Inter-zonal epithelial thickness differences for early keratoconus detection using optical coherence tomography.

PURPOSE: To develop and test a parameter for early keratoconus screening by quantifying the localized epithelial thickness differences in keratoconic eyes. METHODS: The cross-sectional study included 189 eyes of 116 subjects in total: 86 eyes of 54 keratoconus patients with bilateral ectasia and 40 eyes of 20 healthy subjects in the parameter-development dataset and 42 eyes of 21 keratoconus patients with asymmetric ectasia and 21 eyes of 21 healthy subjects in the parameter-validation dataset. Epithelial thickness maps were obtained using anterior segment optical coherence tomography and the inter-zonal epithelial thickness differences were calculated. The developed parameter was tested in keratoconus patients with asymmetric ectasia. RESULTS: Compared to healthy controls, the inferior-temporal and global inter-zonal epithelial thickness differences were higher not only in eyes with tomographically significant keratoconus (median [interquartile range] of 4.42 [3.13] µm vs. 0.78 [0.42] µm, p < 0.001, and 3.05 [1.51] µm vs. 1.07 [0.26] µm, p < 0.001, respectively), but also in tomographically normal keratoconus fellow eyes (1.36 [0.85] µm vs. 0.78 [0.42] µm, p = 0.005, and 1.31 [0.32] µm vs. 1.07 [0.26] µm, p = 0.01, respectively). The inferior-temporal inter-zonal epithelial thickness differences had an area under the receiver operating characteristic curve (95% confidence interval) of 0.991 (0.972-1) for detecting tomographically significant keratoconus and 0.749 (0.598-0.901) for differentiating between tomographically normal keratoconus fellow eyes and healthy controls. CONCLUSIONS: The inter-zonal epithelial thickness differences are increased in keratoconus fellow eyes which still have a normal Scheimpflug corneal tomography, and therefore may serve as a useful parameter to detect early ectatic changes.

Early intraocular lens explantations: 10-year database analysis.

BACKGROUND: The aim of this study was to analyze the causes and characteristics of IOL explantation within the first year after primary implantation. METHODS: In this retrospective, cross sectional database study, a database consisting of over 2500 IOL explants sent from 199 national and international doctors over the past 10 years was analyzed. All IOLs explanted within the first year after implantation were included in this analysis. Explants with insufficient information as well as phakic and Add-on IOLs were excluded. Main outcome measures were the reason for explantation, the time between implantation and explantation, as well as IOLs' and patients' characteristics. Additionally, the explanted IOLs were microscopically and histologically analyzed, as required. RESULTS: Of all explanted IOLs from the database, 1.9% (n = 50) were explanted within the first year after implantation. The most frequent reasons for early IOL explantation were IOL dislocation (32%), visual intolerance (26%), opacification (20%), and intraoperative complications (16%). The time between implantation and explantation was the shortest in cases with intraoperative complications (1.5 ± 3.1 days), followed by IOL dislocation (90.9 ± 103.9 days), visual intolerance (98.3 ± 86.5 days), opacifications (253.5 ± 124.0 days) and other indications (249.7 ± 124.0 days). Calcification of hydrophilic IOLs was the main type of opacification (80%). Notably, seven IOLs required immediate intraoperative exchange due to an intraoperative crack in the optic or a torn off haptic. CONCLUSION: Indications for early IOL explantation were IOL dislocation, visual intolerance, opacification, and intraoperative complications. Especially intraoperative damages to the IOL and early calcification show a potential for improvement of affected IOLs and implantation systems.

Clinical outcomes of conjunctivochalasis treatment with a new ophthalmic radiofrequency device.

PURPOSE: To investigate the safety and efficacy of a new micro-controlled radiofrequency device for treatment of conjunctivochalasis (Cch). METHODS: Data of 127 patients (230 eyes) who underwent ophthalmic radiofrequency treatment for Cch from January 2020 to June 2023 were analyzed retrospectively. Cch coagulation was performed with a radiofrequency electrode tip (OcuRF®, Ilooda, Korea) and a high-frequency radio-wave electric unit (0.6 ~ 0.8 watts, 2 MHz, Acutron™, Ilooda, Korea). Pre- and postoperative Cch grading, slit-lamp photography, tear film break-up time (TBUT), and bulbar conjunctival hyperemia using Keratograph 5 M (Oculus, Wetzlar, Germany) were evaluated. Cch grade 0 or 1 after surgery was regarded as 'success'. Complications, recurrence, and additional treatment rates were analyzed. RESULTS: In 227 (98.7%) eyes, the radiofrequency treatment led to marked improvement of Cch, with 224 (97.4%) eyes achieving grade 0 or 1 at 2 months postoperatively. Eight eyes (3.5%) received additional treatment. TBUT improved from 3.17 ± 0.82 s to 5.28 ± 1.10 s after surgery (P < 0.001). The total bulbar conjunctival hyperemia value showed an improvement from 1.7 ± 0.6 to 1.4 ± 0.6 postoperatively (P < 0.05). No serious complications were observed. CONCLUSION: The novel ophthalmic radiofrequency device led to a marked improvement of Cch with no serious adverse events during the entire follow-up period. Our results suggest that the radiofrequency device presents a safe and efficacious treatment option for Cch.

Biomechanical changes following corneal crosslinking in keratoconus patients.

PURPOSE: To evaluate the biomechanical and tomographic outcomes of keratoconus patients up to four years after corneal crosslinking (CXL). METHODS: In this longitudinal retrospective-prospective single-center case series, the preoperative tomographic and biomechanical results from 200 keratoconus eyes of 161 patients undergoing CXL were compared to follow-up examinations at three-months, six-months, one-year, two-years, three-years, and four-years after CXL. Primary outcomes included the Corvis Biomechanical Factor (CBiF) and five biomechanical response parameters obtained from the Corvis ST. Tomographically, the Belin-Ambrósio deviation index (BAD-D) and the maximal keratometry (Kmax) measured by the Pentacam were analyzed. Additionally, Corvis E-staging, the thinnest corneal thickness (TCT), and the best-corrected visual acuity (BCVA) were obtained. Primary outcomes were compared using a paired t-test. RESULTS: The CBiF decreased significantly at the six-month (p < 0.001) and one-year (p < 0.001) follow-ups when compared to preoperative values. E-staging behaved accordingly to the CBiF. Within the two- to four-year follow-ups, the biomechanical outcomes showed no significant differences when compared to preoperative. Tomographically, the BAD-D increased significantly during the first year after CXL with a maximum at six-months (p < 0.001), while Kmax decreased significantly (p < 0.001) and continuously up to four years after CXL. The TCT was lower at all postoperative follow-up visits compared to preoperative, and the BCVA improved. CONCLUSION: In the first year after CXL, there was a temporary progression in both the biomechanical CBiF and E-staging, as well as in the tomographic analysis. CXL contributes to the stabilization of both the tomographic and biomechanical properties of the cornea up to four years postoperatively.

Ectasia Detection by Anterior Segment Optical Coherence Tomography in Scheimpflug Tomographically Normal Keratoconus Fellow Eyes.

PURPOSE: The purpose of this study was to determine whether the Scheimpflug tomographically normal fellow eyes of keratoconus patients are also classified as normal using an ectasia screening algorithm based on anterior segment optical coherence tomography (AS-OCT). METHODS: This monocentric cross-sectional study included 22 very asymmetric ectasia patients with tomographically significant keratoconus in 1 eye and normal Scheimpflug tomography in the fellow eye. Twenty-two eyes of 22 healthy subjects served as a control group. We performed corneal tomography using Pentacam AXL (Oculus, Wetzlar, Germany) and used Belin/Ambrósio Enhanced Ectasia total deviation index as well as Belin ABCD keratoconus classification to identify Scheimpflug tomographically normal eyes. We also performed AS-OCT using Anterion (Heidelberg Engineering, Heidelberg, Germany) and analyzed for the presence of ectasia using the Screening Corneal Objective Risk of Ectasia (SCORE) algorithm, with positive values indicating ectasia suspect tomography. RESULTS: The SCORE value was positive in 9.1% (n = 2) of the healthy eyes, in 45.5% (n = 10) of the Scheimpflug tomographically normal eyes of keratoconus patients and in all eyes (n = 22) with tomographically significant keratoconus. The Scheimpflug tomographically normal eyes of keratoconus patients had higher SCORE values compared with healthy controls (P < 0.001). The median (interquartile range) SCORE value was -1.7 (1.3) in healthy controls, -0.5 (2.2) in Scheimpflug tomographically normal eyes of keratoconus patients, and 11.1 (11.0) in tomographically significant keratoconus eyes. CONCLUSIONS: The Scheimpflug tomographically normal fellow eyes of keratoconus patients had higher AS-OCT-based SCORE values than healthy controls, with positive SCORE values found in 46% of the eyes, indicating early tomographic ectatic changes.

Longitudinal Evaluation of Biomechanical Indices in Fellow Eyes of Patients With Keratoconus Classified as Having Very Asymmetric Ectasia With Normal Topography.

PURPOSE: To evaluate the biomechanical longitudinal variability and progression of tomographically normal fellow eyes of patients with keratoconus. METHODS: Of 513 patients with keratoconus, 30 patients with tomographically normal fellow eyes were included in this study. Tomographic and biomechanical parameters of the Pentacam and Corvis ST (Oculus Optikgeräte GmbH) were analyzed in multiple follow-up examinations, including the ABCD grading, Belin/Ambrósio Enhanced Ectasia total deviation index (BAD-D), Corvis Biomechanical Index (CBI), Corvis Biomechanical Factor (CBiF), and Tomographic and Biomechanical Index (TBI). A mixed regression model was applied. The results were compared to a healthy control group (n = 17) and a keratoconus group (n = 20). RESULTS: Within a maximum observation period of 3.3 years, no fellow eye (0%) showed a progression to tomographically evident keratoconus. No significant change in tomographic or biomechanical parameters was detected over the study period. The indices BAD-D, CBI, CbiF, and TBI exhibited a certain variability over time, whereas the tomographic ABC parameters and maximum keratometry barely changed. This was also shown in the control group and for all parameters in the keratoconus group, except the TBI. CONCLUSIONS: During the observation period none of the normal fellow eyes progressed to tomographically detectable keratoconus. However, biomechanical parameters CBI, CbiF, and TBI showed pathological values in 43.3% of eyes and certain variability. Subsequent studies with a longer observation period are warranted to confirm the biomechanical trends seen in this study and to rate the ability of single measurements to diagnose early keratoconus. [J Refract Surg. 2024;40(1):e48-e56.].

Material Analysis of Explanted Calcified Silicone Intraocular Lenses in Association with Asteroid Hyalosis.

INTRODUCTION: The aim of this study was to analyze posterior surface opacification in explanted silicone intraocular lenses (IOLs) with clinicopathologic correlation to asteroid hyalosis. METHODS: In a laboratory setup, 12 explanted silicone IOLs underwent laboratory analyses, including light microscopy, scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy for elemental composition (EDX). Relevant clinical data were obtained for each case, including gender, age at IOL implantation, dates of implantation and explantation, as well as history of neodymium-dopped yttrium aluminum garnet (Nd:YAG) laser treatments or other opacification removal attempts. High-resolution optical coherence tomography (OCT) images were obtained in vitro with an anterior segment OCT device (Anterion, Heidelberg Engineering, Heidelberg, Germany). RESULTS: Calcification located at the posterior optic surface of each lens was identified through SEM and EDX analyses, revealing deposits composed of hydroxyapatite. In all cases, IOL polishing using Nd:YAG laser had been attempted prior to IOL exchange. The clinical functional data showed that this type of IOL opacity led to increase in straylight and subjective symptoms of glare. CONCLUSIONS: Silicone IOLs can develop posterior surface calcification in eyes with asteroid hyalosis. There are mechanical techniques of cleaning the IOL surface but in many cases, IOL explantation is the only sustainable way to reduce the patients' straylight levels and glare symptoms. Due to the risk of posterior surface calcification, silicone IOL implantation should be avoided in eyes with asteroid hyalosis.

Collagen type XII is undetectable in keratoconus Bowman's layer.

PURPOSE: Corneal biomechanical failure is the hallmark of keratoconus (KC); however, the cause of this failure remains elusive. Collagen type XII (COL12A1), which localises to Bowman's layer (BL), is thought to function in stress-bearing areas, such as BL. Given the putative protective role of COL12A1 in biomechanical stability, this study aims to characterise COL12A1 expression in all corneal layers involved in KC. METHODS: TaqMan quantitative PCR was performed on 31 corneal epithelium samples of progressive KC and myopic control eyes. Tissue microarrays were constructed using full-thickness corneas from 61 KC cases during keratoplasty and 18 non-KC autopsy eyes and stained with an antibody specific to COL12A1. Additionally, COL12A1 was knocked out in vitro in immortalised HEK293 cells. RESULTS: COL12A1 expression was reduced at transcript levels in KC epithelium compared with controls (ratio: 0.58, p<0.03). Immunohistochemical studies demonstrated that COL12A1 protein expression in BL was undetectable, with reduced expression in KC epithelium, basement membrane and stroma. CONCLUSIONS: The apparent absence of COL12A1 in KC BL, together with the functional importance that COL12A1 is thought to have in stress bearing areas, suggests that COL12A1 may play a role in the pathogenesis of KC. Further studies are necessary to investigate the mechanisms that lead to COL12A1 dysregulation in KC.

Factors Associated With Receipt of Crosslinking for Keratoconus.

PURPOSE: The aim of this study was to identify factors associated with receipt of standard fluence epithelium-off crosslinking (CXL) for keratoconus (KCN). METHODS: This retrospective, cross-sectional study reviewed electronic health records of treatment-naive patients with KCN seen at the Wilmer Eye Institute between January 2017 and September 2020. Tomographic data were derived from Pentacam (Oculus, Wetzlar, Germany) devices. Multivariable population-average model using generalized estimating equations adjusting for age, sex, race, national area deprivation index, vision correction method, and disease severity was used to identify factors associated with receipt of CXL. RESULTS: From 583 patients with KCN, 97 (16.6%) underwent CXL for KCN. Patients who received CXL in at least 1 eye were significantly younger (mean 24.0 ± 7.8 years) than patients who had never undergone CXL (33.4 ± 9.3 years) ( P < 0.001). In multivariable analysis, Black patients had 63% lower odds of receiving CXL for KCN (OR: 0.37, 95% CI, 0.18-0.79) versus White patients, and older age was protective against receipt of CXL (OR: 0.89 per 1-year increase, 95% CI, 0.86-0.93). Comparison of characteristics by race demonstrated that Black patients presented with significantly worse vision, higher keratometric indices (K1, K2, and Kmax), and thinner corneal pachymetry at baseline versus White or Asian patients. CONCLUSIONS: In this clinical cohort of patients with KCN from a tertiary referral center, Black patients were less likely to receive CXL presumably because of more advanced disease at presentation. Earlier active population screening may be indicated to identify and treat these patients before they become ineligible for treatment and develop irreversible vision loss. Such strategies may improve health equity in KCN management.

Visual Acuity Outcomes and Complications after Intraocular Lens Exchange: An IRIS® Registry (Intelligent Research in Sight) Analysis.

PURPOSE: To assess risk factors for worse visual acuity (VA) outcomes after intraocular lens (IOL) exchange, and the most common postsurgical complications. DESIGN: Retrospective cohort study. PARTICIPANTS: Eyes from patients 18 years of age and older in the IRIS® Registry (Intelligent Research in Sight) that underwent IOL exchange in the United States between 2013 and 2019. METHODS: Vision improvement compared with baseline was determined at 1 year after surgery. A multivariable generalized estimating equation model adjusting for demographic factors and baseline vision was used to identify factors associated with VA worse than 20/40 at 1 year. MAIN OUTCOME MEASURES: Visual outcomes and postoperative complications after lens exchange. RESULTS: A total of 46 063 procedures (n = 41 925 unique patients) were included in the analysis. Overall, VA improved from a mean ± standard deviation (SD) of 0.53 ± 0.58 logarithm of the minimum angle of resolution (logMAR; Snellen equivalent, 20/70) before surgery to a mean ± SD of 0.31 ± 0.40 logMAR (Snellen equivalent, 20/40) at 1 year. Among eyes with VA recorded at both baseline and 1 year after surgery, 60.5% achieved VA of 20/40 or better at 1 year. Vision of worse than 20/40 at 1 year was associated with greater age (odds ratio [OR], 1.16 per 5-year increase; 95% confidence interval [CI], 1.14-1.18) and higher logMAR baseline VA (OR, 1.14 per 0.1-logMAR increase; 95% CI, 1.14-1.15), as well as Black or African American (OR, 1.96; 95% CI, 1.68-2.28), Hispanic (OR, 1.82; 95% CI, 1.59-2.08), and Asian (OR, 1.48; 95% CI, 1.21-1.81) race or ethnicity versus White race, Medicaid (OR, 1.78; 95% CI, 1.40-2.25) versus private insurance, smoking history (OR, 1.22; 95% CI, 1.11-1.35), and concurrent anterior (OR, 1.65; 95% CI, 1.51-1.81) and posterior (OR, 1.53; 95% CI, 1.41-1.66) vitrectomy versus no vitrectomy. Female sex was associated with better VA at 1 year. At 1 year, epiretinal membrane (10.9%), mechanical lens complication (9.4%), and dislocation of the replacement lens (7.1%) were the most common complications. CONCLUSIONS: In this large national cohort, the annual number of IOL exchanges rose steadily over time. Vision improved in 60.2% of patients; worse visual outcomes were associated with greater age, worse baseline vision, Black race, Hispanic ethnicity, Medicaid insurance, smoking, and concurrent vitrectomy. Epiretinal membrane was the most common complication. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Racial Variation in Visual Impairment of Patients With Keratoconus at Presentation.

PURPOSE: This study aimed to investigate racial disparities in the severity of keratoconus (KCN) at presentation, their intersection with socioeconomic variables, and other factors associated with visual impairment. METHODS: This retrospective cohort study examined medical records of 1989 patients (3978 treatment-naive eyes) with a diagnosis of KCN seen at Wilmer Eye Institute between 2013 and 2020. A multivariable regression model adjusting for age, sex, race, insurance type, KCN family history, atopy, smoking status, and vision correction method examined factors associated with visual impairment, defined as a best available visual acuity of worse than 20/40 in the better eye. RESULTS: Demographically, Asian patients were the youngest (33.4 ± 14.0 years) ( P < 0.001), and Black patients had the highest median area deprivation index (ADI) of 37.0 [interquartile range (IQR): 21.0-60.5] ( P < 0.001). Multivariable analysis showed a higher risk of visual impairment for Black (OR 2.25, 95% CI, 1.71-2.95) versus White patients. Medicaid (OR 2.59, 95% CI, 1.75-3.83) and Medicare (OR 2.48, 95% CI, 1.51-4.07) were also associated with a higher odds of visual impairment compared with private insurance, and active smokers were more likely to have visual impairment than those with no prior smoking history (OR 2.17, 95% CI, 1.42-3.30). Eyes of Black patients had the highest maximum keratometry (Kmax) (56.0 ± 11.0D) ( P = 0.003) and the lowest thinnest pachymetry (463.2 ± 62.5 µm) ( P = 0.006) compared with eyes of other races. CONCLUSIONS: Black race, government-funded insurance, and active smoking were significantly associated with increased odds of visual impairment in adjusted analyses. Black race was also associated with higher Kmax and lower thinnest pachymetry, suggesting that Black patients have more severe disease at presentation.

Influence of Subclinical Corneal Edema on Contrast Sensitivity in Fuchs Endothelial Corneal Dystrophy.

PURPOSE: The aim of this study was to compare visual function, with a focus on contrast sensitivity, between patients with Fuchs endothelial corneal dystrophy (FECD) with and without subclinical corneal edema. METHODS: In this cross-sectional, observational, single-center study, 46 pseudophakic eyes of 31 patients with FECD were divided into 2 groups depending on the presence of subclinical corneal edema. All eyes presented with a Krachmer grade of 5 and no clinical corneal edema. The criteria for subclinical corneal edema were loss of regular isopachs, displacement of the thinnest point, and focal posterior surface depression in Scheimpflug tomography. If more than 1 criterion was present, subclinical corneal edema was diagnosed. The corrected distance visual acuity, contrast sensitivity (Pelli-Robson chart and CSV-1000 test with optional glare), and straylight were measured. The differences between both groups were analyzed using clustered Wilcoxon rank-sum tests. RESULTS: The corrected distance visual acuity and the contrast sensitivity, measured with a Pelli-Robson chart, were significantly inferior in eyes with subclinical corneal edema compared with eyes without subclinical edema ( P < 0.05). At all spatial frequencies, eyes with subclinical edema demonstrated lower contrast sensitivity with a statistically significantly reduction in total contrast sensitivity when tested with ( P = 0.005) and without ( P = 0.002) glare. The straylight did not significantly differ between both groups ( P > 0.05). CONCLUSIONS: The corrected distance visual acuity and contrast sensitivity were significantly reduced in FECD eyes with subclinical corneal edema compared with those with no subclinical edema. This decrease in visual quality may be considered when evaluating the need for surgical intervention at earlier stages of FECD.

Biomechanical Analysis of Tomographically Regular Keratoconus Fellow Eyes Using Corvis ST. / Biomechanische Analyse von tomografisch unauffälligen Keratokonus-Partneraugen mit dem Corvis ST.

BACKGROUND: Keratoconus is a bilateral, yet asymmetric disease. In rare cases, the second eye may show no signs of tomographic changes. The purpose of this study was to analyze the biomechanical characteristics in tomographically regular keratoconus fellow eyes. MATERIALS AND METHODS: This retrospective, consecutive case series analyzed 916 eyes of 458 patients who presented to our keratoconus clinic between November 2020 and October 2022. Primary outcome measures included best-corrected visual acuity (BCVA), tomographic Scheimpflug analysis using Pentacam AXL (Oculus, Wetzlar, Germany), and biomechanical assessment using Corvis ST (Oculus, Wetzlar, Germany). Tomographic changes were assessed via analysis of the anterior and posterior curvature, K-max, thinnest corneal thickness (TCT), the Belin/Ambrosio Deviation Display (BAD-D), and the ABCD-Grading. Biomechanical changes were analyzed using Corvis Biomechanical Index (CBI) and Tomographic Biomechanical Index (TBI). RESULTS: Of 916 eyes, 34 tomographically regular fellow eyes (7.4%) were identified and included in the analysis. Overall, the mean BCVA was - 0.02 ± 0.13 logMAR. Tomographic analysis showed mean K-max of 43.87 ± 1.21 D, mean TCT of 532 ± 23 µm, and mean BAD-D of 1.02 ± 0.43. Biomechanical analysis demonstrated mean CBI of 0.28 ± 0.26 and mean TBI of 0.34 ± 0.30. While normal CBI-values were observed in 16 (47%) of 34 eyes, only 13 eyes (38%) showed a regular TBI and only 7 eyes (21%) showed regular TBI and CBI. The sensitivity of CBI and TBI to detect a tomographically normal keratoconus fellow eye was 53% and 62%, respectively. CONCLUSION: A highly asymmetric corneal ectasia with regular tomographic finding in a fellow eye is rare among keratoconus patients. In such cases, a biomechanical analysis may be useful in detecting early signs of corneal ectasia. In our analysis, the TBI showed high sensitivity for detecting a biomechanical abnormality in tomographically regular fellow eyes.

Differential Diagnosis of Changes in Intraocular Lenses. / Differenzialdiagnostik von Veränderungen in Intraokularlinsen.

Differentiating between various intraocular lens (IOL) changes can be a challenge. In particular, certain IOL models carry the risk of late postoperative calcification. A major cause of IOL exchange surgery could be avoided if appropriate modifications were made during the IOL manufacturing process. The use of a hydrophilic acrylate carries the risk of IOL calcification, especially when a secondary procedure, such as a pars plana vitrectomy or other procedures using gas or air, is performed. In secondary IOL calcification, there is a wide range of opacification patterns, which are usually located in the centre on the anterior surface of the IOL or sometimes elsewhere. Often, granular deposits accumulate just below or on the surface of the IOL, leading to significant deterioration in visual quality and eventually requiring IOL exchange surgery. Therefore, in the case of eyes requiring secondary surgical intraocular intervention in the future, the use of hydrophilic IOLs should be critically evaluated. With regard to hydrophobic IOL materials, there are clear differences in the susceptibility to the formation of glistenings. Over time, there has been a significant decrease in glistening formation over the past 30 years due to optimisation of the material. With hydrophobic IOLs, special care should also be taken to avoid mechanical damage. In general, the only treatment option for functionally-impairing IOL opacification is surgical lens exchange, which carries potential risks of complications. In cases with a low degree of functional impairment, and especially in eyes with additional ocular diseases, it may be difficult to weigh the risk of additional surgery against the potential benefit. In some cases, it may be more appropriate not to perform an IOL exchange despite the IOL opacification. Recent visualisation methods that allow high-resolution analysis of the opacities in vivo and in vitro may be used in the future to estimate the functional effects of various IOL material changes on the optical quality.

Late central graft detachment due to double endothelial layer after repeat Descemet membrane endothelial keratoplasty.

Purpose: To report late central graft detachment after repeat Descemet membrane endothelial keratoplasty (DMEK) without visual reduction. Observations: A 71-year-old patient with Fuchs' endothelial corneal dystrophy received a DMEK in his left eye. At 11 month post-operatively, a subtotal graft detachment was noted. Due to increasing corneal edema with vision loss, the first DMEK was removed and a repeat-DMEK was performed. At four months post repeat-DMEK, the graft was fully adherent to the posterior stroma. There was no significant corneal edema, and the best corrected visual acuity was 20/25. At 16-months after repeat-DMEK, a central graft detachment was noted, but there was no concurrent corneal edema or any loss of visual acuity. The mean density of the central endothelial cells was measured at 842 cells/mm2. Given the lack of corneal edema, visual reduction or subjective visual complaint, the graft detachment was followed-up for up to 20-months post repeat-DMEK with no further intervention, where the central cornea remained clear. Conclusions and Importance: To our knowledge, this is the first report of a central repeat-DMEK graft detachment that occurred 16 months after surgery despite initial attachment. Interestingly, there was no concurrent corneal edema or vision reduction. We describe a potential mechanism for clear central cornea in the presence of a central graft detachment after repeat-DMEK.

Refractive outcomes after DMEK: meta-analysis.

In this meta-analysis and systematic literature review of refractive outcomes after Descemet membrane endothelial keratoplasty (DMEK), the extent of the refractive shift and an overview of reasons for refractive shift after DMEK are provided. The PubMed library was screened for articles containing the terms "Descemet membrane endothelial keratoplasty," "DMEK," "Descemet membrane endothelial keratoplasty combined with cataract surgery," "triple-DMEK" combined with "refractive outcomes," "refractive shift," and "hyperopic shift." The refractive outcomes after DMEK were analyzed and compared using a fixed and random effects model. The overall mean change of the spherical equivalent outcome when compared with the preoperative value in cases of DMEK or when compared with the preoperative target refraction in cases of DMEK combined with cataract surgery was +0.43 diopters (D) (95% CI, 0.31-0.55). When DMEK is combined with cataract surgery, a target refraction of -0.5 D is recommended to achieve emmetropia. Changes in the posterior corneal curvature are identified as the main cause of the refractive hyperopic shift.

Clinical outcomes of bilateral implantation of new generation monofocal IOL enhanced for intermediate distance and conventional monofocal IOL in a Korean population.

BACKGROUND: To compare the clinical outcomes of bilateral implantation of enhanced intermediate function intraocular lenses (IOLs) and standard monofocal IOLs. METHODS: In this prospective, randomized, comparative controlled study, we compared the visual outcomes of patients who underwent bilateral cataract surgery at the Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, with either enhanced monofocal IOLs (Tecnis Eyhance, ICB00, Johnson and Johnson Vision Care, Inc) (Group 1) or standard monofocal IOLs (Tecnis, ZCB00, Johnson and Johnson Vision Care, Inc) (Group 2). The assessment included monocular and binocular uncorrected distance visual acuity (UDVA), uncorrected intermediate (UIVA at 60 cm) and near (UNVA at 40 cm) visual acuity, uncorrected defocus curves, contrast sensitivity testing (CST), and reading speed test using Quality of vision was evaluated using the Visual Function Questionnaire (VFQ-25). RESULTS: At 3-months postoperatively, monocular and binocular outcomes of UIVA and UNVA were statistically significantly better in Group 1 (P < 0.05). The binocular uncorrected defocus curve of Group 1 showed statistically significantly better outcomes at vergence ranges of -1.5 to -4.0 D (P < 0.05). Significantly higher reading speed test was also observed in Group 1 in all ranges tested (1.0 to 0.1 LogMAR) (P < 0.05). There were no statistically significant differences in CST between groups. CONCLUSIONS: Bilateral implantation of enhanced monofocal IOLs provided better vision at intermediate and near distances compared to standard monofocal IOLs, while maintaining good distance vision and contrast sensitivity.

Histological Comparative Analysis of Bowman Layer Grafts Procured Using 3 Different Techniques.

PURPOSE: The objective of this study is to perform a histological analysis of Bowman layer (BL) grafts. METHODS: BL grafts were procured from 13 human cadaver corneal tissues using 3 different donor preparation techniques. Subsequently, the grafts were fixed in 10% buffered formalin phosphate and embedded in paraffin. Hematoxylin and eosin sections of BL grafts were obtained and analyzed under a light microscope. BL and full graft thickness were measured using an image-processing software. RESULTS: All 13 BL grafts contained residual anterior stromal tissue. BL stripping using Kelman-McPherson and Moorfield forceps (technique 3) achieved the thinnest graft thickness with a mean full graft thickness of 18.7 µm (95% confidence interval [CI], -9.8 to 47.2) at the thinnest point of the graft, whereas BL procurement using the Melles lamellar dissector (technique 2) led to the highest mean full graft thickness of 279.9 µm (95% CI, 251.4-308.5) even at the thinnest area of the graft. By contrast, BL dissection using a blunt dissector (technique 1) provided a mean full graft thickness of 70.2 µm (95% CI, 40.4-100.1) at the graft's thinnest point. Although peripheral graft tears occurred in 50%, 50%, and 100% of techniques 1, 2, and 3, respectively, intact 6.25-mm diameter BL grafts could be secured in 50%, 100%, and 80% of techniques 1, 2, and 3, respectively. CONCLUSIONS: None of the techniques used led to the procurement of pure BL grafts devoid of the anterior stroma. Peripheral scoring with a thin needle and tissue manipulation with Kelman-McPherson and Moorfield forceps led to the thinnest grafts in this study.