Quantifying refractive error in companion dogs with and without nuclear sclerosis: 229 eyes from 118 dogs.

OBJECTIVE: To evaluate the relationship between nuclear sclerosis (NS) and refractive error in companion dogs. ANIMALS STUDIED: One hundred and eighteen companion dogs. PROCEDURES: Dogs were examined and found to be free of significant ocular abnormalities aside from NS. NS was graded from 0 (absent) to 3 (severe) using a scale developed by the investigators. Manual refraction was performed. The effect of NS grade on refractive error was measured using a linear mixed effects analysis adjusted for age. The proportion of eyes with >1.5 D myopia in each NS grade was evaluated using a chi-square test. Visual impairment score (VIS) was obtained for a subset of dogs and compared against age, refractive error, and NS grade. RESULTS: Age was strongly correlated with NS grade (p < .0001). Age-adjusted analysis of NS grade relative to refraction showed a mild but not statistically significant increase in myopia with increasing NS grade, with eyes with grade 3 NS averaging 0.58-0.88 D greater myopia than eyes without NS. However, the myopia of >1.5 D was documented in 4/58 (6.9%) eyes with grade 0 NS, 12/91 (13.2%) eyes with grade 1 NS, 13/57 (22.8%) eyes with grade 2 NS, and 7/23 (30.4%) eyes with grade 3 NS. Risk of myopia >1.5 D was significantly associated with increasing NS grade (p = .02). VIS was associated weakly with refractive error, moderately with age, and significantly with NS grade. CONCLUSIONS: NS is associated with visual deficits in some dogs but is only weakly associated with myopia. More work is needed to characterize vision in aging dogs.

DeepLensNet: Deep Learning Automated Diagnosis and Quantitative Classification of Cataract Type and Severity.

PURPOSE: To develop deep learning models to perform automated diagnosis and quantitative classification of age-related cataract from anterior segment photographs. DESIGN: DeepLensNet was trained by applying deep learning models to the Age-Related Eye Disease Study (AREDS) dataset. PARTICIPANTS: A total of 18 999 photographs (6333 triplets) from longitudinal follow-up of 1137 eyes (576 AREDS participants). METHODS: Deep learning models were trained to detect and quantify nuclear sclerosis (NS; scale 0.9-7.1) from 45-degree slit-lamp photographs and cortical lens opacity (CLO; scale 0%-100%) and posterior subcapsular cataract (PSC; scale 0%-100%) from retroillumination photographs. DeepLensNet performance was compared with that of 14 ophthalmologists and 24 medical students. MAIN OUTCOME MEASURES: Mean squared error (MSE). RESULTS: On the full test set, mean MSE for DeepLensNet was 0.23 (standard deviation [SD], 0.01) for NS, 13.1 (SD, 1.6) for CLO, and 16.6 (SD, 2.4) for PSC. On a subset of the test set (substantially enriched for positive cases of CLO and PSC), for NS, mean MSE for DeepLensNet was 0.23 (SD, 0.02), compared with 0.98 (SD, 0.24; P = 0.000001) for the ophthalmologists and 1.24 (SD, 0.34; P = 0.000005) for the medical students. For CLO, mean MSE was 53.5 (SD, 14.8), compared with 134.9 (SD, 89.9; P = 0.003) for the ophthalmologists and 433.6 (SD, 962.1; P = 0.0007) for the medical students. For PSC, mean MSE was 171.9 (SD, 38.9), compared with 176.8 (SD, 98.0; P = 0.67) for the ophthalmologists and 398.2 (SD, 645.4; P = 0.18) for the medical students. In external validation on the Singapore Malay Eye Study (sampled to reflect the cataract severity distribution in AREDS), the MSE for DeepSeeNet was 1.27 for NS and 25.5 for PSC. CONCLUSIONS: DeepLensNet performed automated and quantitative classification of cataract severity for all 3 types of age-related cataract. For the 2 most common types (NS and CLO), the accuracy was significantly superior to that of ophthalmologists; for the least common type (PSC), it was similar. DeepLensNet may have wide potential applications in both clinical and research domains. In the future, such approaches may increase the accessibility of cataract assessment globally. The code and models are available at https://github.com/ncbi/deeplensnet.

Visual Prognosis Following Cataract Surgery in Highly Myopic Patients with Prior History of Verisyse Phakic Intraocular Lens Implantation.

Background/Objectives: This study aimed to evaluate the visual outcomes and prognosis after cataract surgery in patients with prior history of Verisyse phakic intraocular lens (pIOL) implantation. Methods: A retrospective cohort study involving 215 Verisyse pIOL implantations and 17 explantations was conducted. The Verisyse pIOL was disenclaved and removed through a superior scleral tunnel incision. Cataract extraction with phacoemulsification was then performed through a temporal clear corneal incision. Results: An occurrence rate of 7.9% of eyes with cataract formation was found. Both uncorrected (UDVA) and corrected visual acuity (CDVA) three months after cataract surgery were significantly improved (0.24 ± 0.30 vs. 0.73 ± 0.48; p < 0.001 and 0.10 ± 0.14 vs. 0.30 ± 0.31; p = 0.004, respectively). The UDVA was 20/20 or better in 41% of eyes and 20/40 or better in 65% of eyes. The CDVA was 20/20 or better in 53% of eyes and 20/40 or better in 88% of eyes. The safety and efficacy indices were 1.96 ± 1.68 and 1.60 ± 1.36, respectively. Conclusions: Various complications including cataracts may develop in these patients. Verisyse pIOLs have a lower incidence of cataract formation and are more likely to lead to age-related cataracts rather than the anterior subcapsular cataracts commonly seen in implantable collamer lens (ICL) patients. Patients with a prior history of Verisyse pIOL can expect to have a good visual prognosis after cataract extraction.

Eye-Related Factors That Can Be Associated With the Plane of Phacoemulsification.

PURPOSE: To evaluate the effect of eye-related factors such as biometric and surgical parameters, nuclear sclerosis (NS) grade, and pupil and capsulorhexis diameters on the plane of phacoemulsification (PP). MATERIAL AND METHODS: This prospective study included 328 eyes of 328 patients who underwent phacoemulsification surgery. The phaco-chop technique was performed in all patients and changes in PP that occurred during surgery were recorded. Patients were grouped as follows: Group 1, > 75% of lens nucleus emulsified in the capsular bag; Group 2, > 75% of lens nucleus emulsified at the pupillary plane; and Group 3, > 50% of lens nucleus emulsified in the anterior chamber. The association between PP and eye-related factors was evaluated. RESULTS: There were 153 patients (46.7 %) in Group 1, 104 patients (31.7 %) in Group 2 and 71 patients (21.6 %) in Group 3. The factors associated with PP were anterior chamber depth (ACD) (p = 0.020) and NS grade (p = 0.028). No significant relationship was detected between PP and age, surgical parameters or other biometric values. Moreover, PP was found to be more anterior in patients with soft cataracts and deeper ACD values (p values were 0.002 and 0.036, respectively). CONCLUSION: The present study has reported that PP may move to more anterior, as softer cataracts may increase the fear of posterior capsule rent. Moreover, PP may move to more posterior due to shallow anterior chambers or high-grade cataracts that could potentially increase the fear of endothelial injury.

Comparing retinal sensitivities on blue-on-yellow and green-on-yellow perimetry in glaucoma suspects.

Purpose: To compare the retinal sensitivities between the blue-on-yellow perimetry (BYP)/short-wavelength automated perimetry (SWAP) and green-on-yellow perimetry (GYP) among patients with and without nuclear sclerosis among glaucoma suspects. Methods: After ophthalmic examination, patients were subjected to two perimetric tests: BYP and GYP. The visual field (VF) parameters were compared between the two perimeters (p < 0.05 was considered significant). Results: Fifty-five eyes of 39 patients with a mean age of 60.53 ± 9.70 years were included in the study. Twenty-one eyes had clear lens or pseudophakia. Twenty-six eyes had lower grades of nuclear sclerosis (NO2NC2, NO3NC3) and eight eyes had higher grades of cataract (NO4NC4, NO5NC5). The mean retinal sensitivity (RS) in BYP was 22.08 ± 5.02 (dB) and in GYP was 23.84 ± 5.50 (dB) (p = 0.08). The mean defect in BYP was -2.56 ± 4.40 (dB) and in GYP was -3.24 ± 5.05 (dB), pattern standard deviation (PSD) in BYP was 3.65 ± 1.91 (dB) and in GYP was 3.83 ± 1.99 (dB), and foveal threshold (FT) was 24.20 ± 4.32 (dB) in BYP and 28.10 ± 4.50 (dB) in GYP. The two perimeters showed good agreement by the Bland-Altman plot for all parameters. Fourteen eyes showed perimetric changes suggestive of glaucoma by BYP. In these, GYP had a sensitivity of 92.86% (95% CI of 66.13% to 99.82%) and specificity of 95.12% (95% CI of 83.47% to 99.40%). Conclusion: BYP and GYP show good agreement. They are comparable in clear media as well as in different grades of nuclear sclerosis. GYP showed good sensitivity and specificity compared to BYP.

A Modified Customized Rigid Gas Permeable Contact Lens to Improve Visualization During Phacoemulsification in Ectatic Corneas.

Advanced Keratoconus and ectatic corneal diseases may lead to corneal thinning and irregular astigmatism. The optical distortion caused by these pathologies may result in poor visibility for the surgeon during phacoemulsification. Thus, the risk of complication would be increased intraoperatively (capsular rupture, vitreous loss). The aim of this case series was to use a modified customized Rigid Gas Permeable (RGP) contact lens to improve visualization during all the stages of phacoemulsification in irregular corneas and to avoid open sky technique for cataract removal during penetrating keratoplasty (PK). A customized, 12 mm, RGP contact lens was designed and manufactured. Two peripheral notches were customized to fit the hand position of the surgeon (at 11 O'clock and 2 Clock in this case series) to allow clear corneal incisions. Six eyes of 6 patients were included (3 eyes with advanced keratoconus and a severely optically distorted, yet clear corneas, planned for PK on the same day; 2 eyes were status post-intracorneal ring segment implantation for stage 4 keratoconus and 1 eye had combined phacoemulsification with superficial keratectomy to remove paracentral corneal Salzmann's nodule). Lens opacities ranged from +2 to +4 nuclear sclerosis in all eyes. Good visualization of the anterior lens and capsule attained with the RGP contact lens fitting. Improved visualization was reported during all the steps (Capsulorhexis, Irrigation/Aspiration, Phaco. Intraocular lens implantation). The phacoemulsification was smooth and non-complicated in a total of 6 eyes of 6 patients. In these cases, without RGP fitting, the operation was not technically possible. The customized notches allowed any insertion of surgical instruments, and with the help of viscoelastic maintained a good stability of the contact lens during the operation. We concluded that customized method RGP contact lens, may help reducing complications during phacoemulsification in advanced corneal ectasia and perhaps in irregular corneas as well.

Exome Array Analysis of Nuclear Lens Opacity.

PURPOSE: Nuclear cataract is the most common subtype of age-related cataract, the leading cause of blindness worldwide. It results from advanced nuclear sclerosis, or opacity in the center of the optic lens, and is affected by both genetic and environmental risk factors, including smoking. We sought to understand the genetic factors associated with nuclear sclerosis through interrogation of rare and low frequency coding variants using exome array data. METHODS: We analyzed Illumina Human Exome Array data for 1,488 participants of European ancestry in the Beaver Dam Eye Study who were without cataract surgery for association with nuclear sclerosis grade, controlling for age and sex. We performed single-variant regression analysis for 32,138 variants with minor allele frequency (MAF) ≥0.003. In addition, gene-based analysis of 11,844 genes containing at least two variants with MAF < 0.05 was performed using a gene-based unified burden and non-burden sequence kernel association test (SKAT-O). Additionally, both single-variant and gene-based analyses were analyzed stratified by smoking status. RESULTS: No single-variant test was statistically significant after Bonferroni correction (p < 1.6 × 10-6; top single nucleotide polymorphism (SNP): rs144458991, p = 2.83 × 10-5). Gene-based tests were suggestively associated with the gene RNF149 overall (p = 8.29 × 10-6) and among never smokers (N = 790, p = 2.67 × 10-6). CONCLUSIONS: This study did not find a significant genetic association with nuclear sclerosis, the possible association with the RNF149 gene highlights a potential candidate gene for future studies that aim to understand the genetic architecture of nuclear sclerosis.

Photoperiodic regime influences onset of lens opacities in a non-human primate.

BACKGROUND: Opacities of the lens are typical age-related phenomena which have a high influence on photoreception and consequently circadian rhythm. In mouse lemurs, a small bodied non-human primate, a high incidence (more than 50% when >seven years) of cataracts has been previously described during aging. Previous studies showed that photoperiodically induced accelerated annual rhythms alter some of mouse lemurs' life history traits. Whether a modification of photoperiod also affects the onset of age dependent lens opacities has not been investigated so far. The aim of this study was therefore to characterise the type of opacity and the mouse lemurs' age at its onset in two colonies with different photoperiodic regimen. METHODS: Two of the largest mouse lemur colonies in Europe were investigated: Colony 1 having a natural annual photoperiodic regime and Colony 2 with an induced accelerated annual cycle. A slit-lamp was used to determine opacities in the lens. Furthermore, a subset of all animals which showed no opacities in the lens nucleus in the first examination but developed first changes in the following examination were further examined to estimate the age at onset of opacities. In total, 387 animals were examined and 57 represented the subset for age at onset estimation. RESULTS: The first and most commonly observable opacity in the lens was nuclear sclerosis. Mouse lemurs from Colony 1 showed a delayed onset of nuclear sclerosis compared to mouse lemurs from Colony 2 (4.35 ± 1.50 years vs. 2.75 ± 0.99 years). For colony 1, the chronological age was equivalent to the number of seasonal cycles experienced by the mouse lemurs. For colony 2, in which seasonal cycles were accelerated by a factor of 1.5, mouse lemurs had experienced 4.13 ± 1.50 seasonal cycles in 2.75 ± 0.99 chronological years. DISCUSSION: Our study showed clear differences in age at the onset of nuclear sclerosis formation between lemurs kept under different photoperiodic regimes. Instead of measuring the chronological age, the number of seasonal cycles (N = four) experienced by a mouse lemur can be used to estimate the risk of beginning nuclear sclerosis formation. Ophthalmological examinations should be taken into account when animals older than 5-6 seasonal cycles are used for experiments in which unrestricted visual ability has to be ensured. This study is the first to assess and demonstrate the influence of annual photoperiod regime on the incidence of lens opacities in a non-human primate.

Myopic refractive shift represents dense nuclear sclerosis and thin lens in lenticular myopia.

BACKGROUND: It is not rare to meet unilateral nuclear sclerotic cataracts with myopic refractive changes (lenticular myopia) compared with the fellow eye in the ophthalmic examination of patients with decreased visual acuity. To determine the relationship between the myopic refractive changes and interocular differences of parameters, we investigated the interocular differences of ocular parameters between a lenticular myopic eye and the fellow eye. METHOD: This retrospective study included 68 eyes of 34 patients, who showed unilateral lenticular myopia. We compared the dimensions of ocular component, such as anterior chamber depth, anterior chamber volume, lens thickness, vitreous chamber depth, lens position, lens density of nuclear sclerosis, anterior lens curvature and myopic refractive changes (spherical equivalent refraction) between the lenticular myopic eye and the myopic refractive change were examined. RESULTS: Statistically significant differences were found between the lenticular myopic eye and the fellow eye for anterior chamber depth (p = 0.015) anterior chamber volume (p = 0.031), lens thickness (p < 0.001), lens density of the nuclear sclerosis (p < 0.001) and the spherical equivalent myopic refractive changes (p < 0.001). Based on univariate analysis, the interocular difference in spherical equivalent refraction was significantly correlated with interocular differences of the density of the nuclear sclerosis (r = 0.79, p < 0.001), lens thickness (r = -0.70, p < 0.001) and vitreous chamber depth (r = 0.43, p = 0.012). Based on multiple regression analysis, the interocular difference in spherical equivalent refraction was significantly correlated with interocular differences of density of nuclear sclerosis (p < 0.001) and lens thickness (p = 0.007). CONCLUSION: The difference in myopic spherical change reflects the differences in the severity of nuclear sclerosis and lens thickness between the lenticular myopic eye and the fellow eye.