Color vision devices for color vision deficiency patients: A systematic review and meta-analysis.

Background and Aims: There is insufficient evidence to support that using electronic or optical color vision devices improve color perception with current advanced technology. The purpose of this study is to compare and analyze the different color vision devices available for patients with color vision deficiency (CVD) and evaluate whether these devices improved their color perception. Methods: This review included randomized, experimental, comparative studies, as well as narrative reviews, prototype and innovation studies, and translational studies, followed by case-control and clinical trials with nonsurgical interventions studies, that is, electronic color vision devices, optical devices, and contact lens-based studies, with standardized inclusion and exclusion criteria. Results: The primary outcome studied was the performance of color vision devices, both objective and subjective. Secondary outcomes included the ease of use and accessibility of color vision devices and technology. The grading of recommendation, assessment, development, and evaluation framework was used to develop a systematic approach for consideration and clinical practice recommendation for CVD devices for color-deficient populations. We incorporated meta-analysis reports from a total of n = 16 studies that met the criteria which consisted of case-control studies, prototype and innovation studies, comparative studies, pre- and post-clinical trial studies, case studies, and narrative reviews. Proportion and standard errors, as well as correlations, were calculated from the meta-analysis for various available color vision devices. Conclusion: This review concludes that commercially available color vision devices, such as EnChroma Glasses, Chromagen filters, and EnChroma Cx-14 do not provide clinically significant evidence that subjective color perception has improved. As a result, recommending these color vision devices to the CVD population may not prove high beneficial/be counterproductive. However, only a few color shades can be perceived differently. This systematic review and analysis will aid future research and development in color vision devices.

Statistical analysis plan for the family-led rehabilitation after stroke in India (ATTEND) trial: A multicenter randomized controlled trial of a new model of stroke rehabilitation compared to usual care.

Background In low- and middle-income countries, few patients receive organized rehabilitation after stroke, yet the burden of chronic diseases such as stroke is increasing in these countries. Affordable models of effective rehabilitation could have a major impact. The ATTEND trial is evaluating a family-led caregiver delivered rehabilitation program after stroke. Objective To publish the detailed statistical analysis plan for the ATTEND trial prior to trial unblinding. Methods Based upon the published registration and protocol, the blinded steering committee and management team, led by the trial statistician, have developed a statistical analysis plan. The plan has been informed by the chosen outcome measures, the data collection forms and knowledge of key baseline data. Results The resulting statistical analysis plan is consistent with best practice and will allow open and transparent reporting. Conclusions Publication of the trial statistical analysis plan reduces potential bias in trial reporting, and clearly outlines pre-specified analyses. Clinical Trial Registrations India CTRI/2013/04/003557; Australian New Zealand Clinical Trials Registry ACTRN1261000078752; Universal Trial Number U1111-1138-6707.

Elimination of avoidable blindness due to cataract: where do we prioritize and how should we monitor this decade?

BACKGROUND: In the final push toward the elimination of avoidable blindness, cataract occupies a position of eminence for the success of the Right to Sight initiative. AIMS: Review existing situation and assess what monitoring indicators may be useful to chart progress towards attaining the goals of Vision 2020. SETTINGS AND DESIGN: Review of published papers from low and middle income countries since 2000. MATERIALS AND METHODS: Published population-based data on prevalence of cataract blindness/visual impairment were accessed and prevalence of cataract blindness/visual impairment computed, where not reported. Data on prevalence of cataract blindness, cataract surgical coverage at different visual acuity cut offs, surgical outcomes, and prevalence of cataract surgery were analyzed. Scatter plots were used to look at relationships of some variables, with Human Development Index (HDI) rank. Available data on Cataract Surgical Rate (CSR) was plotted against prevalence of cataract surgery reported from surveys. RESULTS: Worse HDI Ranks were associated with higher prevalence of cataract blindness. Most studies showed that a significant proportion of the blind were covered by surgery, while a fifth showed that a significant proportion, were operated before they went blind. A good visual outcome after surgery was positively correlated with higher surgical coverage. CSR was positively correlated with cataract surgical coverage. CONCLUSIONS: Cataract surgical coverage is increasing in most countries at vision <3/60 and visual outcomes after cataract surgery are improving. Establishing population-based surveillance of cataract surgical need and performance is a strong monitoring tool and will help program planners immensely.

Relationship between visual impairment and eye diseases and visual function in Andhra Pradesh.

OBJECTIVE: To determine the impact of visual impairment and eye diseases on visual function in an older population of Andhra Pradesh in southern India. DESIGN: Population-based cross-sectional study. PARTICIPANTS: The visual function questionnaire (VFQ) was completed by 7363 (99.1% of the 7431 eligible) persons aged 16 years or older participating in the Andhra Pradesh Eye Disease Study identified from 70 clusters in 3 rural areas and 24 clusters in 1 urban area. Participants aged 40 years or older (n = 3676), 98.7% of the 3724 eligible, who underwent an interview and a detailed dilated ocular eye evaluation by trained professionals were included in this study. METHODS: The psychometric properties of the VFQ were evaluated among visually impaired persons. The authors examined the relationships of overall visual function score with presenting visual acuity in the better eye, specific eye diseases, and demographic variables. MAIN OUTCOME MEASURE: Visual function score. RESULTS: Internal consistency was high for the entire questionnaire (Cronbach's alpha, 0.92). All the items of the visual function scale had an adequate item-total correlation (range, 0.44-0.75) of more than 0.2. After adjusting for demographic variables and ocular disease, persons with visual impairment had significantly lower scores of functional vision. Persons with glaucoma, corneal disease, or retinal disease independent of visual acuity had lower scores compared with persons without these eye diseases. Persons with cataract had significantly lower scores than those without cataract in the model without visual acuity, but did not have significantly lower scores when visual acuity was added to the model. CONCLUSIONS: The VFQ may be used as a measure of functional vision across a range of visual problems among older adults in Andhra Pradesh. Presenting visual acuity in the better eye was associated with functional vision in this population. Decrease in functional vision was associated with the presence of glaucoma, corneal disease, or retinal disease independent of visual acuity, and with cataract as a function of visual acuity.

Risk factors for diabetic retinopathy: Findings from The Andhra Pradesh Eye Disease Study.

OBJECTIVE: To assess prevalence, potential risk factors and population attributable risk percentage (PAR%) for diabetic retinopathy (DR) in the Indian state of Andhra Pradesh. METHODS: A population-based study, using a stratified, random, cluster, systematic sampling strategy, was conducted in the state of Andhra Pradesh in India during 1996 and 2000. Participants from 94 clusters in one urban and three rural areas representative of the population of Andhra Pradesh, underwent a detailed interview and a comprehensive dilated ocular evaluation by trained professionals. DR was defined according to the international classification and grading system. For subjects more than or equal to 30 years of age, we explored associations of DR with potential risk factors using bivariable and multivariable analyses. Population attributable risk percent was calculated using Levin's formula. RESULTS: Diabetic retinopathy was present in 39 of 5586 subjects, an age-gender-area-adjusted prevalence of 0.72% (95% confidence interval (CI): 0.49%-0.93%) among subjects aged >/= 30 years old, and 0.27% (95% CI: 0.17%-0.37%) for all ages. Most of the DR was either mild (51.3%) or moderate (35.9%) non-proliferative type; one subject (2.6%) had proliferative retinopathy. Multivariable analysis showed that increasing age, adjusted odds ratio (OR); 4.04 (95% CI: 1.88-8.68), middle and upper socioeconomic status group (OR); 2.34 (95% CI: 1.16-4.73), hypertension (OR); 3.48 (95% CI: 1.50-8.11) and duration of diabetes >/= 15 years (OR); 8.62 (95% CI: 2.63-28.29) were significantly associated with increasing risk of DR. The PAR % for hypertension was 50%; it was 10% for cigarette smokers. CONCLUSIONS: Extrapolating the prevalence of diabetic retinopathy in our sample to the Indian population suggests that there may be an estimated 2.77 million people with DR, approximately 0.07 million people with severe DR. As the population demographics change towards aging, this number is likely to increase further. Health care programs in India need to examine strategies to prevent diabetes and DR, as well as create the infrastructure required to manage this condition.

Impact of impaired vision and eye disease on quality of life in Andhra Pradesh.

PURPOSE: To determine the impact of visual impairment and eye diseases on quality of life (QOL) in an older population of Andhra Pradesh in southern India. METHODS: The World Health Organization (WHO) QOL (WHOQOL) instrument was adapted as a health-related quality of life (HRQOL) instrument for administration to adults participating in the Andhra Pradesh Eye Disease Study. Participants aged 40 years and older (n = 3702), 99.4% of the 3723 eligible, who underwent interview and detailed dilated ocular eye evaluation by trained professionals were included in this study. Psychometric properties of the HRQOL instrument were evaluated among visually impaired people. Relationships among overall QOL scores and presenting visual acuity in the better eye, specific eye diseases, and demographic variables were examined. RESULTS: Internal consistency was high for the entire questionnaire (alpha = 0.94). Each item of the QOL scale had an adequate item-total correlation (range, 0.25-0.77) greater than 0.2. After adjusting for demographic variables and ocular disease, Subjects with blindness had significantly lower QOL scores. Subjects with glaucoma or corneal disease independent of visual acuity had lower scores than subjects without those eye diseases. Subjects with cataract or retinal disease had significantly lower scores than those without cataract or retinal disease in the model without visual acuity but not when visual acuity was added to the model. CONCLUSIONS: Decreased QOL was associated with the presence of glaucoma or corneal disease independent of visual acuity and with cataract or retinal disease as a function of visual acuity. Visual impairment from uncorrected refractive errors was not associated with decreased QOL.

Ocular trauma in a rural population of southern India: the Andhra Pradesh Eye Disease Study.

OBJECTIVE: To determine the prevalence of ocular trauma and proportion of blindness and visual impairment due to ocular trauma in a rural population of southern India. DESIGN: Population-based cross-sectional epidemiological study. PARTICIPANTS: A total of 7771 subjects of all ages, representative of the rural population of Andhra Pradesh. METHODS: The subjects underwent a detailed interview and comprehensive ocular evaluation as part of the population-based Andhra Pradesh Eye Disease Study. MAIN OUTCOME: An eye was considered to be blind due to trauma if best-corrected distance visual acuity was worse than 6/60 and the cause was attributed to ocular trauma. RESULTS: A total of 824 (10.6%) subjects gave a history of ocular trauma in either eye, including 76 (1.0%) persons reporting trauma in both eyes. The overall age- and gender-adjusted prevalence of history of eye injury in this rural population was 7.5% (95% confidence interval [CI], 7.0%-8.1%). Men were more likely to have an eye injury than women (odds ratio [OR], 2.1 [95% CI, 1.8-2.5]). After adjusting for gender and other demographic factors, ocular trauma was significantly more frequent among laborers (OR, 1.5 [95% CI, 1.2-1.7]) when compared with other occupational groups. After adjusting for gender, injury with vegetable matter such as a thorn, branch of a tree, plant secretion, etc. (n = 373 [45.3%]) was the major cause of trauma reported in this population. The majority of the eye injuries occurred at the workplace (n = 461 [55.9%]), followed by home (n = 179 [21.7%]). The majority of those affected (n = 806 [97.8%]) did not wear any eye protection at the time of trauma. A significant proportion (n = 307 [43.1%]) of subjects who sought treatment for an eye injury went to an ophthalmologist. Trauma was responsible for unilateral blindness in 39 subjects, an age- and gender-adjusted prevalence of 0.6% (95% CI, 0.4%-0.8%). CONCLUSIONS: Most ocular injuries in this rural population occurred at the workplace, suggesting the need to explore workplace strategies to minimize ocular trauma as a priority. Eye care programs targeting high-risk ocular trauma groups may need to consider ocular trauma as a priority in eye health awareness strategies to reduce blindness due to trauma.

A population-based assessment of presbyopia in the state of Andhra Pradesh, south India: the Andhra Pradesh Eye Disease Study.

PURPOSE: To determine the prevalence of presbyopia in the state of Andhra Pradesh in south India. METHODS: Comprehensive ocular examinations including logMAR (logarithm of the minimum angle of resolution) distance and near (presenting and best corrected) visual acuity, slit lamp biomicroscopy of the anterior segment, and dilated posterior segment examinations were performed using a standardized protocol for subjects identified through a random cluster-sampling strategy in Andhra Pradesh. Information of difficulty in performing near tasks was collected as part of a visual function questionnaire administered to all subjects. A person was defined as having presbyopia if the person required an addition of at least 1.0 D in either eye for near vision in addition to their best corrected distance correction to improve near vision to at least N8 and if they had graded lens opacities (Lens Opacities Classification System [LOCS III] system). RESULTS: Examined in the study were 5587 subjects 30 years of age or older (mean age 47.5+/-13.0 years). The age-, gender-, and area-adjusted prevalence of presbyopia was 55.3% (95% confidence interval [CI]: 54.0-56.6). One third (n=1173; 30.0%) of the 3907 subjects with presbyopia were currently using spectacles. Of the 2734 subjects with presbyopia and not using spectacles, 528 (19.3%) had moderate to severe difficulty in reading small print, and 2085 (76.3%) had moderate to severe difficulty in recognizing small objects and performing near work, including 1057 (38.6%) subjects who were unable to manage any near work. On multivariate analysis, female sex (OR: 1.4, 95% CI: 1.1-1.8), rural residence (OR: 1.5, 95% CI: 1.2-1.8), alcohol consumption (OR: 0.8, 95% CI: 0.6-0.9), nuclear opacity of the lens greater than grade 2 LOCS III (OR: 4.8, 95% CI: 1.4-16.8), myopia (OR: 1.6, 95% CI: 1.3-2.1), and hyperopia (OR: 3.6, 95% CI: 2.7-5.2) were associated with presbyopia. CONCLUSIONS: The high prevalence of presbyopia and the stated effect on performing activities related to near vision needs to be translated into programs and strategies that specifically target presbyopia.

Consanguinity and eye diseases with a potential genetic etiology. Data from a prevalence study in Andhra Pradesh, India.

PURPOSE: To determine the prevalence of consanguinity and its potential associations with eye diseases in Andhra Pradesh state of south India. METHODS: As part of a demographic interview schedule, prior to clinical examinations, trained investigators collected information regarding consanguinity of the parents from subjects randomly chosen for a population-based cross-sectional epidemiological study. Each subject underwent a detailed ocular examination including visual acuity measurements, anterior segment examinations with slit-lamp biomicroscopy, and posterior segment examinations. Adjusted odds ratios (OR), attributable risks (AR) and population attributable risks (PAR) were estimated. RESULTS: We obtained details regarding consanguinity of the parents from 10,290 of the 10,293 subjects who were enumerated and examined in the study. Parental consanguinity was reported by 1822 (24.7%) rural subjects and 782 (32.9%) urban subjects. Eighty (0.008%, 95% CI: 0.006, 0.010) of the 9757 subjects had an ocular disease with a potential genetic basis. We found microcornea to be significantly associated with both an uncle-niece relationship (adjusted OR: 7.32, 95% CI: 1.73, 30.97, AR = 86.34%, PAR = 42.11%) and a first-cousin relationship between the parents (adjusted OR 4.51, 95% CI: 1.05, 19.40, AR = 77.83%, PAR = 29.02%). Retinitis pigmentosa was significantly associated with a first-cousin relationship between the parents (adjusted OR: 5.31, 95% CI: 1.00, 28.25, AR = 81.17%, PAR = 33.43%). CONCLUSIONS: The high prevalence of consanguinity in this population does not appear to translate into a high prevalence of ocular malformations; however, studies with larger sample sizes are required to further explore the strength of these associations.

Risk factors for age-related macular degeneration: findings from the Andhra Pradesh eye disease study in South India.

PURPOSE: To assess prevalence, potential risk factors, and population attributable risk percentage (PAR%) for age-related macular degeneration (AMD) in the Indian state of Andhra Pradesh. METHODS: A population-based study, using a stratified, random, cluster, systematic sampling strategy, was conducted in the state of Andhra Pradesh in India from 1996 to 2000. Participants from 94 clusters in one urban and three rural areas representative of the population of Andhra Pradesh underwent a detailed interview and a detailed dilated ocular evaluation by trained professionals. In this report, the authors present the prevalence estimates of AMD and examine the association of AMD with potential risk factors in persons aged 40 to 102 years (n = 3723). AMD was defined according to the international classification and grading system. Standard bivariate and multivariate analyses were performed to identify the potential risk factors for AMD. PAR% was calculated by Levin's formula. RESULTS: AMD was present in 71 subjects--an age-gender-area-adjusted prevalence of 1.82% (95% confidence interval [CI], 1.39%-2.25%). Risk factors that were significant in bivariate analyses were considered for multivariate logistic regression analysis. Multivariate analysis showed that the adjusted prevalence of AMD was significantly higher in those 60 years of age or older (odds ratio [OR], 3.55; 95% CI, 1.61-7.82) and history of prior cigar smoking (OR, 3.29; 95%CI, 1.42-7.57). Presence of cortical cataract and prior cataract surgery were significantly associated with increased prevalence of AMD (adjusted OR, 2.87; 95% CI, 1.57-5.26 and 3.79; 95% CI, 2.1-6.78), respectively. The prevalence of AMD was significantly lower in light alcohol drinkers (adjusted OR, 0.38; 95% CI, 0.19-0.76) compared with nondrinkers. The PAR% for hypertension and heavy cigar smoking was 10% and 14%, respectively, in this population. CONCLUSIONS: The prevalence of AMD in this south Indian population is similar to those reported in other developed countries. Abstinence from smoking may reduce the risk of AMD in this population.

Awareness of glaucoma in the rural population of Southern India.

PURPOSE: To explore the awareness of glaucoma amongst the rural population of Andhra Pradesh, India. MATERIALS AND METHODS: A total of 7775 subjects of all ages, representative of the rural population of Andhra Pradesh, participated in the Andhra Pradesh Eye Disease Study. The responses of subjects older than 15 years (n=5573) who completed a structured questionnaire regarding awareness (heard of glaucoma) and knowledge (understanding of disease) of glaucoma formed the basis of this study. RESULTS: Awareness of glaucoma (n=18; 0.32%) was very poor in this rural population, and females were significantly less aware (p=0.007). Awareness of glaucoma was also significantly less among illiterate persons (p<0.0001), and socially backward population (p<0.0001). Majority of the respondents who were aware of glaucoma (n=10; 55.6%) did not know if visual loss due to glaucoma was permanent or reversible. The major source of awareness of glaucoma in this population was TV/magazines and other media followed by information from a relative or acquaintance suffering from the disease. CONCLUSION: Awareness of glaucoma is very poor in the rural areas of southern India. The data suggest the need for community-based health education programmes to increase the level of awareness and knowledge about glaucoma.

Smoking and its association with cataract: results of the Andhra Pradesh eye disease study from India.

PURPOSE: To investigate the associations between tobacco smoking and various forms of cataracts among the people of a state in India. METHODS: A population-based cross-sectional epidemiologic study was conducted in the south Indian state of Andhra Pradesh (AP). A total of 10,293 subjects of all ages from one urban and three rural areas, representative of the population of AP, were interviewed, and each underwent a detailed dilated ocular evaluation by trained professionals. Data were analyzed for 7416 (72%) of the subjects aged >15 years. RESULTS: Increasing age was significantly associated with all cataract types and history of prior cataract surgery and/or total cataract. In multivariate analyses, after adjusting for all demographic factors and for history of smoking, females, illiterate persons, and those belonging to the extreme lower socioeconomic status group were found to have a significantly higher prevalence of any cataract, adjusted odds ratio (OR)=1.60 (95% confidence interval [CI]: 1.24-1.96), 1.46 (95% CI: 1.17-1.70), and 1.92 (95% CI: 1.14-3.24), respectively. After adjustment, cigarette and cigar smokers had a significantly higher prevalence of any cataract, adjusted OR=1.51 (95% CI: 1.10-2.06) and 1.44 (95% CI: 1.12-1.84), respectively, compared with those who had never smoked ("never-smokers"). A significantly higher prevalence of nuclear, cortical cataract, and history of prior cataract surgery and/ or total cataract was found among cigarette smokers. A dose-response relationship was seen with respect to cigarette and cigar smoking. After adjustment, compared with never-smokers, cigarette smokers who smoked heavily (>14 "pack-years" of smoking) had a significantly higher prevalence of nuclear cataract (OR=1.65; 95% CI: 1.10-2.59), cortical cataract (OR=2.11; 95% CI: 1.38-3.24), and history of prior cataract surgery and/or total cataract (OR=2.10; 95% CI: 1.05-4.22). Nuclear cataract was significantly higher in cigar smokers (adjusted OR=1.55; 95% CI: 1.16-2.01) and in cigar smokers who smoked heavily (>21 person-years of smoking; OR=1.50; 95% CI: 1.10-1.95), compared with never-smokers. CONCLUSIONS: Consistent with other studies, tobacco smoking was strongly associated with a higher prevalence of nuclear and cortical cataracts and history of prior cataract surgery in this population. These findings suggest yet another need to educate the community on the importance of cessation of tobacco smoking and perhaps incorporating an antismoking message into school health programs.

Perceived visual ability for functional vision performance among persons with low vision in the Indian state of Andhra Pradesh.

PURPOSE: To determine the distribution of perceived visual ability for functional vision performance among persons with low vision in the Indian state of Andhra Pradesh. METHODS: As part of a population-based epidemiologic study, the Andhra Pradesh Eye Disease Study (APEDS), a 16-item visual function questionnaire was designed and applied to 7363 persons older than 15 years, to record the levels of difficulty perceived by the subjects. Of these, 123 persons were found to have low vision. Rasch analysis was used to convert the ordinal difficulty ratings of these 123 persons into interval measures of perceived visual ability for functional vision. RESULTS: Content validity of the questionnaire was demonstrated by good separation indices (3.17 and 5.44) and high reliability scores (0.91 and 0.97) for person and item parameters. Construct validity was shown with model fit statistics. Criterion validity of the questionnaire was shown by good discrimination among the general vision ratings. The functional situation that required the least visual ability was "reaching an object farther or closer than you thought"; the situation requiring the most visual ability was "recognizing small objects." Bivariate regression analysis determined that for every unit of logMAR visual acuity, perceived visual ability for functional vision decreased by 2.9 logit, which could explain 32% of the variability in the person measure. CONCLUSIONS: The described assessment, across a range of visual problems, is a valid way to measure perceived ability for functional vision in persons with low vision. Perceived visual ability varies with every unit of logarithm of the minimum angle of resolution (logMAR) visual acuity.

Awareness of eye donation in the rural population of India.

PURPOSE: To determine the "awareness of eye donation" and "willingness to pledge eyes for donation" in the rural population of Andhra Pradesh, southern India. METHODS: A total of 7,775 subjects of all ages, representative of the rural population of Andhra Pradesh, participated in the Andhra Pradesh Eye Disease Study (APEDS). Subjects older than 15 years were interviewed regarding awareness of eye donation and willingness to pledge eyes for donation. RESULTS: Age-gender adjusted prevalence of awareness of eye donation in this population was 30.7% (95% CI: 29.5-31.9) but only 0.1% (age-gender adjusted prevalence) (95% CI: 0.05-0.25) had pledged eyes. On multivariate analysis the awareness of eye donation was significantly less in those subjects > or = 70 years old (OR 0.7; 95% CI: 0.6-0.8), illiterates (OR 0.2; 95% CI: 0.1-0.2), females (OR 0.8; 95% CI: 0.7-0.9), lower socioeconomic status group (OR 0.4; 95% CI: 0.4-0.5) and Christians (OR 0.2; 95% CI: 0.1-0.6). Media comprised the major source of information about eye donation. Of those aware of eye donation, 32.9% were willing to pledge eyes, and 50.6% needed more information to decide whether or not to pledge their eyes. CONCLUSIONS: There needs to be more transfer of knowledge if more eyes are to be pledged. One-third of those aware of eye donation have not pledged their eyes, and an additional 50.6% needed more information to decide. This means only about one-fifth of those aware of eye donations have pledged their eyes.