Effects of cataract type and location on visual function: the Blue Mountains Eye Study

AI-based diagnosis of nuclear cataract from slit-lamp videos

In ophthalmology, the availability of many fundus photographs and optical coherence tomography images has spurred consideration of using artificial intelligence (AI) for diagnosing retinal and optic nerve disorders. However, AI application for diagnosing anterior segment eye conditions remains unfeasible due to limited standardized images and analysis models. We addressed this limitation by augmenting the quantity of standardized optical images using a video-recordable slit-lamp device. We then investigated whether our proposed machine learning (ML) AI algorithm could accurately diagnose cataracts from videos recorded with this device. We collected 206,574 cataract frames from 1812 cataract eye videos. Ophthalmologists graded the nuclear cataracts (NUCs) using the cataract grading scale of the World Health Organization. These gradings were used to train and validate an ML algorithm. A validation dataset was used to compare the NUC diagnosis and grading of AI and ophthalmologists. The results of individual cataract gradings were: NUC 0: area under the curve (AUC) = 0.967; NUC 1: AUC = 0.928; NUC 2: AUC = 0.923; and NUC 3: AUC = 0.949. Our ML-based cataract diagnostic model achieved performance comparable to a conventional device, presenting a promising and accurate auto diagnostic AI tool.

Comparing Rod-Mediated Dark Adaptation in Older Adults before and after Cataract Surgery

PURPOSE

Studies on age-related macular degeneration often use rod-mediated dark adaptation (RMDA) to evaluate macular functional health, studying eyes with cataract and pseudophakic eyes within the same sample. We examine a poorly understood issue-whether rod intercept time (RIT), a measure of RMDA, changes after cataract surgery and intraocular lens (IOL) insertion as compared to RIT before cataract surgery. Cataract may serve as a filter reducing photo-bleach magnitude prior to surgery, biasing RMDA interpretation.

METHODS

A pre-/post-cataract surgery design was used. Persons with nuclear sclerotic and/or cortical cataract per the electronic health record were enrolled. Prior to cataract surgery, visual acuity, RMDA, and the LOCS III classification documenting cataract presence/severity were measured. Thirty days after surgery (mean), visual acuity and RMDA were repeated, followed by fundus photos to document macular health.

RESULTS

Twenty-four participants (mean age 72.7 years, standard deviation 5.6) enrolled. All eyes had nuclear sclerotic and nuclear color cataract; 68% had cortical cataract. All IOLs were monofocal with 21 having blue blocking characteristics and 3 had clear IOLs. Most eyes had higher RIT post-surgery (15.6 min, SD 6.7) as compared to pre-surgery (13.7 min, SD 6.4), p = 0.0006, meaning that RMDA was slower post-surgery. Eyes with moderate cataract (<4 on any LOCS III grade) had RIT that increased on average by 0.7 min; those with more advanced cataract (≥4) had RIT that increased by 3.1 min (p = 0.0116). Results were unchanged when clear IOLs were removed from analysis.

CONCLUSION

RMDA was significantly slower (RIT was greater) following cataract surgery, with the greatest impact on RIT in older eyes after surgery for more advanced cataract. These findings suggest that persons with more advanced cataract may bias results when evaluating RMDA using RIT.

Retinitis Pigmentosa: Current Clinical Management and Emerging Therapies

Retinitis pigmentosa (RP) comprises a group of inherited retinal dystrophies characterized by the degeneration of rod photoreceptors, followed by the degeneration of cone photoreceptors. As a result of photoreceptor degeneration, affected individuals experience gradual loss of visual function, with primary symptoms of progressive nyctalopia, constricted visual fields and, ultimately, central vision loss. The onset, severity and clinical course of RP shows great variability and unpredictability, with most patients already experiencing some degree of visual disability in childhood. While RP is currently untreatable for the majority of patients, significant efforts have been made in the development of genetic therapies, which offer new hope for treatment for patients affected by inherited retinal dystrophies. In this exciting era of emerging gene therapies, it remains imperative to continue supporting patients with RP using all available options to manage their condition. Patients with RP experience a wide variety of physical, mental and social-emotional difficulties during their lifetime, of which some require timely intervention. This review aims to familiarize readers with clinical management options that are currently available for patients with RP.

Outcome of Cataract Surgery in Patients With Retinitis Pigmentosa

PURPOSE

To assess the visual outcome of cataract surgery in patients with retinitis pigmentosa (RP).

DESIGN

Retrospective, noncomparative clinical study.

METHODS

Preoperative, intraoperative, and postoperative data of patients with RP who were undergoing cataract surgery were collected from several expertise centers across Europe.

RESULTS

In total, 295 eyes of 226 patients were included in the study. The mean age at surgery of the first eye was 56.1 ± 17.9 years. Following surgery, best-corrected visual acuity (BCVA) improved significantly from 1.03 to 0.81 logMAR (ie, 20/214 to 20/129 Snellen) in the first treated eye (-0.22 logMAR; 95% CI = -0.31 to -0.13; P < .001) and from 0.80 to 0.56 logMAR (ie, 20/126 to 20/73 Snellen) in the second treated eye (-0.24 logMAR; 95% CI = -0.32 to -0.15; P < .001). Marked BCVA improvements (postoperative change in BCVA of ≥0.3 logMAR) were observed in 87 of 226 patients (39%). Greater odds for marked visual improvements were observed in patients with moderate visual impairment or worse. The most common complications were zonular dialysis (n = 15; 5%) and (exacerbation of) cystoid macular edema (n = 14; 5%), respectively. Postoperative posterior capsular opacifications were present in 111 of 295 eyes (38%).

CONCLUSION

Significant improvements in BCVA are observed in most patients with RP following cataract surgery. Baseline BCVA is a predictor of visual outcome. Preoperative evaluation should include the assessment of potential zonular insufficiency and the presence of CME, as they are relatively common and may increase the risk of complications.

Self-reported driving difficulty in patients with bilateral cataract

PURPOSE

The presence of cataract causes reduction in visual acuity (VA) and contrast sensitivity (CS) and thus can affect individual's daily activities. The aim of this study was to investigate self-reported driving difficulty in patients with bilateral cataract.

METHODS

A total of 99 participants aged 50 and above, with bilateral cataract, who possessed a valid driving license and drove regularly were chosen for this cross-sectional study that looked into their visual functions (VA and CS) and driving difficulty using the self-reported Driving Difficulty Questionnaire.

RESULTS

The mean age of the participants was 65.04±7.22 years old. Results showed that the mean composite driving difficulty score was 83.18±11.74 and most of the participants were having difficulty for driving in the rain (73.7%) and at night (85.9%). Furthermore, the study found that there was a significant correlation between driving difficulty score and CS (rs = 0.40, p = 0.03). However, there was no significant correlation between driving difficulty score and VA (rs = -0.14, p = 0.17). A linear regression was calculated to predict driving difficulty score based on binocular CS and a significant regression equation was found (F (1,28) = 8.115, p = 0.008) with R² of 0.225. Drivers with bilateral cataract will most likely experience some forms of difficulty, especially when driving under low contrast conditions.

CONCLUSION

The findings of this study demand that a comprehensive eye examination should be made compulsory for older adult drivers when issuing or renewing their driving license for the safety of all road users.

Active Learning to Characterize the Full Contrast Sensitivity Function in Cataracts

Background

To characterize contrast sensitivity function (CSF) in cataractous and pseudophakic eyes compared to healthy control eyes using a novel quantitative CSF test with active learning algorithms.

Methods

This is a prospective observational study at an academic medical center. CSF was measured in eyes with visually significant cataract, at least 2+ nuclear sclerosis (NS) and visual acuity (VA) ≥ 20/50, in pseudophakic eyes and in healthy controls with no more than 1+ NS and no visual complaints, using the Manifold Contrast Vision Meter. Outcomes included Area under the Log CSF (AULCSF) and CS thresholds at 1, 1.5, 3, 6, 12, and 18 cycles per degree (cpd). A subgroup analysis as performed on cataract eyes with VA ≥ 20/25.

Results

A total of 167 eyes were included, 58 eyes in the cataract group, 77 controls, and 32 pseudophakic eyes with respective median AULCSF of 1.053 (0.352) vs 1.228 (0.318) vs 1.256 (0.360). In our multivariate regression model, cataract was associated with significantly reduced AULCSF (P= 0.04, β= −0.11) and contrast threshold at 6 cpd (P= 0.01, β= −0.16) compared to controls. Contrast threshold at 6 cpd was significantly reduced even in the subgroup of cataractous eyes with VA ≥ 20/25 (P=0.02, β=−0.16).

Conclusion

The novel qCSF test detected disproportionate significant contrast deficits at 6 cpd in cataract eyes; this remained significant even in the cataractous eyes with VA ≥ 20/25. CSF testing may enhance cataract evaluation and surgical decision-making, particularly in patients with subjective visual complaints despite good VA.

Cataract surgery in patients with Fuchs' dystrophy and corneal decompensation indicated for Descemet's membrane endothelial keratoplasty

The availability of corneal donor tissue is limited in most developing countries. This study evaluated whether patients with coexisting cataract and Fuchs’ dystrophy with corneal decompensation awaiting Descemet’s membrane endothelial keratoplasty (DMEK) benefited from phacoemulsification. This is a retrospective case–control study which included patients with Fuchs’ dystrophy and evidence of corneal decompensation awaiting DMEK. Best-corrected visual acuity (BCVA) and central corneal thickness (CCT) were documented at baseline (pre-cataract surgery in the case group, or at the time of transplantation registry in the control group), 1-month and pre-DMEK. A total of 16 phakic patients with visually significant cataracts had cataract surgery during the study period, and 15 pseudophakic patients were included as controls. There was no significant difference with regard to BCVA at baseline, 1-month or pre-DMEK between the case and control groups. Similarly, no significant difference in CCT was found at baseline, 1-month or pre-DMEK. In the case group, 4 patients with improved visual acuity post-cataract surgery chose to defer DMEK. After stratification, statistical analysis showed significantly better BCVA in the deferred group (n = 4) at 1-month post-cataract surgery, compared to the DMEK group (n = 12) (0.21 ± 0.21 vs. 0.86 ± 0.29 LogMAR, P = 0.004). The other parameters, including baseline BCVA and CCT at any time point documented, were not statistically different. In conclusion, in patients with Fuchs’ dystrophy and decompensated corneas awaiting transplantation, phacoemulsification did not lead to significant increase of corneal thickness nor deterioration of visual acuity. A few patients achieved satisfactory vision after cataract surgery and deferred endothelial keratoplasty.

The Effect of Induced Intraocular Stray Light on Recognition Thresholds for Pseudo-High-Pass Filtered Letters

Purpose

The Moorfields Acuity Chart (MAC)—comprising pseudo-high-pass filtered “vanishing optotype” (VO) letters—is more sensitive to functional visual loss in age-related macular degeneration (AMD) compared to conventional letter charts. It is currently unknown the degree to which MAC acuity is affected by optical factors such as cataract. This is important to know when determining whether an individual's vision loss owes more to neural or optical factors. Here we estimate recognition acuity for VOs and conventional letters with simulated lens aging, achieved using different levels of induced intraocular light scatter.

Methods

Recognition thresholds were determined for two experienced and one naive participant with conventional and VO letters. Stimuli were presented either foveally or at 10 degrees in the horizontal temporal retina, under varying degrees of intraocular light scatter induced by white resin opacity-containing filters (WOFs grades 1 to 5).

Results

Foveal acuity only became significantly different from baseline (no filter) for WOF grade 5 with conventional letters and WOF grades 4 and 5 with VOs. In the periphery, no statistical difference was found for any stray-light level for both conventional and VOs.

Conclusions

Recognition acuity measured with conventional and VOs is robust to the effects of simulated lens opacification, and thus its higher sensitivity to neural damage should not simultaneously be confounded by such optical factors.

Translational Relevance

The MAC may be better able to differentiate between neural and optical deficits of visual performance, making it more suitable for the assessment of patients with AMD, who may display both types of functional visual loss.

Absence of Genotype/Phenotype Correlations Requires Molecular Diagnostic to Ascertain Stargardt and Stargardt-Like Swiss Patients

We genetically characterized 22 Swiss patients who had been diagnosed with Stargardt disease after clinical examination. We identified in 11 patients (50%) pathogenic bi-allelic ABCA4 variants, c.1760+2T>C and c.4496T>C being novel. The dominantly inherited pathogenic ELOVL4 c.810C>G p.(Tyr270*) and PRPH2-c.422A>G p.(Tyr141Cys) variants were identified in eight (36%) and three patients (14%), respectively. All patients harboring the ELOVL4 c.810C>G p.(Tyr270*) variant originated from the same small Swiss area, identifying a founder mutation. In the ABCA4 and ELOVL4 cohorts, the clinical phenotypes of “flecks”, “atrophy”, and “bull’s eye like” were observed by fundus examination. In the small number of patients harboring the pathogenic PRPH2 variant, we could observe both “flecks” and “atrophy” clinical phenotypes. The onset of disease, progression of visual acuity and clinical symptoms, inheritance patterns, fundus autofluorescence, and optical coherence tomography did not allow discrimination between the genetically heterogeneous Stargardt patients. The genetic heterogeneity observed in the relatively small Swiss population should prompt systematic genetic testing of clinically diagnosed Stargardt patients. The resulting molecular diagnostic is required to prevent potentially harmful vitamin A supplementation, to provide genetic counseling with respect to inheritance, and to schedule appropriate follow-up visits in the presence of increased risk of choroidal neovascularization.

Association between central retinal thickness and low luminance visual acuity in early age-related macular degeneration

PURPOSE/AIM

To examine whether central retinal thickness (CRT) is related to mesopic visual acuity (VA) and low luminance deficit (LLD, difference between photopic and mesopic VA) in eyes with early and intermediate age-related macular degeneration (AMD).

MATERIALS AND METHODS

In a cross-sectional study, 50 pseudophakic subjects older than 63 years were divided into three groups (no AMD, early AMD and intermediate AMD). Spectral domain optical coherence tomography (SD-OCT) was used to measure CRT in the 1 mm-central-area. Best-corrected distance VA was measured under photopic or mesopic luminance conditions and LLD calculated. Subjects were stratified by VA impairment to compare CRTs across these groups. Relationships were examined by stepwise multiple linear regression.

RESULTS

No significant differences in mean CRT, photopic and mesopic VA or LLD were detected between the groups no AMD, early AMD and intermediate AMD. However, mean CRTs were 20 microns and 18 microns thicker in the eyes with impaired mesopic VA (> 0.3 logMAR) and impaired LLD (⩾ 0.3 logMAR) compared to the eyes with non-impaired VA or LLD respectively (both p < 0.01). CRT and mesopic pupil size were independent predictors of mesopic VA (p = 0.001). CRT emerged as the only independent predictor of LLD (p = 0.004).

CONCLUSIONS

Increased CRT was linked to worse retinal function when measured under mesopic conditions in eyes without AMD and eyes with early to intermediate AMD. SD-OCT imaging combined with VA measurements under low luminance conditions could be a useful tool to detect early AMD.

Changes in patient subjective happiness and satisfaction with cataract surgery

The purpose of this study was to investigate the changes in patient subjective happiness and satisfaction with cataract surgery and evaluate the association between satisfaction and types of cataract. This study surveyed 247 participants (mean age, 67.9 years) and they completed questionnaires on their satisfaction with the surgery, the subjective happiness scale (SHS) and the Pittsburgh Sleep Quality Index (PSQI) before and after surgery. The SHS increased postoperatively from 4.6 ± 0.7 to 4.8 ± 0.7 (P = 0.007) and 83.4% of patients were satisfied with the surgical results and the average satisfaction score was 4.2 out of a possible 5.0. Multiple regression analysis showed that patient satisfaction was significantly associated with the postoperative SHS (β = 0.380; P < 0.001), the postoperative PSQI (β = −0.041; P = 0.035) and the presence of a posterior subcapsular cataract (PSC) (β = 0.277; P = 0.026). This study clarified that cataract surgery may improve both visual function and patient happiness and that patient satisfaction was affected by postoperative sleep quality and the disappearance of a PSC.

Patient-centred and economic effectiveness of a decision aid for patients with age-related cataract in China: study protocol of a randomised controlled trial

INTRODUCTION

The need for cataract surgery is on the rise due to our ageing population and high demands for greater visual functioning. Although the majority of patients want to participate in a shared decision-making process, no decision aid has been available to improve the quality of decision. The present study aims to determine whether a decision aid increases informed decision about cataract surgery.

METHODS AND ANALYSIS

A parallel randomised controlled trial (772 participants) will be conducted. The decision aid will be implemented among patients with any age-related cataract in Yuexiu District, which is socioeconomically representative of a major metropolitan region in Southern China. Participants will be randomly assigned to receive either a patient decision aid or a traditional booklet, and they will complete three surveys: (1) baseline assessment before the intervention (time point (T)1), 2 weeks (T2) and 1 year (T3) after the intervention. The control group receives a traditional booklet with standard general information developed by the National Eye Institute to help patients understand cataract, whereas the intervention group receives a patient decision aid that includes not only the standard general information, but also the quantitative risk information on the possible outcomes of cataract surgery as well as value clarification exercise. The primary study outcome is the informed decision, the percentage of patients who have adequate knowledge and demonstrate consistency between attitudes and intentions. Secondary outcomes include perceived importance of cataract surgery benefits/harms, decision conflict and confidence, anticipated regret and booklet utilisation and acceptability at 2 weeks, and surgical rates and a cost-utility estimate of the decision aid at 1 year.

ETHICS AND DISSEMINATION

Ethics approval was obtained from the Ethics Committee of Zhongshan Ophthalmic Center (reference number: 2019KYPJ090). Results will be published in peer-reviewed journals and presented at scientific meetings for academic audiences.

TRIAL REGISTRATION NUMBER

NCT03992807.

Effect of Cataract Extraction on Retinal Sensitivity Measurements

INTRODUCTION

Central and paracentral retinal function is often compromised in various retinal diseases. In these conditions, microperimetry is an important tool for assessing retinal sensitivity values. As retinal diseases are prevalent among the elderly, cataract often coexists. This study investigates the effect of cataract surgery on retinal sensitivity in patients with cataract without retinal disease.

MATERIAL AND METHODS

A total of 30 patients already scheduled for cataract surgery were enrolled and microperimetry and visual acuity evaluation was performed before and after cataract extraction. The patients were allocated to 1 of 3 study groups in accordance with the main cataract subtype: nuclear, cortical, or posterior subcapsular (PSC) cataract.

RESULTS

Visual acuity increased significantly after cataract surgery (from 0.34 to 0.00 logMar, p < 0.001, paired t test). Similarly, median retinal sensitivity increased significantly from 23 dB (IQR 21-25 dB) to 27 dB (IQR 25.75-28 dB) (p < 0.001, Wilcoxon test). The increase of retinal sensitivity after cataract surgery was highest in the PSC cataract group.

CONCLUSION

This study showed an increase in retinal sensitivity values after cataract removal, especially in the PSC group. Therefore, coexisting cataract should be considered when interpreting microperimetry results.

Effect of Cataract Grade according to Wide-Field Fundus Images on Measurement of Macular Thickness in Cataract Patients

Purpose

To investigate the effects of cataract grade based on wide-field fundus imaging on macular thickness measured by spectral domain optical coherence tomography (SD-OCT) and its signal-to-noise ratio (SNR).

Methods

Two hundred cataract patients (200 eyes) with preoperative measurements by wide-field fundus imaging and macular SD-OCT were enrolled. Cataract severity was graded from 1 to 4 according to the degree of macular obscuring by cataract artifact in fundus photo images. Cataract grade based on wide-field fundus image, the Lens Opacity Classification System III, macular thickness, and SD-OCT SNR were compared. All SD-OCT B-scan images were evaluated to detect errors in retinal layer segmentation.

Results

Cataract grade based on wide-field fundus imaging was positively correlated with grade of posterior subcapsular cataracts (rho = 0.486, p < 0.001), but not with nuclear opalescence or cortical cataract using the Lens Opacity Classification System III. Cataract grade was negatively correlated with total macular thickness (rho = −0.509, p < 0.001) and SD-OCT SNR (rho = −0.568, p < 0.001). SD-OCT SNR was positively correlated with total macular thickness (rho = 0.571, p < 0.001). Of 200 eyes, 97 (48.5%) had segmentation errors on SD-OCT. As cataract grade increased and SD-OCT SNR decreased, the percentage of eyes with segmentation errors on SD-OCT increased. All measurements of macular thickness in eyes without segmentation errors were significantly greater than those of eyes with segmentation errors.

Conclusions

Posterior subcapsular cataracts had profound effects on cataract grade based on wide-field fundus imaging. As cataract grade based on wide-field fundus image increased, macular thickness tended to be underestimated due to segmentation errors in SD-OCT images. Segmentation errors in SD-OCT should be considered when evaluating macular thickness in eyes with cataracts.

Foveal light and dark adaptation in patients with glaucoma and healthy subjects: A case-control study

INTRODUCTION

To determine whether foveal light and dark adaptation are affected in glaucoma.

METHODS

Case-control study with 23 glaucoma patients and 51 controls. Light and dark adaptation were measured twice. After 10 minutes pre-adaptation to 0.0032 cd/m2, the background luminance increased stepwise to 320 (5 log unit step) or 10,000 cd/m2 (6.5 log unit step) for 10 minutes, then it decreased back to 0.0032 cd/m2 for 30 minutes. Foveal contrast sensitivity [CS]) as a function of time was determined using a 1.15 degree increment. Time resolution of the experiments was 30 seconds. Multiple linear regression was used to analyse the effect of glaucoma on the CS plateau and adaptation time (time to reach the plateau minus 3 dB); analyses were adjusted for age and gender.

RESULTS

After light adaptation to 320 and 10,000 cd/m2, glaucoma patients had a 0.22 (P<0.001) and 0.13 (P = 0.010) log unit lower CS plateau than controls, respectively. After dark adaptation, this difference was 0.21 (P = 0.018) and 0.30 (P<0.001) log unit, respectively. Light adaptation occurred too fast to determine an accurate light adaptation time. Dark adaptation times of glaucoma patients and controls were similar, for both the 5 (7.2 versus 5.5 minutes; P = 0.10) and the 6.5 (18.2 versus 16.6 minutes; P = 0.14) log unit step.

CONCLUSION

After a sudden increase or decrease in luminance, the logCS adaptation curves of glaucoma patients are shifted downwards compared to the curves of healthy subjects. Glaucoma patients have a lower CS plateau than healthy subjects, for both light and dark adaptation; dark adaptation times are similar.

Prevalence and Causes of Unilateral Vision Impairment and Unilateral Blindness in Australia: The National Eye Health Survey

Importance

This study determines the prevalence of unilateral vision impairment (VI) and unilateral blindness to assist in policy formulation for eye health care services.

Objective

To determine the prevalence and causes of unilateral VI and unilateral blindness in Australia.

Design, Setting, and Participants

This cross-sectional population-based survey was conducted from March 2015 to April 2016 at 30 randomly selected sites across all strata of geographic remoteness in Australia. A total of 1738 indigenous Australians 40 years or older and 3098 nonindigenous Australians 50 years or older were included.

Main Outcomes and Measures

The prevalence and causes of unilateral vision impairment and blindness, defined as presenting visual acuity worse than 6/12 and 6/60, respectively, in the worse eye, and 6/12 or better in the better eye.

Results

Of the 1738 indigenous Australians, mean (SD) age was 55.0 (10.0) years, and 1024 participants (58.9%) were female. Among the 3098 nonindigenous Australians, mean (SD) age was 66.6 (9.7) years, and 1661 participants (53.6%) were female. The weighted prevalence of unilateral VI in indigenous Australians was 12.5% (95% CI, 11.0%-14.2%) and the prevalence of unilateral blindness was 2.4% (95% CI, 1.7%-3.3%), respectively. In nonindigenous Australians, the prevalence of unilateral VI was 14.6% (95% CI, 13.1%-16.3%) and unilateral blindness was found in 1.4% (95% CI, 1.0%-1.8%). The age-adjusted and sex-adjusted prevalence of unilateral vision loss was higher in indigenous Australians than nonindigenous Australians (VI: 18.7% vs 14.5%; P = .02; blindness: 2.9% vs 1.3%; P = .02). Risk factors for unilateral vision loss included older age (odds ratio [OR], 1.60 for each decade of age for indigenous Australians; 95% CI, 1.39-1.86; OR, 1.65 per decade for nonindigenous Australians; 95% CI, 1.38-1.96), very remote residence (OR, 1.65; 95% CI, 1.01-2.74) and self-reported diabetes (OR, 1.52; 95% CI, 1.12-2.07) for indigenous Australians, and having not undergone an eye examination in the past 2 years for nonindigenous Australians (OR, 1.54; 95% CI, 1.04-2.27). Uncorrected refractive error and cataract were leading causes of unilateral VI in both populations (70%-75%). Corneal pathology (16.7%) and cataract (13.9%) were leading causes of unilateral blindness in indigenous Australians, while amblyopia (18.8%), trauma (16.7%), and age-related macular degeneration (10.4%) were major causes of unilateral blindness in nonindigenous Australians.

Conclusions and Relevance

Unilateral vision loss is prevalent in indigenous and nonindigenous Australians; however, most cases are avoidable. As those with unilateral vision loss caused by cataract and posterior segment diseases may be at great risk of progressing to bilateral blindness, national blindness prevention programs may benefit from prioritizing examination and treatment of those with unilateral vision loss.

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).

Contrast Sensitivity in Patients With Emmetropic Presbyopia Before and After Small-Aperture Inlay Implantation

PURPOSE

To develop a normative contrast sensitivity function and examine the postoperative contrast sensitivity outcomes for emmetropic patients with presbyopia implanted with a KAMRA intracorneal inlay (AcuFocus Inc., Irvine, CA) in their non-dominant eyes.

METHODS

A prospective, non-randomized, multicenter clinical trial was conducted on 507 patients between 45 and 60 years of age who were monocularly implanted with the KAMRA inlay. A predetermined subgroup of 335 patients in the contrast sensitivity substudy were measured preoperatively and postoperatively with the Functional Acuity Contrast Test (FACT) chart in the Optec 6500 Vision Tester (Stereo Optical Co., Chicago, IL) under monocular and binocular, photopic and mesopic without glare, and binocular mesopic with glare conditions each over four spatial frequencies (3, 6, 12, and 18 cycles per degree for photopic conditions and 1.5, 3, 6, and 12 cycles per degree for mesopic conditions). Normative ranges were developed using 1.96 standard deviations from the preoperative mean logCS (log10 unit of contrast sensitivity).

RESULTS

The preoperative contrast sensitivity measurements were used to develop the normative contrast sensitivity curves. Postoperatively, contrast sensitivity was stable both monocularly and binocularly and average contrast sensitivity remained within the normative ranges. Postoperative contrast sensitivity was mildly reduced monocularly but not binocularly, and the ratio of area under logCS function comparing postoperative to preoperative values was above 90% for all but one condition.

CONCLUSIONS

Normative contrast sensitivity curves for a presbyopic population are established to provide a referent in the investigation of the impact of other presbyopia-correcting ophthalmic procedures on contrast sensitivity. [J Refract Surg. 2016;32(6):386-393.].

Contrast sensitivity and its determinants in people with diabetes: SN-DREAMS-II, Report No 6

PurposeTo assess contrast sensitivity (CS) and to elucidate the factors associated with CS among subjects with type 2 diabetes in a cross-sectional population-based study.Patients and methodsSubjects were recruited from a follow-up cohort, Sankara Nethralaya Diabetic Retinopathy Epidemiology and Molecular genetics Study (SN-DREAMS II). Of 958 subjects who were followed up in SN-DREAMS II, a subset of 653 subjects was included in the analysis. All subjects underwent a comprehensive eye examination, which included CS assessment using the Pelli-Robson chart. The cross-sectional association between CS and independent variables was assessed using stepwise linear regression analysis. A P-value of <0.05 was considered statistically significant.ResultsThe mean age of the study sample was 58.7±9.41 (44-87) years. Mean CS of the study sample was 1.32±0.20 (range: 0-1.65) log units. CS was negatively and significantly correlated with age, duration of diabetes, hemoglobin level, vibration perception threshold (VPT) value, albuminuria, best corrected visual acuity (BCVA), refractive error, total error score (TEM) of FM 100 hue test, and mean retinal sensitivity. In multiple regression analysis, after adjusting for all the related factors, CS was significantly associated with BCVA (β=-0.575; P<0.001), VPT (β=-0.003; P=0.010), severity of cataract (β=-0.018; P=0.032), diabetic retinopathy (β=-0.016; P=0.019), and age (β=-0.002; P=0.029). These factors explained about 29.3% of the variation in CS.ConclusionAmong the factors evaluated, differences in BCVA were associated with the largest predicted differences in CS. This association of CS with visual acuity highlights the important role of visual assessment in type 2 diabetes.

Development and validation of a vision and night driving questionnaire

PURPOSE

Night-time driving difficulties are a common concern of older drivers and those with eye disease. This study aimed to develop and validate a questionnaire for assessing vision-related night driving difficulties in older drivers.

METHODS

Items from existing vision-related quality of life questionnaires and driving studies were used to develop a questionnaire that was completed by 283 participants who reported visual difficulties for night driving (65% female, 50 to >80 years). The questionnaire included items relating to demographic and night driving characteristics (seven items), general vision ratings (eight items), vision-related night driving difficulties (11 items), and a single open question about specific night driving difficulties. The vision-related night driving difficulty items were analysed separately using Rasch analysis to form the vision and night driving questionnaire (VND-Q). Rasch analysis assessed validity and psychometric properties of the scale. Generalised linear regression models examined associations between VND-Q scores and age, gender, amount of night driving, self-rated vision, and eye conditions. Test-retest repeatability was assessed using intra-class correlation analysis and Bland-Altman methods of agreement for a subset of 30 participants.

RESULTS

Rasch analysis indicated that a nine-item VND-Q scale was unidimensional, valid and reliable, and showed excellent discriminant ability (person separation index 3.04; person reliability 0.90). Targeting was better for those with greater self-reported night driving difficulties. Participants with self-reported bilateral eye conditions and worse self-reported general vision ratings had significantly more night driving difficulties with the VND-Q scale than individuals without eye conditions (p = 0.03) and with better general vision ratings (p < 0.001). Females reported more difficulties than males (p < 0.001) and drove shorter distances at night per week which was also associated with greater difficulties (p < 0.001). A repeatability coefficient (Rc ) of 2.07 demonstrated excellent test-retest repeatability.

CONCLUSIONS

The nine-item VND-Q is a unidimensional and reliable questionnaire allowing quantification of the level of visual difficulties that older drivers report at night. The development of this questionnaire is an important step in providing a reliable and validated instrument for use to guide appropriate investigations, referrals, or interventions in clinical and research settings.

Straylight and Visual Quality on Early Nuclear and Posterior Subcapsular Cataracts

PURPOSE

To measure log(s) and OSI parameters, both related to forward light scattering in the eye, in subjects with different kinds of early cataracts-nuclear or posterior subcapsular-and corrected visual acuity (CVA).

METHODS

34 eyes of 19 patients ranged between 50 and 75 years old with diagnosed nuclear (14 eyes) or posterior subcapsular cataract (20 eyes) were recruited. Only NO1, NO2, P1, and P2 opacity scores according to LOCS III were included. Observer examination included visual acuity, contrast threshold (Ct), and measurements performed by straylightmeter (straylight parameter log(s)) and double-pass instrument (objective scatter index (OSI)).

RESULTS

OSI and log(s) were correlated with LOCSIII in nuclear opacities (p = 0.015 and 0.004, respectively) and in the whole data (p = 0.027 and 0.019, respectively) but did not for posterior subcapsular opacities alone. OSI was strongly correlated with log(s) in nuclear (r = 0.885 and p < 0.001) but not in posterior subcapsular cases (r = 0.382 and p = 0.097). Ct was correlated with log(s) for both cataract types (p = 0.043 for nuclear and p= 0.005 for posterior subcapsular cataract) but not with OSI (p = 0.093 for nuclear and p = 0.064 for posterior subcapsular cataract).

CONCLUSIONS

OSI and log(s) discriminate early stages of nuclear cataracts when taking LOCS III as reference, so these opacities could be graded by any of those parameters. LOCSIII does not represent the visual condition for posterior subcapsular cataract. Straylightmeter measurements express the loss in contrast sensitivity caused by nuclear and posterior subcapsular opacities. Studies of lens opacities must be separated according to the type of opacity present in eyes.

Comparison of Contrast Sensitivity and Through Focus in Small-Aperture Inlay, Accommodating Intraocular Lens, or Multifocal Intraocular Lens Subjects

PURPOSE

To compare monocular and binocular mesopic contrast sensitivity and through focus following monocular implantation with KAMRA small-aperture inlay (AcuFocus, Irvine, California, USA) vs binocular implantation with an accommodating or multifocal intraocular lens (IOL) implant.

DESIGN

Three-treatment randomized clinical trial of presbyopia-correcting IOLs with comparison to results from a previous nonrandomized multicenter clinical trial on the KAMRA corneal inlay.

METHODS

Study population of 507 subjects with KAMRA inlays; predetermined subgroups included 327 subjects that underwent contrast sensitivity testing and another 114 subjects for defocus curve testing, along with 78 subjects randomized between bilateral Crystalens Advanced Optics (AO) (Bausch + Lomb Surgical, Aliso Viejo, California, USA), AcrySof IQ ReSTOR +3.0 D (Alcon Laboratories, Fort Worth, Texas, USA), or Tecnis +4D Multifocal (MF) (Abbott Medical Optics, Santa Ana, California, USA) IOL.

RESULTS

KAMRA inlay subjects demonstrated improved intermediate and near vision with minimal to no change to distance vision, better contrast sensitivity in the inlay eye when compared to the multifocals, and better binocular contrast sensitivity when compared to all 3 intraocular lenses. Crystalens AO was superior in uncorrected intermediate vision compared to the KAMRA inlay, but not in distance-corrected intermediate, and was worse in near vision. The multifocals were superior in near vision at their respective optimum near focus points, but worse in intermediate vision compared to both KAMRA inlay and Crystalens AO.

CONCLUSIONS

The demonstrated performance of these devices should be considered, along with subjects' visual demands and expectations, degree of crystalline lens dysfunction, and other ocular characteristics, in guiding the selection of small-aperture corneal inlay or specific intraocular lens in the correction of presbyopia.

Refractive changes in nuclear, cortical and posterior subcapsular cataracts. effect of the type and grade

PURPOSE

To determine the effect of main morphological types and grades of age-related cataracts on refractive error.

METHODS

We measured 276 subjects with optical compensation prior to the development of cataract. We evaluated 224 eyes with nuclear cataract, 125 with cortical cataract, and 103 with posterior subcapsular (PSC) cataract classified with LOCSIII. We measured visual acuity (VA) with their spectacles and best-corrected visual acuity (BCVA) with chart in decimal scale to obtain the optimal compensation with cataract. We evaluated the differences between compensations.

RESULTS

A significant myopic shift was observed in nuclear cataract from low to mild grade (p=0.031), the same as for PSC cataract from mild to advanced grade (p=0.025). No significant changes were found for cortical cataract (p=0.462). Regarding astigmatism, we observed power changes in cortical cataract from low to mild grade (p=0.03) and axis changes in PSC from low to mild grade (p=0.02) and in nuclear cataract from mild to advanced grade (p=0.02).

CONCLUSIONS

Cataract produces changes in patient's compensation which depend on severity and type of cataract. For nuclear and PSC cataract, we observed that the higher the grade of severity, the greater the myopic shift. Power astigmatic changes were found in cortical cataract and axis changes in PSC and nuclear cataract.

Different Impacts of Luminosity on Contrast Vision in Eyes with Transparent Optic Media and with Cataract Simulation

OBJECTIVE

To evaluate the effect of luminous intensity on contrast vision under different ocular conditions.

MATERIALS AND METHODS

Ninety eyes of 45 persons were included in this study as follows: 30 healthy eyes, 30 eyes with cataract simulation (using translucent glasses), and 30 myopic eyes. Contrast sensitivity was examined using 5 spatial frequencies (1.5, 3.0, 6.0, 12.0, and 18.0 cycles per degree) of sine wave contrast test optotypes for 4 light intensities (34, 68, 154, and 240 cd/m2).

RESULTS

The mean linear contrast sensitivities averaged over the frequencies for each of the 4 light intensities were: healthy eyes: 59 ± 11, 72 ± 16, 79 ± 23, and 80 ± 19; myopic eyes: 52 ± 13, 67 ± 15, 73 ± 21, and 75 ± 18, and cataract simulation eyes: 15 ± 7, 21 ± 8.6, 28.7 ± 13, and 28.6 ± 13, respectively. The linear contrast sensitivities averaged over the light intensities for each of the 5 spatial frequencies were: healthy eyes: 78, 87, 117, 59, and 21; myopic eyes: 65, 84, 109, 54, and 29, and cataract simulation eyes: 37, 41, 28, 8, and 2.

CONCLUSIONS

The light intensity level had a positive effect on the contrast sensitivity of the examined eyes, except for eyes with cataract simulation, where even the maximum light intensity did not improve the contrast vision. This indicates that patients with cataracts require increased contrast of text rather than brighter illumination to improve the quality of their vision.

[Quality of vision studied by comparative measurement of light scattering]

PURPOSE

To assess quality of vision by measuring ocular light scattering with two platforms and comparing them to traditional tests, in healthy subjects and cataract patients.

PATIENTS AND METHODS

One hundred and sixty-eight eyes divided in two groups were examined by the same clinician in a prospective study (group 1, healthy controls, with a mean age of 31.22 [± 6.76]; and group 2, patients presenting with cataract, with a mean age of 60.36 [± 10.27]). Patients with ocular surface disease were excluded from this study. Each group responded to the VF-14 questionnaire, underwent an examination with lens opacities assessed by LOCS III and a measurement of ocular light scattering with two platforms: the OQAS (Visiometrics(©)) and the C-Quant (Oculus(©)). We analyzed correlations between indices of light scattering with the two platforms (respectively OSI and log(s)) and traditional quality of vision tests (VF-14 questionnaire and LOCS III).

RESULTS

Strong correlations were found between the OSI and LOCS III. Moderate correlations were found between the OSI and the VF-14 questionnaire, as well as between log(s), VF-14 questionnaire and LOCS III.

CONCLUSION

Indices of light scattering seems to be valid tools to assess quality of vision, thus lending themselves to routine testing of visual function.

Evaluation of contrast sensitivity measurements after retrobulbar optic neuritis in Multiple Sclerosis

Background

The evaluation of contrast sensitivity is an important additional examination that allows the physician to achieve the full picture of a patient's quality of vision. In low-contrast conditions, more discrete visual dysfunctions may be revealed, which could be overlooked in high-contrast tests.

Methods

The examined group consisted of 33 eyes of 27 patients with multiple sclerosis. The study included patients with full or almost full visual acuity, without visual field defects or any other ophthalmic condition, and who had never undergone any ocular surgery or trauma. The reference group consisted of 49 eyes of 37 patients. This group included healthy subjects with full visual acuity. Contrast sensitivity was examined with a Functional Vision Analyzer™ device in photopic conditions (with and without glare) and in mesopic conditions (with and without glare).

Results

In patients with multiple sclerosis who had experienced optic neuritis, contrast sensitivity was found to be significantly reduced in all spatial frequencies in both mesopic and photopic conditions (with and without glare).

Conclusions

Contrast sensitivity in patients with multiple sclerosis who have also had optic neuritis is significantly reduced. This may explain patients' complaints regarding their quality of vision, despite good visual acuity. Contrastometry is a useful basis for further examination, providing additional information regarding a patient's quality of vision.

Persistent biases in subjective image focus following cataract surgery

We explored the perception of image focus in patients with cataracts, and how this perception changed following cataract removal and implantation of an intraocular lens. Thirty-three patients with immature senile cataract and with normal retinal function were tested before surgery and 2 days after surgery, with 18 of the patients retested again at 2 months following surgery. The subjective focus of natural images was quantified in each session by varying the slope of the image amplitude spectra. At each time, short-term adaptation to the spectral slope was also determined by repeating the measurements after exposure to images with blurred or sharpened spectra. Despite pronounced acuity deficits, before surgery images appeared "best-focused" when they were only slightly blurred, consistent with a strong compensation for the acuity losses. Post-operatively, the image slopes that were judged "in focus" before surgery appeared too sharp. This bias remained strong at 2 months, and was independent of the rapid blur aftereffects induced by viewing filtered images. The focus settings tended to renormalize more rapidly in patients with higher post-operative acuity, while acuity differences were unrelated to the magnitude of the short-term blur aftereffects. Our results suggest that subjective judgments of image focus are largely compensated as cataracts develop, but potentially through a very long-term form of adaptation that results in persistent biases after the cataract is removed.

Age-related change in contrast sensitivity among Australian male adults: Florey Adult Male Ageing Study

PURPOSE

To describe the age-related change in contrast sensitivity seen in 35- to 80-year-old men in an Australian population.

METHODS

The Florey Adelaide Male Ageing Study (FAMAS) is a prospective population-based study of men aged 35-80 years randomly selected from the north-west suburbs of Adelaide. We conducted a nested ophthalmic substudy of these men. Contrast sensitivity (CS) was measured at four spatial frequencies (3, 6, 12 and 18 cycles/degree [cpd]) using the Vectorvision CSV-1000 contrast sensitivity test chart (Vectorvision, Dayton, OH, USA), and results were statistically analysed relative to age and cataract type.

RESULTS

There were 2650 eligible subjects in the FAMAS and 1195 participated (45.1%); 472 of those participated in the ophthalmic substudy. A statistically significant decrease in contrast sensitivity was seen with advancing age at each spatial frequency tested [Generalized estimating equations (GEE) multiple linear regression: p ≤ 0.01]. The decline with age was greatest in the highest spatial frequency (18 cpd) and least in the lowest spatial frequency (3 cpd). Posterior subcapsular cataract caused the greatest reduction in contrast sensitivity at all spatial frequencies, while nuclear cataract caused significant reduction only in the intermediate (12 cpd) and high (18 cpd) spatial frequencies. Cortical cataract failed to reach statistical significance in contrast sensitivity reduction at all spatial frequencies tested.

CONCLUSION

Contrast sensitivity declines with age in all spatial frequencies tested with a greater decline occurring in the higher spatial frequencies. Age and cataracts are independently associated with contrast sensitivity decline, and posterior subcapsular cataracts caused the greatest reduction at all spatial frequencies.

Objective assessment of crystalline lens opacity level by measuring ocular light scattering with a double-pass system

PURPOSE

To assess the crystalline lens opacity level by measuring ocular light scattering with a double-pass system.

DESIGN

Prospective, single-center, cross-sectional study.

METHODS

Two hundred fifty-three eyes of 135 patients referred for cataract evaluation were enrolled. Patients with corneal or retinal anomalies potentially impairing ocular transparency were excluded. Lens opacification was assessed by the Lens opacities classification system III. Optical Quality Analysis System (Visiometrics SL) measurements provided ocular Modulation Transfer Function cutoff frequency and Objective Scatter Index. Best-corrected visual acuity and Quality of Vision questionnaire scores (Rasch-scaled) were recorded. We analyzed correlations between visual acuity, type and severity of cataract, Optical Quality Analysis System measurements, and discomfort level in each group.

RESULTS

In patients with best-corrected visual acuity better than 20/32, we found correlations between Objective Scatter Index, Modulation Transfer Function, and visual acuity (r = 0.4, P < .0001). The Objective Scatter Index, Modulation Transfer Function, and visual acuity were correlated with each type of cataract. In patients with good visual acuity and moderate functional symptoms, the Objective Scatter Index values also were correlated to the severity of posterior subcapsular cataract (r = 0.4, P = .0006).

CONCLUSIONS

Patients with incipient cataract may report visual discomfort, despite minor lens opacity on slit-lamp examination, minor loss of best-corrected visual acuity, or both. The measurement of ocular scattering with the Optical Quality Analysis System device may be a useful tool in the preoperative evaluation of patients with early cataract.

Lens opacities in Valencia, Spain

PURPOSE

To evaluate the most common lens opacities in Valencia (Spain), analyzed by gender, grade, and type of cataracts. The results are compared with other studies performed at other geographical latitudes and on different races.

METHODS

A total of 1951 eyes of patients diagnosed with cataracts, aged between 30 and 96 years, were evaluated in accordance with age, gender, type and degree of the cataract, bilaterality, and symmetry of this disease. Lens Opacities Classification System III was used to classify the cataract and the degree was graded as mild or moderate to advanced.

RESULTS

The most common type of cataract is corticonuclear in the elderly and subcapsular in younger subjects. The most common are nuclear (28.4%) followed by cortical (6.2%), if combined cataracts are ruled out. There is a greater incidence of cortical cataracts in women (70%) and subcapsular cataracts in men (70%).

CONCLUSIONS

The results suggest the existence of a gender factor in cataract formation and coincide with those obtained in similar studies performed in areas at a similar latitude (40º N) and with different race population. The geographical location (intensity and length of exposure to solar radiation) seems to be a determining factor in the formation of a specific type of cataract, more than race, although there are other factors that contribute in the formation of a specific type of cataract.

The Infant Aphakia Treatment Study: evaluation of cataract morphology in eyes with monocular cataracts

PURPOSE

To describe a video-documented assessment of cataract type in the eyes of patients with monocular infantile cataract who were enrolled in the Infant Aphakia Treatment Study.

METHODS

The Infant Aphakia Treatment Study is a randomized clinical trial in which the investigators compared intraocular lens (IOL) versus contact lens correction in 114 infants, aged 28 days to <7 months. A total of 83 videos were available for morphological analysis of cataract. Three examiners reviewed all surgical recordings and agreed on the cataract characteristics by using a score sheet to record the lens layer or configuration of the opacity.

RESULTS

Nuclear cataract was present in 45 of 83 eyes (54%). Posterior capsule plaque was observed in 73 eyes (88%). All eyes with fetal nuclear cataract had associated posterior capsule plaque. Cortical cataract without nuclear involvement was seen in 21 eyes (25%). Posterior bowing of the posterior capsule was noted in 4 eyes (5%). Evidence of persistent fetal vasculature (PFV) was present in 18 eyes (22%). PFV was the only finding in 5 eyes but was also seen in combination with nuclear (7 eyes) and cortical cataracts (6 eyes). The entire lens was white in 3 eyes (4%), whereas the lens was partially resorbed in 7 (8%) eyes. Anterior capsule fibrosis was noted in 5 eyes with advanced cataract (1 with total cataract, 4 with partially resorbed lens).

CONCLUSIONS

Nuclear opacities were common, but many different cataract types presented in infancy. PFV occurred in isolation or in association with cataract. Posterior capsule plaque was frequently noted, especially when a nuclear cataract was present.

Development and validation of clinical scores for visual outcomes after cataract surgery

PURPOSE

To develop and validate a clinical score to predict visual acuity (VA) and functional changes after phacoemulsification on the basis of readily obtainable preoperative history data and patient assessment.

DESIGN

Prospective follow-up study.

PARTICIPANTS

A sample of 5512 patients on waiting lists for phacoemulsification at 17 hospitals in Spain.

METHODS

Data were obtained at the baseline examination from the 5512 patients. The patients were divided randomly into 2 subgroups: derivation (n = 3285; 60%) and validation (n = 2227; 40%). The preoperative predictors of postoperative gains in VA and visual function index 14 (VF-14) were determined by multivariate logistic regression analysis and implemented using a prediction score.

MAIN OUTCOME MEASURES

Probability of postoperative improvement in VA and VF-14 scores. The cutoff points were established for each outcome on the basis of the minimal clinically important difference values.

RESULTS

The predictive variables for VA gain were the baseline VA, patient age, ocular comorbidity, and surgical complexity. Regarding the VF-14, the predictive factors were the preoperative VF-14, the eye with the better VA, and the surgical complexity. In the multivariate logistic model in the derivation sample, the final VA and VF-14 scores ranged from 0 to 44 and from 0 and 24, respectively. Receiver operating characteristic curves were developed in the derivation and validation samples, and no statistical significance was found when their areas under the curve were compared. Areas under the curve ranged from 65% to 80%. Both scores had a positive predictive value from 74% to 85%.

CONCLUSIONS

Newly developed and validated clinical prediction scores may assist physicians and patients in decision making about the expected outcomes and benefits of cataract surgery.

Visual impairment from age-related cataract among an indigenous African population

AIM

To determine the magnitude of visual impairment (VI) resulting from lens opacity/cataract among a rural population in southwestern Nigeria.

METHOD

A population-based cross-sectional survey using a multistage sampling method to select subjects >or=50 years. Participants with pinhole visual acuity of <or=6/18 in their better eye, exclusively from lens opacity/cataract, were further examined by an ophthalmologist. Their level of VI was categorised using the International Classification of Disease tenth revision and lens opacity was graded using the World Health Organization's cataract grading system.

RESULTS

From the enumerated population of 1200 subjects, 1031 subjects were examined. The prevalence of VI from cataract/lens opacity in the population studied was 11.9% (95% CI: 10.1-14.0) with a cataract blindness prevalence of 2.0% (95% CI: 1.3-3.0). The odds for VI increased with increasing age and female patients had 1.6 times the odds for cataract blindness than did male patients. Mixed cataract was the most prevalent of the visually disabling cataract. (3.9% (95% CI: 2.8-5.2)), whereas posterior subcapsular cataract was the least prevalent (2.5% (95% CI: 1.7-3.7)).

CONCLUSION

VI from cataract remains a public health problem in the Akinyele district of Nigeria. The need for a comprehensive cataract surgical service using the VISION 2020 model is necessary in the district if the burden from the backlog of visually disabling cataract is to be reduced.

Quels bénéfices visuels peut-on attendre d’un implant sans aberration sphérique dans la chirurgie de la cataracte ?

PURPOSE

To assess the quality of vision in pseudophakic patients with aspheric intraocular lens (IOL) without spherical aberration compared to patients with spherical IOL.

METHODS

Twenty-four patients (48 eyes) undergoing cataract surgery were randomly divided into two groups: 12 patients received an aspheric IOL in both eyes and 12 received spherical IOLs. The integrity of ocular functions was assessed with clinical examination and multifocal electroretinogram. Postoperative evaluations were conducted 3 months after surgery. Refraction, best-corrected visual acuity, contrast sensitivities, and wavefront ocular aberrations were analyzed. Patient-centered visual functions were evaluated according to the Activities of Daily Vision Scale.

RESULTS

The ADVS score was better in the aspheric IOL group (p=0.01), particularly concerning the best-corrected near vision (p=0.006). Refraction and BCVA were similar. Contrast sensitivities in photopic conditions was better in the aspherical IOL group (p<0.001). Higher-order aberration was not different, except from spherical aberration (p=0.022).

CONCLUSION

Patients with the aspherical IOLs felt they had better quality of vision, particularly near vision, compared with the spherical IOL group. These patient-centered benefits were associated with better photopic contrast sensitivity and reduced spherical aberration.

Quality of vision after cataract surgery after Tecnis Z9000 intraocular lens implantation: effect of contrast sensitivity and wavefront aberration improvements on the quality of daily vision

PURPOSE

To compare ocular performance and quality of vision in pseudophakic eyes with an aspherical intraocular lens (IOL) or a conventional spherical IOL.

SETTING

Bretonneau University Hospital, Tours, France.

METHODS

Twenty patients (40 eyes) were randomly divided in 2 equal groups to bilaterally receive the aspherical Tecnis Z9000 IOL (AMO) or the spherical CeeOn Edge 911 IOL (AMO). Contrast sensitivity was measured and ocular wavefront analysis performed before surgery and 6 months after. Patients completed the Activities of Daily Vision Scale (ADVS) to evaluate patient-centered visual outcomes. Other examinations included refraction before and after mydriasis and pupil diameter.

RESULTS

The mean postoperative best corrected visual acuity (logMAR) was 0.03 +/- 0.05 (SD) in the Tecnis group and 0.01 +/- 0.05 in the CeeOn Edge group (P = .41). Refractive evaluation with mydriasis showed a mean myopic shift as low as -0.02 +/- 0.36 diopter (D) in the Tecnis group and -0.51 +/- 0.37 D in the CeeOn Edge group (P = .001). Mesopic contrast sensitivity at high spatial frequencies was significantly better in the Tecnis group (P<.001), while contrast sensitivity under photopic and glare conditions was not different between the 2 groups. Spherical aberration was significantly lower in the Tecnis group, which had a mean Z(4)(0) of 0.01 +/- 0.06 microm, than in the CeeOn Edge group, which had a mean Z(4)(0) of 0.16 +/- 0.12 microm (P<.001). The global score on the ADVS was not statistically different between groups; however, quality of distance vision was better in the Tecnis group than in the CeeOn Edge group (mean 99.0 +/- 2.0 versus 89.2 +/- 3.4) (P<.001).

CONCLUSION

Implantation of an aspherical IOL with a negative spherical aberration resulted in reduced ocular spherical aberration and improved mesopic contrast sensitivity and led to better subjective quality of vision.

Lens opacities associated with performance-based and self-assessed visual functions

OBJECTIVE

To investigate the relationship of lens opacities to performance-based and self-assessed visual function in persons free of other ocular comorbidities.

DESIGN

Cross-sectional cohort study.

PARTICIPANTS

Beaver Dam Eye Study participants.

METHODS

Lens photographs were taken and graded by protocols for age-related lens opacities. During the study evaluation, best-corrected visual acuity, near vision, and contrast sensitivity (performance-based visual functions) were measured. Questions were asked about visual function in particular settings (self-assessed visual functions).

RESULTS

After the exclusion of other ocular comorbidities, performance-based visual functions were associated significantly (P< or =0.001 for each association) with severity of lens opacities, including relatively early lens opacities. Self-assessed visual functions were associated less consistently with severity of lens opacities (P<0.02 for all). In age-stratified analyses, there were fewer significant associations of self-assessed visual functions with severity of lens opacities for persons younger than 65 years than for persons 65 or older.

CONCLUSIONS

Lens opacities across the range of severities were associated with measurable decreases in visual functions; the associations, especially for self-assessed functions, tended to be greater at older ages. It is likely that successful measures to decrease the severity of lens opacities will have a greater impact on older persons.

Qualité de vision des patients porteurs d’un implant asphérique prolate après chirurgie de la cataracte

PURPOSE

To assess the quality of vision in pseudophakic patients with a prolate aspherical intraocular lens (IOL) compared to patients with a spherical IOL.

PATIENTS AND METHODS

Twenty patients undergoing cataract surgery were divided into two groups according to the type of IOL: ten prolate aspherical IOLs (TECNIS Z9000, AMO, USA) and ten spherical IOLs (911 CeeOn Edge, AMO, USA). The integrity of ocular functions was assessed with clinical examination and multifocal electroretinogram. Contrast sensitivities were tested preoperatively in photopic, mesopic, and glared conditions. Postoperative examinations included refractive evaluation before and after mydriasis, pupil diameter, contrast sensitivities, and wavefront aberration analysis.

RESULTS

Postoperative best-corrected visual acuity was 0.95 +/- 0.13 for the TECNIS group vs 0.98 +/- 0.11 for the 911 group (p=0.32). Refractive evaluation revealed mydriasis myopic shift in patients with the 911 IOL (- 0.10+/-0.30 D for the TECNIS group vs - 0.68+/-0.21 D for the 911 group, p=0.002). Mesopic contrast sensitivity was improved in the TECNIS group regarding medium and high spatial frequencies (p=0.003 and p=0.002, respectively), whereas photopic and glared contrast sensitivities were equal in both groups. RMS for high-order aberrations was 0.36 +/- 0.07 microm in the TECNIS group vs 0.33 +/- 0.19 microm in the 911 group (p=0.21), and spherical aberration was lower in patients with TECNIS IOL (Z40=0.03+/-0.06 microm vs 0.20+/-0.14 microm, for the TECNIS group and the 911 group, respectively, p=0.029).

CONCLUSION

Combining contrast sensitivities and wavefront aberration analysis provided an objective assessment of the quality of vision in pseudophakic patients. Using prolate aspherical IOL could reduce spherical aberration and improve visual acuity, especially in mesopic conditions.

Simulated Impairment of Contrast Sensitivity: Performance and Gaze Behavior during Locomotion through a Built Environment

PURPOSE

An experimental study investigated the effects of simulated impairment of contrast sensitivity (CS) on performance and eye gaze patterns during locomotion through a library.

METHOD

Normally sighted participants with simulated CS impairment (diffusive blur) walked two routes, one entailing limited change in direction (simple) and the other entailing several changes in direction (complex), while eye movements relative to the scene were recorded. Performance variables included walking speed in completing the route, pauses during travel, and collisions with objects on the route. For eye movements, dwell time and saccades were determined for each of three object classes: (1) objects on the route below eye level; (2) objects on the route extending above eye level; and (3) elsewhere-objects not on the route.

RESULTS

Walking speed was significantly affected by CS level and by route; pauses and collisions were rare. Dwell times and saccades suggested limited attention directed to low-level objects, except for CS impairment on the complex route. In the complex route, saccades and dwell times in the object class "elsewhere" were also reduced.

CONCLUSIONS

The results for the simple route suggest ballistic strategies: the participant appraises the scene and follows a more or less predetermined path. For the complex route, CS impairment appears to adversely affect information processing and locomotion. The results have implications for the design of built environments, especially with regard to the safety of visually impaired occupants during emergency scenarios.