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Background: The utilities of anterior segment optical coherence tomography (AS-OCT) for characterization, differential diagnosis, postoperative monitoring, and evaluation/comparison of surgical techniques in pterygium are described. Through AS-OCT, it is also possible to study the corneal astigmatic effect of pterygium. Our purpose is to study the associations between the anatomical characteristics of pterygium and the corneal topography through AS-OCT. Methods: Fifty eyes with primary pterygium in a tertiary hospital were evaluated before surgery by measuring 10 anatomical variables of pterygium and 13 topographic variables using AS-OCT (Casia 2; Tomey Corp., Nagoya, Japan). Statistical analysis was used to study the association between them. Results: Pterygium classified as flat pattern exhibited lower preoperative values of flat keratometry (K1), real flat keratometry (K1r), average keratometry (AvgK), and real average keratometry (AvgKr) compared to nodular ones. The flat pattern showed greater cylinder (CYL) and real cylinder (CLYr) values. The horizontal corneal invasion proportionally increased CYL and CYLr. Overall, larger anatomical pterygium measurements (limbus thickness (LimbusT), central pterygium thickness (CentreT), head pterygium thickness (HeadT), epithelial thickness at 1 mm (EpitT1mm), stromal thickness at 1 mm (stromT1mm), total thickness at 1 mm (TotalT1mm), total thickness at 2 mm (TotalT2mm), and total thickness at 3 mm (TotalT3mm)) resulted in lower anterior K1, K1r, AvgK, and AvgKr, and posterior K1 and AvgK values. CentreT was greater in astigmatisms against the rule than in oblique ones. Conclusions: This study demonstrates associations between preoperative topography and the NF (nodular or flat) classification of pterygium and its anatomical measurements assessed by AS-OCT. [ABSTRACT FROM AUTHOR]

In May 2023, a 36-year-old carpenter complained of a sudden decrease in visual acuity in both eyes after his fourth COVID-19 vaccination. He underwent extensive evaluation by ophthalmological, neurological, and internal medicine specialists elsewhere, which was unremarkable, except for a computed tomography scan of his brain showing minor occipital calcifications. In 2021, he had been diagnosed with anterior basement membrane dystrophy and treated with phototherapeutic keratectomy (PTK) of the left eye, leading to significant postoperative haze. On referral in July 2023, slitlamp examination showed significant anterior basement membrane dystrophy in the right eye, whereas the left eye had an extensive central scar in the anterior stroma, measuring up to 6 mm in width and 140 µm in depth (Figures 1-3). His corrected distance visual acuity was 20/80 in his right eye and 20/200 in his left eye, with a manifest refraction of -0.50 -3.75 × 170 and +0.00 -4.75 × 180, respectively. Corneal Scheimpflug topography showed regular corneal astigmatism of 3.3 diopters (D) and 5.5 D in the right and left eyes, respectively, with a corneal thickness of 550 and 566 µm (Figure 4). The Schirmer tear test was 20-20 mm. Fundoscopy, electrophysiological testing, and retinal optical coherence tomography (OCT) showed no abnormalities. The patient mentioned he had Crohn disease, managed with ustekinumab (a monoclonal antibody inhibitor of cytokines interleukin [IL]-12 and IL-23), but he had discontinued it because of the apparent remission of the disease. Attempts to improve visual acuity involved a soft bandage contact lens in the right eye, which was discontinued after 2 days because of the occurrence of a small corneal infiltrate that healed with a short course of topical antibiotics. Unfortunately, because of his vision, he cannot perform his tasks as a carpenter anymore. Which is your recommended treatment for both eyes. [ABSTRACT FROM AUTHOR]

Objectives: To report the outcomes of novel modified transepithelial phototherapeutic keratectomy (PTK) in treating band keratopathy (BK). Methods: A retrospective analysis was performed on patients who underwent PTK for BK at the Sussex Eye Laser Clinic, Nuffield Health, Brighton. Patients with BK obscuring the visual axis, affecting visual acuity, or causing discomfort were considered for PTK. All the patients underwent preoperative evaluation, including preoperative corneal topography and optical coherence tomography. Modified transepithelial PTK was performed without using EDTA for chelation or alcohol for epithelium debridement. Patients were followed up for one week and then every two weeks after that until two months. Preoperative and postoperative best corrected visual acuities (BCVA) were compared using a paired t-test. Results: We studied 15 eyes of nine patients undergoing novel PTK for BK. The mean age was 80 ± 5.73 years. The mean pre-treatment visual acuity was 0.68 ± 0.17 logMAR (range: 0.6 logMAR to 1 logMAR) and improved to 0.22 ± 0.09 logMAR (p < 0.05), ranging from 0.18 to 0.48 logMAR at two months following PTK. None of the patients complained of ocular discomfort following the procedure. A repeat procedure was not required for any of these patients. Conclusions: Modified transepithelial PTK is an effective procedure for improving visual outcomes in patients with band keratopathy and should be considered for the treatment of band keratopathy. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate curvature changes in different regions and their correlation with corneal epithelial remodeling in myopic patients undergoing femtosecond laser-assisted in situ keratomileusis (FS-LASIK) and transepithelial refractive keratectomy (Trans-PRK) after surgery. Methods: One hundred and sixty-three patients (163 right eyes) undergoing Trans-PRK and LASIK were evaluated for up to 6 months using anterior segment optical coherence tomography (OCT) to measure the epithelial thickness and corneal topography to measure corneal curvature in different areas (2 mm, 5 mm, and 7 mm). We calculated the curvature ΔK (ΔK = preoperative - postoperative), ΔK5-2 (ΔK5-2 = K5mm - K2mm), ΔK7-5 (ΔK7-5 = K7mm - K5mm), and the epithelial thickness ΔET5-2 (ΔET5-2 = ET5mm - ET2mm) and ΔET7-5 (ΔET7-5= ET7mm - ET5mm). Results: Corneal curvature flattened in each region of the two groups (all p < 0.001) and gradually steepened during the follow-up period. The Trans-PRK group flattened more significantly within 2 mm and 5 mm, while the FS-LASIK group at 7 mm. Both groups of ΔK decreased over time. Both groups of ΔK5-2 and ΔK7-5 gradually decreased during the follow-up period (P5-2=0.025 and P7-5 < 0.001 for Trans-PRK, P5-2 = 0.011 and P7-5 < 0.001 for FS-LASIK). The corneal epithelium of the two groups gradually thickened during the follow-up period, with Trans-PRK significantly thickening in the central and peripheral regions and FS-LASIK in the central and paracentral regions. There is a significant correlation between the ΔK5-2 and ΔET5-2, ΔK7-5 and ΔET7-5 (all r > 0.37, p < 0.001). Conclusions: All groups showed significant curvature flattening after surgery and gradually steepening during the follow-up period. The corneal epithelium thickness in both groups of 17 regions became thicker,. In contrast, Trans-PRK group showed more significant thickening to the periphery and the central 5 mm area of the FS-LASIK. This study indicates a significant positive correlation between differences in epithelial thickening in different regions and differences in curvature changes in the corresponding areas PRK, FS-LASIK, curvature, corneal epithelial thickness [ABSTRACT FROM AUTHOR]

Copyright of Pamukkale Medical Journal is the property of Pamukkale Journal of Medicine and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objective: This study aimed to explore corneal curvature changes following strabismus surgery using a quadric surface fitting model to address ocular misalignment. Material and Methods: In this prospective cross-sectional study, 54 completed cases (84 eyes) of patients aged 6-60 years old (mean 10 years old) undergoing horizontal rectus muscle surgery were examined using placidobased keratometry with the Oculus Keratograph 5M system. Data on corneal curvature were collected one week preoperatively, and again one week, one month, and three months post-operation. Asphericity in the vertical meridian (Qy) and horizontal meridian (Qx), and surgically induced astigmatism (SIA) were calculated. Results: The 84 eyes included were categorized into three groups: horizontal muscle surgeries, oblique muscle surgery, and combined horizontal and oblique muscle surgeries. Significant corneal prolation (steep central, flat peripheral) was revealed in the vertical meridian (Qy) at 3 months postoperatively for lateral rectus (LR) recession in the first group (p < 0.001), and the mean SIA was 0.45 D (95% CI: 0.35-0.56 D). A similar effect was seen in the vertical meridian of the third group (p < 0.01), with a mean SIA at 3 months of 0.27 D (95% CI: 0.23-0.32 D). Conclusion: Lateral rectus muscle recession induces corneal vertical prolation for up to 3 months post-operation. Surgeons are thus advised to re-evaluate refraction and defer contact lens refitting, refractive surgery, and intraocular lens calculations for at least 3 months after the procedure. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to compare and correlate specular microscope indices and corneal topography indices in different stages of keratoconus. Methods: Two hundred forty-six eyes of 123 participants were enrolled in the study. Corneal topography was performed using Sirius (CSO, Italy), with a rotating Scheimpflug camera and a Placido disc topographer. Corneal endothelial cell indices were assessed using a specular microscope (Nidek CEM-530, Japan). Eyes were graded as keratoconus stages 0–4 according to the Amsler-Krumeich classification. Corneal topography and endothelial cell indices were compared among the groups, and the correlations between them were analyzed. Results: The mean age of the patients was 23.26 ± 6.75 years (range, 14–47 years). Forty-eight cases were male (39%) and 75 were female (61%). There were no statistically significant age (p = 0.578) or sex ratio (p = 0.529) differences between the groups. Twenty-nine eyes were included in the control group (11.78%), while 41 (16.67%) had stage 1 keratoconus, 88 (35.77%) had stage 2, and 88 (35.77%) had stage 3. Measurement was not possible in stage 4 keratoconus. No statistically significant difference was determined in specular microscopy values according to the stage of keratoconus, except for the number of analyzed cells (NUM) (p > 0.05). The lowest NUM values were observed in stages 1, 2, and 3, with values of 184.34 ± 67.62 cells/mm2, 155.07 ± 59.48 cells/mm2, and 127.06 ± 64.39 cells/mm2, respectively (p = 0.001). In the keratoconus group, weak statistically significant negative correlations were observed between NUM and SimK1, SimK2, KVf, BCVf, KVb, and BCVb, while a weak positive correlation was noted between NUM and central corneal thickness (p < 0.05). Conclusions: NUM seems to decrease, while endothelial cell density exhibits no significant changes, with the progression of keratoconus. It appears that as keratoconus index values increase, NUM may decrease in different stages of keratoconus. [ABSTRACT FROM AUTHOR]

Introduction: The aim of this study was to evaluate alterations in corneal astigmatism, axial anterior corneal curvature, anterior chamber depth, and central corneal thickness (CCT) two months after the unilateral recession of lateral rectus muscle in children. Methods: This prospective study included 37 children with intermittent exotropia who would undergo unilateral lateral rectus muscle recession. All measurements were performed using Pentacam®. Comparisons were made between the operated and fellow unoperated eyes, pre- and post-operatively. The assessment was made for changes in the radius of axial curvature on major meridians at 3 and 3.5 mm from the optical corneal center in the mid-peripheral zone. Astigmatism changes of the anterior and posterior corneal surface were calculated using vector analysis software (astigMATIC®). The interaction between age or CCT and postoperative changes in anterior and posterior surface corneal astigmatism were examined with ANOVA model. Results: In the intervention group, changes in anterior and posterior corneal surface astigmatism were statistically significant, with a mean increase of 0.56Dx90 and 0.08Dx87, respectively. In the mid-peripheral corneal zone, an increase was observed in the radius of anterior corneal axial curvature, more evident temporal 3 and 3.5 mm from the corneal center on the horizontal meridian, with corresponding decrease superiorly and inferiorly at 3 and 3.5 mm from the corneal center on the vertical meridian. Discussion: The changes in total astigmatism of the operated eyes are mainly attributed to the anterior corneal surface. These changes are associated with flattening in the 180 meridian of the cornea, leading to a shift to “with-the-rule” astigmatism. [ABSTRACT FROM AUTHOR]

Refractive error is becoming a significant public health issue. Photorefractive Keratectomy (PRK) is a corneal surface surgical technique that removes the corneal epithelium before stromal photoablation by ultraviolet radiation from the Excimer laser. We designed a retrospective study to characterize corneal remodeling after myopic Photorefractive Keratectomy and assess the accuracy of laser-predicted ablation depth (AD). This study took place in 15–20 National Ophthalmology Hospital, Paris, France. 150 eyes with preoperative manifest spherical equivalent between − 10.00D and − 0.25D and cylinder < 3D, treated with the WaveLight® EX500 laser between 01/2019 and 01/2023, were followed for at least three months. The main outcome measurements were postoperative changes in epithelial (ET) and stromal (ST) thicknesses measured with spectral domain optical coherence tomography and mean simulated keratometry (SimK) assessed with corneal topography. The central ET significantly decreased at M1, increased over the preoperative value from M1 to M6, and stabilized after M6. The increase in central ET after M1 was associated with an increase in mean SimK (r = 0.34). The achieved AD was 7.9 ± 8.0 µm greater than the laser-predicted AD. Stromal over-ablation was significantly and independently associated with myopia > 6D preoperative mean SimK > 44D and transepithelial procedures. [ABSTRACT FROM AUTHOR]

Purpose: To optimise the precision and efficacy of orthokeratology, this investigation evaluated a deep neural network (DNN) model for lens fitting. The objective was to refine the standardisation of fitting procedures and curtail subjective evaluations, thereby augmenting patient safety in the context of increasing global myopia. Methods: A retrospective study of successful orthokeratology treatment was conducted on 266 patients, with 449 eyes being analysed. A DNN model with an 80%–20% training‐validation split predicted lens parameters (curvature, power and diameter) using corneal topography and refractive indices. The model featured two hidden layers for precision. Results: The DNN model achieved mean absolute errors of 0.21 D for alignment curvature (AC), 0.19 D for target power (TP) and 0.02 mm for lens diameter (LD), with R2 values of 0.97, 0.95 and 0.91, respectively. Accuracy decreased for myopia of less than 1.00 D, astigmatism exceeding 2.00 D and corneal curvatures >45.00 D. Approximately, 2% of cases with unique physiological characteristics showed notable prediction variances. Conclusion: While exhibiting high accuracy, the DNN model's limitations in specifying myopia, cylinder power and corneal curvature cases highlight the need for algorithmic refinement and clinical validation in orthokeratology practice. [ABSTRACT FROM AUTHOR]

Copyright of Arquivos Brasileiros de Oftalmologia is the property of Arquivos Brasileiros de Oftalmologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Purpose. To analyze changes of the corneal topography in the long-term period after hyperopic FS-LASIK in patients with low, moderate and high hyperopia.Patients and Methods. This retrospective non-randomized study included data of 174 patients (174 eyes). All patients were performed hyperopic FS-LASIK. All patients were divided into three groups. Group I included patients with low hyperopia (34 eyes), group II included patients with moderate hyperopia (97 eyes), group III included patients with high hyperopia (43 eyes). Before the surgery, the mean cycloplegic spherical equivalent in group I was +1.94 ± 0.61 D, in group II +3.8 ± 2.19 D, in group III +5.7 ± 0.9 D. The stability of corneal topography after surgery was analyzed: mean keratometry, Surface Asymmetry Index (SAI), Surface Regularity Index (SRI). The results were evaluated the day after the surgery, 1 month later, 6 months later, 1 year later and 3 years after the surgery.Results. There were no statistically significant changes in keratometry in groups I and II on the first day after surgery and 3 years later (p > 0.05). In group III, there was a statistically significant decrease in keratometry at 6 months after surgery by 1.35 ± 2.48. D (p = 0.003); however, keratometry remained stable for 3 years thereafter (p > 0.05). In groups I and II, SRI increased at all periods after surgery (p < 0.05), in group II there was an increase in SAI (p < 0.05), in group III, SRI and SAI increased at all periods after surgery (p < 0.05). Although the increase in the indices was statistically significant, it slightly exceeded the normal limits.Conclusions. After correction of low and moderate hyperopia by FS-LASIK, corneal topography remains stable for 3 years after surgery. Correction of high hyperopia is associated with gradual flattening of the cornea within six months after surgery, but then keratometry remains stable for 3 years. It is important to take it into account in clinical practice.

Corneal topography instruments have limited parameter constraints for calculating precise defect ratios on the basis of the cone base area of the anterior axial curvature map for patients with Keratoconus (KC).

Background: Keratoconus (KCN) is considered a bilateral corneal ectatic disorder characterized by cone-like steepening of the cornea and irregular stromal thinning, which can lead to decreased visual acuity. This study aimed to assess the prevalence and risk factors for the KCN development in Kosovo. Methods and Results: This retrospective study was conducted in the Department of Ophthalmology at the University Clinical Center of Kosovo. The study included 131 respondents, with a total of 262 eyes. Keratometry basis parameters, such as flat keratometry (K1), and steep keratometry (K2), and maximal corneal curvature (Kmax) were determined. Corneal pachymetry was applied to measure the thickness of the cornea. Staging of KCN was done according to the adapted Amsler-Krumeich staging classification system (AK) for anterior data and corneal thickness (CT). Of 262 examined eyes, 240 (91.6%) were KCN eyes, 2(0.8%) were suspect for KCN, and 20(7.6%) were normal. KCN Stage 1 on the AK classification was predominant (P

AIM: To evaluate the safety and efficacy of accelerated corneal cross-linking(A-CXL)with application of isotonic riboflavin under pedicled corneal epithelial flap in the treatment of thin keratoconus(corneal thickness less than 400 μm after epithelial removal).METHODS: Retrospective study. A total of 46 patients(74 eyes)with keratoconus treated in the refractive surgery department of Ineye Hospital of Chengdu University of TCM from September 2017 to December 2020 were enrolled. According to the preoperative thinnest corneal thickness(TCT), the patients were divided into two groups: 16 patients(20 eyes)with TCT ranging from 400 to 0.005), while patients in the epithelial-off group showed a significant reduction in Kmax compared with pre-surgery(P0.005). The comparisons of the changes in various parameters between 12 mo post-surgery and pre-surgery for both groups showed no significant differences(all P>0.05).CONCLUSION: Accelerated corneal cross-linking with application of isotonic riboflavin under pedicled corneal epithelial flap surgery is safe and feasible for patients with thin keratoconus, achieving similar control of keratoconus progression as epithelial-off A-CXL.

Purpose: This study aimed to analyze variations in intraoperative corneal thickness during corneal cross-linking in patients with keratoconus and to investigate its possible correlation with presurgical maximal keratometry (Kmax) and pachymetry. Methods: This was a prospective case series. We used a method similar to the Dresden protocol, with the application of hydroxypropyl methylcellulose 0.1% hypoosmolar riboflavin in corneas between 330 and 400 µm after epithelium removal. Corneal thickness was measured using portable calipers before and immediately after epithelium removal, and 30 and 60 min after the procedure. Results: The 30 patients in this study were followed up for one year. A statistically significant difference was observed in pachymetry values during the intraoperative period (p<0.0001) and an increase of 3.05 µm (95%CI: 0.56–5.54) for each diopter was seen after epithelium removal (p0.019). We found an average Kmax difference of −2.12 D between men and women (p0.013). One year after treatment, there was a statistically significant reduction in pachymetry (p<0.0001) and Kmax (p0.0170) values. Conclusions: A significant increase in pachymetry measurements was seen during the procedure, and most patients showed a regression in Kmax and pachymetry values one year after surgery. [ABSTRACT FROM AUTHOR]

This case series reports eight eyes with keratoconus treated with laser implantation of one or two segments of progressive thickness corneal intrastromal ring (PT-ICRS). In this case series, it was evident that the insertion of PT-ICRS induces more pronounced corneal flattening at the thickest point, causing a reduction in distortion (coma) and lower astigmatism, resulting in a remarkable improvement in vision. Compared to the implementation of traditional intrastromal rings, the PT-ICRS variant showed superior results despite the small sample size. However, the same degree of asymmetry enhancement was not observed in cases in which a 330° PT-ICRS was implanted, despite the improvement in visual results when replacing a 320° traditional ring with a 330° PT-ICRS. These conclusions are limited as this is a case series with few cases.

Abstract Background Visual impairment can cause balance problems. Therefore, visual impairment caused by an increase in corneal deviations can lead to sudden and unstable loads in the lower extremities. We aimed to investigate the possible relationship between low-energy meniscal injuries and corneal structural measures. Methods This prospective, observational study included individuals aged between 18–40 years with a normal body-mass index. The study group consisted of 54 patients with grade 2 or 3 meniscus injuries after low-energy activity. The control group consisted of 54 healthy individuals without any complaints in the knee joint. The corneal parameters of all participants were evaluated with a Scheimpflug corneal topography and specular microscopy device. Simulated keratometry (SimK), minimum central corneal thickness (MCCT), cylindrical diopter (ClyD), corneal volume (CVol) spheric aberrations (SphAbb), high-order aberration (HOA), coma values, and endothelial parameters were recorded. Results The research and control groups were similar in terms of age, body mass index, and gender distribution. There was no significant difference between the groups in the corneal SimK and CylD, parameters. However, HOA, Coma, SphAbb, and cell variability (Cv) values were significantly higher in the study group, and contrarily MCCT, CVol, and endothelial count (Cd) values were significantly lower. Conclusions Our findings suggest that individuals with relatively lower MCCT values tend to develop meniscal damage after low-energy activity. Hence, the loss of corneal strength in these patients may be a sign of possible weakness in the meniscus. The HOA value above 0.26, the coma value above 0.16, and the SphAbb value above 0.1 may significantly increase the possible meniscus injury.

Objectives: To investigate the clinical efficacy and safety of the modified Cretan protocol in patients with post-laser in situ keratomileusis ectasia (PLE). Materials and Methods: In this retrospective study, 26 eyes of 16 patients with PLE were treated with the modified Cretan protocol (combined transepithelial phototherapeutic keratectomy and accelerated corneal collagen cross-linking). Visual, refractive, tomographic, and aberrometric outcomes and point spread function (PSF) were recorded preoperatively and at 6, 12, and 24 months after treatment. Results: Both uncorrected and best corrected visual acuity were stable at 24 months postoperatively compared to baseline (from 0.89±0.36 to 0.79±0.33 logarithm of the minimum angle of resolution [LogMAR] and 0.31±0.25 to 0.24±0.19 LogMAR, respectively, p>0.05 for all values). The mean K1, K2, Kmean, thinnest corneal thickness, and spherical aberration at baseline were 45.76±5.75 diopters (D), 48.62±6.17 D, 47.13±5.89 D, 433.16±56.86 µm, and -0.21±0.63 µm respectively. These values were reduced to 42.86±6.34 D, 45.92±6.74 D, 44.21±6.4 D, 391.07±54.76 µm, and -0.51±0.58 µm at 24 months postoperatively (p0.05 for all variables), while anterior and posterior elevation were significantly improved at 24 months postoperatively (p

Abstract 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.

AIM: To investigate the risk factors of refractive regression after correction of moderate and high myopia by femtosecond laser assisted in situ keratomileusis(FS-LASIK)for 1 a, and construct prediction model.METHODS: A retrospective analysis was performed on the clinical data of 400 patients(800 eyes)with moderate and high myopia undergoing FS-LASIK correction in Xi'an Gaoxin Hospital from June 2017 to November 2018, and the patients were randomly divided into modeling group(n=300)and verification group(n=100)according to a ratio of 3:1. The modeling group was divided into regression group and non-regression group according to the occurrence of refractive regression at 1 a after surgery. The changes of corneal curvature and corneal thickness were observed. Logistic regression analysis was used to screen the risk factors of refractive regression in patients with moderate and high myopia at 1 a after FS-LASIK correction, and the prediction model was built based on the regression coefficient. Receiver operating curve(ROC)was used to evaluate model differentiation.RESULTS:Refractive regression occurred in 44 eyes of the modeling group and 15 eyes of the verification group at 1 a after surgery. The anterior corneal surface curvature in the modeling group was lower than that in the regression group at 6 and 12 mo after surgery(all P

We aimed to assess long-term disease progression in patients with severe keratoconus (KC). Clinical records of 125 patients (201 eyes) with severe KC followed-up for > 12 months were retrospectively analyzed. From these, 28 patients (31 eyes) were included. Corneal topography parameters evaluated included thinnest corneal thickness (TCT), maximum keratometry (Kmax), anterior and posterior mean corneal radii of 3 mm (aKM, pKM), steep keratometry, and KC screening indices. All patients wore rigid gas permeable contact lenses (RGPCLs) for an extended period. The median patient age and follow-up period were 20 (interquartile range [IQR] 17–22) years and 25 (15–38) months, respectively. Compared to baseline, the aKM, Kmax, and KC screening indices on the anterior corneal surface were reduced at the final follow-up (P < 0.05). No changes were observed in RGP-corrected visual acuity, TCT, pKM, or KC screening indices on the posterior corneal surface. The higher the baseline value, the greater the reduction in aKM and Kmax. Five patients (16%) experienced disease progression during follow-up. Patients with severe KC showed reduced anterior corneal surface curvature and no change in corneal thickness during an average follow-up period of 2–3 years while wearing RGPCLs. [ABSTRACT FROM AUTHOR]

This review aimed to evidence the predisposing conditions for Salzmann nodular degeneration (SND), where particular attention was paid to its association with ocular and systemic diseases. SND is a rare disease characterized by bluish-white nodules located in the mid-periphery of the cornea, which are otherwise completely clear. SND has been found in association with different systemic and ocular diseases, and it may have unilateral or bilateral presentation. Initial forms are only diagnosed occasionally as they are asymptomatic, whereas, in advanced disease, the visual acuity might be seriously impaired. Although SND is well described, its exact etiopathology is currently still unknown and is frequently misdiagnosed. It is associated with ocular surface inflammatory conditions and previous corneal surgery, and it has been described in different systemic diseases. Diagnosis is clinically based with slit lamp examinations, and instrumental assessments with corneal topography permit one to observe the alterations of the corneal profile, whereas anterior segment–optical coherence tomography (AS-OCT) is used to investigate the stromal depth of the nodules. Therapy might be conservative with the objective of improving the ocular surface homeostasis and surgical outcomes, where the aim is to restore the corneal regularity and visual acuity. Ophthalmologists should pay particular attention when detecting nodules in patients with ocular and non-ocular inflammatory diseases to guarantee the patient a timely diagnosis and a better therapeutic outcome. Additionally, collaboration between specialists who deal with treating patients suffering from disorders potentially associated with SND is recommended. [ABSTRACT FROM AUTHOR]

Introduction. Peripheral retinal refraction plays a crucial role in myopia, but the specific mechanism is not clear. We refined the retinal partitions to explore the characteristics of peripheral retinal refraction and its role in emmetropic, low, and moderate myopic children aged 6 to 12 years. Methods. A total of 814 subjects (814 eyes) were enrolled in the study. The participants were divided into three groups according to the central spherical equivalent refraction (SER), which were emmetropia group (E), low myopia group (LM) and moderate myopia group (MM). Multispectral refractive topography (MRT) was used to measure the retinal absolute and relative refractive difference value (RDV) in different regions. The range was divided into superior, inferior, temporal, and nasal RDV (SRDV, IRDV, TRDV, and NRDV) on the basis of several concentric circles extending outward from the macular fovea (RDV15, RDV30, RDV45, RDV30–15, RDV45–30, and RDV‐45). Kruskal–Wallis test was used to analyze the differences of peripheral refraction for all the regions among the three groups. Spearman rank correlation was performed to explore correlations between SER and RDV, axial length (AL) and RDV. Results. The absolute value of RDV decreased with increasing degree of myopia in all regions (P < 0.01). Subjects with different refractive degrees had different relative value of RDV. In nasal position within 45° and temporal position within 30°, the peripheral retina exhibited significantly different relative hyperopic refractive status among Group E, Group LM, and Group MM (P < 0.05). SER was negatively correlated with NRDV within 30° (especially in the range of NRDV30–15) (r = −0.141, P < 0.01), positively correlated with TRDV within 15° (r = 0.080, P = 0.023), and not significantly correlated with SRDV and IRDV when the retina was divided into four parts. AL was positively correlated with NRDV within 30° (especially in the range of NRDV30–15) (r = 0.109, P = 0.002), negatively correlated with TRDV within 15° (r = −0.095, P = 0.007). Conclusions. The peripheral defocus has significant implications for the genesis of myopia. The peripheral defocus of the horizontal direction, especially within the range of NRDV30, has greater effect on the development of myopia in children. Higher NRDV30 is associated with lower SER and longer AL. [ABSTRACT FROM AUTHOR]

Background: Visual impairment can cause balance problems. Therefore, visual impairment caused by an increase in corneal deviations can lead to sudden and unstable loads in the lower extremities. We aimed to investigate the possible relationship between low-energy meniscal injuries and corneal structural measures. Methods: This prospective, observational study included individuals aged between 18–40 years with a normal body-mass index. The study group consisted of 54 patients with grade 2 or 3 meniscus injuries after low-energy activity. The control group consisted of 54 healthy individuals without any complaints in the knee joint. The corneal parameters of all participants were evaluated with a Scheimpflug corneal topography and specular microscopy device. Simulated keratometry (SimK), minimum central corneal thickness (MCCT), cylindrical diopter (ClyD), corneal volume (CVol) spheric aberrations (SphAbb), high-order aberration (HOA), coma values, and endothelial parameters were recorded. Results: The research and control groups were similar in terms of age, body mass index, and gender distribution. There was no significant difference between the groups in the corneal SimK and CylD, parameters. However, HOA, Coma, SphAbb, and cell variability (Cv) values were significantly higher in the study group, and contrarily MCCT, CVol, and endothelial count (Cd) values were significantly lower. Conclusions: Our findings suggest that individuals with relatively lower MCCT values tend to develop meniscal damage after low-energy activity. Hence, the loss of corneal strength in these patients may be a sign of possible weakness in the meniscus. The HOA value above 0.26, the coma value above 0.16, and the SphAbb value above 0.1 may significantly increase the possible meniscus injury. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study was to assess changes in corneal parameters 6 months after corneal cross-linking for progressive keratoconus, using the ABCD system. Patients and Methods: This retrospective study was conducted at the King Khaled Eye Specialist Hospital (Riyadh, Saudi Arabia) between January 1 and July 30, 2022. This study included 16 eyes of 16 patients with keratoconus who underwent corneal cross-linking at the same hospital and were at least 18 years old. At least one preoperative (T0) and one postoperative examination was performed for each patient. Six months after the procedure (T1), patients underwent corneal tomography. The parameters A, B, C, and D were also evaluated. Other parameters monitored included maximal keratometry (Kmax) (K1 and K2), Belin/Ambrósio Enhanced Ectasia Display, and index vertical asymmetry. The progression of ectasia was identified by a consistent change in at least two parameters: steepening of the anterior corneal surface or the posterior corneal surface, thinning or an increase in the rate at which the corneal thickness changed from the periphery to the thinnest point, where the magnitude of the change was greater than the normal noise of the testing system. Results: Among the patients, 68.8% were men. The patients' average age was 25.8± 5 years. Throughout the 6-month postoperative follow-up, parameters A, B, and C exhibited substantial changes (P = 0.000 for parameters A, B, and C). Parameter A increased 6 months after surgery, whereas parameters B and C decreased. Preoperatively and 6 months after surgery, Kmax, K1, and Belin/Ambrosio-enhanced ectasia demonstrated substantial differences. However, parameter D, K2, and the average pachymetric progression index did not change significantly. Conclusion: Anterior and posterior corneal curvatures and corneal thickness profiles can be useful for monitoring the progression of keratoconus and the success of the corneal cross-linking operation. [ABSTRACT FROM AUTHOR]

Purpose: The relationship between attention deficit hyperactivity disorder (ADHD) and visual impairment remains poorly understood, and the impact of visual impairment on the development of ADHD is uncertain. The aim of this study was to investigate the refractive profile and ocular biometric characteristics in patients diagnosed with ADHD and compare them with a control group. Additionally, we aimed to explore the potential influence of sex and medication intake. Methods: A cohort of 100 participants, including 50 individuals with ADHD and 50 age‐ and sex‐matched control subjects, was included in this study. Ocular biometric parameters were measured, and refractive error was assessed using cycloplegic and non‐cycloplegic autorefraction. Subgroup analyses were performed within the ADHD group based on sex, medication intake and age to investigate potential associations with the ocular findings. Results: We observed no statistically significant differences in axial length, corneal topography parameters or anterior chamber characteristics between ADHD and control subjects. However, subgroup analysis within the ADHD group revealed that the prevalence of ametropia under cycloplegia was significantly higher in unmedicated (69.6%) compared to medicated (37.5%) (X2(2) = 7.320, p = 0.026) participants. Pupil diameter was significantly larger in medicated (3.91 mm) compared to unmedicated (3.58 mm; p = 0.017) individuals. Males had flatter (p = 0.004) and thicker (p = 0.008) corneas than females. Older ADHD participants had higher refractive error (p = 0.008 for non‐cycloplegic and p = 0.0.003 for cycloplegic), axial length (p = 0.002) and corneal astigmatism (p = 0.049). Conclusions: Our study provides compelling evidence that individuals diagnosed with ADHD exhibit a similar incidence of refractive errors and ocular parameters compared to normal subjects. Nonetheless, the prevalence of refractive errors appears to be higher in unmedicated ADHD patients, suggesting the potential benefit of stimulant treatment. Additionally, stimulant use is associated with an increase in pupil diameter. [ABSTRACT FROM AUTHOR]

Purpose: To examine complications, visual outcomes, photic patient‐reported symptoms, corneal morphology, IOL tilt, and intraocular pressure after implantation of an intraocular lens (IOL) and iris prosthesis (IP) following iridocyclectomy. Methods: Patients with previous iridocyclectomy treated with an IOL and IP at the Copenhagen University Hospital Rigshospitalet between 2007 and 2018 were included in this national retrospective non‐comparative case series. The assessment encompassed BCVA, PRO questionnaire, corneal topography, and anterior segment OCT. Results: 45 patients were included. Eight of 45 patients were previously treated with ruthenium‐106 brachytherapy in conjunction with iridocyclectomy. Six of 45 patients developed endothelial dysfunction four of whom had received ruthenium‐106 brachytherapy. Five of 45 patients had subluxation of the IOL/IP complex due to incomplete zonula apparatus. BCVA improved for all patients after lens surgery. 26 patients participated in the invited follow‐up examination. 19 of 26 (73%) reported none or mild photic symptoms after IP instalment. Five (19%) reported ongoing severe photic symptoms. The corneal astigmatism significantly increased after iridocyclectomy but did not change after lens surgery. Conclusions: Implantation of an IOL and IP is a safe procedure, alleviating photic symptoms in most patients. It comes with higher risk of complications due to a more demanding procedure and larger surgical traumas from previous treatments. Ruthenium‐106 brachytherapy increases the complication risk. Corneal astigmatism is induced by iridocyclectomy but does not change after lens surgery. [ABSTRACT FROM AUTHOR]

This document is a journal article titled "Continuing Professional Development" from the Clinical & Experimental Ophthalmology journal. It provides information on two articles included in the issue and presents multiple-choice questions related to the articles. The first article discusses the retention time of different ophthalmic viscosurgical devices during phacoemulsification in a rabbit ocular model. The second article evaluates keratometry and corneal astigmatism data from biometers and anterior segment tomographers and maps them to reconstructed corneal astigmatism. Another article in the journal discusses the natural history and biomarkers of KCNV2-associated retinopathy, while the last article explores the potential use of lipids from ocular meibum and tears as biomarkers for depression and post-traumatic stress disorder. The questions provided in the document test the reader's understanding of the articles' content. [Extracted from the article]

Purpose: This study aimed to estimate the corneal keratometric index in the eyes of cataract surgery patients who received zero-power intraocular lenses (IOLs). Methodology: This retrospective study analyzed postoperative equivalent spherical refraction and axial length, mean anterior curvature radius and aqueous humor refractive index to calculate the theoretical corneal keratometric index value (nk). Data was collected from 2 centers located in France and Germany. Results: Thirty-six eyes were analyzed. The results revealed a mean corneal keratometric index of 1.329 ± 0.005 for traditional axial length (AL) and 1.331 ± 0.005 for Cooke modified axial length (CMAL). Results ranged from minimum values of 1.318/1.320 to maximum values of 1.340/1.340. Conclusion: The corneal keratometric index is a crucial parameter for ophthalmic procedures and calculations, particularly for IOL power calculation. Notably, the estimated corneal keratometric index value of 1.329/1.331 in this study is lower than the commonly used 1.3375 index. These findings align with recent research demonstrating that the theoretical corneal keratometric index should be approximately 1.329 using traditional AL and 1.331 using CMAL, based on the ratio between the mean anterior and posterior corneal curvature radii (1.22). [ABSTRACT FROM AUTHOR]

Copyright of Balikesir Health Sciences Journal / Balıkesir Sağlık Bilimleri Dergisi is the property of Balikesir Health Sciences Journal (BAUN Health Sci J) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: This study assessed the agreement of ocular parameters of patients with myopia measured using Colombo intraocular lens (IOL) 2 and IOLMaster 700. Methods: Eighty patients (male, 22; average age, 29.14 ± 7.36 years) with myopia (159 eyes) were included in this study in May 2023. The participants' axial length (AXL), central corneal thickness (CCT), lens thickness (LT), white-to-white distance (WTW), front flat (K1), steep (K2), mean (Km) corneal keratometry, astigmatism (Astig), J0 vector, and J45 vector were measured using the IOLMaster 700 and Colombo IOL 2. The measurements from both devices were compared using the generalized estimating equation, correlation analysis, and Bland-Altman plots. Results: With the Colombo IOL 2, lower values for K2 and J0 (odds ratio [OR] = 0.587, p = 0.033; OR = 0.779, p < 0.0001, respectively), and larger values for WTW, Astig, and J45 (OR = 1.277, OR = 1.482, OR = 1.1, all p < 0.0001) were obtained. All ocular measurements by both instruments showed positive correlations, with AXL demonstrating the strongest correlation (r = 0.9996, p < 0.0001). The intraclass correlation coefficients for AXL and CCT measured by both instruments was 0.999 and 0.988 (both p < 0.0001), and Bland-Altman plot showed 95% limits of agreement (LoA) of -0.078 to 0.11 mm and − 9.989 to 13.486 μm, respectively. The maximum absolute 95% LoA for LT, WTW, K1, K2, and J0 were relatively high, achieving 0.829 mm, 0.717 mm, 0.983 D, 0.948 D, and 0.632 D, respectively. Conclusions: In young patients with myopia, CCT and AXL measurements obtained with the Colombo IOL 2 and IOLMaster 700 were comparable. However, WTW, LT, corneal refractive power, and astigmatism values could not be used interchangeably in clinical practice. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to report the long-term results of combined topography-guided photorefractive keratectomy (PRK) and accelerated corneal collagen cross-linking (CXL) for keratoconus using the Zeiss refractive coordinated system. Methods: A prospective interventional study was conducted in a tertiary eye care hospital in South India. Patients with mild-to-moderate progressive keratoconus and corneal pachymetry greater than 450 |im were included. They underwent customized topography-guided PRK followed by CXL. Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), and keratometry readings and complications were evaluated at 1, 3, 6, 12, and 24 months postoperatively. Results: Thirty patients (30 eyes) were included in the study. All study parameters showed a statistically significant improvement postoperatively over baseline values. At 24 months, the mean UDVA improved from 0.8 ± 0.180 logarithm of the minimum angle of resolution (logMAR) to 0.38 ± 0.118 logMAR (P-value <0.001) and CDVA improved from 0.467 ± 0.142 logMAR to 0.227 ± 0.078 logMAR (P-value <0.001). The mean flat, steep, and maximum keratometry values were significantly reduced by 2.133, 3, and 4.54 diopters, respectively, at the last follow-up examination (P-value <0.001). Conclusion: The combined topography-guided PRK and accelerated CXL procedure seem to be a promising treatment alternative for early keratoconus. This is the first such study on the Zeiss refractive coordinated system. However, further studies with a larger study population and longer follow-up periods are required to draw final conclusions about the benefits of this procedure in keratoconus. [ABSTRACT FROM AUTHOR]

High-definition pyramidal aberrometers show high repeatability in normal and mild keratoconus eyes and moderate repeatability in advanced cases. These findings are significant for ocular wavefront-guided treatments. Purpose: To evaluate the intrasubject repeatability of pyramidal aberrometer measurements in a sample of keratoconus and normal eyes. Setting: American University of Beirut Medical Center, Beirut, Lebanon. Design: Prospective comparative repeatability analysis. Methods: Study population: Keratoconus and normal eyes from adult patients. Observation procedures: Each eye was evaluated with 3 consecutive acquisitions using a pyramidal aberrometer. Main outcome measures: The repeatability of different ocular higher-order aberrations and lower-order aberrations (HOAs and LOAs, respectively), and Zernike coefficients down to the fifth order, was evaluated. Repeatability was assessed by within-subject SDs (Sw), repeatability limits (r), and intraclass correlation coefficients (ICCs), among other parameters. Results: 72 keratoconus patients (72 eyes) and 76 normal patients (76 eyes) were included. In normal and keratoconus eyes, the ICC of total LOAs and HOAs, as well as each of the Zernike coefficients, was >0.9. The Sw for keratoconus eyes with mean maximal keratometry (Kmax) <50 diopters (D) was 0.1345 for total LOAs, 0.0619 for total HOAs, 0.0292 for horizontal coma, 0.0561 for vertical coma, and 0.0221 for spherical aberration as compared with 0.2696, 0.1486, 0.0972, 0.1497, and 0.0757 for keratoconus eyes with Kmax ≥50 D. Similar trend of better repeatability for grade 1 keratoconus and HOAs <2 D as compared with grades 2 and 3 keratoconus and eyes with HOAs >2 D were also noted. Conclusions: Ocular aberrometer measurements generated by high definition pyramidal aberrometers have high repeatability in both normal and mild keratoconus eyes and moderate repeatability, yet still clinically acceptable, in advanced keratoconus. This is of particular importance in ocular wavefront-guided treatments. [ABSTRACT FROM AUTHOR]

Copyright of Arquivos Brasileiros de Oftalmologia is the property of Arquivos Brasileiros de Oftalmologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objectives: To investigate the clinical efficacy and safety of the modified Cretan protocol in patients with post-laser in situ keratomileusis ectasia (PLE). Materials and Methods: In this retrospective study, 26 eyes of 16 patients with PLE were treated with the modified Cretan protocol (combined transepithelial phototherapeutic keratectomy and accelerated corneal collagen cross-linking). Visual, refractive, tomographic, and aberrometric outcomes and point spread function (PSF) were recorded preoperatively and at 6, 12, and 24 months after treatment. Results: Both uncorrected and best corrected visual acuity were stable at 24 months postoperatively compared to baseline (from 0.89±0.36 to 0.79±0.33 logarithm of the minimum angle of resolution [LogMAR] and 0.31±0.25 to 0.24±0.19 LogMAR, respectively, p>0.05 for all values). The mean K1, K2, Kmean, thinnest corneal thickness, and spherical aberration at baseline were 45.76±5.75 diopters (D), 48.62±6.17 D, 47.13±5.89 D, 433.16±56.86 µm, and -0.21±0.63 µm respectively. These values were reduced to 42.86±6.34 D, 45.92±6.74 D, 44.21±6.4 D, 391.07±54.76 µm, and -0.51±0.58 µm at 24 months postoperatively (p<0.001, p=0.002, p<0.001, p=0.001, and p=0.02, respectively). The mean spherical equivalent, manifest cylinder, Kmax, central corneal thickness, other corneal aberrations (root mean square, trefoil, coma, quatrefoil, astigmatism), and PSF remained stable (p>0.05 for all variables), while anterior and posterior elevation were significantly improved at 24 months postoperatively (p<0.001 and p=0.02, respectively). No surgical complications occurred during the 24-month follow-up. Conclusion: The modified Cretan protocol is a safe and effective treatment option for PLE patients that provides visual stabilization and significant improvement in topographic parameters during the 24-month follow-up. Further studies are needed to support our results. [ABSTRACT FROM AUTHOR]

Introduction: This study aims to evaluate the accuracy of 12 different intraocular lens (IOL) power calculation formulas for post-radial keratotomy (RK) eyes. The investigation utilizes recent advances in topography/tomography devices and artificial intelligence (AI)-based calculators, comparing the results to those reported in current literature to assess the efficacy and predictability of IOL calculations for this patient group. Methods: In this retrospective study, 37 eyes from 24 individuals with a history of RK who underwent cataract surgery at Hoopes Vision Center were analyzed. Biometry and corneal topography measurements were taken preoperatively. Subjective refraction was obtained 6 months postoperatively. Twelve different IOL power calculations were used, including the American Society of Cataract and Refractive Surgery (ASCRS) post-RK online formula, and the Barrett True K, Double K modified-Holladay 1, Haigis-L, Panacea, Camellin-Calossi, Emmetropia Verifying Optical (EVO) 2.0, Kane, and Prediction Enhanced by Artificial Intelligence and output Linearization-Debellemanière, Gatinel, and Saad (PEARL-DGS) formulas. Outcome measures included median absolute error (MedAE), mean absolute error (MAE), arithmetic mean error (AME), and percentage of eyes achieving refractive prediction errors (RPE) within ± 0.50 D, ± 0.75 D, and ± 1 D for each formula. A search of the literature was also performed by two independent reviewers based on relevant formulas. Results: Overall, the best performing IOL power calculations were the Camellin-Calossi (MedAE = 0.515 D), the ASCRS average (MedAE = 0.535 D), and the EVO (MedAE = 0.545 D) and Kane (MedAE = 0.555 D) AI-based formulas. The EVO and Kane formulas along with the ASCRS calculation performed similarly, with 48.65% of eyes scoring within ± 0.50 D of the target range, while the Equivalent Keratometry Reading (EKR) 65 Holladay formula achieved the greatest percentage of eyes scoring within ± 0.25 D of the target range (35.14%). Additionally, the EVO 2.0 formula achieved 64.86% of eyes scoring within the ± 0.75 D RPE category, while the Kane formula achieved 75.68% of eyes scoring within the ± 1 D RPE category. There was no significant difference in MAE between the established and newer generation formulas (P > 0.05). The Panacea formula consistently underperformed when compared to the ASCRS average and other high-performing formulas (P < 0.05). Conclusion: This study demonstrates the potential of AI-based IOL calculation formulas, such as EVO 2.0 and Kane, for improving the accuracy of IOL power calculation in post-RK eyes undergoing cataract surgery. Established calculations, such as the ASCRS and Barrett True K formula, remain effective options, while under-utilized formulas, like the EKR65 and Camellin-Calossi formulas, show promise, emphasizing the need for further research and larger studies to validate and enhance IOL power calculation for this patient group. [ABSTRACT FROM AUTHOR]

Objective: This study aimed to explore corneal curvature changes following strabismus surgery using a quadric surface fitting model to address ocular misalignment. Material and Methods: In this prospective cross-sectional study, 54 completed cases (84 eyes) of patients aged 6–60 years old (mean 10 years old) undergoing horizontal rectus muscle surgery were examined using placido-based keratometry with the Oculus Keratograph 5M system. Data on corneal curvature were collected one week pre-operation, and again one week, one month, and three months post-operation. Asphericity in the vertical meridian (Qy) and horizontal meridian (Qx), and surgical-induced astigmatism (SIA) were calculated. Results: The 84 eyes included were categorized into three groups: horizontal muscle surgeries, oblique muscle surgery, and combined horizontal and oblique muscle surgeries. Significant corneal prolation (steep central, flat peripheral) was revealed in the vertical meridian (Qy) at 3 months postoperatively for lateral rectus (LR) recession in the first group (p < 0.001), and the mean SIA was 0.45 D (95% CI: 0.35–0.56 D). A similar effect was seen in the vertical meridian of the third group (p < 0.01), with a mean SIA at 3 months of 0.27 D (95% CI: 0.23–0.32 D). Conclusion: Lateral rectus muscle recession induces corneal vertical prolation for up to 3 months post-operation. Surgeons are thus advised to re-evaluate refraction and defer contact lens refitting, refractive surgery, and intraocular lens calculations for at least 3 months after the procedure.

The document titled "Continuing Professional Development" provides information for RANZCO Fellows to earn CPD points by reading two articles in the Clinical & Experimental Ophthalmology journal. The first article discusses angle-based minimally invasive glaucoma surgery in normal tension glaucoma, including the postoperative time points with the largest reductions in intraocular pressure and number of anti-glaucoma medications. The second article evaluates the use of multimodal imaging in predicting late age-related macular degeneration development, highlighting the imaging modalities assessed and the parameters included in the prediction model. Another article examines the retention time of different ophthalmic viscosurgical devices during phacoemulsification, while the last article explores the evaluation of keratometry and corneal astigmatism data from biometers and anterior segment tomographers. [Extracted from the article]

Majid Moshirfar,1– 3 Shreya Pandya,4 Stephanie Zhang,5 Isabella M Stoakes,1,6 Azraa Ayesha,7 Phillip C Hoopes1 1Hoopes Vision Research Center, Hoopes Vision, Draper, UT, USA; 2John A. Moran Eye Center, University of Utah School of Medicine, Salt Lake City, UT, USA; 3Utah Lions Eye Bank, Murray, UT, USA; 4University of Louisville School of Medicine, Louisville, KY, USA; 5University of Arizona College of Medicine-Phoenix, Phoenix, AZ, USA; 6Pacific Northwest University of Health Sciences, Yakima, WA, USA; 7University of Utah School of Medicine, Salt Lake City, UT, USACorrespondence: Majid Moshirfar, Hoopes Vision Research Center, 11820 S. State St. &num;200, Draper, UT, 84020, USA, Tel +1 801-568-0200, Fax +1 801-563-0200, Email cornea2020@me.comPurpose: To determine whether the AvaGen (AG) Genetic Eye Test provided additional information for screening for the presence of keratoconus (KC) and assessing KC risk in refractive surgery candidates, as compared to the Keratoconus Severity Score (KSS) and Randleman Ectasia Risk Score System (ERSS).Methods: This retrospective study analyzed patients seeking refractive surgery at an eye clinic in the United States between January 2022 and July 2023. The inclusion criteria encompassed those with a family history of KC, positive KC indices, or both. Corneal evaluations and demographic information were recorded and analyzed. KSS and ERSS criteria were utilized to evaluate postoperative KC and ectasia risk, respectively. Patients were categorized on how the AG genetic test compared to KSS and ERSS criteria. Clinicians assessed topographic indices, criteria scoring, and AG testing to deliver a definitive surgical recommendation.Results: Among the 19 patients evaluated for ectasia risk, AG testing showed lower KC risk than ocular screening in three patients (15.8%), equal risk in three patients (15.8%), and higher risk in 13 patients (68.4%). The mean AG scores were 45.7 ± 7.0, 49.0 ± 3.46, and 61 ± 13.0 for these respective categories. The most frequently identified KC risk genes were ADAMTS18, COL2A1, and COL4A1. The AG test modified the physician’s recommendation for refractive surgery in nine cases (47.4%).Conclusion: Despite the promising application of AG testing for assessing KC risk, further research and development are needed to enhance its applicability for screening refractive surgery candidates, in addition to standard ocular screening approaches.Keywords: AvaGen, keratoconus, severity, corneal topography, Randleman, ectasia risk score system, keratoconus severity score

AIM: To compare the anterior and posterior corneal astigmatism and total refractive astigmatism before and after MyoRing implantation in keratoconus(KCN)patients.METHODS: In this historical cohort study, the preoperative and postoperative total refractive, anterior and posterior corneal astigmatism of KCN patients implanted with a 360-degree full-ring implant(MyoRing)were compared before and after four consecutive follow-up sessions at 3, 6, 9, and 12 mo after surgery.RESULTS: The study encompassed 79 KCN patients(85 eyes), comprising 43 males and 36 females. The mean age of the patients was 29±7.41 years, ranging from 17 to 48 years. Throughout the follow-up sessions, a gradual decrease was observed in the trend of changes for total refractive astigmatism, anterior corneal astigmatism, and posterior corneal astigmatism. Postoperatively, total refractive astigmatism measurements exhibited a significant decrease of 2.09 D at 12 mo after MyoRing implantation(4.27±3.15 vs 2.18±1.63 D, P

AIM:To investigate the effect of wearing corneoscleral contact lens on visual acuity, and corneal parameters in keratoconus patients.METHODS:In this prospective study, 43 cases(83 eyes)with keratoconus were included and examined. A corneoscleral contact lens was fitted, and thorough exams were carried out at baseline, 3 and 6 mo after wearing lenses, including slit lamp examination, objective and subjective refraction, uncorrected visual acuity(UCVA), and best-corrected visual acuity(BCVA), keratometry(Kmax, K1 and K2), central corneal thickness and endothelial cells count.RESULTS: Mean BCVA(LogMAR)improved from 0.34±0.23 with the spectacles to 0.03±0.05 with the corneoscleral contact lenses in 6 mo(P

PurposeThe purpose of this study was to investigate the social determinants of health for keratoconus.MethodsIn this retrospective cohort study of patients with keratoconus, the electronic health record was reviewed for keratometry, treatments received, clinical comorbidities, and social characteristics. Outcomes included severe keratoconus at presentation (steep keratometry ≥52 diopters), disease progression (≥0.75 diopters increase from the first to the most recent clinical visit), and corneal transplantation. Logistic regression was used to evaluate factors associated with severity at presentation and corneal transplantation. Cox proportional hazards modeling was used to evaluate progression.ResultsA total of 1038 patients with keratoconus were identified, 725 (70%) of whom had baseline imaging. Compared with commercially insured patients, Medicaid recipients were more likely to have severe keratoconus, independent of social and clinical confounders [odds ratio (OR) 1.94, 95% confidence interval (CI), 1.12-3.35, P = 0.017]. Male sex was independently associated with progression (hazard ratio = 1.38, 95% CI, 1.03-1.84, P = 0.030). Medicare and Medicaid recipients were more likely to require transplantation compared with commercially insured patients (OR 2.71, 95% CI, 1.65-4.46, P < 0.001 and OR 1.74, 95% CI, 1.08-2.80, P = 0.022, respectively). Other social determinants of health, including non-White race/ethnicity, limited English proficiency, and unemployment, were associated with the outcomes only in univariate analysis. Obstructive sleep apnea, atopy, body mass index, and tobacco use were not associated with any outcome.ConclusionsSocioeconomic factors were more consistent predictors of keratoconus severity and corneal transplantation compared with clinical factors that have received relatively greater attention in the keratoconus literature.