Assessment of cataracts from photographs in the Beaver Dam Eye Study

Intraoperative quantitative crystalline lens nuclear opacities analysis based on crystalline lenSx platform

PURPOSE

The main objective is to quantify the lens nuclear opacity using spectral-domain optical coherence tomography (SD-OCT) and to evaluate its association with Lens Opacities Classification System III (LOCS-III) system, lens thickness (LT), and surgical parameters. The secondary objective is to assess the diagnostic model performance for hard nuclear cataract.

METHODS

This study included 70 eyes of 57 adults with cataract, with 49 (70%) and 21 (30%) in training and validation cohort, respectively. Correlations of the average nuclear density (AND) /maximum nuclear density (MND) with LOCS-III scores, LT, and surgical parameters were analyzed. Univariate and multivariate logistic regression analysis, receiver operating characteristic curves and calibration curves were performed for the diagnostic of hard nuclear cataract.

RESULTS

The pre-operative uncorrected distance visual acuity (UDVA), intraocular pressure (IOP), mean axial length (AL), and LT were 1.20 ± 0.47 log MAR, 15.50 ± 2.87 mmHg, 27.34 ± 3.77 mm and 4.32 ± 0.45 mm, respectively. The average nuclear opalescence (NO) and nuclear colour (NC) scores were 3.61 ± 0.94 and 3.50 ± 0.91 (ranging from 1.00 to 6.90), respectively. The average AND and MND were 137.94 ± 17.01 and 230.01 ± 8.91, respectively. NC and NO scores both significantly correlated with the AND (rNC = 0.733, p = 0.000; rNO = 0.755, p = 0.000) and MND (rNC = 0.643, p = 0.000; rNO = 0.634, p = 0.000). In the training cohort, the area under the curve (AUC) of the model was 0.769 (P < 0.001, 95%CI 0.620-0.919), which had a good degree of differentiation (Fig. 2a). The calibration curve showed good agreement between predicted and actual probability.

CONCLUSION

The nuclear density measurement on SD-OCT images can serve as an objective and reliable indicator for quantifying nuclear density.

Association of Central Retinal Arteriolar and Venular Equivalents with Brain-aging and Macular Ganglion Cell-inner Plexiform Layer Thickness

INTRODUCTION

Neurodegeneration and cognitive decline in aging are growing public health concerns. This study investigates associations between central retinal arteriolar and venular equivalents (CRAE, CRVE) and brain-aging, a sensory and cognitive test composite measure, and macular ganglion cell-inner plexiform layer (mGCIPL) thickness, a biomarker of neurodegeneration.

METHODS

Beaver Dam Offspring Study (BOSS) participants are adult children (baseline (2005-2008) age 21-84 years) of the population-based Epidemiology of Hearing Loss Study participants. Follow-up occurred every 5 years. In 2010-2013, fundus photographs were used to measure retinal vessels. A brain-aging score was constructed by principal component analysis using sensorineural and cognitive data. Associations between incident brain-aging and vessel measures were investigated using logistic regression. Associations between CRAE and CRVE and mGCIPL thickness, measured in 2015-2017, were also investigated.

RESULTS

Participants (N = 2381; mean age: 53.9 years (SD = 9.8); 54% women) had a mean CRAE and CRVE of 148.8 µm (SD = 14.5) and 221.7 µm (SD = 20.7), respectively. Among those without ocular conditions, wider CRAE was associated with decreased 5-year brain-aging risk (33% per SD CRAE increase). Both vessel measures were independently associated with mGCIPL thickness. The mGCIPL thickness increased by approximately 1.7 µm and 2.0 µm per SD increase in CRAE and CRVE, respectively.

DISCUSSION

The association of CRAE with incident brain-aging indicates its potential use as a screening tool among those without eye disease. The associations between CRAE and CRVE and mGCIPL thickness indicate narrower vasculature could affect neuronal health. These associations point to potential usefulness of retinal vessel measurements to identify people at higher risk of sensorineural declines and neurodegeneration.

Postoperative Complications in the Primary Tube Versus Trabeculectomy Study During 5 Years of Follow-up

PURPOSE

To describe postoperative complications encountered in the Primary Tube Versus Trabeculectomy (PTVT) Study during 5 years of follow-up.

DESIGN

Multicenter randomized clinical trial.

PARTICIPANTS

A total of 242 eyes of 242 patients with medically uncontrolled glaucoma and no previous incisional ocular surgery, including 125 patients in the tube group and 117 patients in the trabeculectomy group.

METHODS

Patients were enrolled at 16 clinical centers and randomly assigned to treatment with a tube shunt (350-mm2 Baerveldt glaucoma implant) or trabeculectomy with mitomycin C (MMC, 0.4 mg/ml for 2 minutes).

MAIN OUTCOME MEASURES

Surgical complications, reoperations for complications, visual acuity, and cataract progression.

RESULTS

Early postoperative complications occurred in 24 patients (19%) in the tube group and 40 patients (34%) in the trabeculectomy group (P = 0.013). Late postoperative complications developed in 27 patients (22%) in the tube group and 32 patients (27%) in the trabeculectomy group (P = 0.37). Serious complications producing vision loss and/or requiring a reoperation were observed in 3 patients (2%) in the tube group and 9 patients (8%) in the trabeculectomy group (P = 0.11). Cataract progression was seen in 65 patients (52%) in the tube group and 52 patients (44%) in the trabeculectomy group (P = 0.30). Surgical complications were not associated with a higher rate of treatment failure (P = 0.61), vision loss (P = 1.00), or cataract progression (P = 0.77) CONCLUSIONS: A large number of surgical complications were observed in the PTVT Study, but most were transient and self-limited. The incidence of early postoperative complications was higher following trabeculectomy with MMC than with tube shunt surgery. The rates of late postoperative complications, serious complications, and cataract progression were similar with both surgical procedures after 5 years of follow-up. Surgical complications did not increase the risk of treatment failure, vision loss, or cataract progression.

Pseudophakia and Lens Opacities in 70-Year-Olds in Gothenburg, Sweden; Gender Differences, Impact on Self-Reported Visual Function and Validation of Self-Reported Cataract and Pseudophakia

Purpose

The study aimed at determining the prevalence and sex differences in cataract, pseudophakia, lens opacities and self-reported cataract in 70-year-old people in Gothenburg, Sweden. The purpose was also to identify correlations between lens opacities, visual acuity and subjective visual function, and to validate self-reported cataract and cataract surgery.

Patients and Methods

Population-based cross-sectional study where participants (n=1182) answered questions about self-reported diagnosis of cataract and cataract surgery. A total of 1139 subjects completed the National Eye Institute Visual Functioning Questionnaire-25 (NEI VFQ-25), 560 subjects underwent ophthalmic examination including visual acuity and lens photography. t-test, Pearson chi-square and Mann-Whitney U-test were used for obtaining p-values. ANOVA (analysis of variances, Kruskal-Wallis, one-way) was used to compare VFQ-25 between 3 groups; no cataract, cataract and pseudophakia. To clarify the differences between specific pairs of groups post-hoc test (Bonferroni) was used after ANOVA.

Results

Self-reported cataract was more common in women than in men (27.2% vs 19.1%, p=0.001, chi-square). Cataract surgery was reported by 16.3% of women and 12.6% of men (p=0.072). Upon eye examination, the prevalence of pseudophakia was 16.9% in women compared to 10.2% in men (p=0.020). The prevalence of cataract, including pseudophakia, was 31.9% in women versus 23.8% in men (p=0.033). Significant correlations (Spearman's rho) were found between lens opacities and visual acuity. Self-reported cataract surgery showed a very high specificity and high sensitivity. The composite score from NEI VFQ-25 was lower in people with pseudophakia than in people with/without cataract (p=0.012, Kruskal-Wallis).

Conclusion

The prevalence of cataract including pseudophakia in 70-year-olds in Gothenburg is higher compared to previous studies in similar geographical areas. Also, it is more common in women than in men. The lack of significant sex differences in lens opacities may be due to cataract surgery at an earlier stage. Validation showed very good agreement between pseudophakia and self-reported cataract surgery.

Detecting visually significant cataract using retinal photograph-based deep learning

Age-related cataracts are the leading cause of visual impairment among older adults. Many significant cases remain undiagnosed or neglected in communities, due to limited availability or accessibility to cataract screening. In the present study, we report the development and validation of a retinal photograph-based, deep-learning algorithm for automated detection of visually significant cataracts, using more than 25,000 images from population-based studies. In the internal test set, the area under the receiver operating characteristic curve (AUROC) was 96.6%. External testing performed across three studies showed AUROCs of 91.6-96.5%. In a separate test set of 186 eyes, we further compared the algorithm's performance with 4 ophthalmologists' evaluations. The algorithm performed comparably, if not being slightly more superior (sensitivity of 93.3% versus 51.7-96.6% by ophthalmologists and specificity of 99.0% versus 90.7-97.9% by ophthalmologists). Our findings show the potential of a retinal photograph-based screening tool for visually significant cataracts among older adults, providing more appropriate referrals to tertiary eye centers.

Deep Learning Automated Diagnosis and Quantitative Classification of Cataract Type and Severity

PURPOSE

To develop and evaluate deep learning models to perform automated diagnosis and quantitative classification of age-related cataract, including all three anatomical types, from anterior segment photographs.

DESIGN

Application of deep learning models to Age-Related Eye Disease Study (AREDS) dataset.

PARTICIPANTS

18,999 photographs (6,333 triplets) from longitudinal follow-up of 1,137 eyes (576 AREDS participants).

METHODS

Deep learning models were trained to detect and quantify nuclear cataract (NS; scale 0.9-7.1) from 45-degree slit-lamp photographs and cortical (CLO; scale 0-100%) and posterior subcapsular (PSC; scale 0-100%) cataract from retroillumination photographs. Model performance was compared with that of 14 ophthalmologists and 24 medical students. The ground truth labels were from reading center grading.

MAIN OUTCOME MEASURES

Mean squared error (MSE).

RESULTS

On the full test set, mean MSE values for the deep learning models were: 0.23 (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 the models was 0.23 (SD 0.02), compared to 0.98 (SD 0.23; p=0.000001) for the ophthalmologists, and 1.24 (SD 0.33; p=0.000005) for the medical students. For CLO, mean MSE values were 53.5 (SD 14.8), compared to 134.9 (SD 89.9; p=0.003) and 422.0 (SD 944.4; p=0.0007), respectively. For PSC, mean MSE values were 171.9 (SD 38.9), compared to 176.8 (SD 98.0; p=0.67) and 395.2 (SD 632.5; p=0.18), respectively. In external validation on the Singapore Malay Eye Study (sampled to reflect the distribution of cataract severity in AREDS), MSE was 1.27 for NS and 25.5 for PSC.

CONCLUSIONS

A deep learning framework was able to perform automated and quantitative classification of cataract severity for all three types of age-related cataract. For the two most common types (NS and CLO), the accuracy was significantly superior to that of ophthalmologists; for the least common type (PSC), the accuracy was similar. The framework 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 publicly available at https://XXX.

Assessing the correlation between swept-source optical coherence tomography lens density pattern analysis and best-corrected visual acuity in patients with cataracts

Objective

To assess linear correlation between swept-source optical coherence tomography (SS-OCT) lens density variation and patients’ best-corrected visual acuity (BCVA).

Methods and analysis

Linear densitometry was performed on horizontal lens images from 518 eyes, obtained using SS-OCT. All densities from the anterior to the posterior side of the cataract were exported for detailed analysis. The algorithm used a classical random forest regression machine learning approach with fourfold cross-validation, meaning four batches of data from 75% of the eyes with known preoperative best-corrected visual acuity (poBCVA) were used for training a model to predict the data from the remaining 25% of the eyes. The main judgement criterion was the ability of the algorithm to identify linear correlation between measured and predicted BCVA.

Results

A significant linear correlation between poBCVA and the algorithm’s prediction was found, with Pearson correlation coefficient (R)=0.558 (95% CI: 0.496 to 0.615, p<0.001). Mean BCVA prediction error was 0.0965±0.059 logarithm of the minimal angle of resolution (logMAR), with 312 eyes (58%) having a BCVA prediction correct to ±0.1 logMAR. The best algorithm performances were achieved for 0.20 logMAR, with 79%±0.1 logMAR correct prediction. Mean, anterior cortex, nucleus and posterior cortex pixel density were all not correlated with patient BCVA.

Conclusion

Pixel density variations based on axial lens images provided by SS-OCT biometer provide reasonably accurate information for machine learning analysis to estimate patient BCVA in all types of cataracts. This study demonstrates significant linear correlation between patients’ poBCVA and the algorithmic prediction, with acceptable mean prediction error.

Visual field defects and myopic macular degeneration in Singapore adults with high myopia

AIMS

To characterise the association between visual field (VF) defects and myopic macular degeneration (MMD) in highly myopic adults without glaucoma.

METHODS

Participants (n=106; 181 eyes) with high myopia (HM; spherical equivalent ≤-5.0 D or axial length (AL) ≥26 mm), after excluding glaucoma and glaucoma suspects, from the Singapore Epidemiology of Eye Diseases-HM study were included in this cross-sectional study. Humphrey VF (central 24-2 threshold), cup-disc ratio (CDR) and intraocular pressure (IOP) measurements were performed. Mean deviation (MD) and pattern SD (PSD), VF defects (normal or abnormal; p<0.05 in ≥3 non-edge contiguous locations) and pattern (eg, generalised sensitivity loss) were analysed. MMD presence was diagnosed from fundus photographs. Generalised estimating equations were used for analysing factors (MD, PSD, VF defects, CDR and IOP) associated with MMD.

RESULTS

Mean age was 55.4±9.9 years and 51.9% were women (AL=26.7±1.1 mm). MMD eyes had lower MD (-3.8±2.9 dB vs -1.1±1.4 dB) and higher PSD (2.8±1.7 dB vs 1.7±0.6 dB). A higher percentage of MMD eyes (n=48) had abnormal VF (62.5% vs 28.6%; p<0.001) compared with no MMD (n=133 eyes). VF pattern in MMD eyes was significantly different from eyes without MMD (p=0.001) with greater generalised sensitivity loss (53.3% vs 10.5%) and arcuate defects (16.7% vs 10.5%). In multivariate analyses, MD (OR=1.52) and PSD (OR=1.67) were significantly (p=0.003) associated with MMD, but VF defects were not associated with MMD.

CONCLUSION

Highly myopic adults with MMD may have VF loss when compared with highly myopic patients without MMD even in adults without glaucoma.

Automatic classification of heterogeneous slit-illumination images using an ensemble of cost-sensitive convolutional neural networks

Background

Lens opacity seriously affects the visual development of infants. Slit-illumination images play an irreplaceable role in lens opacity detection; however, these images exhibited varied phenotypes with severe heterogeneity and complexity, particularly among pediatric cataracts. Therefore, it is urgently needed to explore an effective computer-aided method to automatically diagnose heterogeneous lens opacity and to provide appropriate treatment recommendations in a timely manner.

Methods

We integrated three different deep learning networks and a cost-sensitive method into an ensemble learning architecture, and then proposed an effective model called CCNN-Ensemble [ensemble of cost-sensitive convolutional neural networks (CNNs)] for automatic lens opacity detection. A total of 470 slit-illumination images of pediatric cataracts were used for training and comparison between the CCNN-Ensemble model and conventional methods. Finally, we used two external datasets (132 independent test images and 79 Internet-based images) to further evaluate the model's generalizability and effectiveness.

Results

Experimental results and comparative analyses demonstrated that the proposed method was superior to conventional approaches and provided clinically meaningful performance in terms of three grading indices of lens opacity: area (specificity and sensitivity; 92.00% and 92.31%), density (93.85% and 91.43%) and opacity location (95.25% and 89.29%). Furthermore, the comparable performance on the independent testing dataset and the internet-based images verified the effectiveness and generalizability of the model. Finally, we developed and implemented a website-based automatic diagnosis software for pediatric cataract grading diagnosis in ophthalmology clinics.

Conclusions

The CCNN-Ensemble method demonstrates higher specificity and sensitivity than conventional methods on multi-source datasets. This study provides a practical strategy for heterogeneous lens opacity diagnosis and has the potential to be applied to the analysis of other medical images.

Factors Associated with the Macular Ganglion Cell-Inner Plexiform Layer Thickness in a Cohort of Middle-aged U.S. Adults

SIGNIFICANCE

The macular ganglion cell-inner plexiform layer (mGCIPL) may serve as a quick and easily obtained measure of generalized neurodegeneration. Investigating factors associated with this thickness could help to understand neurodegenerative processes.

PURPOSE

This study aimed to characterize and identify associated factors of the mGCIPL thickness in a Beaver Dam Offspring Study cohort of middle-aged U.S. adults.

METHODS

Baseline examinations occurred from 2005 to 2008, with follow-up examinations every 5 years. Included participants had baseline data and measured mGCIPL at 10-year follow-up (N = 1848). The mGCIPL was measured using the Cirrus 5000 HD-OCT Macular Cube Scan. Associations between mean mGCIPL thickness and thin mGCIPL, defined as 1 standard deviation (SD) below the population mean, and baseline risk factors were investigated using generalized estimating equations.

RESULTS

Participants (mean [SD] baseline age, 48.9 [9.3] years; 54.4% women) had mean (SD) mGCIPL thicknesses of 78.4 (8.1) μm in the right eye and 78.1 (8.5) μm in the left (correlation coefficient = 0.76). In multivariable models, age (-1.07 μm per 5 years; 95% confidence interval [CI], -1.28 to -0.86 μm), high alcohol consumption (-1.44 μm; 95% CI, -2.72 to -0.16 μm), higher interleukin 6 levels (50% increase in level: -0.23 μm; 95% CI, -0.45 to 0.00 μm), myopia (-2.55 μm; 95% CI, -3.17 to -1.94 μm), and glaucoma (-1.74 μm; 95% CI, -2.77 to -0.70 μm) were associated with thinner mGCIPL. Age (per 5 years: odds ratio [OR], 1.38; 95% CI, 1.24 to 1.53), diabetes (OR, 1.89, 95% CI, 1.09 to 3.27), myopia (OR, 2.11; 95% CI, 1.63 to 2.73), and increasing and long-term high C-reactive protein (ORs, 1.46 [95% CI, 1.01 to 2.11] and 1.74 [95% CI, 1.14 to 2.65], respectively) were associated with increased odds of thin mGCIPL.

CONCLUSIONS

Factors associated cross-sectionally with mGCIPL thickness, older age, high alcohol consumption, inflammation, diabetes, myopia, and glaucoma may be important to neural retina structure and health and neuronal health system-wide.

FACTORS ASSOCIATED WITH PREVALENT LENS OPACITIES IN CHINESE AMERICAN ADULTS: THE CHINESE AMERICAN EYE STUDY

PURPOSE

To identify risk factors associated with lens opacities in Chinese Americans.

METHODS

A cross-sectional population-based study of 4,582 Chinese Americans ≥50 years residing in Monterey Park, California. Participants completed a comprehensive clinical examination with lens assessment using the Lens Opacities Classification System II, with lens opacities defined by a grade ≥2 in either eye. Participants were considered to have nuclear-only, cortical-only, or posterior subcapsular (PSC)-only if that was the only type of opacity present in both eyes.

RESULTS

Cortical-only opacity was associated with older age, diabetes mellitus (OR 1.5, 95%CI 1.1-2.1), and family history of cataracts (OR 1.5, 95%CI 1.2-1.9). Nuclear-only opacity was associated with older age, diabetes mellitus (OR 1.4, 95%CI 1.1-1.9), greater waist-to-hip ratio (OR 1.2, 95%CI 1.1-1.4), and high-density lipoprotein (OR 1.1, 95%CI 1.02-1.2). Mixed-type opacities were associated with older age, greater waist-to-hip ratio (OR 1.3, 95%CI 1.1-1.6), and higher HbA1 c (OR 1.3, 95%CI 1.1-1.4). Taller height (OR 0.7, 95%CI 0.6-0.8), greater weight (OR 0.98, 95%CI 0.97-0.99), and higher diastolic pressure (OR 0.98, 95%CI 0.96-0.99) were protective.

CONCLUSION

CHES identified a strong, dose-response association between age and all types of prevalent lens opacities, which suggests an increasing cataract burden in Chinese Americans based on aging populations. CHES results demonstrate general consistency with previous population-based studies in regard to more sedentary lifestyle exposures (e.g., Westernized lifestyle) and prevalent cortical-only, nuclear-only, and mixed-type opacities, yet also identified further sedentary lifestyle exposures associated with prevalent lens opacities. Improved glycemic control and a more active lifestyle that minimizes factors contributing to metabolic syndrome may help reduce the burden of vision loss associated with lens opacities.

Machine learning to determine relative contribution of modifiable and non-modifiable risk factors of major eye diseases

AIMS

To use machine learning (ML) to determine the relative contributions of modifiable and non-modifiable clinical, metabolic, genetic, lifestyle and socioeconomic factors on the risk of major eye diseases.

METHODS

We conducted analyses in a cross-sectional multi-ethnic population-based study (n=10 033 participants) and determined a range of modifiable and non-modifiable risk factors of common eye diseases, including diabetic retinopathy (DR), non-diabetic-related retinopathy (NDR); early and late age-related macular degeneration (AMD); nuclear, cortical and posterior subcapsular (PSC) cataract; and primary open-angle (POAG) and primary angle-closure glaucoma (PACG). Risk factors included individual characteristics, metabolic profiles, genetic background, lifestyle patterns and socioeconomic status (n~100 risk factors). We used gradient boosting machine to estimate the relative influence (RI) of each risk factor.

RESULTS

Among the range of risk factors studied, the highest contributions were duration of diabetes for DR (RI=22.1%), and alcohol consumption for NDR (RI=6.4%). For early and late AMD, genetic background (RI~20%) and age (RI~15%) contributed the most. Axial length was the main risk factor of PSC (RI=30.8%). For PACG, socioeconomic factor (mainly educational level) had the highest influence (20%). POAG was the disease with the highest contribution of modifiable risk factors (cumulative RI~35%), followed by PACG (cumulative RI ~30%), retinopathy (cumulative RI between 20% and 30%) and late AMD (cumulative RI ~20%).

CONCLUSION

This study illustrates the utility of ML in identifying factors with the highest contributions. Risk factors possibly amenable to interventions were intraocular pressure (IOP) and Body Mass Index (BMI) for glaucoma, alcohol consumption for NDR and levels of HbA1c for DR.

Prevalence and risk factors for age-related cataract in Sweden

BACKGROUND

Cataract is a major cause of visual impairment worldwide. There is a paucity of prevalence studies from Sweden. Therefore, we report the prevalence of cataract and its risk factors in a population-based study of older adults in Sweden.

METHODS

The Tierp Glaucoma Survey was conducted in the municipality of Tierp, Sweden, including 760 subjects aged 65-74 years. The presence of cataract was determined based on retroillumination, with lens opacities evident on slit-lamp examination. To assess risk factors for cataract, odds ratios (ORs) were calculated, adjusted for age and gender.

RESULTS

A total of 234 individuals were found to have cataract, 12 of whom had undergone cataract surgery. The prevalence adjusted for nonparticipation was 31.5% (95% confidence interval [CI] 29.4-33.6), 35.2% (95% CI 28.7-41.8) in females and 26.2% (95% CI 19.8-32.6) in males. Cataract was associated with age ≥70 years (OR 1.93; 95% CI 1.41-2.64), female gender (OR 1.54; 95% CI 1.12-2.11), and myopia (OR 2.3; 95% CI 1.16-3.56), while pseudoexfoliation, smoking, diabetes, hypertension, and ischaemic heart disease were not.

CONCLUSION

Nearly one-third of the sample were estimated to have lens opacities, or had undergone cataract surgery, making cataract a frequent disorder of older age. The study provided further evidence that increasing age, female gender, and myopia are associated with cataract.

Six-Year Changes in Myopic Macular Degeneration in Adults of the Singapore Epidemiology of Eye Diseases Study

Purpose

To examine the 6-year incidence, progression, associated risk factors, and impact of myopic macular degeneration (MMD) in a myopic population in Singapore.

Methods

We examined myopic (spherical equivalent ≤-0.5 diopters) adults (N = 2157 persons and 3661 eyes) who were phakic at baseline and participated in both baseline and 6-year follow-up visits of the Singapore Epidemiology of Eye Diseases study. Eye examinations, including visual acuity, subjective refraction and axial length (AL) measurements, were performed. MMD was graded from fundus photographs following the META-PM classification. Vision-related quality of life was assessed with Rasch-transformed scores from reading, mobility, and emotional domains of the Impact of Vision Impairment questionnaire.

Results

The 6-year eye-specific incidence of MMD among myopic eyes was 1.2% (95% CI, 0.9%-1.6%). Older age, worse spherical equivalent, and longer AL at baseline were associated with MMD incidence (all P < 0.001). The 6-year eye-specific progression of MMD in 288 eyes with baseline MMD was 17.0% (95% CI, 12.6%-21.4%). More severe MMD at baseline, worse spherical equivalent, and longer AL (all P < 0.05) were associated with MMD progression. Patients with Meta-PM categories 3 and 4 had worse best-corrected visual acuity and poorer vision-related quality of life outcomes than those without MMD (all P < 0.05).

Conclusions

Over a 6-year period, one in 80 myopic eyes developed MMD and one in six with existing MMD had MMD progression. Myopia severity and AL were strong predictors of MMD development and progression. Eyes with severe MMD were at higher risk of MMD progression than those with less severe MMD, and were associated with poorer visual acuity and vision-related quality of life.

Wholegrain and legume consumption and the 5-year incidence of age-related cataract in the Blue Mountains Eye Study

The present study aims to investigate the effect of wholegrain and legume consumption on the incidence of age-related cataract in an older Australian population-based cohort. The Blue Mountains Eye Study (BMES) is a population-based cohort study of eye diseases among older adults aged 49 years or older (1992-1994, n 3654). Of 2334 participants of the second examination of the BMES (BMES 2, 1997-2000), 1541 (78·3 % of survivors) were examined 5 years later (BMES 3) who had wholegrain and legume consumption estimated from the FFQ at BMES 2. Cataract was assessed using photographs taken during examinations following the Wisconsin cataract grading system. Multivariable-adjusted logistic regression models were used to assess associations with the 5-year incidence of cataract from BMES 2 (baseline) to BMES 3. The 5-year incidence of cortical, nuclear and posterior subcapsular (PSC) cataract was 18·2, 16·5 and 5·9 %, respectively. After adjustment for age, sex and other factors, total wholegrain consumption at baseline was not associated with incidence of any type of cataract. High consumption of legumes showed a protective association for incident PSC cataract (5th quintile: adjusted OR 0·37; 95 % CI 0·15, 0·92). There was no significant trend of this association across quintiles (P = 0·08). In this older Australian population, we found no associations between wholegrain intake at baseline and the 5-year incidence of three cataract types. However, intake of legumes in the highest quintile, compared with the lowest quintile, may protect against PSC formation, a finding needing replication in other studies.

Evaluation of Nuclear Cataract with Smartphone-Attachable Slit-Lamp Device

Background: Visual impairments and age-related eye diseases need to be detected and treated in a timely manner. However, this is often hampered by lack of appropriate medical equipment. We have invented a portable, recordable, and smartphone-attachable slit-lamp device, called the Smart Eye Camera (SEC). The aim of this study was to compare evaluating nuclear cataract (NUC) between the SEC and the conventional, non-portable slit-lamp microscope. Methods: A total of 128 eyes of 64 Japanese patients (mean age: 73.95 ± 9.28 years; range: 51‒92 years; female: 34) were enrolled. The NUC was classified into four grades (grade 0 to 3) based on three standard photographs of nuclear opacities according to the WHO classification by ophthalmologists. An ophthalmic healthcare assistant (non-ophthalmologist) filmed the eyes in video mode by the SEC and an ophthalmologist graded the NUC. Grade correlation and inter-rater reproducibility were determined. Results: NUC grading by the two approaches correlated significantly (both eyes: r = 0.871 [95%CI: 0.821 to 0.907; p < 0.001]). Inter-rater agreement was high (weighted κ = 0.807 [95%CI: 0.798 to 0.816; p < 0.001]). Conclusions: This study suggests that the SEC is as reliable as the conventional non-portable slit-lamp microscope for evaluating NUC.

Imaging of Age-Related Macular Degeneration by Adaptive Optics Scanning Laser Ophthalmoscopy in Eyes With Aged Lenses or Intraocular Lenses

Purpose

To assess the performance of adaptive optics scanning laser ophthalmoscopy (AOSLO) in a large sample of eyes with or without age-related macular degeneration (AMD) and with cataracts or intraocular lenses (IOLs).

Methods

Patients with various degrees of AMD and age-similar normal subjects underwent fundus photography. Cataract severity and IOL clarity were assessed by fundus reflex photographs. In phakic eyes, lenticular opacity was graded as nuclear, cortical, or posterior subcapsular cataract. In eyes with IOLs, lens clarity was assessed by posterior capsule opacification (PCO). Quality of AOSLO images of the macular photoreceptor mosaic was classified as good, adequate or inadequate by human graders in a subjective assessment of cone visibility.

Results

A total of 159 eyes in 80 subjects (41 males, 39 females, aged 72.5 ± 11.5 years, 16 normals) were examined. Seventy-nine eyes had IOLs, and 80 eyes were phakic. AOSLO produced good images in 91 eyes (57%), adequate images in eight eyes (5%), and inadequate images in 27 eyes (17%). AOSLO did not acquire images in 33 eyes (21%), because of dense lenticular opacity, widespread PCO, or problems specific to individual subjects.

Conclusions

AOSLO images considered at least Adequate or better for visualizing cone photoreceptors were acquired from 62% of study eyes.

Translational Relevance

AOSLO can be used as an additional imaging modality to investigate the structure of cone photoreceptors in research on visual function in AMD and in clinical trials involving older patients.

Generational Differences in the 10-year Incidence of Impaired Contrast Sensitivity

PURPOSE

To determine if incidence of contrast sensitivity (CS) impairment differs by generation and identify factors to explain these differences.

METHODS

The Beaver Dam Eye Study (BDES) and Beaver Dam Offspring Study (BOSS) are cohort studies of aging adults in Beaver Dam, Wisconsin. Baseline examinations occurred from 1993 to 1995 (BDES) and 2005-2008 (BOSS). Follow-up examinations occurred in five-year intervals. CS testing was conducted with Pelli-Robson letter sensitivity charts; Incident impairment was a log CS score <1.55 in either eye at follow-up. Associations of incidence with generation were investigated using estimated hazard ratios (HR) with 95% confidence intervals (CI).

RESULTS

Participants (N = 3185) had a mean age of 51.9 years at baseline (standard deviation = 9.9) and 51.9% were female. Ten-year cumulative incidence of CS impairment was 40.1%, was higher among women (41.7%) than men (38.8%), and increased by age group. The risk of incident CS impairment decreased by 39% per generation. In multivariable models, the Baby Boom Generation (HR = 0.42, 95%CI = 0.31, 0.58) and Generation X (HR = 0.56, 95%CI = 0.34, 0.91) had a significantly decreased risk of CS impairment compared to the Greatest Generation. Results were similar in sensitivity analyses excluding those with cataract, age-related macular degeneration, or visual acuity impairment.

CONCLUSION

The risk of incident CS impairment decreased by birth cohort, with the greatest reduction in the Baby Boom Generation. The difference in risk suggests that there are unknown modifiable risk factors that may help to further explain the etiology of CS impairment and provide potential pathways for prevention in the future.

Ophthalmic image acquired by ophthalmologists and by allied health personnel as part of a telemedicine strategy: a comparative study of image quality

OBJECTIVES

This study evaluates the quality of ophthalmic images acquired by a nurse technician trained in teleophthalmology as compared with images acquired by an ophthalmologist, in order to provide a better understanding of the workforce necessary to operate remote care programs.

METHODS

A cross-sectional study was performed on 2044 images obtained from 118 participants of the TeleOftalmo project, in Brazil. Fundus and slit-lamp photography were performed on site by an ophthalmologist and by a nurse technician under the supervision of a remote ophthalmologist. Image quality was then evaluated by masked ophthalmologists. Proportion of suitable images in each group was compared.

RESULTS

The proportion of concordant classification regarding quality was 94.8%, with a corrected kappa agreement of 0.94. When analyzing each type of photo separately, there was no significant difference in the proportion of suitable images between on-site ophthalmologist and nurse technician with remote ophthalmologist assistance for the following: slit-lamp views of the anterior segment and anterior chamber periphery, and fundus photographs centered on the macula and on the optic disc (P = 0.825, P = 0.997, P = 0.194, and P = 0.449, respectively). For slit-lamp views of the lens, the proportion of suitable images was higher among those obtained by an ophthalmologist (99.6%) than by a technician (93.8%, P < 0.01).

CONCLUSIONS

Ophthalmic photographs acquired by a trained technician consistently achieved >90% adequacy for remote reading. Compared with ophthalmologist-acquired photos, the proportion of images deemed suitable achieved a high overall agreement. These findings provide favorable evidence of the adequacy of teleophthalmological imaging by nurse technicians.

Effects of chronic low-dose radiation on cataract prevalence and characterization in wild boar (Sus scrofa) from Fukushima, Japan

This study evaluated cataracts in wild boar exposed to chronic low-dose radiation. We examined wild boar from within and outside the Fukushima Exclusion Zone for nuclear, cortical, and posterior subcapsular (PSC) cataracts in vivo and photographically. Plausible upper-bound, lifetime radiation dose for each boar was estimated from radioactivity levels in each animal's home range combined with tissue concentrations of 134+137Cesium. Fifteen exposed and twenty control boar were evaluated. There were no significant differences in overall prevalence or score for cortical or PSC cataracts between exposed and control animals. Nuclear (centrally located) cataracts were significantly more prevalent in exposed boar (p < 0.05) and had statistically higher median scores. Plausible upper-bound, lifetime radiation dose ranged from 1 to 1,600 mGy in exposed animals, with no correlation between dose and cortical or PSC score. While radiation dose and nuclear score were positively associated, the impact of age could not be completely separated from the relationship. Additionally, the clinical significance of even the highest scoring nuclear cataract was negligible. Based on the population sampled, wild boar in the Fukushima Exclusion Zone do not have a significantly higher prevalence or risk of cortical or PSC cataracts compared to control animals.

Artificial Intelligence for Cataract Detection and Management

The rising popularity of artificial intelligence (AI) in ophthalmology is fuelled by the ever-increasing clinical "big data" that can be used for algorithm development. Cataract is one of the leading causes of visual impairment worldwide. However, compared with other major age-related eye diseases, such as diabetic retinopathy, age-related macular degeneration, and glaucoma, AI development in the domain of cataract is still relatively underexplored. In this regard, several previous studies explored algorithms for automated cataract assessment using either slit lamp of color fundus photographs. However, several other study groups proposed or derived new AI-based calculation for pre-cataract surgery intraocular lens power. Along with advancements in digitization of clinical data, data curation for future cataract-related AI developmental work is bound to undergo significant improvements in the foreseeable future. Even though most of these previous studies reported early promising performances, limitations such as lack of robust, high-quality training data, and lack of external validations remain. In the next phase of work, apart from algorithm's performance, it will also be pertinent to evaluate deployment angles, feasibility, efficiency, and cost-effectiveness of these new cataract-related AI systems.

Evaluating the associations between obesity and age-related cataract: a Mendelian randomization study

BACKGROUND

The obesity-cataract association has been inconsistently reported. The fat mass and obesity-related (FTO) single-nucleotide polymorphism (SNP) rs9939609 is a major SNP associated with obesity and has been used as an instrumental variable for obesity in a Mendelian randomization (MR) approach. An interaction between the FTO SNP and macronutrient intake for obesity was suggested previously.

OBJECTIVE

The aim of this study was to assess the associations between obesity and cataract, using FTO SNP rs9939609 as an instrumental variable in an MR approach, and explore interactions of this SNP with macronutrient intake in relation to risk of cataract in a population-based cohort.

METHODS

The Blue Mountains Eye Study (BMES) is a longitudinal population-based study of common eye disease. Of 3654 baseline participants of the BMES (1992-1994), 2334 (75.8% of survivors) and 1952 (76.7% of survivors) were followed 5 and 10 y later. During the 5-y follow-up, 1174 new participants were examined. Cumulative cataract was defined as the presence of cortical, nuclear, or posterior subcapsular (PSC) cataract at any visit, following the Wisconsin Cataract Grading System. Imputed dosage of the FTO SNP rs9939609 was used. Quintiles of macronutrient intake (carbohydrates, protein, fats) were derived from an FFQ. ORs and 95% CIs were estimated using multivariable-adjusted logistic regression models.

RESULTS

After multivariable adjustment, there were no associations between BMI and any cataract types in MR models using rs9939609 as an instrumental variable. However, an interaction between rs9939609 and protein intake for PSC cataract risk was suggested (P = 0.03). In analyses stratified by quintiles of protein intake, each minor allele of rs9939609 was associated with increased odds of PSC (OR: 2.14; 95% CI: 1.27, 3.60) in the lowest quintile subgroup only.

CONCLUSIONS

Obesity was not causally associated with age-related cataract. However, among persons in the lowest quintile of protein intake, obesity may be associated with PSC cataract.

The Combination of Healthy Diet and Healthy Body Weight Is Associated with Lower Risk of Nuclear Cataract in the Blue Mountains Eye Study

BACKGROUND

Greater adherence to dietary guidelines has previously been found to be associated with decreased risk of visual impairment. However, whether or not this association extends to age-related cataract, 1 of the leading causes of visual impairment, is unknown.

OBJECTIVES

The aim of this study was to assess the association between adherence to dietary guidelines, using total diet score, and incidence of age-related cataract.

METHODS

Of 3654 baseline participants of the population-based Blue Mountains Eye Study cohort (1992-1994), 2334 (75.8% survivors) and 1952 (76.7% survivors) were examined after 5 and 10 y, respectively. Cataract was assessed from lens photographs using the Wisconsin Cataract Grading System. Baseline total diet score was calculated from FFQ data following a modified version of the Healthy Eating Index for Australians. OR with 95% CI were estimated using discrete logistic regression analyses, adjusting for age, sex, and other confounders. To test interaction, a cross-product term of 2 factors was included in regression models.

RESULTS

Of 2173 participants (84.7% of those returned for 1 or both follow-ups) with total diet score estimated, 57% were women, mean baseline age was 63.9 ± 8.4y, and mean baseline BMI was 26.3 ± 4.3 kg/m2. After multivariable adjustment, baseline total diet score was not associated with incidence of any cataract. A multiplicative interaction was observed between total diet score and BMI for incident nuclear cataract (P-interaction = 0.04): increasing baseline total diet score was associated with decreased risk of nuclear cataract among participants with BMI <25 (per unit increased total diet score, OR: 0.90; 95% CI: 0.81, 0.99; P = 0.02), but not among participants with BMI ≥25 (OR: 1.00; 95% CI: 0.92, 1.10; P = 0.95).

CONCLUSIONS

Adherence to dietary guidelines had no appreciable influence on cataract development overall in this older Australian population. However, adherence to dietary guidelines combined with healthy BMI is associated with decreased risk of nuclear cataract, an aging marker.

Systemic medications and cortical cataract: the Singapore Epidemiology of Eye Diseases Study

BACKGROUND/AIMS

To evaluate the association between systemic medications and cortical cataract prevalence in an Asian population.

METHODS

The Singapore Epidemiology of Eye Diseases Study recruited 10 033 Chinese, Malay and Indian residents aged 40+ years living in Singapore. Information on medication use was collected at interview using questionnaires. The presence and severity of cortical cataract were assessed from lens photographs using the modified Wisconsin Cataract Grading System. Associations between medications and the presence of cortical cataract were assessed using logistic regression. Associations between medications and greater severity of cortical cataract (none, minimal, early and late) were assessed using ordinal logistic regression.

RESULTS

A total of 8965 participants were included, the mean age was 57.6 (SD=9.8) years, and 4555 (50.8%) were women. After adjusting for age, gender, ethnicity, body mass index, smoking status, socioeconomic status, hypertension, hyperlipidaemia, diabetes, duration of diabetes and cardiovascular disease, ACE inhibitors (OR=1.27; 95% CI 1.05 to 1.55), fibrates (OR=1.57; 95% CI 1.05 to 2.35), alpha-glucosidase inhibitors (AGIs) (OR=1.85; 95% CI 1.13 to 3.02) and insulin (OR=1.80; 95% CI 1.11 to 2.93) were significantly associated with the presence of cortical cataract. Further adjusting for concurrent medication use did not alter these associations. Consistently, the four medications were also associated with a greater severity level of cortical cataract.

CONCLUSION

ACE inhibitors, fibrates and AGIs were associated with increased prevalence of cortical cataract in this Asian population, independent of the presence of hypertension, hyperlipidaemia and diabetes, respectively. Whether they contribute to the risk of cortical cataract needs confirmation in longitudinal studies.

The Post-illumination Pupil Response (PIPR) Is Associated With Cognitive Function in an Epidemiologic Cohort Study

We conducted a cross-sectional study on 403 participants in the 10-year follow-up examination of the Beaver Dam Offspring Study. The participants included 172 male and 231 female, with age ranging from 33 to 81 years (mean ± SD, 60.7 ± 9.3). The post-illumination pupil response (PIPR) was recorded using binocular infrared pupillometer (Neur-Optics, Inc., Irvine, CA). Cognitive testing consisted of Trail Making Test (TMT) Parts A and B, Rey Auditory Verbal Learning Test (AVLT), Digit Symbol Substitution Test (DSST), and Verbal Fluency Test (VFT) (F, A, and S). Principal component analysis (PCA) was used to calculate an overall cognitive function score. There was a significant reduction in the mean baseline pupil diameter by 0.21 mm for every 5-year increase in age (95% CI: -0.25, -0.17). There was also a significant increase in the PCA cognitive score by 0.20 (linear regression, 95% CI: 0.08, 0.32) for every 0.1 unit increase in the PIPR. The association remained significant after adjusting for age, sex, education, medications, systemic and ocular disease, and short form-12 physical and mental component score. The results of this study demonstrated a modest association between the PIPR and cognitive function, warranting longitudinal studies to evaluate the role of the PIPR in predicting cognitive function in the middle-aged and older adults.

Refraction and Change in Refraction Over a 20-Year Period in the Beaver Dam Eye Study

Purpose

Hyperopic shifts in refraction have been consistently reported in adults over 40, followed by myopic shifts after age 70. Although potential factors underlying these changes in refraction in older adults have been investigated previously, the studies were restricted by the limited longitudinal data available. The authors of this study sought to better characterize the long-term trajectory of refraction in older adults using 20 years of prospective data.

Methods

The impact of cohort effects on refraction over 20 years was examined. Generalized estimating equations were used to evaluate the etiologic factors underlying refraction and changes in refraction measured over a 20-year period (1988–2010) among adults over age 40 from the Beaver Dam Eye Study.

Results

Only individuals with nuclear cataract experienced a myopic shift in refraction, showing a 0.25 diopter (D) decrease (95% confidence interval [CI]: −0.44 D to −0.07 D) over a five-year period. Individuals with mild and moderate nuclear sclerosis showed varying degrees of hyperopic shifts over five years (0.22 D: 95% CI: 0.20 D–0.25 D; 0.23 D: 95% CI: 0.20 D–0.27 D, respectively).

Conclusions

Nuclear cataract is the primary contributor to the myopic shift among older individuals. Birth cohort effects on baseline refraction but not change in refraction were observed.

Aldose Reductase Polymorphisms, Fasting Blood Glucose, and Age-Related Cortical Cataract

Purpose

To determine whether there is an association between polymorphisms of the AKR1B1 gene and cortical cataract in the presence of hyperglycemia.

Methods

In the second cross section of the Blue Mountains Eye Study (BMES), 3508 participants (2334 at 5-year follow-up and 1174 newly recruited participants) were examined during 1997 to 2000. Cataract was graded from lens photographs using the Wisconsin Cataract Grading System. Fasting blood glucose (FBG) was measured. Continuous imputed dosages of minor alleles of 17 AKR1B1 single nucleotide polymorphisms (SNPs) were assessed for associations with prevalent cortical cataract. Gene-environment interactions between SNPs and FBG were examined. Odds ratios (OR) and 95% confidence intervals (CI) for prevalent cortical cataract were estimated using logistic regression adjusting for age, sex, smoking, hypertension, education, and myopia. A P value of 0.005 was considered statistically significant after correction for 10 independent tests. Replication of significant associations found in the BMES sample was conducted in the Singapore Epidemiology of Eye Diseases (SEED) study (n = 10,033).

Results

No polymorphism was associated with prevalent cortical cataract. A significant interaction was observed between rs9640883 and FBG (Pinteraction = 0.004), with increased cortical cataract prevalence associated with rs9640883 minor allele dosage in those with FBG >6.0 mM (strata-specific OR 1.72, 95% CI 1.09-2.72). No similar association was found in participants with normal FBG (OR 0.85, 95% CI 0.69-1.04). This interaction was not evident in the SEED study.

Conclusions

The identified interaction between rs9640883 and FBG in relation to cortical cataract was not replicated but may warrant further investigation.

Statins in ophthalmology

Statins, 3-hydroxy-3-methyl-gutaryl coenzyme A reductase inhibitors, are a class of lipid-lowering drugs with anti-inflammatory, immunomodulatory, and vascular effects. Statins are increasingly being used in the treatment of a variety of medical conditions. We examine the actions of statins on the eye and its associated ophthalmic disorders. Statins can be synthetic or nonsynthetic, and their differentiating derivations may contribute to their varying cholesterol-lowering and pleiotropic effects. There is conflicting evidence on the ocular therapeutic and adverse effects of the statins. Statins may play a role in reducing the burden of dry eye, corneal ulcer scarring, thyroid-associated orbitopathy, glaucoma, uveitis and other associated ocular inflammatory states, cataract, proliferative vitreoretinopathy, diabetic retinopathy, macular degeneration, and choroidal melanoma. Topical preparations of statins can be formulated, thereby extending the range of ocular diseases that may be amenable to treatment. Statins have a relatively safe side effect profile, but rare and serious adverse reactions have been reported with their usage in ophthalmology, including myopathies and rhabdomyolysis with acute renal failure.

The Effect of Gender on Visual Field Sensitivity: The Singapore Chinese Eye Study

PURPOSE

Visual field (VF) sensitivity is known to be age-dependent, but there is a paucity of evidence on whether it is gender-dependent. We therefore investigated the effect of gender on VF sensitivity.

METHODS

An observational study involving 491 adults from the population-based Singapore Chinese Eye Study (SCES). Study participants underwent a comprehensive and standardised ocular examination and VF assessment on the Humphrey Field Analyzer II (Carl Zeiss Meditec, Inc., Dublin, CA, USA). The effect of gender on the mean deviation (MD) and pattern standard deviation (PSD) was analysed with linear regression models.

RESULTS

The mean age was 52.9 ± 5.9 years, and 229 (46.6%) participants were women. A total of 800 reliable VFs from 655 healthy eyes without visual impairment, glaucoma and significant cataract were included. The mean (± standard deviation) MD was -0.45 ± 1.01 dB in men, and -0.84 ± 1.20 dB in women. The MD [95% confidence interval] was 0.28 [-0.44 to -0.12] dB lower in females compared to males (P = 0.001) after adjusting for reliability indices, degree of lens opacity, and other potential confounders. The PSD was not significantly different between the genders.

CONCLUSIONS

In the SCES, the population-average of the central VF sensitivity was significantly lower in women compared to men by a small amount (0.28 dB). This effect was observed in healthy eyes, and was not explained by multiple potential confounders. Hence, this likely represents a physiological gender-based difference that is unaccounted for in standard automated perimetry. Further studies in other populations would be needed to corroborate our findings.

Fornix-Based Trabeculectomy Conjunctival Closure: Winged Sutures versus Modified Wise Closure

PURPOSE

To compare the midterm safety and efficacy profile of winged sutures versus modified Wise closure for fornix-based trabeculectomy.

DESIGN

Retrospective comparative study.

PARTICIPANTS

Consecutive cases that underwent fornix-based trabeculectomy by a single surgeon between January 5, 2015, and May 8, 2017.

METHODS

Potential cases were identified using the Current Procedural Terminology code, and their charts were reviewed thoroughly. Only 1 eye per patient was included. Demographic and clinical data were collected.

MAIN OUTCOME MEASURES

Primary outcomes were bleb leak and subsequent surgical revision rates. Secondary outcomes included intraocular pressure (IOP), number of glaucoma medications (NGM), visual acuity (VA), and other complications.

RESULTS

A total of 313 patients were identified, 157 with winged sutures and 156 with modified Wise closure. Baseline demographic and clinical characteristics were similar between the 2 groups. Twenty-six cases (16.6%) of winged sutures and 10 cases (6.4%) of modified Wise group developed bleb leak (P = 0.007), but only a total of 10 eyes needed bleb revision (P = 0.336). Other complications were similar in rates between the groups (P > 0.05). At 6 months, the modified Wise group had significantly greater IOP reduction (-3.10±1.29 [standard error], P = 0.016). Number of glaucoma medications reduction and VA evolution were similar between the 2 groups (P > 0.05).

CONCLUSIONS

Fornix-based trabeculectomy with either closure technique was effective in lowering IOP and NGM with comparable safety profile at 6 months. Furthermore, modified Wise closure provided larger IOP reduction and lower bleb leak rate, suggesting a potential superiority to winged sutures. Our study was limited by mitomycin C (MMC) delivery method change near the time of conjunctival closure change, although MMC delivery methods did not show significance in any outcome model.

Cataract grading systems: a review of past and present

PURPOSE OF REVIEW

To provide a comprehensive summary of past cataract grading systems, how they have shaped current grading systems, and the developing technologies that are being used to assess and grade cataracts.

RECENT FINDINGS

This summary of cataract grading systems examines the development and limitations that existed in past grading systems and how they have shaped the grading systems of present time. The Lens Opacities Classification System III (LOCS III) system is currently used both clinically and for research purposes. Recent advancements in imaging technologies have allowed researchers to create automatic systems that can locate lens landmarks and provide cataract grading scores that correlate well with LOCS III clinical grades. Utilizing existing technologies, researchers demonstrate that fundus photography and optical coherence tomography can be used as cataract grading tools. Lastly, deep learning has proved to be a powerful tool that can provide objective and reproducible cataract grading scores.

SUMMARY

Cataract grading schemes have provided ophthalmologists with a way to communicate clinical findings and to compare new developments in diagnostic technologies. As technologies advance, cataract grading can become more objective and standardized, allowing for improved patient care.

Sparse Range-Constrained Learning and Its Application for Medical Image Grading

Sparse learning has been shown to be effective in solving many real-world problems. Finding sparse representations is a fundamentally important topic in many fields of science including signal processing, computer vision, genome study, and medical imaging. One important issue in applying sparse representation is to find the basis to represent the data, especially in computer vision and medical imaging where the data are not necessary incoherent. In medical imaging, clinicians often grade the severity or measure the risk score of a disease based on images. This process is referred to as medical image grading. Manual grading of the disease severity or risk score is often used. However, it is tedious, subjective, and expensive. Sparse learning has been used for automatic grading of medical images for different diseases. In the grading, we usually begin with one step to find a sparse representation of the testing image using a set of reference images or atoms from the dictionary. Then in the second step, the selected atoms are used as references to compute the grades of the testing images. Since the two steps are conducted sequentially, the objective function in the first step is not necessarily optimized for the second step. In this paper, we propose a novel sparse range-constrained learning (SRCL) algorithm for medical image grading. Different from most of existing sparse learning algorithms, SRCL integrates the objective of finding a sparse representation and that of grading the image into one function. It aims to find a sparse representation of the testing image based on atoms that are most similar in both the data or feature representation and the medical grading scores. We apply the new proposed SRCL to two different applications, namely, cup-to-disc ratio (CDR) computation from retinal fundus images and cataract grading from slit-lamp lens images. Experimental results show that the proposed method is able to improve the accuracy in CDR computation and cataract grading.

Association of Cadmium and Lead Exposure With the Incidence of Contrast Sensitivity Impairment Among Middle-aged Adults

Importance

Contrast sensitivity (CS) is an important indicator of visual function that affects daily life, including mobility, visually intensive tasks, safety, and autonomy. Understanding the risk factors for CS impairment could prevent decreases in visual function.

Objective

To determine the incidence of and factors associated with CS impairment in a large cohort.

Design, Setting, and Participants

The Beaver Dam Offspring Study is an ongoing longitudinal cohort study of aging involving adults in Beaver Dam, Wisconsin. Participants who were free of CS impairment in both eyes at baseline were included (N = 1983). Baseline data collection occurred from June 8, 2005, through August 4, 2008, when the participants ranged from 21 to 84 years of age. Two follow-up examinations occurred at 5-year intervals: one was conducted between July 12, 2010, and March 21, 2013, and the other between July 1, 2015, and November 13, 2017. Data analysis was performed from November 27, 2017, to February 27, 2018.

Main Outcomes and Measures

Contrast sensitivity testing was conducted with Pelli-Robson letter sensitivity charts, and incident impairment was defined as a log CS score less than 1.55 in either eye at any follow-up examination. Cadmium and lead levels were measured in whole blood with inductively coupled plasma mass spectrometry. Associations between baseline characteristics and CS impairment incidence were examined using Cox proportional hazard models and quantified as hazard ratios (HRs) with 95% CI.

Results

Of the 1983 participants included, 1028 (51.8%) were female and 955 (48.2%) were male, with a mean (SD) age of 48 (9.3) years. The 10-year cumulative incidence of CS impairment was 24.8% (95% CI, 22.9-26.8), similar in women (24.9%) and men (24.6%), and highest in the oldest age group (65-84 years) at 66.3%. In multivariable models, cadmium level in the highest quintile (HR, 1.35; 95% CI, 1.02-1.78), older age (HR, 1.36; 95% CI, 1.25-1.47), larger waist circumference (HR, 1.06; 95% CI, 1.01-1.11), and more plaque sites (1-3 sites: HR, 1.43; 95% CI, 1.07-1.92; 4-6 sites: HR, 2.75; 95% CI, 1.26-6.05) were among the factors associated with increased risk, while male sex (HR, 0.77; 95% CI, 0.60-0.98) and any alcohol consumption (HR, 0.61; 95% CI, 0.43-0.88) were associated with decreased risk. Results were similar when smoking status replaced cadmium exposure in the models. Lead level was not associated with increased risk.

Conclusions and Relevance

This study's findings suggest that incident CS impairment was common in the 10-year follow-up, with cadmium, but not lead, exposure associated with increased risk. The associations of diminished CS with other modifiable risk factors found appear to imply that changes in behavior may reduce future incidence of CS impairment.

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.

Monitoring and Morphologic Classification of Pediatric Cataract Using Slit-Lamp-Adapted Photography

Purpose

To investigate the feasibility of pediatric cataract monitoring and morphologic classification using slit lamp–adapted anterior segmental photography in a large cohort that included uncooperative children.

Methods

Patients registered in the Childhood Cataract Program of the Chinese Ministry of Health were prospectively selected. Eligible patients underwent slit-lamp adapted anterior segmental photography to record and monitor the morphology of their cataractous lenses. A set of assistance techniques for slit lamp–adapted photography was developed to instruct the parents of uncooperative children how to help maintain the child's head position and keep the eyes open after sleep aid administration.

Results

Briefly, slit lamp–adapted photography was completed for all 438 children, including 260 (59.4%) uncooperative children with our assistance techniques. All 746 images of 438 patients successfully confirmed the diagnoses and classifications. Considering the lesion location, pediatric cataract morphologies could be objectively classified into the seven following types: total; nuclear; polar, including two subtypes (anterior and posterior); lamellar; nuclear combined with cortical, including three subtypes (coral-like, dust-like, and blue-dot); cortical; and Y suture. The top three types of unilateral cataracts were polar (55, 42.3%), total (42, 32.3%), and nuclear (23, 17.7%); and the top three types of bilateral cataracts were nuclear (110, 35.8%), total (102, 33.2%), and lamellar (34, 11.1%).

Conclusions

Slit lamp–adapted anterior segmental photography is applicable for monitoring and classifying the morphologies of pediatric cataracts and is even safe and feasible for uncooperative children with assistance techniques and sleep aid administration.

Translational Relevance

This study proposes a novel strategy for the preoperative evaluation and evidence-based management of pediatric ophthalmology (Clinical Trials.gov, NCT02748031).

Visualization of Dietary Patterns and Their Associations With Age-Related Macular Degeneration

Purpose

We aimed to visualize the relationship of predominant dietary patterns and their associations with AMD.

Methods

A total of 8103 eyes from 4088 participants in the baseline Age-Related Eye Disease Study (AREDS) were classified into three groups: control (n = 2739), early AMD (n = 4599), and advanced AMD (n = 765). Using principle component analysis, two major dietary patterns and eight minor dietary patterns were characterized. Applying logistic regression in our analysis, we related dietary patterns to the prevalence of AMD. Qualitative comparative analysis by operating Boolean algebra and drawing Venn diagrams was used to visualize our findings.

Results

In general, the eight minor patterns were subsets or extensions of either one of the two major dietary patterns (Oriental and Western patterns) and consisted of fewer characteristic foods than the two major dietary patterns. Unlike the two major patterns, which were more strongly associated with both early and advanced AMD, none of the eight minors were associated with early AMD and only four minor patterns, including the Steak pattern (odds ratio comparing the highest to lowest quintile of the pattern score = 1.73 [95% confidence interval: 1.24 to 2.41; P_trend = 0.02]), the Breakfast pattern (0.60 [0.44 to 0.82]; P_trend = 0.004]), the Caribbean pattern (0.64 [0.47 to 0.89; P_trend = 0.009]), and the Peanut pattern (0.64 [0.46 to 0.89; P_trend = 0.03]), were significantly associated with advanced AMD. Our data also suggested several potential beneficial (peanuts, pizza, coffee, and tea) and harmful (salad dressing) foods for AMD.

Conclusions

Our data indicate that a diet of various healthy foods may be optimal for reducing AMD risk. The effects of some specific foods in the context of overall diet warrant further study.

A longitudinal population study of the impact of cataract extraction on sleep quality

PURPOSE

To investigate the longitudinal effects of cataract extraction on sleep quality in two discrete population cohorts.

METHODS

301 participants who had senile cataract in both eyes at the baseline examination were selected from two large longitudinal epidemiologic studies of age-related eye disease, hearing, olfaction, and cognition. The participants were divided into two groups: one had cataract surgery (CS) in both eyes, and the other had no cataract surgery (NCS) in either eye by the follow up examination. Cataract was graded from photos or digital images using a standardized protocol. The quality of sleep was assessed using a modified Wisconsin Sleep Cohort Study Questionnaire. The NCS and CS groups were compared as to the change in the number of sleep problems reported from the baseline to the follow-up examination. Systemic co-morbidity data were included as potential confounders, including diabetes mellitus, obesity, hypertension, cerebrovascular disease, thyroid disease, tobacco and alcohol use, and the SF-12 physical component and mental component summary scores.

RESULTS

The average (mean±SD) age was 71.0±8.8 years in the NCS (n=237) group and 73.4±9.1 years (n=64) in the CS group. There was no statistically significant difference in the change in the number of sleep problems reported between the NCS and CS groups (mean: -0.068 for NCS and 0.016 for CS, p=0.57). The multivariable linear regression models, when adjusted for confounders, yielded similar results.

CONCLUSION

In this longitudinal, community-based population study, we found no significant impact of cataract extraction on sleep quality. Studies of the effect of cataract extraction on sleep should allow a longer follow up to demonstrate sustainability.

The Relation between Sleep Disruption and Cataract in a Large Population-Based Study

PURPOSE

To investigate the relation between sleep disruption and nuclear cataract, as well as the impact of cataract removal on sleep, in two discrete population-based cohorts.

METHODS

This is a cross-sectional study of 5070 participants from three large longitudinal epidemiologic studies of age-related eye disease, hearing, olfaction, and cognition. Slit-lamp photos of the lens were obtained to grade nuclear cataract using a standardized protocol. The quality of sleep was assessed using a modified Wisconsin Sleep Cohort Study questionnaire. Multiple linear regression analyses were used to assess the associations between levels of nuclear cataract/cataract extraction and the number of sleep problems. Systemic co-morbidity data were included as potential confounders, including diabetes mellitus, obesity, hypertension, cerebrovascular disease, thyroid disease, tobacco and alcohol use, and physical component summary score and mental component summary score.

RESULTS

The mean age of the cohort was 57.6 years (range 22-95 years). The majority of the cohort demonstrated nuclear cataract levels 2 or 3 (36.8% and 30.1%, respectively). A total of 8% of the cohort had an intraocular lens (IOL) in at least one eye. There was no statistically significant correlation between sleep problems with presence of either nuclear cataract or IOL implant (p > 0.05).

CONCLUSION

In this cross-sectional, population-based study, we found no significant association between nuclear cataract or presence of IOL with poor sleep quality after adjusting for potential confounders. Studies of the longitudinal impact of nuclear cataract and cataract removal on sleep are needed to elucidate the role of nuclear cataract and cataract removal on sleep.

Prevalence, Risk Factors, and Impact of Undiagnosed Visually Significant Cataract: The Singapore Epidemiology of Eye Diseases Study

Objective

To determine the prevalence, risk factors, and impact of undiagnosed visually significant cataract in an Asian population.

Methods

The Singapore Epidemiology of Eye Diseases is a population-based study where 8,697 adults of Malay, Indian, and Chinese ethnicities aged > 40 years were invited for an eye examination, including lens photograph, to establish cataract diagnosis. Visually significant cataract was defined by Wisconsin Cataract Grading System and a best-corrected visual acuity <20/40 with cataract as the primary cause of vision impairment. Participants were deemed ‘undiagnosed’ if they had visually significant cataract and reported no prior physician diagnosis of cataract. Visual functioning (VF) was assessed with the VF-11 questionnaire validated using Rasch analysis.

Results

Among the 925 participants with visually significant cataract, 636 (68.8%) were unaware of their cataract status. Age-standardized prevalence varied according to ethnicity, with Malays having higher rates than Chinese and Indians. Factors independently associated with having undiagnosed visually significant cataract were: Malay ethnicity, lower educational attainment, in employment, and without a history of diabetes (all P<0.05). In those with undiagnosed visually significant cataract, half had bilateral visual impairment, which was significantly associated with 24.8% poorer visual functioning compared to those with unilateral visual impairment (P<0.001).

Conclusions

Two-thirds of Singaporean adults with visually significant cataract were previously undiagnosed. Half of these cases had bilateral visual impairment and substantially reduced quality of life. Public health strategies targeting elderly patients, such as regular screening for visual impairment and timely referral to ophthalmologists in order to prevent progression to bilateral visual impairment when visual function is compromised are warranted.

Predicting postoperative visual outcomes in cataract patients with maculopathy

Purpose:

To assess the accuracy of the potential acuity meter (PAM) in predicting postcataract surgery visual acuity outcome in patients with healed inactive maculopathies.

Study Design:

Prospective interventional clinical trial.

Patients and Methods:

Patients scheduled for phacoemulsification had preoperative and 1 month postoperative best-corrected visual acuity (BCVA), PAM test, fluorescein angiography, and macular optical coherence tomography. Patients were grouped to following preoperative BCVA: PRE1: 0.29 and better, PRE2: 0.25–0.13, and PRE3: 0.1 or worse; age: G1 <60, G2 = 60–70, and G3 >70 years. PAM accuracy was divided into: Grade 1: Postoperative BCVA ≤1 or less line error of the PAM score, Grade 2: Between 1 and 2 lines error, and Grade 3: ≥3 lines or more error.

Results:

This study enrolled 57 patients with a mean age of 71.05 ± 6.78 years where 34 were females. There were 21 (36.84%) patients with diabetic maculopathy and 36 (63.16%) with age-related macular degeneration. The mean preoperative BCVA was 0.198 ± 0.12 (0.1–0.5). The mean PAM score was 0.442 ± 0.24 (0.1–1.3). The mean postoperative BCVA was 0.4352 ± 0.19 (0.17–1.00). The PAM score was in Grade 1, 2, and 3 in 46 (80.7%), 54 (94.7%), and 56 (98.2), respectively. There was a highly significant correlation between the PAM score and the postoperative BCVA (P < 0.001, Chi-square test). There was no correlation between the PAM test accuracy and age, gender, diagnosis, and preoperative BCVA (P = 0.661, 0.667, 0. 0.991, 0.833, Chi-square test; respectively).

Conclusion:

The PAM is an accurate method of predicting postoperative visual acuity for eyes with nuclear cataracts Grade I and II and inactive maculopathies.

Lens opacity detection for serious posterior subcapsular cataract

Cataract leads to visual impairment. Among different types of cataract, posterior subcapsular cataract (PSC) can develop rapidly and surgery is usually needed. An approach to detect PSC opacities in retro-illumination images is proposed. Watershed and Markov random fields (MRF) method are employed to opacities in anterior retro-illumination images. It results in a mixture of PSC, cortical opacities and noise. Then, information in both anterior and posterior retro-illumination images is utilized. Two features are extracted to identify PSC: mean gradient comparison (MGC) between anterior and posterior retro-illumination images, and spatial location. This is the first time that comparison between anterior and posterior retro-illumination images is proposed and MGC is proposed as the feature of comparison in PSC detection. Experiments show that the sensitivity and specificity of PSC screening is 91.2 and 90.1 %, respectively, based on the 519 pairs of testing images. To the best of our knowledge, it is the best performance reported in automatic detection of PSC. Compared with the methods in the literatures, considerable improvement is achieved when there are large areas of PSC opacities.

Useful Prediction of Phacodynamics by Scheimpflug Lens Densitometry in Patients over Age 70

PURPOSE

To evaluate the relationship between lens density using the Scheimpflug system and phacodynamics in nuclear cataracts as related to patient age.

METHODS

In 262 eyes with nuclear cataracts, the objective lens density was determined by Pentacam Nucleus Staging (PNS) software while subjective grading was achieved using the Lens Opacities Classification System III (LOCS III).

RESULTS

Overall, cumulated dissipated energy (CDE) had a positive correlation with Scheimpflug lens density and LOCS III nuclear scores. When analysis was done by patient age, LOCS III nuclear scores and Scheimpflug lens density had a positive correlation with CDE for patients in all age groups. Of interest, patients >70 years old showed a higher correlation coefficient (r) with Scheimpflug lens density than with LOCS III nuclear score.

CONCLUSIONS

Scheimpflug lens densitometry may be more useful for predicting phacodynamics than LOCS III scores in nuclear cataract patients, especially in old age (>70 years).