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Background: Proper calculation of ablation depth associated with LASIK and FEMTOLASIK surgeries is mandatory to estimate the post-refractive surgery remaining stroma to avoid the possibility of post-operative ectasia and to correct the maximum error to meet the patient’s needs and safety.Purpose: The current work aimed to assess the actual depths of ablation after the LASIK versus the FEMTO-LASIK surgeries.Patients and Methods: Forty eyes of 20 patients were included in this prospective non-randomized interventional study. They had myopia or myopic astigmatism, and scheduled for LASIK or FEMTOLASIK surgery. Pentacam was used to check the thickness of the thinnest corneal location and to exclude the possibility of keratoconus. They were divided into two groups according to the technique used to correct the error. Group I for LASIK and Group II for FEMTOLASIK surgery. Ablation was performed in all cases using the Allegretto excimer laser machine. After surgery, all patients received a combination of topical tobramycin 0.3% and dexamethasone 0.1% eye drops four times daily for 10 days, and topical Sodium Hyaluronate eye drops [2 mg/ml] four times daily for one month. All patients were examined at one day and one week postoperatively for evidence of flap malposition, striae, epithelial defects, or diffuse lamellar keratitis. Pentacam was used for follow up at 3 months after surgery to re-evaluate the thinnest central location.Results: In group I, the mean actual tissue ablation per one diopter was 13.3 microns for 6.5 mm treatment zone, and 11.9 microns for 6.0 mm treatment zone, while in group II, it was 13.4 microns for 6.5 treatment zone, and 11.8 microns for 6.0 treatment zone. There was insignificant difference between actual tissue ablation following the LASIK versus the FEMTOLASIK surgeries.Conclusion: The actual ablation depth should be considered to calculate the remaining stromal depth after LASIK or FEMTOLASIK surgeries for treatment of myopia or myopic astigmatism to avoid the possibility of post- LASIK or FEMTOLASIK ectasia and to correct the maximum error that meets the patient’s needs.

Ahmed El-Massry, Khalid Rashid ,† Seham Saad, Ihab Osman Department of Ophthalmology, Alexandria Faculty of Medicine, Alexandria, Egypt†Professor Khalid Rashid passed away on January 9, 2021.Correspondence: Ahmed El-MassryDepartment of Ophthalmology, Alexandria Faculty of Medicine, Champollion Street, El-Khartoum Square, El Azareeta Medical Campus, Alexandria, 21131, EgyptTel +20 122 215 2435Email ahmad.elmassry@gmail.comPurpose: To assess the results of simultaneously performed femtosecond laser–assisted Keraring intrastromal corneal ring–segment insertion and corneal collagen cross-linking for the treatment of keratoconus.Patients and Methods: In this retrospective, noncomparative, interventional study, 30 eyes of 24 progressive-keratoconus patients of both sexes aged 18– 36 years old with poor best-corrected visual acuity (BCVA) and intolerance to contact lenses were included. All patients had been subjected to complete preoperative and postoperative ophthalmological examinations — unaided VA, BCVA, refraction, Pentacam, and contrast sensitivity examinations at 3-month, 6-month, and 1-year follow-ups.Results: Mean unaided VA had changed significantly from 0.649± 0.239 logMAR preoperatively to 0.514± 0.222 (P=0.014), 0.419± 0.162 (P< 0.001), and 0.379± 0.142 (P< 0.001) logMAR at the three follow-up visits, respectively. Mean BCVA had changed significantly from 0.326± 0.144 logMAR preoperatively to 0.231± 0.140 (P=0.006) at 1-year follow-up. Mean spherical equivalent refraction had decreased significantly at 6-month (P=0.0298) and 1-year follow-up (P=0.0081). Mean steep keratometry (K2) had also significantly reduced from 51.89± 3.81 D to 49.87± 4.57 D (P=0.034) at 6 months and 49.40± 4.39 D (P=0.011) at 1 year. Mean refractive and keratometric astigmatism had significantly decreased at all follow-up visits.Conclusion: At 1-year follow-up, keraring intrastromal corneal ring–segment insertion assisted by femtosecond laser performed simultaneously with corneal collagen cross-linking resulted in an improvement in visual, refractive, and topographic outcomes, which may suggest it is an effective treatment of keratoconus.Keywords: keratoconus, corneal collagen cross-linking, Pentacam, ICRS

Ahmed El-Massry, Khalid Rashid ,†Seham Saad, Ihab Osman Department of Ophthalmology, Alexandria Faculty of Medicine, Alexandria, Egypt†Professor Khalid Rashid passed away on January 9, 2021.Correspondence: Ahmed El-MassryDepartment of Ophthalmology, Alexandria Faculty of Medicine, Champollion Street, El-Khartoum Square, El Azareeta Medical Campus, Alexandria, 21131, EgyptTel +20 122 215 2435Email ahmad.elmassry@gmail.comPurpose: To assess the results of simultaneously performed femtosecond laser–assisted Keraring intrastromal corneal ring–segment insertion and corneal collagen cross-linking for the treatment of keratoconus.Patients and Methods: In this retrospective, noncomparative, interventional study, 30 eyes of 24 progressive-keratoconus patients of both sexes aged 18– 36 years old with poor best-corrected visual acuity (BCVA) and intolerance to contact lenses were included. All patients had been subjected to complete preoperative and postoperative ophthalmological examinations — unaided VA, BCVA, refraction, Pentacam, and contrast sensitivity examinations at 3-month, 6-month, and 1-year follow-ups.Results: Mean unaided VA had changed significantly from 0.649± 0.239 logMAR preoperatively to 0.514± 0.222 (P=0.014), 0.419± 0.162 (P< 0.001), and 0.379± 0.142 (P< 0.001) logMAR at the three follow-up visits, respectively. Mean BCVA had changed significantly from 0.326± 0.144 logMAR preoperatively to 0.231± 0.140 (P=0.006) at 1-year follow-up. Mean spherical equivalent refraction had decreased significantly at 6-month (P=0.0298) and 1-year follow-up (P=0.0081). Mean steep keratometry (K2) had also significantly reduced from 51.89± 3.81 D to 49.87± 4.57 D (P=0.034) at 6 months and 49.40± 4.39 D (P=0.011) at 1 year. Mean refractive and keratometric astigmatism had significantly decreased at all follow-up visits.Conclusion: At 1-year follow-up, keraring intrastromal corneal ring–segment insertion assisted by femtosecond laser performed simultaneously with corneal collagen cross-linking resulted in an improvement in visual, refractive, and topographic outcomes, which may suggest it is an effective treatment of keratoconus.Keywords: keratoconus, corneal collagen cross-linking, Pentacam, ICRS

AIM:To compare the difference, correlation and consistency of corneal biological parameters measured by IOL Master 700 and Pentacam before cataract extraction and intraocular lens implantation in different age groups.METHODS: Cross-sectional study. A total of 87 cataract patients(162 eyes)in Weifang Eye Hospital from February to September 2020 were collected, including 44 males(80 eyes)and 43 females(82 eyes)(age 61.2±9.87 years). The patients were divided into four groups: group A [17 cases(32 eyes), 40-50 years old], group B [25 cases(47 eyes), 51-60 years old], group C [28 cases(53 eyes), 61-70 years old], and group D [17 cases(30 eyes), 71-80 years old]. The preoperative corneal biological parameters of cataract patients were measured by IOL Master 700 and Pentacam, and the flat axis corneal curvature(K1), steep axis corneal curvature(K2), mean corneal curvature(Km), corneal astigmatism, anterior chamber depth(ACD)and central corneal thickness(CCT)were recorded. The difference and correlation of measurement results between two kinds of biometric instruments in different age groups were analyzed. RESULTS: Except for the corneal astigmatism in group C and K1 and corneal astigmatism in group D, there were significant differences between the two instruments(t=2.746, -2.582, 2.637, all P

Background To assess alterations in backscatter from the corneal epithelium, anterior stroma and lens surface in eyes with subclinical, mild and moderate keratoconus (KC). Methods In this single-centre, cross-sectional study involving 24 eyes with subclinical KC, 107 eyes with manifest KC (mild = 40 and moderate = 67 eyes) and 90 controls, line densitometry was performed with Pentacam (Oculus Optikgerate GmbH, Wetzlar, Germany) to obtain simultaneous backscatter values for the corneal epithelium, anterior stroma and anterior lens surface. Backscatter values and Pentacam parameters were used in subsequent statistical analyses. Results Eyes with subclinical, mild and moderate KC had similar epithelial and stromal backscatter (P > 0.05) that was significantly increased compared with the controls (P < 0.05). Although anterior lens surface backscatter did not differ between the control and KC groups (P > 0.05), it was significantly higher in the mild and moderate KC groups than in the subclinical KC group (P < 0.05). In the KC group (n = 131) epithelial backscatter was strongly correlated with stromal backscatter (r = 0.911, P < 0.0001). Conclusions Increased epithelial backscatter and a strong correlation with anterior stromal backscatter in the KC groups were consistent with the epithelium-stroma interaction involved in KC pathogenesis. Single-point backscatter analysis can be used with point clouds to construct epithelial and stromal backscatter maps in Pentacam to aid the detection of KC as a novel feature.

AIM: To compare the differences of corneal curvature and astigmatism measured by Pentacam, IOL Master and iTrace of cataract patients.METHODS:In this prospective clinical trial,68 cataract patients(82 eyes)received treatment at the ophthalmology department of our hospital. In the treatment process, used the IOL Master, Pentacam and iTrace to measure the patient's corneal curvature(K1, K2, Km)and astigmatism(J0, J45). The difference, correlation and consistence among three instruments were analysed. RESULTS: Differences analysis showed that in the measurement of K1, K2, Km, there was no difference among Pentacam, IOL Master and iTrace(P>0.05). Pearson correlation analysis showed that K1, K2, Km were highly correlated among three instruments(|r|>0.5, P

PURPOSE: To determine the changes in intraocular pressure (IOP) and anterior chamber parameters following intravitreal bevacizumab injection with different sizes of cannulas. METHODS: This clinical trial was conducted with 70 eyes of 70 patients who received an intravitreal injection of bevacizumab with 26 G (Group 1) or 30 G (Group 2) needle. Preinjection and postinjection 30th-min IOP and pentacam measurements were obtained. Anterior chamber depth (ACD), anterior chamber volume (ACV), central corneal thickness (CCT), corneal volume (CV), and iridocorneal angle (ICA) measurements were evaluated in pentacam. RESULTS: Preinjection mean IOP values in Group 1 and 2 were 14.7 ± 3.29 mm Hg and 15.1 ± 2.87 mm Hg, respectively. Postinjection mean IOP in Group 1 was 16.8 ± 6.24 mm Hg and in Group 2 was 20.3 ± 3.66 mm Hg. Postinjection mean IOP values were significantly higher than preinjection values in both groups (Group 1 P < 0.005 and Group 2 P < 0.001). IOP change was significantly higher in Group 2 after injection (P < 0.05). In both groups, the change in IOP found to be more significant in phakic eyes than pseudophakic eyes (Group 1 P < 0.001, Group 2 P < 0.001). CCT and CV were significantly higher in both groups 30 min after the injection than preinjection (Group 1 and Group 2; P < 0.01). In Group 2 ACD, ACV and ICA values were significantly lower than preinjection values (P < 0.05). CONCLUSION: Needle bore size is an important parameter that influences anterior segment parameters and IOP change in the intravitreal injection. IOP rise and anterior segment changes are more prominent with a thinner cannula.

AIM:To investigate the function of Pentacam in accurately selecting the model and axial position of Toric artificial lens. METHODS: Totally 53 eyes of 46 cataract patients who were scheduled to receive phacoemulsification from January 2018 to December 2018 were selected in our hospital. Before the operation, corneal astigmatism was greater than 1.0D according to the examination results by AL-Scan and automatic corneal curvature instrument, and Pentacam was used to evaluate the corneal astigmatism to guide the accurate selection of Toric IOL model and the axial position to be implanted. Surgery was done by the same doctor. After operation, the patients were traced and visited for 3mo to collect the uncorrected visual acuity(UCVA), the best corrected visual acuity(BCVA), the whole-eye astigmatism, the corneal curvature and target induced astigmatism(TIA)before and after the operation as well as the postoperative astigmatism, the rate not relying on the glasses, visual quality assessment and so on. RESULTS: There was no obvious change on patients' corneal astigmatism before and after the operation. The whole-eye astigmatism was reduced and UCVA and BCVA were obviously improved. The difference was statistically meaningful(P0.05). The rate of distant vision defecation and visual quality were significantly improved. CONCLUSION: Pentacam can evaluate the corneal astigmatism more comprehensively and accurately, which is helpful to guide the accurate selection of Toric artificial lens model, and to improve the postoperative expected effect.

Background To explore the possible causes of tomography suspect keratoconus (TSK) marked by Tomography in screening keratoconus in a Chinese cohort, and the reasonable range of corneal horizontal diameter and thickness for decreasing the proportion of TSK. Methods Nested case-control study from a single center prospective cohort. All subjects were selected from the Peking University Third Hospital Ectasia Cornea Disease Cohort Project database, which included myopic patients seeking corneal refractive surgical corrections since 2013. Demographic information, basic eye examination, and auxiliary equipment examination including refraction, IOL-master, Pentacam, Sirius, and Topolyzer were recorded. In this study, all cases were classified into two groups: TSK group and normal control (NC) group, and all of them were followed up at least 2 years. The former is consisted of those whose screening examinations of tomography are abnormal, the latter is those whose screening examinations are normal. All of them have already been followed up at least 2 years without abnormalities after excimer laser corneal refractive surgeries. Unpaired t tests and Chi-square tests were used to compare the differences of indices from the tomography between the two groups. Results Of 183 TSK eyes (109 patients) and 160 NC eyes (83 patients), the mean age is 28.0 and 26.3 years old respectively. The corneal horizontal diameter is 11.5–11.8 mm in TSK group and 11.8–12.0 mm in NC group. The central corneal thickness is nearly 520 μm in the former and 550 μm in the latter. For Sirius, the TSK ratio of indices of SIf and SIb is 41.5 and 39.9% respectively in TSK group. For Pentacam, the TSK ratio of index IHD is 59.0% and “final D” is 72.7%. Conclusions Corneal horizontal diameter and central corneal thickness have great influences on the results of corneal tomography in detecting the suspect keratoconus.

Background and Objectives: Keratoconus is a non-inflammatory asymmetric corneal degenerative disease characterized by the steepening and distortion of the cornea. In this disease, irregular astigmatism makes the subjective refraction difficult. Using the Pentacam, we aimed to determine the corrective astigmatism of the spectacle. Methods: The subjective refraction and Pentacam imaging were performed for 317 keratoconic patients who referred to the Salouti Eye Clinic, Shiraz, Iran. Then, the astigmatism values obtained with subjective refraction were compared with the values of anterior and posterior corneal surface astigmatism obtained with the Pentacam imaging. Results: The mean age of 317 keratoconic patients was 29.81 years (range: 15 to 45 years). The minimum, maximum, and average astigmatism of the corneal front surface were 0.3, 16.8, and 3.21 diopters, respectively. Also, the minimum, maximum, and average astigmatism of the corneal back surface were 0, 2.8, and 0.67 diopters, respectively. Moreover, the P value was lower than 0.001 in the regression analysis of the subjective refraction for both the power and axis of the cylinder. Conclusion: The regression formulas obtained in this study can accurately (with a probability of 99%) predict refractive astigmatism, using corneal astigmatism.

Purpose To evaluate and compare the repeatability and agreement of Scheimpflug vs scanning-slit tomography of the cornea and the anterior chamber in terms of keratometric and tomographic indices in healthy eyes. Methods The 20 eyes of 10 healthy participants underwent 3 consecutive measurements using both Scheimpflug-tomography and scanning-slit tomography, diagnostic devices. Multiple corneal and anterior chamber tomographic parameters were recorded and evaluated to include corneal keratometry and its axis; corneal best-fit sphere (BFS), pachymetry mapping, angle kappa, anterior chamber depth (ACD), pupil diameter, and location. Repeatability for each device was assessed using the within each subject standard deviation of sequential exams, the coefficient variation (CV) and the intraclass correlation coefficient (ICC). Agreement between the two devices was assessed using Bland–Altman plots with 95% limits of agreement (LoA) and correlation coefficient (r). Results Both devices were found to have high repeatability (ICC>0.9) both in keratometric and other tomographic measurements. Scheimpflug tomography’s repeatability though appeared superior in the average keratometry values, anterior and posterior BFS, thinnest corneal pachymetry value and location (p0.8) in respective measurements with Scheimpflug delivering consistently lower values than the scanning-slit tomography device. Conclusion Scheimpflug-tomography repeatability was found to be superior to that of scanning-slit tomography in this specific study, in most parameters evaluated. Inter-device agreement evaluation suggests that reading from the two devices may not be used interchangeably in absolute values, yet they are well correlated with Scheimpflug delivering consistently lower values in most., Video abstract Point your SmartPhone at the code above. If you have a QR code reader the video abstract will appear. Or use: https://youtu.be/GtAfCy3JbBs

Anastasios John Kanellopoulos1,2 1Department of Ophthalmology, The LaserVision Clinical and Research Eye Institute, Athens, Attiki, Greece; 2Department of Ophthalmology, New York University Medical School, New York City, NY, USACorrespondence: Anastasios John KanellopoulosThe LaserVision Clinical and Research Eye Institute, Athens, GreeceTel + 30 210 7472777Fax + 30 210 7472789Email ajkmd@mac.comPurpose: To evaluate and compare the repeatability and agreement of Scheimpflug vs scanning-slit tomography of the cornea and the anterior chamber in terms of keratometric and tomographic indices in healthy eyes.Methods: The 20 eyes of 10 healthy participants underwent 3 consecutive measurements using both Scheimpflug-tomography and scanning-slit tomography, diagnostic devices. Multiple corneal and anterior chamber tomographic parameters were recorded and evaluated to include corneal keratometry and its axis; corneal best-fit sphere (BFS), pachymetry mapping, angle kappa, anterior chamber depth (ACD), pupil diameter, and location. Repeatability for each device was assessed using the within each subject standard deviation of sequential exams, the coefficient variation (CV) and the intraclass correlation coefficient (ICC). Agreement between the two devices was assessed using Bland–Altman plots with 95% limits of agreement (LoA) and correlation coefficient (r).Results: Both devices were found to have high repeatability (ICC> 0.9) both in keratometric and other tomographic measurements. Scheimpflug tomography’s repeatability though appeared superior in the average keratometry values, anterior and posterior BFS, thinnest corneal pachymetry value and location (p< 0.05). Agreement: Statistically significant inter-device differences were noted in the mean values of K1, K2, BFS, ACD and thinnest corneal pachymetry (p< 0.05). Despite the agreement differences noted, the two devices were well correlated (r> 0.8) in respective measurements with Scheimpflug delivering consistently lower values than the scanning-slit tomography device.Conclusion: Scheimpflug-tomography repeatability was found to be superior to that of scanning-slit tomography in this specific study, in most parameters evaluated. Inter-device agreement evaluation suggests that reading from the two devices may not be used interchangeably in absolute values, yet they are well correlated with Scheimpflug delivering consistently lower values in most.Keywords: Pentacam, Orbscan, Scheimpflug corneal tomography, scanning-slit corneal tomography

Purpose To investigate the agreement and reliability of anterior segment optical coherence tomography (AS-OCT) and Scheimpflug imaging in measuring the distance from the anterior edge of an iris-fixated phakic intraocular lens (IF-pIOL) to the corneal endothelium. Methods Anterior segment configuration was assessed in a total of 62 eyes of which 25 hyperopic and 37 myopic eyes, all corrected with an IF-pIOL. Measurements were performed by two independent observers using AS-OCT (Visante, Model 1000, Carl Zeiss Meditec Inc.) and Scheimpflug imaging (Pentacam HR, Oculus Optikgerate). The distance from the anterior edge of the pIOL to the endothelium was measured in five different positions using both modalities with their corresponding pIOL software. The measurements as well as the inter- and intra-observer reliability of the two imaging modalities were then compared. Results Distance measurements for all positions performed by AS-OCT were found to be significantly larger than those performed by Scheimpflug imaging, with mean differences ranging from 0.11 to 0.22 mm. Both instruments exhibited good inter- and intra-observer reliability. Conclusion Anterior pIOL edge to endothelium distance measurements by AS-OCT and Scheimpflug imaging have good intra- and inter-observer reliability. However, as AS-OCT provides larger measurements, these two modalities cannot be used interchangeably. Correction of this difference might be essential for proper decision-making during pre-operative screening for pIOL implantation and post-operative safety monitoring.

AIM: To assess the inter-device consistency of corneal curvature and central corneal thickness between Pentacam and a swept-source Fourier-domain anterior segment optical coherence tomography (AS-OCT) in ectopia lentis patients. METHODS: Totally 72 eyes of ectopia lentis patients were recruited. Central corneal thickness (CCT), corneal curvature values and corneal astigmatism were obtained from both the Pentacam and AS-OCT (CASIA2). Repeatability was evaluated for both devices. The coefficient of repeatability (COR) and the relative COR was calculated. Bland-Altman plots were conducted to evaluate the inter-device agreement of measurement. Orthogonal linear regression was used to examine any proportional bias. RESULTS: The mean difference of CCT, steep anterior corneal curvature (anterior K(S)), flat anterior corneal curvature (anterior K(f)), anterior corneal astigmatism (ACA), steep posterior corneal curvature (posterior K(S)), flat posterior corneal curvature (posterior K(f)), posterior corneal astigmatism (PCA), steep true net power (TNP K(S)), flat true net power (TNP K(f)) and total corneal astigmatism (TCA) between Pentacam and CASIA2 were 7.03±9.70 µm, -0.19±0.41 D, -0.27±0.35 D, 0.04±0.47 D, -0.17±0.23 D, -0.11±0.11 D, -0.02±1.02 D -0.41±0.43 D, -0.52±0.46 D, and -0.15±0.96 D, respectively. For measurement of TNP K(f) with the Pentacam and CASIA2, a mean difference of 0.52 D and COR of 0.90 with P=0.02 was detected. There was no significant difference in CCT (P=0.393), anterior K(f) (P=0.107), anterior Ks (P=0.414), ACA (P=0.131), posterior K(f) (P=0.286), posterior K(s) (P=0.418), PCA (P=0.105), TNP K(s) (P=0.054), and TCA (P=0.977) between Pentacam and CASIA2. CONCLUSION: Our study reveals good agreement of CCT, corneal curvature and corneal astigmatism measured by CASIA2 and Pentacam in ectopia lentis patients. However, there was significant difference for CCT and corneal curvature values obtained by the two devices.

AIM: To compare differences and consistency of corneal curvatures in adolescent patients with low and moderate myopia measured by Pentacam, IOL Master and corneal topographic.METHODS: A prospective clinical study. 291 adolescent patients(291 eyes)with low and moderate myopia who underwent orthokeratology in the Affiliated Eye Hospital of Nanjing Medical University from January 2019 to September 2019 were selected. Among them, 141 cases(141 eyes)were low myopia and 150 cases(150 eyes)were moderate myopia. Corneal curvature(K1, k2, Km)and corneal Astigmatism(J0, J45)were examined by Pentacam, IOL Master, and corneal topography. And then the difference, correlation and consistency of the measurement results of three instruments were analyzed.RESULTS: Differences analysis showed that in the measurement of J45, there was no difference between Pentacam and corneal topography(P>0.05)in patients with low and moderate myopia; in the measurement of J0,there was no difference between Pentacam and IOL Master(P>0.05)in patients with low myopia; in the measurement of K2,there was no difference between Pentacam and corneal topography(P>0.05)in patients with low myopia; in the measurement of J0,there was no difference between Pentacam and corneal topography(P>0.05)in patients with moderate myopia. But there were significant differences in other measurements among three instruments(P1, K2, Km, J0, and J45 were highly correlated among three instruments(r=0.545-0.997, all PCONCLUSION: Pentacam, IOL Master and corneal topographic have good consistency and can be used as a mutual reference before orthodontic fitting of low and moderate myopia patients. The measurement difference between Pentacam and corneal topography is the smallest among three instruments, but whether three instruments can be replaced by each other needs to be considered in combination in clinical application.

AIM: To compare the anterior chamber volume and corneal volume using Pentacam in people with early keratoconus, subclinical keratoconus, and healthy subjects.METHODS: This epidemiologic study was performed on 63 patients who were candidates for refractive surgery. We classified our patients into three groups as normal, subclinical keratoconus, and early keratoconus according to the Amsler-Krumeich criteria. We collected demographic information, including age and sex, and obtained a full medical history of the patients. Complete visual examination was performed for all patients. Then, using Pentacam, corneal volume and anterior chamber volume were measured among three groups. RESULTS: Corneal volume in the control group was significantly higher than the subclinical keratoconus and early keratoconus groups(PP>0.05).CONCLUSION: Measuring the corneal volume can help to distinguish the eyes with subclinical keratoconus and early keratoconus from normal eyes. The chamber volume might not differ remarkably among people with subclinical keratoconus, early keratoconus, and those with normal eyes.

AIM: To assess the changes in the anterior chamber parameters using Pentacam following four different lines of treatment of primary angle-closure glaucoma (PACG). METHODS: A retrospective comparative study included 126 patients (126 eye) presented within 24-48h after acute angle-closure glaucoma (AACG). Patients were divided into 2 groups: group A (68 eyes) with controlled intraocular pressure (IOP) ≤21 mm Hg, which included subgroup A1 (34 eyes) with clear lens underwent Nd:YAG laser peripheral iridotomy (LPI) and subgroup A2 (34 eyes) with cataract underwent standard phacoemulsification; and group B (58 eyes) with uncontrolled IOP, which included subgroup B1 (30 eyes) with clear lens underwent trabeculectomy and subgroup B2 (28 eyes) with cataract underwent combined phacoemulsification and trabeculectomy. Patients were followed up for at least 3mo. Primary outcomes were Pentacam anterior segment measurements [anterior chamber angle (ACA) and depth (ACD)]. Secondary outcomes were changes in IOP, visual acuity (VA) and recorded complications. RESULTS: At the 3(rd) month, there was significant increase in the ACA values in all studied groups compared to preoperative values (P

The University of Granada (``Plan Propio'' program; grant reference: PJIA2020.13) provided financial support in the form of grant funding. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript., Objectives. The execution of isometric resistance training has demonstrated to cause changes in the ocular physiology. The morphology of the cornea and anterior chamber is of paramount importance in the prevention and management of several ocular diseases, and thus, understating the impact of performing isometric exercise on the eye physiology may allow a better management of these ocular conditions. We aimed to determine the short-term effects of 2-minutes upper-body isometric effort at two different intensities on corneal and anterior eye morphology. Methods. Eighteen healthy young adults performed a 2-minutes isometric bicepscurl exercise against two loads relative to their maximum strength capacity (highintensity and low-intensity) in a randomized manner. An Oculus Pentacam was used to measure the corneal morphology and anterior chamber parameters in both experimental conditions at baseline, during the isometric effort (after 30, 60, 90 and 120 seconds), and after 30 and 120 seconds of passive recovery. Results. We found that isometric effort causes an increase in pupil size (P < 0.001), and a decrease in the iridocorneal angle (P = 0 .005), anterior chamber volume (P < 0.001) and K-flat (P < 0.001) during isometric effort, with these effects being more accentuated in high-intensity condition (P < 0.005 in all cases).Performing 2-minutes upper-body isometric effort did not alter anterior chamber depth, central corneal thickness, corneal volume, and K-steep (P > 0.05 in all cases). Conclusions. Our data exhibit that performing 2-minutes of upper-body isometric exercise modifies several parameters of the corneal morphology and anterior eye biometrics, with these changes being greater for the high-intensity exercise condition. The findings of this study may be of relevance for the prevention and management of corneal ectasias and glaucoma., University of Granada (``Plan Propio'' program) PJIA2020.13

PURPOSE: To monitor the changes in the ABCD grading system during a one-year follow-up after a corneal cross-linking (CXL) procedure. METHODS: This prospective study included 30 eyes of 25 patients with keratoconus, who received the CXL treatment. The patients with a history of ocular trauma or surgery and other corneal pathology were excluded from the study. The patients were examined at the baseline visit and followed up at 3, 6, and 12 months after the CXL. All the patients underwent a standard CXL procedure with visual acuity and Scheimpflug tomography testing at each visit. The corneal parameters and ABCD grading were monitored throughout the follow-up period. RESULTS: There were no significant changes of parameter A and anterior radius curvature (ARC) in the ABCD grading system. Parameters B and D showed progression postoperatively, with an improvement of parameter D on the final visit. Parameter C showed a statistically significant increase at all three post-CXL visits, but a constant gradual decrease in the value over time. CONCLUSION: The ABCD grading system can be very useful in monitoring the progression of keratoconus (KC), but it can also help in monitoring the efficacy of corneal cross-linking. The anterior surface parameters in the ABCD grading system did not show progression in the post-CXL period, and parameters C and D showed improvement and stability a year after the procedure.

Purpose: To find the accuracy of Scheimpflug imaging for the evaluation of posterior lens capsule and to assess the incidence of pre-existing posterior capsular tear (PCT) in pediatric traumatic cataracts. Methods: It was a prospective, non-randomized, and interventional study. Scheimpflug imaging was done preoperatively to detect pre-existing PCT in pediatric traumatic cataracts after blunt trauma. All patients underwent cataract extraction with intraocular lens implantation. Intraoperatively, the posterior capsule status was noted and compared with the preoperative Scheimpflug images. Results: Forty-seven eyes of 47 children having traumatic cataracts following closed-globe injury were included. There were 32 males and 15 females with a mean age of 10.91 ± 2.75 years. The mean duration of performing the Scheimpflug imaging from injury was 41.7 ± 7.78 days. Preoperative Scheimpflug imaging showed intact posterior lens capsule in 36 eyes and PCT in 11 eyes. Intraoperative, 37 eyes had an intact posterior lens capsule and 10 eyes had PCT. The Scheimpflug imaging did not detect the PCT in three eyes (false-negative), and in four eyes, PCT was detected falsely on Scheimpflug imaging (false-positive). The sensitivity and specificity of the Scheimpflug imaging were 70 and 89.18%, respectively. The accuracy of the technique was 85.11%. Conclusion: Scheimpflug imaging is a useful modality for the detection of PCT preoperatively in cases with doubtful posterior lens capsule integrity.

Purpose: To evaluate the influence of analysis mode selection on prediction accuracy of corneal astigmatism using Pentacam.Methods: Fifty-nine eyes of 59 patients implanted with toric intraocular lenses (IOLs) were included in the retrospective study. Preoperative corneal astigmatism (total refractive power) measured with Pentacam was analyzed based on 2-, 3-, 4-, or 5-mm ring or zone mode either centered on corneal apex or pupil center. Actual corneal astigmatism was calculated based on residual astigmatism on the corneal plane, surgical-induced astigmatism, and effective toric power on the corneal plane. Prediction error, the difference between actual corneal astigmatism and measured astigmatism, was compared among different analysis modes. Influences of local topography on prediction error were also evaluated.Results: Based on the zone mode, prediction error was lower when centered on corneal apex than on pupil center at different diameters, whereas based on the ring mode, this difference was only seen at 2-mm cornea (all P < 0.05). When centered on the corneal apex, the zone mode showed lower prediction error than the ring mode at 4- and 5-mm corneas (both P < 0.001), regardless of asymmetric or symmetric astigmatism. In symmetric bowtie, the zone mode showed lower prediction error than the ring mode at 2-mm cornea of the small bowtie, and 4- and 5-mm corneas of the large bowtie (all P < 0.05).Conclusions: For toric IOL planning, the corneal apex may be a better reference center. At a cornea diameter ≥4 mm, the zone mode is more accurate than the ring mode. Local topography affects prediction accuracy in the symmetric bowtie.

To pursue the least corneal implication during cataract surgery, this study aimed to monitor corneal wound injury after cataract surgery with a novel method. The prospective cohort study involved thirty-two patients, who were assessed by a Scheimpflug tomography AxL® (Oculus GmbH, Wetzlar, Germany) via the following two kinds of indices: whole corneal optical density (COD) and corneal thickness (CT), two weeks before and one month after cataract surgery. The results of the COD revealed that corneal annuli 0.0–2.0 mm and 2.0–6.0 mm, and the average and maximal values at the incisional site significantly increased postoperatively. Also, the anterior and central stroma of 0.0–2.0 mm, and all three depths of 2.0–6.0 mm, increased remarkably after the operation. For the CT, all ranges of diameters plus incisional sites showed significant increases postoperatively. Furthermore, we analyzed the differences (delta) of COD and CT between pre- and post-operation, and found significant correlations between the delta of COD and the delta of CT, regarding annuli 0.0–2.0 mm, 2.0–6.0 mm, and 6.0–10.0 mm, but no correlation at the incisional site, with either average density or maximal density, was detected. We concluded that whole COD and CT, especially at the central zones of the cornea (annulus &lt, 6 mm), are both valuable parameters in the assessment of corneal damage post-cataract surgery, and are independent indices at the incisional site.

Introduction: Accurate assessment of the corneal shape is important in cataract and refractive surgery, both in screening of candidates as well as for analyzing postoperative outcomes. Although corneal topography and tomography are widely used, it is common that these technologies are confused. The aim of this study was to present the current developments of these technologies and particularly distinguish between corneal topography and tomography. Methods: The PubMed, Web of Science and Embase databases were the main resources used to investigate the medical literature. The following keywords were used in various combinations: cornea, corneal, topography, tomography, Scheimpflug, Pentacam, optical coherence tomography. Results: Topography is the study of the shape of the corneal surface, while tomography allows a three-dimensional section of the cornea to be presented. Corneal topographers can be divided into large- and small-cone Placido-based devices, as well as devices with color-LEDs. For corneal tomography, scanning slit or Scheimpflug imaging and optical coherence tomography may be employed. In several devices, corneal topography and tomography have been successfully combined with tear-film analysis, aberrometry, optical biometry and anterior/posterior segment optical coherence tomography. Conclusion: There is a wide variety of imaging techniques to obtain corneal power maps. As different technologies are used, it is imperative that doctors involved in corneal surgery understand the science and clinical application of devices for corneal evaluation in depth.

This study aims to present a case of transient myopia due to aripiprazole used in the treatment of depression. A 21-year-old female who was being treated for depression with 15 mg/day Aripiprazole during two months. She normally used -3.75 D glasses. She was admitted to our outpatient clinic with sudden onset blurring of vision in both eyes despite using glasses for about three days. Using of aripiprazole was observed in the patient’s history. She was found to have myopia of -6.0 diopters in both eyes with measurement of otorefractometer; her visual acuity was 6/10 in both eyes with her glasses. The other eye examination findings of the patient were normal. The drug was discontinued, and the patient was followed. One mount later on examination, the patient’s visual acuity increased to 10/10 in both eyes. Following the first day of the Alx values measured were 0.3 mm longer than one month after the measurement; the minimal difference between the other anterior segment findings were recorded. Although the specific mechanisms that cause acute myopia has not been fully revealed, it can be ciliary spasm, ciliary bodies effusion, peripheral uveal effusion and effects of ocular serotonergic intraneural fibers. We believe that it would be important for clinicians. They should keep in mind these conditions when prescribing aripiprazole and need to inform patients about the side effects related to the eye.

Background and Objective: Cataract is one of the most common causes of blindness in the world, and posterior capsular opacification (PCO) is the most common complication after cataract surgery. Nd: YAG laser posterior capsulotomy is a standard method for the treatment of PCO. The aim of this study was to investigate the effects of Yas laser capsulotomy on anterior segment parameters and lenticular astigmatism. Materials and Methods: In this randomized clinical trial study, a total of 37 eyes from 30 patients with posterior capsular opacity after uneventful phacoemulsification were enrolled and underwent Nd: YAG laser capsulotomy. Full ocular examination, including intraocular pressure and refractive errors, was performed on the samples. The AC depth, volume, and angle were measured by Pentacam before capsulotomy and 3 months following that. Results: Mean visual acuity improved preoperatively (0.505±0.276) and 3 months after capsulotomy (0.646±0.268); )P

Purpose To evaluate the correlation of corneal elevation and difference elevation with severity of keratoconus. Methods Anterior and posterior corneal elevations with both conventional and enhanced best-fit spheres (using rotating Scheimpflug camera) were measured. Front and back difference elevation were extrapolated from difference map of Belin/Ambrỏsio Enhanced Ectasia Display of the Scheimpflug system. Data from corneal elevations and difference elevations were correlated with maximum keratometry, minimal corneal thickness, and severity of keratoconus as assessed by Amsler-Krumiech classification of keratoconus. Results Ninety eyes of 55 keratoconus patients of different clinical stages were evaluated. There was a significant positive correlation between keratoconus severity and corneal elevations (anterior and posterior elevation as measured with both conventional and enhanced best-fit spheres) and also between keratoconus severity and corneal elevation differences (P 0.625 for all). Maximum keratometry (Kmax), mean keratometry (Kmean), and all corneal elevations and difference elevations were highly correlated (P 0.840 for all). A significant negative correlation was found between minimum corneal thickness and all corneal elevations and difference elevations (P

AIM: To compare anterior segment parameters in eyes with cataracts and different axial lengths measured with Pentacam and IOL Master.METHODS: This study included 170 eyes of 143 patients diagnosed as cataract at Tangdu Hospital, Air Force Medical University. For each patient, anterior segment parameters were measured before surgery with Pentacam and IOL Master system, respectively.RESULTS: There were no statistically significant differences in K1 and K2 values of eyes with long axial length(P>0.05). And there were statistically significant differences in K2 values(PP>0.05)of eyes with short and middle axial lengths. There were statistically significant differences in ACD values of eyes with any axial length(PCONCLUSION: Pentacam and IOL Master can be interchanged for keratometry in eyes with long axial length, but the measurements of keratometry in eyes with short and middle axial lengths and ACD of eyes with any axial length should be compared in clinical application.

AIM: To compare the difference of corneal curvature, astigmatism, central corneal thickness and anterior chamber depth between the Pentacam anterior segment analyzer and anterior segment optical coherence tomography(AS-OCT)in young myopic preoperative and senile cataract patients.METHODS: Prospective clinical study.Totally 64 preoperative examinations(124 eyes)and 61 senile cataract patients(85 eyes)were selected. Pentacam and AS-OCT were used to measure the people's parameters of the ophthalmic anterior segment. Paired sample t-test was used to compare the differences of the two devices' measurement results of the two groups. The correlation of the obtained data was analyzed by Pearson correlation analysis. The consistency of the measurement results was analyzed by Bland-Altman plot analysis.RESULTS: There were significant differences in measuring steep Keratometry(Ks), flat Keratometry(Kf)and mean Keratometry(Km)between the two devices of myopia(PP>0.05). The astigmatic parameters J0, central corneal thickness(CCT), and anterior chamber depth(ACD)measured by the devices and there were statistically significant differences between the two devices(P45(P>0.05). The results of Ks, Kf, Km, J0, J45, CCT and ACD measured by the two devices in both groups were linearly related(P0, J45, CCT and ACD. The consistency of Ks, Kf and Km measured by the myopia group was good, while the consistency of Ks, Kf and Km measured by the cataract group was poor.CONCLUSION: Pentacam and AS-OCT measurements of the ophthalmic anterior segment are consistent with astigmatic parameters, CCT and ACD, and can be used interchangeably. The consistency of Ks, Kf and Km is affected by age related factors, and Pentacam is preferred.

Corneal biomechanical properties have garnered significant interest in their relation to the development of ectatic corneal disease. Alongside the advent of corneal tomography and Scheimpflug imaging such as Pentacam and Galilei, there have been advances in assessing the cornea based on its biomechanical characteristics. Though the aforementioned imaging systems are highly capable of identifying morphologic abnormalities, they cannot assess mechanical stability of the cornea. This article, in contrast to Parts I and II of this article series, will focus on in vivo corneal biomechanical imaging systems. The two most readily available commercial systems include the Corvis ST and the Ocular Response Analyzer. Both of these systems aimed to characterize corneal biomechanics via distinct measurements. While in Parts I and II of this article series the authors focused on elevation, pachymetric, and keratometric data, the purpose of this article was to summarize biomechanical parameters and their clinical use in screening refractive surgery candidates. Moreover, this article explores biomechanical decompensation and its role in the development of corneal ectasia and keratoconus. There is a focus on the diagnostic accuracy of biomechanical indices in the identification of diseases such as keratoconus that may preclude a patient from undergoing refractive surgery.

Purpose evaluating effect of type 2 DM using pentacam and specular microscopy, and correlate changes to DM and its control. Methods A randomized cross sectional study . Ninty eyes of 45 patients were examined by pentacam HR; where elevation based "anterior corneal elevation (ACE)" and "PCE" and thickness based "TCT" and "ARTmax" indices were recorded and Specular Microscopy were "ECD" and "CV" indices were evaluated . Corneas were categorized into 3 groups according to HBA1C level; group 1 (30eyes) with uncontrolled DM,group 2 (30eyes) with controlled DM,while group 3 (30 eyes) with healthy controls. Possible effect of DM on the forementioned indices was evaluated and a correlation between HBA1C and these indices was investigated. Results regarding Pentacam elevation indices (ACE, PCE), PCE showed a significant increase in group 1 compared to group 3 (p-value=0.005), while ACE showed a significant increase between group 2 and each of group 1 (p-value =0.031) and group 3 (p-value=0.025). AS regard to pachymetric indices, TCT and ART max showed a significant difference between group 1 and group 3 (p=0.001 and 0.048). Specular Microscopy indices; ECD showed a significant difference between each of (group 1, group 2) diabetics and group 3 (p=0.001), while CV showed a significant increase in group 1 compared to group 3 (p=0.005). Regression analyses showed positive correlations between HBA1C and each of PCE, TCT, ART max, ECD, CV. Conclusion Some pentacam indices showed significant changes with variations in HBA1C level ,which are sensitive indices in ectasia detection. Regular follow up of type 2 diabetics by performing pentacam is recommended, especially for uncontrolled DM.

Corneal topography is the most widely used technology for examining the anterior corneal surface. Scheimpflug imaging is a newer technique that allows for measurement of both the anterior and posterior corneal surface, which allows for three-dimensional reconstruction of the cornea. This is of particular interest and value in the field of cataract and refractive surgery. The Galilei camera is a commercially available dual Scheimpflug system that combines curvature data from Placido disc-based corneal topography with elevation data from Scheimpflug technology. The addition of Placido disc topography makes the Galilei unique from its more popular counterpart, the Pentacam, which was discussed in Part I. Compared to the Pentacam, and however, the Galilei analyzer is a newer system that has emerged as a valuable screening tool given its dual Scheimpflug capability. In the first article of this series, the authors summarized the refractive indices available on the Pentacam system with the purpose of identifying the best diagnostic parameters for keratoconus. Similarly, the purpose of this article is to summarize corneal surface indices available on the Galilei system and evaluate their use in screening of the refractive surgery candidate. Since post-operative keratectasia is still prevalent, this paper aims to identify the most clinically relevant indices that may be used in pre-operative evaluation.

AIM: To compare the corneal outcome in Fuchs' endothelial dystrophy (FED) patients between femtosecond laser-assisted cataract surgery (FLACS) and conventional phaco surgery (CPS). METHODS: This was a randomized controlled study comparing one eye surgery by FLACS and the contralateral eye operated by CPS (stop and chop technique) in FED patients. Central corneal thickness, corneal light backscatter, corneal densitometry, and central corneal endothelial cell count and hexagonality (noncontact endothelial cell microscope), and corrected distance visual acuity (CDVA) were assessed preoperatively and at day 1, 40, and 180 postoperatively. RESULTS: Totally 31 patients (16 women) were included. At day 40 postoperatively, the mean endothelial cell loss (ECL) was 23.67% by FLACS and 17.30% by CPS (P=0.53). At day 180 postoperatively, ECL was 25.58% in FLACS and 21.32% in CPS (P=0.69). Densitometry data in all layers and all annuli from anterior layer to posterior layer in annuli 0-2, 2-6, 6-10 and 10-12, total densitometry with all layers and all annuli was performed. A significant difference was found in 6-10 (posterior layer) at day 1 with -1.42 grayscale units (GSU; 95%CI: -2.66 to -0.19, P=0.02). In 10-12 (anterior layer, central layer and all layers) at day 40 were significant different with 7.7 (95%CI: 1.89 to 13.50, P=0.009), 3.97 (95%CI: 0.23 to 7.71, P=0.03), 4.73 GSU (95%CI: 0.71 to 8.75, P=0.02), respectively. In the remaining parameters we found no difference between the two groups (P>0.05). Three CPS eyes suffered from corneal decompensation. CONCLUSION: There is no significant difference in corneal outcome between FLACS and CPS. Endothelial cell density and pentacam corneal outcome may be inadequate as outcome parameters in FED patients.

Purpose: To analyse topographic and tomographic changes in fellow eyes of unilateral keratoconus patients by comparing them with normal eyes. Methods: This five-year retrospective observational comparative case study included 15 advanced keratoconus eyes of unilateral keratoconus (KCN group), 15 normal fellow eyes of unilateral keratoconus (Fellow eye group) and 34 eyes of normal refractive surgery candidates (Normal group). Topographic and tomographic data, data from enhanced elevation maps, and keratoconus indices were measured in all study eyes using Pentacam. Receiver operating characteristic (ROC) curves were used to evaluate the area under the curve (AUC), sensitivity and specificity of each parameter and identify cut-off points in discriminating between the fellow and normal eyes. Results: Corneal thickness at the apex (CTA, P = 0.001) and at the thinnest point (CTT, P < 0.001), corneal volume (CV, P = 0.007), Belin/Ambrosio Enhanced Ectasia Display (BAD) - thinnest point (Dt, P = 0.002) and thinnest point displacement (Da, P = 0.002) were significantly lower in the fellow group compared to eyes of normal subjects. On ROC curve analysis, the most efficient distinguishing indices between the fellow group and normal controls were BAD - overall D value (AUC = 0.859), Dt (AUC =0.827), Da (AUC = 0.789) followed by pachymetric progression index maximum (AUC = 0.741). Conclusion: BAD-D value and pachymetric progression index could be useful in detecting the earliest form of subclinical keratoconus. However, every single parameter alone is not enough to detect early changes; a combination of different data is required to distinguish subclinical keratoconus.

Aim: Many changes occur in the body with aging, from which the eye is also affected. In this study, we aimed to investigate the relationship of corneal densitometry (CD), corneal volume (CV), and central corneal thickness (CCT) with age in healthy individuals.Methods: This prospective cross-sectional study included 89 healthy individuals aged between 18-79 years. CD, CV, CCT measurements were performed with Pentacam HR (Oculus, Wetzlar, Germany) with a Scheimpflug camera. CD measurements were performed manually in the central 6 mm optical zone, 90-270 degrees plane. The data obtained were analyzed with SPSS 21 program.Results: CD correlated positively, and CV correlated negatively with age (P=0.01, r=0.25 and P=0.04, r=-0.213, respectively). There was no significant correlation between age and CCT (P=0.42, r=-0.08).Conclusion: Age is a crucial factor affecting overall health. It positively correlated with CD and negatively correlated with CV in healthy individuals. According to these results, these parameters responsible for vision health may be affected by age., Amaç: Yaş ile beraber vücutta farklı mekanizmalara bağlı birçok değişiklik meydana gelmektedir. Buna bağlı olarak bu değişimlerden göz de etkilenmektedir. Bu sebeple, çalışmamızda sağlıklı bireylerde kornea dansitometrisinin (KD), kornea hacminin (KH) ve santral korneal kalınlığın (SKK) yaş ile olan ilişkisini araştırmayı amaçladık.Yöntemler: Bu prospektif, kesitsel çalışmaya yaşları 18-79 yaş arasında değişen 89 sağlıklı birey dahil edildi. Bireyler yaşlarına göre 18-40 ve 41-79 yaş olmak üzere iki gruba ayrıldı. KD, KH, SKK ölçümleri Scheimpflug kameraya sahip Pentacam HR (Oculus, Wetzlar, Almanya) ile yapıldı. KD ölçümü, santral 6 mm’lik optik zonda, 90-270 derece düzleminde, manuel olarak ölçüldü. Elde edilen veriler Spss 21. programı ile analiz edildi. Bulgular: KD’nin yaş ile pozitif yönde, KH’nin yaş ile negatif yönde korelasyon gösterdiği bulundu (sırasıyla P=0,018 r=0,25 ve P=0,04 r=-0,213). SKK ile yaş arasında anlamlı bir korelasyon bulunamadı. Sonuç: Yaş, vücut sağlığını etkileyen önemli bir faktördür. Sağlıklı bireylerde yaşın KD ile pozitif yönde, KH ile negatif yönde korelasyon gösterdiği bulunmuştur. Bu sonuçlara göre görme sağlığından sorumlu bu parametreler yaştan etkileniyor olabilir.

Introduction: Keratoconus (KCN) is known to affect all ethnicities but its incidence exhibits geographical variability plausibly due to subclinical forms of the disease, differences in diagnostic methods and criteria, or differences in genetic variations in populations. Aim: To examine the prevalence of keratoconus among the refractive surgery population of Vojvodina, who underwent refractive surgery screening at Eye Clinic Svjetlost Novi Sad, Serbia from September 2018 to September 2019. This is a single-center study. Methods: Retrospective analysis of 876 patients who presented for refractive surgery evaluation. Corneal tomographers represent the gold standard in the detection and classification of corneal ectatic diseases and screening is an essential part of the preoperative diagnostics before any refractive surgery. The corneal tomographer used in this study was a Scheimpflug imaging device (Pentacam AXL, Oculus Optikgeräte GmbH, Wetzlar, Germany). The device was realigned before each measurement. Results: Out of a total number of patients, 619 (70,7%) were candidates for corneal refractive surgery procedure, and 257 patients (29.3%) were not. Out of 257 patients that were not candidates for the procedure 157 (61,0%) patients had thin corneas, high myopia/hypermetropia or had some retinal disease; 75 patients (29,1) were keratoconus suspect and 25 patients (9,7%) had keratoconus. KCN patients had a mean age of 29.5 ± 7.7 years, 18 patients (72.0%) were male and 7 patients were female (28%). Conclusion: The most cited annual incidence of KCN is 2 approximately 1 per 2,000. Recent data from the biggest Netherland study revealed many different epidemiological results which deprive keratoconus of the community of rare diseases. The incidence of keratoconus in Vojvodina refractive surgery population presented in our Clinic was 2.9%.

Purpose: To compare the keratometric and total corneal astigmatism measures provided by three different technologies as well as to assess the level of interchangeability among them. Methods: A Prospective, comparative study enrolling 94 eyes from 53 patients (age, 29-77 years) was carried out. All participants were patients with the diagnosis of cataract or patients with a transparent crystalline lens but seeking surgical presbyopia correction. A complete eye examination was performed in all eyes, including corneal analysis with three different devices: IOL-Master 700 (Carl Zeiss Meditec), Cassini (i-Optics), and Pentacam (Oculus Optikgeräte GmbH). Interchangeability of standard and total keratometric readings (equivalent keratometric readings for Pentacam) and astigmatism measures with these three systems were evaluated with the Bland-Altman analysis. Results: Significantly higher standard and total keratometric readings were obtained with the IOL-Master compared to the other two systems (p Conclusion: Corneal power and astigmatism measures obtained with IOL-Master 700, Cassini, and Pentacam systems cannot be used interchangeably. The impact of these differences on the refractive predictability achieved with different types of intraocular lenses (IOL) should be evaluated in the future in order to define which is the best corneal evaluation approach for optimizing the IOL power calculations.

ABSTRAC: Purpose: To evaluate tomographic variables related to ectasia progression in patients < 18 years with keratoconus (KC) or suspicious tomographies for keratoconus (STK) from a private clinic in Medellin, Colombia, to determine the need for crosslinking in a pediatric population. Design: Mixed prospective-retrospective descriptive study. Participants: Patients were evaluated from 2012 to 2020. All patients had a tomography by rotating Scheimpflug (Pentacam; Oculus Gmbh, Wetzlar, Germany), with a BAD-D ≥ 1.6 in the included eye(s) on the Belin-Ambrósio display and a minimal repeat image at one year. 43 eyes of 24 patients with a follow up ranging from 1 to 8 years were included. Methods, Intervention, or Testing: All potential study subjects were reviewed by two independent cornea specialists with extensive knowledge in corneal imaging. Maps were graded as KC, STK or normal. Only patients where there was an agreement were included. Eye rubbing control was the mainstay of therapy with topical antiallergics, anti-inflammatories and an allergist consult if needed. Crosslinking (CXL) was performed only if progression was documented. The definition of progression from 2012 to 2017 required a significant variation in two of four parameters: anterior best fit sphere (BFS), posterior BFS, minimum corneal thickness or an increase in the Kmax (maximum keratometry) values. After June 2017 the Belin ABCD progression parameters were utilized; crossing beyond the solid red line (95% confidence interval for patients with keratoconus) of either the anterior radius of curvature (A), the posterior radius of curvature (B) or the minimum corneal thickness (C) on at least two consecutive occasions was considered progression. Main Outcome Measures: Percentage of progression as defined above in KC or TSK eyes, number of lines gained or lost of DCVA in all patients, CXL or not, and the variability of the A, B and C values of the ABCD display was calculated in stable, non-progressing TSK eyes. Results: 4 out of 12 eyes with KC (33,33%) and 1 of the 31 eyes with TSK (3.2%) met the criteria for progression and were and were CXL. No patient in either group lost DCVA with an average follow-up of 4,01 years (±1,78) (range 1,66-6,83) in KC group and of 3,47 years (±1,89) (Range 1,08-8) in TSK group. Conclusions: Strict control of eye rubbing combined with careful follow-up of children with tomographies suspiciuous of keratoconus or true keratoconus without undue loss of DCVA is successful to indicate CXL treatment and avoid vision loss

Background: Corneal imaging may support an early diagnosis of monoclonal gammopathy. The goal of our study was to analyze corneal stromal properties using Pentacam and in vivo confocal cornea microscopy (IVCM) in subjects with monoclonal gammopathy. Patients and methods: In our cross-sectional study, patients with monoclonal gammopathy (130 eyes of 65 patients (40.0% males; age 67.65 ± 9.74 years)) and randomly selected individuals of the same age group, without hematological disease (100 eyes of 50 control subjects (40.0% males; age 60.67 ± 15.06 years)) were included. Using Pentacam (Pentacam HR; Oculus GmbH, Wetzlar, Germany), corneal stromal light scattering values were obtained (1) centrally 0–2 mm zone; (2) 2–6 mm zone; (3) 6–10 mm zone; (4) 10–12 mm zone. Using IVCM with Heidelberg Retina Tomograph with Rostock Cornea Module (Heidelberg Engineering, Heidelberg, Germany), the density of hyperreflective keratocytes and the number of hyperreflective spikes per image were manually analyzed, in the stroma. Results: In the first, second and third annular zone, light scattering was significantly higher in subjects with monoclonal gammopathy, than in controls (p ≤ 0.04). The number of hyperreflective keratocytes and hyperreflective spikes per image was significantly higher in stroma of subjects with monoclonal gammopathy (p ≤ 0.012). Conclusions: Our study confirms that increased corneal light scattering in the central 10 mm annular zone and increased keratocyte hyperreflectivity may give rise to suspicion of monoclonal gammopathy. As corneal light scattering is not increased at the limbal 10–12 mm annular zone in monoclonal gammopathy subjects, our spatial analysis provides evidence against the limbal origin of corneal paraprotein deposition. Using IVCM, stromal hyperreflective spikes may represent specific signs of monoclonal gammopathy.

Maged M Roshdy,1,2 Sherine S Wahba,1,2 Ramy R Fikry2,3 1Ophthalmology Department, Ain Shams University, Cairo, Egypt; 2Ophthalmology Department, Al Watany Eye Hospital, Cairo, Egypt; 3Ophthalmology Department, Cairo University, Cairo, Egypt Purpose: The aim of this study was to find indices for keratoconus (KC) detection with higher sensitivity and specificity than the currently available ones with the rotating Scheimpflug imaging (Oculyzer I, Pentacam) software.Patients and methods: Data of 103 normal and 73 KC eyes imaged by Oculyzer I, including slit-lamp examination, refraction, Scheimpflug images, and follow-up data were collected. Logistic regression was done to find new indices with higher area under receiver operating characteristic curves using the currently available ones.Results: The Corneal Assessment Index from Relational thickness and other OCULUS Values 9 (CAIRO 9) index, deduced from the Ambrosio relational thickness-maximum and the anterior elevation at thinnest point from 9 mm best-fit sphere, and the CAIRO 8, deduced from Ambrosio relational thickness-maximum and anterior elevation at thinnest point from 8 mm best-fit sphere, have a very high area under receiver operating characteristic curves for KC detection (0.997 and 0.995, respectively).Conclusion: New corneal assessment index is deduced with better sensitivity and specificity for KC detection. Keywords: keratoconus, pentacam, keratoconus indices, elevation, pachymetry, keratoconus diagnosis

Objectives: To evaluate tomographic and topographic parameters in subclinical and clinical keratoconus eyes by comparing them with normal eyes in a young Caucasian population. Materials and Methods: This cross-sectional study included 88 normal eyes (control group), bilateral data from the preclinical stage of 24 progressive keratoconus eyes (bilateral subclinical keratoconus group), 40 fellow eyes of patients with unilateral keratoconus (fellow eyes group) and 97 eyes with mild keratoconus (clinical keratoconus group). Topographic and tomographic data, data from enhanced elevation maps and keratoconus indices were measured in all study eyes using Scheimpflug tomography. Receiver operating characteristic (ROC) curve analysis was used to assess individual parameters to discriminate eyes of patients with subclinical and clinical keratoconus from control eyes. The sensitivity and specificity of the main effective parameters were evaluated and optimal cut-off points were identified to differentiate subclinical keratoconus and keratoconus from normal corneas. Results: Comparison of all subclinical and clinical keratoconus eyes from the normal group revealed significant differences in most diagnostic parameters. The ROC curve analysis showed high overall predictive accuracy of several Pentacam parameters (overall D value, anterior and posterior elevations and difference elevations, pachymetry progression index, index of surface variance, index of height decentration and keratoconus index) in discriminating ectatic corneas from normal ones. These outcomes were proportionally less pronounced in all subclinical keratoconus eyes than in the clinical keratoconus eyes. Pachymetric readings were progressively lower in the bilateral subclinical keratoconus eyes and sensitivity and specificity of the analyzed tomographic and topographic parameters were higher than the fellow eyes group when differentiating subclinical keratoconus from healthy corneas. Conclusion: Scheimpflug tomography parameters such as D value, elevation parameters, progression index and several surface indices can effectively differentiate keratoconus from normal corneas in a Caucasian population. Nevertheless, a combination of different data is required to distinguish subclinical keratoconus.

We report two cases that underwent corneal inlay implantation under a femtosecond flap. The first case had no complications during the postoperative period. Pentacam maps remained stable over time: corneal densitometry (CD) values had less than 2 units of change across visits up to 3 years. Axial/sagittal topography maps showed a stable Kmax (∼47 D), i.e., less than 1 D change between visits. The second case developed haze at 8 months postoperatively. CD increased by more than 4 units from 3 to 8 M and Kmax increased by 2.6 D. The patient was prescribed steroids and 1 month later the haze regressed, resulting in pre-haze CD and Kmax values, similar to the ones at 3 months.

Purpose: To assess the changes in visual acuity and topographic indices after implantation of single-segment Intacs. Methods: Forty-two keratoconic eyes received Femtosecond-assisted single-segment Intacs. Uncorrected distance visual acuity (UDVA) and best spectacle corrected visual acuity (BSCVA), refractive error, keratometry (K1, K2, Km, and KMax.), and seven Pentacam measured topographical indices; index of surface variance (ISV), index of vertical asymmetry (IVA), keratoconus index (KI), central keratoconus index (CKI), index of height asymmetry (IHA), index of height decentration (IHD), and minimum radius of curvature (R Min) were assessed 4 months after surgery. Correlations between changes of visual acuity and topographical indices changes were evaluated. Results: UDVA increased from 0.92 ± 0.35 to 0.49 ± 0.31 logMAR (P

Noora Mauwafak Ali,1 Furkaan M Hamied,1 Qasim K Farhood2 1Department of Surgery, College of Medicine, Al-Qadisiya University, Diwaniyah, 2Department of Surgery, College of Medicine, University of Babylon, Hillah, Iraq Background: Dry eye disorder is a multifactorial disease of the tears and ocular surface that results in discomfort and visual disturbance. Corneal pachymetry becomes increasingly important in refractive surgery, for the accurate assessment of intraocular pressure, and in the preoperative assessment of other ocular surgeries. Purpose: To assess the effect of dry eye disorder on the central corneal thickness (CCT) by comparing with CCT of normal eyes of age-matched individuals. Patients and methods: The total number of eyes examined was 280 (140 dry eyes from 70 patients and 140 normal eyes from 70 individuals). Pentacam (Scheimpflug imaging system) was used for measuring the CCT of all eyes. Results: Patients with dry eye syndrome had significantly lower CCT compared to the control group (P

Purpose: To evaluate the normative values of anterior chamber parameters measured by Pentacam and corneal hysteresis (CH) and corneal resistance factor (CRF) measured by Ocular Response Analyzer (ORA) and their relationship. Methods: In an observational cross-sectional study, patients aged 18–35 years were included. Exclusion criteria were history of any intraocular or corneal disease, anomaly or surgery; hyperopic spherical refraction more than +3, and myopic spherical refraction less than −5.00 diopters (D) or cylindrical refraction more than 2.00 D. ORA was used to measure CH and CRF. Corneal volume (CV), anterior and posterior Q value (QA and QP), anterior and posterior elevation (AE and PE), central corneal thickness (CCT), corneal thinnest thickness (CTT), anterior chamber depth (ACD), anterior chamber volume (ACV) and anterior chamber angle (ACA) were measured with Pentacam. Results: This study evaluated 506 eyes of 253 cases (182 females) with a mean age of 28.43 ± 6.36 years. The average CH and CRF were 10.07 ± 1.61 and 10.33 ± 1.68 mmHg. CH and CRF were not correlated with PQ, AQ, AE and PE. CH and CRF were significantly correlated with CCT (r = 0.499, p

Purpose: To compare the anterior segment indices measured by two Scheimpflug camera machines; Galilei and Pentacam. Methods: In this observational case series, the anterior segment indices of myopic healthy subjects seeking for refractive surgery were measured by Pentacam and Galilei on the same day. Analyzed parameters were anterior and posterior best fit spheres (BFS), axial curvature, true corneal power, central corneal thickness (CCT), anterior chamber (AC) depth, AC volume, AC angle, and pupil diameter. Results: This study included 176 eyes of 88 participants. Mean radius of the anterior BFS was 7.79 ± 0.34 mm versus 7.75 ± 0.39 mm measured by Pentacam and Galilei, respectively (r = 0.877, P < 0.001). Corresponding values for the mean radius of posterior BFS were 6.42 ± 0.32 and 6.47 ± 0.38 mm, respectively (r = 0.879, P < 0.001). Anterior corneal mean power was 43.8 ± 1.9 diopters (D) with Pentacam and 43.8 ± 2.4 D with Galilei (r = 0.905,P < 0.001). Posterior corneal mean power was measured − 6.3 ± 0.3 and − 6.3 ± 0.4 D using Pentacam and Galilei, respectively (r = 0.873, P < 0.001). True corneal power was 43.9 ± 1.9 D with Pentacam and 43.5 ± 2.3 D with Galilei (r = 0.909, P < 0.001). CCT was 537 ± 44 and 553 ± 51 μm measured by Pentacam and Galilei, respectively (r = 0.796, P < 0.001). AC depth measurements using Pentacam and Galilei were 3.29 ± 0.4 and 3.3 ± 0.38 mm (P < 0.001), respectively; AC volume was 207 ± 50 and 129 ± 39 mm3≥ (P = 0.004), and AC angle was 39.7 ± 9.2 and 54.2 ± 5.2 degrees (P = 0.051), respectively. Average pupil diameter was measured 3.91 ± 1.77 mm by Pentacam and 3.34 ± 0.89 mm by Galilei (P = 0.018). Conclusions: There was a significant correlation between the Pentacam and Galilei in all measured parameters except AC angle, AC volume, and average pupil diameter.

Purpose. To study results of the ReLEx® SMILE operation to correct myopia and myopic astigmatism at a two-year follow-up. Material and methods. The SMILE surgery was performed in the patients of the main group for a correction of myopia with the sphere up to 10.0D and myopic astigmatism up to 4.0D (390 eyes – 200 patients), of them 80 male (40% ) and 120 female (60%). The study had two control groups: LASIK (166 eyes, 86 patients) and PRK (122 eyes, 62 patients). In the main group, the age of patients ranged from 18 to 54 years (29.7±5.9 years). The follow-up was up to 2 years. BCVA was from 0.7 to 1.2 (0.97±0.12). The central corneal thickness (according to US-keratopachymetry) was from 468 to 654 microns. The horizontal diameter of the cornea was from 11.2 to 12.9mm (12.0±0.5mm). The preoperative characteristics of the eyes in the control groups were similar. Results. Already 1 month after the SMILE and LASIK operations, UCVA was 1.0 and higher and remained stably high during the entire two-year follow-up. After PRK, the recovery rate of UCVA was statistically significantly lower in the first 3 months after surgery (p< 0.001), and then significantly increased and approached that after SMILE and LASIK operations. The UCVA in the distance 2 years after the SMILE and LASIK technologies was higher than after the PRK operation (statistically significant difference: p< 0.005). In this period a slightly higher UCVA at distance was noted after the LASIK operation (1.06±0.26) than after the SMILE surgery (1.04±0.28), but this difference was statistically unreliable (p=0.142). In 2.3% of all SMILE operations, insignificant complications were noted that were completely curable and was not affect the recovery and restoration of visual acuity of patients. The SMILE operation was repeated next day in 1 eye with the loss of vacuum. Most complications were revealed during the phase of surgical development and mastering the SMILE surgery in the first 20 patients. Conclusion. The SMILE technology is a safe and effective keratorefractive operation for the correction of myopia with spherical equivalent from 1.0D to 12.0D. The SMILE technology is characterized by a rapid restoration of UCVA and minimal postoperative corneal syndrome, as in LASIK, and at the same time there is no superficial flap of the cornea, as in the PRK operation. The highest UCVA in the distance is noted after the SMILE technology in long-term two-year follow-up period in comparison with the standard operations of LASIK and PRK.

Background/Aims: Obesity is believed to accelerate age-related cataractogenesis through various biomechanisms. On the contrary, there are also studies advocating the protective role of obesity against the cataract formation process. We investigate the correlation of body mass index (BMI) as a measure for obesity with crystalline optical lens density and opacity in a healthy adult population. Methods: In a cross-sectional setting, 93 consecutive disease-free adult individuals who were working staff of a university-based hospital were assessed for the association between crystalline lens density and opalescence [measured by the objective Pentacam HR lens densitometry and subjective Lens Opacity Classification System III (LOCS III), respectively] with the degree of obesity as defined by BMI. Results: LOCS III and crystalline lens density readings were positively correlated [Spearman rho CC (p value) = 0.224 (0.034)]. However, we found neither LOCS III nor crystalline lens density to be correlated with BMI [Spearman rho CC = −0.008 (p = 0.943) and −0.062 (p = 0.560), respectively]. Conclusions: Results from the present study indicate a lack of association between obesity and densitometry of the crystalline in the adult population group. Further studies are required to confirm the order of causality and pathogenesis of this finding.

Corneal tomography and Scheimpflug imaging are frequently used to analyze the corneal surface, especially in the field of cataract and refractive surgery. The Pentacam system is one of the most commonly used commercially available systems for this purpose. Through a rotating Scheimpflug camera, the system is capable of creating a three-dimensional map of the cornea. These advances in tomography have simultaneously enhanced the ability of clinicians to screen surgical candidates and detect subtle corneal changes in diseases such as keratoconus. However, there remains a need to enhance diagnosis in order to recognize mild and early forms of corneal ectasia. As iatrogenic ectasia and keratoconus are dreaded complications of refractive surgery, it is imperative to screen patients appropriately prior to surgery. The Pentacam is one of many systems utilized in the screening process, but the literature has not identified specific protocol nor parameters that are capable of carrying out this process appropriately. Post-operative keratoconus continues to occur despite the advances in technology seen in corneal imaging. Therefore, clear indices for screening are required in order to diagnose early forms of keratoconus and other corneal diseases that may exclude the seemingly asymptomatic patient from undergoing refractive surgery. This article aims to summarize the indices available on the Pentacam system and to identify the most accurate parameters for screening of the refractive surgery candidate.

PURPOSE: The aim of this study was to evaluate the safety and efficacy of collagen cross-linking (CXL) in advanced progressive keratoconus with a maximum keratometry (Kmax) value of more than 58 diopters (D). METHODS: This prospective interventional case series involved patients with advanced progressive keratoconus with a Kmax of more than 58 D. The best-corrected visual acuity (BCVA), uncorrected visual acuity (UCVA), Kmax, mean keratometry (Kmean) value, corneal astigmatism, and thinnest corneal thickness before surgery and 24 months after CXL were determined for 30 eyes of 27 patients. A Pentacam was used to measure the paraclinical parameters. RESULTS: The mean age of the patients was 24.47 ± 3.33 years. The mean logarithm of the minimum angle of resolution (logMAR) of the uncorrected visual acuity UCVA decreased from 0.73 ± 0.36 D at baseline to 0.48 ± 0.30 D (P = 0.01), while the mean thinnest point thickness of the cornea decreased from 438.65 ± 40.11 μm to 431.43 ± 61.92 μm (P = 0.005) after 24 months. The decreases in the mean logMAR of the BCVA, Kmax and Kmean values, and corneal astigmatism were not statistically significant (P > 0.05) at the 24-month follow-up. Progression was halted in 29 eyes (96.6%); only 1 eye (3.3%) showed an increase in the Kmax value of more than 2.0 D, which was indicative of treatment failure. In contrast, most other eyes showed a decrease in the Kmax value although it was not statistically significant. There were no major complications in any of the patients during the study period. CONCLUSION: Standard CXL treatment was safe and stabilized both the visual acuity and tomographic parameters at the 2-year follow-up in eyes with advanced progressive keratoconus.

Background: The objective of this study was to compare the central corneal curvature and astigmatism measurements obtained with three different systems in healthy eyes and to assess the level of interchangeability between them. Methods: This was a comparative study examining 30 healthy eyes of 30 patients (age 15–53 years). A complete eye examination was performed in all cases including analysis of anterior corneal curvature and astigmatism with three devices: the colour‐LED topography system Cassini (i‐Optics) (CAS), the Scheimpflug‐based system Pentacam (Oculus Optikgeräte) (PTC) and the optical biometer IOL‐Master 500 (Carl Zeiss Meditec) (IOLM). Differences between devices in terms of curvature in the flattest (flat K) and steepest meridians (steep K) as well as in the magnitude (AST) and power vector components of astigmatism (J0 and J45) were evaluated. The interchangeability between devices was evaluated with the Bland–Altman method. Results: Statistically significant differences between devices were found in steep K and flat K (p