes with subclinical keratoconus (KC) and mild KC based on different definitions from the Amsler-Krumeich (AK), Collaborative Longitudinal Evaluation of Keratoconus (CLEK), and ABCD systems., Materials and Methods: This cross-sectional university-based study comprised 24 eyes with subclinical KC, 144 eyes with mild KC (based on AK in 101 eyes, CLEK in 28 eyes, and ABCD in 15 eyes), and 70 controls. Diagnostic ability of the thinnest point (TP) pachymetry, KISA% index, inferior-superior asymmetry, corneal aberrations, Pentacam indices, front/back elevations, pachymetric progression index, Ambrósio-Relational Thickness (ARTmax), and Belin/Ambrósio Enhanced Ectasia Display scores (Df, Db, Dp, Dt, Da, and D-final) were evaluated., Results: ARTmax (83.3% sensitivity/74.3% specificity) had the highest ability in distinguishing subclinical KC from normal, followed by TP pachymetry, Dt, and Da. D-final showed excellent sensitivity/specificity in mild KC diagnosis based on AK (98%/100%) and CLEK (97.4%/100%) descriptions. In the mild KC-ABCD group, index of vertical asymmetry accurately detected all eyes with mild KC and 97.1% of the controls., Conclusion: This study points out the gray zone in the detection of eyes with subclinical and mild KC due to overlapping terminology and grading criteria. Pentacam parameters seem to have modest capability in subclinical KC detection, indicating the necessity for additional diagnostic modalities. However, eyes with mild KC can be diagnosed with high accuracy using Pentacam parameters, although the strongest parameters may vary according to the definition of “mild KC.” Nevertheless, uniform and definitive criteria for subclinical and clinical KC classification are required for a diagnostic and therapeutic consensus in KC., Competing Interests: Conflict of Interest: The authors declare no financial or proprietary interest in any product or company associated with any device, instrument or drug mentioned in this article., (©Copyright 2023 by the Turkish Ophthalmological Association / Turkish Journal of Ophthalmology published by Galenos Publishing House.)

Purpose: To evaluate preoperative risk factors (mainly those related to corneal topography/tomography) for post-LASIK ectasia development., Methods: A retrospective case review for post-LASIK ectasia for myopia or myopic astigmatism. The evaluated data included preoperative subjective refraction, method of flap creation, and topometric/tomographic parameters from Oculus Pentacam, including subjective curvature pattern, topometric, elevation, and pachymetric indices from the Belin Ambrosio display "BAD", and the Pentacam Random Forest Index (PRFI). Moreover, preoperative ectasia detection indices were calculated (including Percentage of Tissue Altered "PTA" index, Randleman Ectasia Risk Score System "ERSS", and Navarro Index for Corneal Ectasia "NICE")., Results: Twenty-four eyes of 15 patients were enrolled. Concerning the risk factors, age was lower than 25 in 19 eyes (79%); flaps were created using a microkeratome in 17 eyes (70.8%); thinnest pachymetry was lower than 510μm in eight eyes (33%); total deviation from BAD was higher than 1.6 in 50%; Ambrósio's relational thickness (ART) max was lower than 340 in 45.83%; PTA index was higher than 40% in 16%; ERSS was more than 3 points in 62.5%; NICE was higher than 8 points in three eyes (12.5%); PRFI index was more than 0.125 in 87.5%; two eyes (8%) had no identifiable risk factors., Conclusion: Current ectasia risk assessment criteria were insufficient for detecting a relatively large number of cases. There is an unequivocal need for more information, which may be derived from biomechanical assessment and epithelial thickness mapping. Novel corneal tomography indices derived from artificial intelligence may increase accuracy in characterizing ectasia susceptibility., Competing Interests: Prof. Dr. Renato Ambrósio reports personal fees from Oculus, Alcon, and Mediphacos, during the conduct of the study; personal fees from Oculus, outside the submitted work. The authors report no other conflicts of interest in this work., (© 2023 El-Naggar et al.)

Purpose: We aimed to compare the predictive effect of pre-injection intraocular pressure (IOP) and anterior segment parameters on post-injection IOP values after intravitreal bevacizumab injection for neovascular age-related macular degeneration (NVAMD) in phakic and pseudophakic patient groups., Material and Methods: This retrospective cross-sectional study included 65 eyes of 65 treatment-naive NVAMD patients. Patients were divided into two groups according to their lens status (35 phakic and 30 pseudophakic patients). Pre-injection IOP, anterior segment parameters measured with PENTACAM, and post-injection IOP values measured at the 5th minute were recorded. Univariate and multivariate regression analyses were used to recognise the predictive effect of pre-injection IOP and anterior segment parameters on post-injection IOP for each group., Results: Multivariate regression analyses showed that the decrease in anterior chamber depth (ACD), and the increase in pre-injection IOP were significantly correlated with higher post-injection IOP in the phakic patient group ( p  = 0.019 and 0.031; respectively). No correlation was found in the pseudophakic patient group., Conclusion: Pre-injection ACD and IOP values may be predictive of higher post-injection IOP in phakic patients. Preoperative assessment of these parameters could be beneficial in patients at risk of glaucoma.

Purpose: To analyze the corneal morphological parameters before and one month after the upper eyelid (UE) blepharoplasty and external levator resection (ELR) for ptosis surgery., Materials and Methods: Seventy eyes of 70 patients with dermatochalasis (50 eyes) and acquired aponeurotic ptosis (AAP) (20 eyes) included in this prospective study. Detailed ophthalmologic examination was performed including the best corrected visual acuity (BCVA), slit lamp examination and dilated fundoscopy. Measurements were made before and one month after the surgeries using Pentacam. Central corneal thickness (CCT), pupil center pachymetry (PCP) and thinnest pachymetry (TP), cornea front astigmatism (AST), flat keratometry (K1), steep keratometry (K2) and mean keratometry (Km) values were evaluated., Results: Higher postoperative Km measurements were observed in dermatochalasis (p = 0.038) patients. Postoperative AST values were significantly lower in both dermatochalasis and ptosis cases (p = 0.034, p = 0.003, respectively). Increased PCP and TP were found in the AAP patients (p = 0.014, p = 0.015, respectively)., Discussion: UE blepharoplasty and ELR surgeries both lead to some significant changes on corneal structure post-operatively., Level of Evidence Iv: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 ., (© 2023. Springer Science+Business Media, LLC, part of Springer Nature and International Society of Aesthetic Plastic Surgery.)

Purpose: To evaluate anterior segment parameter changes following scleral buckling (SB) surgery for rhegmatogenous retinal detachment (RRD) using the Pentacam Scheimpflug system., Methods: Twenty-eight phakic eyes of 28 patients who underwent SB surgery for RDD were included. The anterior chamber volume (ACV), central anterior chamber depth (CACD), mean anterior chamber angle (ACA) and ACA in a specific position (buckle quadrant), and central corneal thickness (CCT) were evaluated preoperatively and at 1 day, 1 week, and 1 and 3 months postoperatively by an anterior Pentacam Scheimpflug method., Results: The ACV parameters were significantly decreased compared with preoperative levels at 1 day after SB surgery (P = 0.0004), but had no significant differences at 1 week, and 1 and 3 months (P > 0.05). The mean intraocular pressure (IOP) at 1 day was significantly higher than the preoperative level, but no subsequent significant difference was noted between the preoperative IOP and that at 1 week and 1 and 3 months postoperatively (P > 0.05). The CCT at 1 day after surgery increased significantly (P = 0.0122) and subsequently returned to the normal level postoperatively at 1 week and remained stable until 3 months (P > 0.05). The degree of postoperative ACA displayed different changes in the different quadrants and there was a significant increase in the ACA of the buckle quadrants at 1 day (P < 0.0001), 1 week (P = 0.02), and 1 month (P = 0.0266) after surgery, returning to the normal level at 3 months., Conclusions: The changes of anterior chamber parameters after SB can be demonstrated by Pentacam both objectively and quantitatively. The ACV and CCT changes were mild and resumed their preoperative parameters after 1 week, while the increase of the ACA at the buckle quadrant returned to normal after 3 months. SB surgeries without encircling or conducted with radial buckling might decrease anterior chamber change., Competing Interests: Declaration of Competing Interest The authors declare that they have no competing interests., (Copyright © 2023. Published by Elsevier B.V.)

Purpose: This study aimed to assess the agreement between topographic indices of healthy subjects and keratoconus (KCN) patients using a swept-source optical coherence tomography (SS-OCT CASIA2) versus a Scheimpflug camera (Pentacam)., Methods: 40 eyes of 23 patients with KCN and 40 eyes of 20 healthy subjects were included and evaluated with the CASIA2, followed by the Pentacam. Two consecutive modalities were obtained for one eye of each patient. Corneal parameters, including anterior keratometry at steep (Ks) and flat meridians (Kf), anterior astigmatism, anterior and posterior corneal elevation values, thinnest corneal thickness, and apex corneal thickness, were evaluated., Results: CASIA2 and Pentacam showed perfect agreement (95% limits of agreement (LoA): -0.22 to 0.68, 95% LoA: -1.5 to 1.44 D) and good correlation (Intraclass correlation (ICC):0.986, ICC:0.987; P < 0.01) for anterior (Ks) in normal and ectatic corneas, respectively. The cylinder amount had moderate agreement and correlation (95% LoA: -0.55 to 0.47D, ICC: 0.797, P < 0.01) in normal, and moderate to strong agreement and correlation (95% LoA: -1.57 to 0.87D, ICC=0.911, P < 0.01) in Keratoconic eyes. There was a fair agreement for anterior and posterior corneal elevation values in normal subjects (95% LoA: -3.09 to 4.59, 95% LoA: -6.91 to 7.31D). The thinnest corneal thickness amount had an excellent agreement in normal and KCN patients (ICC: 0.983, 0.953; respectively)., Conclusion: Although the devices had different mean indices values, they had a good agreement based on the Bland-Altman plots. Since Pentacam is accepted as the standard tool for diagnosing ectatic cornea, pentacam CASIA2 is also helpful for early diagnosis of KCN., Competing Interests: None., (Copyright © 2023 Atighehchian et al.)

Background: To investigate the difference between the predicted preoperative corneal ablation depth and the measured ablation depth for femtosecond laser in situ keratomileusis (FS-LASIK) in patients with different degrees of myopia, and to analyze the source of the difference., Methods: A total of 55 patients (109 eyes) were included in this study. Multiple logistics regression was applied to analyze the sources affecting postoperative refractive outcomes. The difference between the preoperative predicted corneal ablation depth and the 1-day postoperative ablation depth in patients with different degrees of myopia was explored using linear regression. Corneal biomechanical parameters influencing error in ablation depth calculation were examined using multiple linear regression., Results: One hundred and nine eyes were divided into low to moderate myopia (55 eyes, myopia of 6 D or less), high myopia (45 eyes, myopia ranging from 6 D to a maximum of 9 D), and very high myopia group (9 eyes, myopia greater than 9 D) based on preoperative refractive error (spherical equivalent). Postoperative visual outcomes were comparable among the three groups of patients, with no significant difference in uncorrected visual acuity (UCVA). We did find notable disparities in spherical equivalent (SE) and central corneal thickness (CCT) in patients with different degrees of myopia at 1 day postoperatively (all p < 0.001). Logistic regression analysis showed that error in ablation depth calculation was an independent risk factor for refractive outcomes one day after surgery (OR = 1.689, 95% CI: 1.366 - 2.089). There was a substantial discrepancy in error in ablation depth calculation at 1 day postoperatively between the three groups. The measured ablation depth of the laser platform was lower than the predicted ablation depth in the low to moderate myopia and very high myopia groups, but the opposite was true in the high myopia group. Pre-operative SE (p < 0.001) and corneal front minimum radius of curvature (Front Rmin) (p = 0.007) obviously influenced the error in ablation depth calculation., Conclusions: Error in ablation depth calculation values vary significantly between patients with different degrees of myopia and correlate highly with preoperative SE and Front Rmin. At the same time, the available evidence suggests that error in ablation depth calculation is an influential factor in postoperative refractive status, so it is imperative to control error in ablation depth calculation., (© 2023. The Author(s).)

Purpose: To investigate the agreement between Pentacam and CASIA2 in the evaluation of corneal densities (CDs) and lens densities (LDs) in myopes., Methods: Fifty-three patients (106 eyes) underwent comprehensive ophthalmologic examinations. CDs and LDs were measured using Pentacam and CASIA2, respectively, based on the grayscale percentage of the obtained images. Agreement between Pentacam and CASIA2 was evaluated using the consistency intraclass correlation coefficient (ICC) and represented using Bland-Altman plots., Results: Compared to Pentacam, CASIA2 showed significantly higher CD and LD values in all measured zones. The ICC of the average CD and LD measured by the Pentacam and CASIA2 were 0.726 and 0.757, respectively. The ICC values of all corneal zones and lenses were above 0.7, except for the measurement of the cornea in the 0-2 mm zone (0.455), suggesting good consistency between the two devices, whose results were of different levels of linear correlation. Bland-Altman plots showed mean percentages of 3.93% for the points falling outside the limits of agreement among the densitometry results. The ICCs in different age groups were similar, but the agreement was poorer in the high myopia group (low and moderate myopia, CD: 0.739, LD: 0.753; high myopia, CD: 0.621, LD: 0.760)., Conclusions: CASIA2 demonstrated good consistency with Pentacam in the measurement of CD and LD, except for measurement of CD in the central cornea and in high myopia. Despite difference in the numerical results compared with Pentacam, which made the two devices uninterchangeable, CASIA2 provides a reliable alternative densitometric measurement method., (© 2023. The Author(s).)

Purpose: This study aimed to investigate the features of progressive keratoconus by means of machine learning. Methods: In total, 163 eyes from 127 patients with at least 3 examination records were enrolled in this study. Pentacam HR was used to measure corneal topography. Steepest meridian keratometry (K 1 ), flattest meridian keratometry (K 2 ), steepest anterior keratometry (K max ), central corneal thickness (CCT), thinnest corneal thickness (TCT), anterior radius of cornea (ARC), posterior elevation (PE), index of surface variation (ISV), and index of height deviation (IHD) were input for analysis. Support vector machine (SVM) and logistic regression analysis were applied to construct prediction models. Results: Age, PE, and IHD showed statistically significant differences as the follow-up period extended. K 2 , PE, and ARC were selected for model construction. Logistic regression analysis presented a mean area under the curve (AUC) score of 0.780, while SVM presented a mean AUC of 0.659. The prediction sensitivity of SVM was 52.9%, and specificity was 79.0%. Conclusion: It is feasible to use machine learning to predict the progression and prognosis of keratoconus. Posterior elevation exhibits a sensitive prediction effect., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Han, Shen, Gu, Zhang, Sun, Chen and Zhou.)

Keratoconus appears to be a rare corneal disease with a prevalence previously estimated at 1:2000. The aim of our study was to investigate the prevalence of keratoconus in a large German cohort and to evaluate possible associated factors., Method: In the population-based, prospective, monocentric cohort study, Gutenberg Health Study, 12,423 subjects aged 40-80 years were examined at the 5-year follow-up. Subjects underwent a detailed medical history and a general and ophthalmologic examination including Scheimpflug imaging. Keratoconus diagnosis was performed in two steps: all subjects with conspicuous TKC analysis of corneal tomography were included in further grading. Prevalence and 95% confidence intervals were calculated. Logistic regression analysis was carried out to investigate association with age, sex, BMI, thyroid hormone, smoking, diabetes, arterial hypertension, atopy, allergy, steroid use, sleep apnea, asthma, and depression., Results: Of 10,419 subjects, 75 eyes of 51 subjects were classified as having keratoconus. The prevalence for keratoconus in the German cohort was 0.49% (1:204; 95% CI: 0.36-0.64%) and was approximately equally distributed across the age decades. No gender predisposition could be demonstrated. Logistic regression showed no association between keratoconus and age, sex, BMI, thyroid hormone, smoking, diabetes, arterial hypertension, atopy, allergy, steroid use, sleep apnea, asthma, and depression in our sample., Conclusion: The prevalence of keratoconus disease in a mainly Caucasian population is approximately tenfold higher than previously reported in the literature using latest technologies (Scheimpflug imaging). Contrary to previous assumptions, we did not find associations with sex, existing atopy, thyroid dysfunction, diabetes, smoking, and depression., (© 2023. The Author(s).)

Purpose: The present study was conducted to determine the corneal topographic indices of Scheimpflug camera in type 2 diabetes patients without diabetic retinopathy (DR), DR and non-diabetic elderly populations., Methods: A total of 1105 participants were selected using random cluster sampling from Tehran, Iran and categorized into three groups including type 2 diabetes patients without diabetic retinopathy (DR), DR and non-diabetic. The diabetic group had HbA1c levels ≥ 6.4% with no other systemic problems. The non-diabetic participants had normal eye findings and no systemic diseases. The pachymetric progression index (PPI) values were measured using the Pentacam AXL., Results: A total of 1105 participants including 429 diabetes patients (38.46% male) and 676 non-diabetic (38.76% male) subjects entered the study. Only PPIavg and PPImax were higher in the diabetics versus non-diabetics (P = 0.019 and 0.010, respectively). There was a significant difference in PPImax between the three groups (P = 0.036). There were significant differences only in index of vertical asymmetry (IVA), central keratoconus index (CKI), PPI average, and PPI max between different stages of diabetic retinopathy (DR) (P = 0.045, 0.005, 0.002, and 0.004, respectively). There was a significant difference in index of Surface Variance (ISV), index of vertical asymmetry (IVA), PPIavg, and PPImax between diabetes patients with and without DR (P = 0.016, 0.022, < 0.001, and < 0.001, respectively)., Conclusion: According to the results, diabetes and DR change several topographic indices. In addition, the HbA1c level may affect pachymetric progression index max. Therefore, special attention should be paid to these patients for different treatment strategies., (© 2023. BioMed Central Ltd., part of Springer Nature.)

Aim: To compare the corneal backward light scattering values in type 2 diabetes mellitus (DM) patients with those of age and sex-matched healthy controls., Methods: The study included 30 patients (30 eyes) with type 2 DM and 30 control subjects (30 eyes). Duration of diabetes, most recent hemoglobin A1c levels, along with the status of diabetic retinopathy, and existing medical treatment of all subjects were recorded. All subjects underwent a complete ophthalmologic examination. In addition, backward light scattering (densitometry) was measured to assess changes in corneal transparency using tomography (Pentacam HR)., Results: The type 2 DM patients included 12 males and 18 females and control subjects included 16 males and 14 females. The age was 50.40±7.80y (range: 40-68y) of the diabetic group and 49.30±9.50y (rang: 40-73y) of control group. The diabetic group demonstrated significantly higher mean densitometry values of the anterior (6-10 mm) zone ( P =0.047), the total anterior layer ( P =0.036) and the total cornea ( P =0.043) than control group. The corneal densitometry of the diabetic eyes demonstrated no significant correlation with hemoglobin A1c levels and DM duration., Conclusion: Diabetic group has higher densitometry in anterior corneal (6-10 mm) zone, total anterior cornea, and total cornea and with no correlation with hemoglobin A1c levels and DM duration., (International Journal of Ophthalmology Press.)

Objectives: The objective of this study is to investigate the changes in topometry, tomography, and corneal densitometry in subclinical keratoconus (SK) at the 6-month interval., Methods: The clinical keratoconus and SK groups included 25 eyes; the control group included 22 eyes from 22 patients. Corneal topographic, tomographic, topometric, and densitometric values obtained using the Pentacam HR imaging system were analyzed., Results: Posterior elevation (PE), Keratoconus index (KI), index of height asymmetry (IHA), index of height decentration (IHD), Dp, Da, Final D, maximum pachymetric progression index (PPImax), and maximum Ambrósio relational thickness parameters showed significant changes between the baseline and the 6th-month follow-up in SK group (p<0.05 for all values). There were significant changes in all zones except a central layer of 6-10 zone, anterior, and central layer of 10-12 zone between the baseline and the 6th-month follow-up in the SK group (p<0.05, for all values). The changes in mean±standard deviation of KI, IHA, IHD, PPImax parameters, and corneal densitometry values of the posterior layer of 0-2 mm and 2-6 mm zones were significant in the SK group compared to the controls (p<0.05, for all values)., Conclusion: PE, KI, IHA, IHD, and PPImax parameters as well as increasing corneal light backscatter of the posterior central layer might be useful for follow-up of progression of SK. New multimeric parameters created by combinations of topometric, tomographic, and corneal densitometry parameters could be the future of SK follow-up., Competing Interests: Conflict of Interest: None declared., (Copyright: © 2023 by Beyoglu Eye Training and Research Hospital.)

Purpose: The present study aimed to evaluate the quality of life of keratoconus patients residing in Nablus city, Palestine. Furthermore, we investigated the possible correlation between Pentacam topographic indices and the quality of life of patients with keratoconus., Methods: This cross-sectional study evaluated keratoconus patients at An-Najah University Hospital in 2019, diagnosed through clinical examination and corneal tomography. A control group was randomly selected from non-keratoconus patients with normal tomography. The NEI-VFQ-25 questionnaire was administered during face-to-face interviews to compare both groups. NEI-VFQ-25 assesses vision-related quality of life and is a validated tool., Results: Keratoconus patients' quality of life is significantly impacted, mainly in near and distant vision, general vision, mental health, and social health, but not in general health, ocular pain, color vision, role difficulties, or dependency. Visual acuity is significantly affected in both eyes of keratoconus patients., Conclusion: Patients with keratoconus exhibit a decreased quality of life related to vision, with physical, emotional, and social impairments demonstrated by the NEI-VFQ-25 when compared to controls. Since keratoconus patients are typically young adults in their productive years, understanding their concerns about their future is an important public health aspect that can aid in modifying their treatments. By addressing the specific needs of this patient population, healthcare providers can better support their long-term well-being and quality of life., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Al Zabadi, Shehadeh, Amro, Ghattass and Taha.)

Purpose: To analyze using Pentacam ® , the corneal and anterior chamber changes following periocular botulinum toxin injection in patients with facial dystonia., Methods: Prospective study that included patients with facial dystonia that were going to receive a periocular botulinum toxin injection for the first time or six months or more after the previous injection. A Pentacam ® examination was carried out in all patients before and 4 weeks after the injection., Results: Thirty-one eyes were included. Twenty-two had a diagnosis of blepharospasm and nine of hemifacial spasm. Analysis of corneal and anterior chamber parameters revealed a significant decrease in iridocorneal angle after botulinum toxin injection (from 35 ± 10º to 33.8 ± 9.7º, p = 0.022). No other corneal or anterior chamber parameters changed significantly after the injection., Conclusions: Periocular botulinum toxin injection causes narrowing of the iridocorneal angle., (© 2023. The Author(s).)

Purpose: To assess the effect of pterygium on corneal densitometry (CD) values., Methods: One hundred and nine patients (155 eyes) with primary pterygium were divided into a severe pterygium group (79 eyes) and a mild-to-moderate pterygium group (76 eyes) according to pterygium severity. Among them, 63 patients had monocular pterygium; and 25 patients (38 eyes) underwent pterygium excision combined with conjunctival autograft follow-up. A Pentacam anterior segment analyzer was used to obtain the CD values and corneal morphological parameters, including central corneal thickness (CCT), flat-axis keratometry (K1), steep-axis keratometry (K2), corneal astigmatism, irregular astigmatism, and spherical aberration. CD was subdivided into four concentric radial regions based on corneal diameter and three layers according to depth., Results: CD values at 0-12 mm of the anterior 120 μm layer, 0-10 mm of the center layer and full thickness, and 2-6 mm of the posterior 60 μm layer were significantly higher in eyes affected by pterygium than in the contralateral unaffected eyes (all P < 0.05). CD values were significantly higher in the severe pterygium group than in the mild to moderate pterygium group (all P < 0.05). Corneal astigmatism, irregular astigmatism, K1, K2, CCT, and spherical aberration correlated with CD values in eyes with pterygium (all P < 0.05). CD values at 6-10, 0-12 mm in the anterior 120 μm layer and full thickness, 10-12 and 0-12 mm in the center layer were significantly decreased 1 month after pterygium surgery compared with those before surgery (all P < 0.05)., Conclusion: Patients with pterygium had increased CD values, particularly in the anterior and central layers. CD values were correlated with pterygium severity grading and corneal parameters. Pterygium surgery partially reduced the CD values., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Zhang, Zhang, Hu, Sun, He, Zhang, Wang, Nie and Liu.)

Background: Keratoconus (KC) is easily recognized by its unique topographic pattern, but it can be difficult to distinguish subclinical form of the disease from the normal cornea. Optovue anterior segment optical coherence tomography (AS-OCT) helps diagnose KC., Aim of the Work: To assess and the level of agreement of Keratometry-readings (K), Central Corneal Thickness (CCT) and Thinnest Corneal Thickness (TCT) measurements obtained by Optovue AS-OCT and Wavelight Oculyzer Pentacam HR in two groups: KC eyes and normal eyes., Patients and Methods: This is a prospective clinical observational study. The study included 110 eyes divided into two groups. The study group included 62 eyes with topographic evidence of KC. The control group included 48 eyes of normal subjects with no topographic evidence of KC. All of the participants underwent full cycloplegic refraction, spectacle best-corrected distance visual acuity, comprehensive slit-lamp biomicroscopy and fundoscopy. All participants underwent corneal topography by Pentacam HR and AS-OCT., Results: There were highly significant differences between the studied groups as regarding BCVA, intraocular pressure and CCT measurements which were found to be lower among KC group compared to the control one. There were highly significant differences between the studied groups regarding TCT measurement detected by Pentacam HR and AS-OCT which was found to be lower among the keratoconus group compared to the control one (470.9, 455.7 versus 541.9 and 518.7 respectively)., Conclusion: Both Scheimpflug-based imaging and AS-OCT provide comparable readings with a good agreement regarding corneal pachymetry in keratoconus group with accurate identification of KC eyes and healthy ones. However, there was a significant difference in K readings between both devices in Keratoconus and control group., (© 2023. The Author(s).)

Purpose: To investigate the impact of drooping eyelid on corneal topographic and tomographic alterations in congenital ptosis eyes., Methods: Seventeen Chinese patients with unilateral congenital ptosis were included in this observational study. Ptosis eyes were included in the ptosis group, while normal contralateral eyes were included in the control group. The marginal reflex distance (MRD) was used to evaluate the severity of ptosis. Topographic and tomographic parameters measured by Pentacam, including keratometric, pachymetric, volumetric parameters as well as topometric indexes and D indexes, were recorded and compared between the ptosis group and the control group. Furthermore, correlation analyses were made between MRD and all measured corneal parameters., Results: The value of anterior K1, Km and posterior K2, Km was significantly decreased in the ptosis eyes (p < 0.05). Corneal thickness at the pupil center point and thinnest point was significantly thicker in ptosis group compared with the ones in control group (p < 0.05). Higher ISV, IVA, KI, IHD values were observed in ptosis eyes (p < 0.05). The intergroup difference in MRD showed significant correlation with the difference in ISV (p < 0.05)., Conclusion: The whole corneal contour is remodeled to be "flatter" in ptosis eyes. The upper eyelid position was closely associated with the corneal irregularity in ptosis eyes. The reasons for the discrepancy in corneal topography and tomography between ptotic and normal eyes were complicated., (© 2022. The Author(s), under exclusive licence to Springer Nature B.V.)

Purpose: To determine the efficacy and safety of pediatric accelerated cross linking (CXL)., Methods: A prospective study on progressive keratoconus (KC) cases under ≤18 years of age. Sixty four eyes of thirty nine cases underwent epithelium-off accelerated CXL protocol. Visual acuity (VA), slit-lamp examination, refraction, pentacam reading of keratometry (K), corneal thickness, and thinnest location pachymetry were noted. Cases were followed up on days 1, 5, and at 1 st , 3 rd , 6 th , and 12th-month post procedure., Results: Statistically, significant improvement of the mean aided VA, K, and mean corneal astigmatism (p < 0.0001) was noted. Mean Kmax reading reduced from 55.5 ± 5.64 (47.4-70.4) diopter (D) preoperatively to 54.41 ± 5.51 (46-68.3) D at 12 months postaccelerated CXL. Two cases had progression. Complications encountered were sterile infiltrate and persistent haze., Conclusion: Accelerated CXL is effective and efficacious in pediatric KC., Competing Interests: None

Objective: Keratoconus is a corneal ectasia that leads to thinning and steepening of the corneal surface. We aimed to assess the relationship between quality of life and corneal tomography indices, irrespective of visual acuity., Methods: This was a cross-sectional study using a translated and validated Keratoconus Outcomes Research Questionnaire (KORQ) in Arabic language. We screened patients with keratoconus using the Belin/Ambrósio D-Index. We included the best-seeing eye in each patient with keratoconus, with a best corrected visual acuity better than 0.5. We collected variables including KORQ scores, flattest meridian keratometry, steepest meridian keratometry, mean keratometry front, maximum simulated keratometry, astigmatism front, Q value front, and thickness at the thinnest location. We performed linear regression analysis to identify predictors of the visual function score and symptom score., Results: Sixty-nine patients were included in this study, 43 (62.3%) male and 26 (37.7%) female patients, with a mean age 34.0 ± 11.50 years. The only predictor for visual function score was sex (β = 11.64, 95% confidence interval: 3.50-19.78). None of the topographic indices were related to quality of life., Conclusion: In this study, quality of life in patients with keratoconus was not related to specific tomography indices and might be related to visual acuity itself.

Purpose: The purpose of the study is to investigate the effects of combined 0.8% tropicamide and 5% phenylephrine on the corneal parameters using Pentacam., Methods: The study was performed on 200 eyes of 100 adult patients visiting the ophthalmology clinic for evaluation of refractive errors or cataract screening. Mydriatic drops (Tropifirin; Java, India) containing tropicamide 0.8%, phenylephrine hydrochloride 5%, and chlorbutol 0.5% (as a preservative) were instilled into the eyes of the patients three times every 10 minutes. The Pentacam was repeated after 30 minutes. The measurement data of various corneal parameters from different Pentacam displays (keratometry, pachymetry, densitometry, and Zernike analysis) was manually compiled on an Excel spreadsheet and analyzed using Statistical Package for the Social Sciences (SPSS) 20 software., Results: Analysis of Pentacam refractive maps revealed a statistically significant increase (P < 0.05) in the values of radius peripheral (cornea front), pupil center Pachymetry, pachymetry apex, thinnest location Pachymetry, and cornea volume. However, pupil dilation did not affect the Q-value (asphericity). Analysis of the densitometry values revealed significant increase in all zones. Aberrations maps revealed statistically significant increase in the value of spherical aberration after the induction of mydriasis, but the values of Trefoil 0º, Trefoil 30º, Koma 90º, and Koma 0º were not affected significantly. We did not observe any untoward effect of the drug, except transient blurring of vision., Conclusion: The current study showed that routine mydriasis in the eye clinics leads to a significant increase in various corneal parameters including corneal pachymetry, cornea densitometry, and spherical aberration as measured by Pentacam, which can influence the decision-making in the management of various corneal diseases. The ophthalmologists should be aware of these issues and make adjustments in their surgical planning accordingly., Competing Interests: None

Purpose: To compare the measured or calculated angle Kappa using Oculus pentacam HR, Sirius and Orbscan III devices., Patients and Methods: A prospective randomized cohort study, conducted on 47 eyes of 47 healthy orthotropic individuals, with an age range of 18-50 years and a corrected Snellen's distance visual acuity (CDVA) of 0.8 decimal or better. Angle Kappa is assessed directly using Orbscan® III software version 1.8.165.1. (Bausch and Lomb Rochester, New York, United States), while Pentacam® HR 1.21r.65 (Oculus Optikgeräte GmbH, Wetzlar, Germany) and Sirius device (CSO, version 3.2.1.60, Costruzione Strumenti Oftalmici, Florence, Italy) were used to calculate angle kappa indirectly., Results: Least mean difference of estimated angle Kappa was between Orbscan and Pentacam devices (- 0.18° ± 1.8), and it was statistically insignificant (p value = 0.1294). Differences between both Orbscan and Sirius, and Pentacam and Sirius were statistically significant (p value = 0.0004 and < 0.0001 consecutively). Bland Altman analysis showed a 95% confidence interval between Orbscan III and Pentacam of - 3.76 to 3.4 and between Orbscan III and Sirius of - 3.79 to 2.26., Conclusion: Pentacam parameters can be used as a reliable method to calculate angle kappa indirectly, without usage of any additional measurements from other machine. Sirius device parameters could also be used, but with less accurate results. A simple modification to those devices' software to calculate it, and incorporate it in the printout is possible, and highly recommended., (© 2022. The Author(s).)

Purpose: To evaluate the corneal topographical changes in vernal keratoconjunctivitis (VKC) subjects using OCULUS Pentacam., Design: This was a cross-sectional study., Methods: VKC patients and normal subjects who fulfilled the inclusion and exclusion criteria were recruited by convenience sampling into the study. Subjects underwent a best-corrected visual acuity measurement with a Snellen chart, retinoscopy, and corneal topography (OCULUS Pentacam®), followed by anterior segment and fundus examination and intraocular pressure measurement. Data were collected and analyzed using SPSS version 26.0 for Windows (SPSS Inc. Chicago, IL, USA). A p-value <0.05 was considered statistically significant., Results: A total of 78 eyes of 43 VKC patients and 84 eyes of normal subjects were included in the study. Most of the VKC subjects were Malay males aged 10 years or less. A majority (71.8%) had palpebral VKC of five years duration or less (57.7%) and presented between the ages of six and 10 years (44.9%). Central corneal curvature and astigmatism were significantly higher in VKC subjects compared to the normal population (p < 0.05). The minimal pachymetry was significantly lower with a longer duration of VKC (p < 0.05). Older age of presentation of VKC was associated with higher central corneal curvatures and thinner minimal pachymetry (p < 0.05). There was no association between the type of VKC and corneal topography changes. The prevalence of keratoconus and subclinical keratoconus among VKC subjects was 10.3% and 11.5%, respectively., Conclusion: Longer duration and older age of presentation of VKC are associated with significant corneal topographical changes, thus exposing them to a higher risk of the future development of keratoconus., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2023, Thiagarajan et al.)

Purpose: To compare the intra-device repeatability and inter-device reproducibility between two anterior segment imaging instruments, the CASIA SS-1000 (Tomey Corp., Nagoya, Japan) and Pentacam (OCULUS, Arlington, WA) in measuring anterior segment parameters., Methods: Single-center, prospective clinical trial. Participants ≥20 years of age were included. One eye was randomly selected, each imaged by three CASIA SS-1000 devices and three Pentacam devices by three different examiners. Each photographer operated a pair of devices, one CASIA SS-1000 and one Pentacam. The image order for each participant was determined by a random permutation table. Three images were taken from each device. A total of 18 images were taken for each eye. Ratios of the standard deviations, referenced as (CASIA/Pentacam), were calculated to compare the repeatability and reproducibility of the two imaging instruments., Results: In all, 66 participants with a mean age of 46.4 years (±21.7) were enrolled in the study. All repeatability ratios and intra-device variability were less than 1 (anterior corneal curvature: flat = 0.86, steep = 0.85; posterior corneal curvature: flat = 0.43, steep = 0.61; and map: thinnest = 0.22; central = 0.24, 2 mm = 0.26, 4 mm = 0.27, and 6 mm = 0.30). All reproducibility ratios, which measure the inter-device variability, were less than 1 (anterior corneal curvature: flat = 0.58, steep = 0.73; posterior corneal curvature: flat = 0.25, steep = 0.31; and pachymetry map: thinnest = 0.20; central = 0.20; 2 mm = 0.20; 4 mm = 0.19; and 6 mm = 0.22). A ratio of less than 1 indicates that the CASIA SS-1000 has more consistent measurements., Conclusions: The CASIA SS-1000 was found to have better repeatability and reproducibility compared to the Pentacam for both corneal curvature and pachymetry maps. This greater consistency may require further study to determine whether the decreased variability can be translated into improved clinical results., (© 2023. The Author(s).)