Pseudoexfoliation and Cataract Syndrome Associated with Genetic and Epidemiological Factors in a Mayan Cohort of Guatemala.

The Mayan population of Guatemala is understudied within eye and vision research. Studying an observational homogenous, geographically isolated population of individuals seeking eye care may identify unique clinical, demographic, environmental and genetic risk factors for blinding eye disease that can inform targeted and effective screening strategies to achieve better and improved health care distribution. This study served to: (a) identify the ocular health needs within this population; and (b) identify any possible modifiable risk factors contributing to disease pathophysiology within this population. We conducted a cross-sectional study with 126 participants. Each participant completed a comprehensive eye examination, provided a blood sample for genetic analysis, and received a structured core baseline interview for a standardized epidemiological questionnaire at the Salama Lions Club Eye Hospital in Salama, Guatemala. Interpreters were available for translation to the patients' native dialect, to assist participants during their visit. We performed a genome-wide association study for ocular disease association on the blood samples using Illumina's HumanOmni2.5-8 chip to examine single nucleotide polymorphism SNPs in this population. After implementing quality control measures, we performed adjusted logistic regression analysis to determine which genetic and epidemiological factors were associated with eye disease. We found that the most prevalent eye conditions were cataracts (54.8%) followed by pseudoexfoliation syndrome (PXF) (24.6%). The population with both conditions was 22.2%. In our epidemiological analysis, we found that eye disease was significantly associated with advanced age. Cataracts were significantly more common among those living in the 10 districts with the least resources. Furthermore, having cataracts was associated with a greater likelihood of PXF after adjusting for both age and sex. In our genetic analysis, the SNP most nominally significantly associated with PXF lay within the gene KSR2 (p < 1 × 10-5). Several SNPs were associated with cataracts at genome-wide significance after adjusting for covariates (p < 5 × 10-8). About seventy five percent of the 33 cataract-associated SNPs lie within 13 genes, with the majority of genes having only one significant SNP (5 × 10-8). Using bioinformatic tools including PhenGenI, the Ensembl genome browser and literature review, these SNPs and genes have not previously been associated with PXF or cataracts, separately or in combination. This study can aid in understanding the prevalence of eye conditions in this population to better help inform public health planning and the delivery of quality, accessible, and relevant health and preventative care within Salama, Guatemala.

Crystalline lens changes after selective laser trabeculoplasty in Afro-Caribbean patients with open-angle glaucoma; report 4 of the West Indies Glaucoma Laser Study (WIGLS).

PURPOSE: To characterize changes in nuclear, cortical, and posterior subcapsular lens opacities after selective laser trabeculoplasty (SLT) in Afro-Caribbean eyes with primary open-angle glaucoma (POAG). SETTING: Three clinical practices, Saint Lucia and Dominica. DESIGN: Prospective case series. METHODS: Patients with POAG in the West Indies Glaucoma Laser Study (WIGLS) had 360-degree SLT after medication washout. No antiinflammatory therapy was used after SLT. Nuclear, cortical, and posterior subcapsular lens opacities were graded through dilated pupils using the Lens Opacification Classification System III (LOCS III) at baseline and 12, 24, and 36 months after SLT, with the grader masked to all previous values after baseline assessment. Changes in opacity scores from baseline were evaluated using paired t tests. RESULTS: Seventy-two patients (142 phakic eyes) were evaluated. The mean (±SD) baseline LOCS III opacity scores in right eyes and left eyes, respectively, were 2.44 ± 1.23 and 2.40 ± 1.16 (nuclear), 0.39 ± 1.08 and 0.30 ± 0.85 (cortical), and 0.22 ± 0.59 and 0.15 ± 0.36 (posterior subcapsular). Other than a small improvement in bilateral nuclear opacity scores at 12 months, no statistically or clinically significant changes in any opacity score occurred in either eye up to 36 months postoperatively. Three eyes (2.1%) with preexisting lens opacities had cataract surgery for progressive lens changes at 3 months, 21 months, and 26 months, respectively, after SLT. CONCLUSIONS: Selective laser trabeculoplasty was not associated with clinically significant changes in nuclear, cortical, or posterior subcapsular lens opacities in glaucomatous Afro-Caribbean eyes. The rate of cataract surgery is consistent with reported rates from longitudinal natural history studies in Caribbean and non-Caribbean populations.

Lens opacity based modelling of the age-related straylight increase.

This work studies ethnic and geographical differences in the age-related straylight increase by means of a stochastic model and unpublished lens opacity data of 559 residents of Villa Maria (Argentina), as well as data of 912 Indonesian subjects published previously by Husain et al. For both cohorts the prevalence of each type and grade of lens opacity was determined as a function of age, from which a stochastic model was derived capable of simulating the lens opacity prevalence for both populations. These simulated lens opacity data were then converted to estimated straylight by means of an equation derived from previously recorded data of 107 eyes with varying degrees of cataract. Based on these opacity templates 2500 random sets of subject age and lens opacity data were generated by the stochastic model for each dataset, from which estimated straylight could be calculated. For the Argentinian data the estimated straylight was found to closely resemble the published models for age-related straylight increase. For younger eyes the straylight variation of the model was the same as what was previously published (in both cases ±0.200logunits), which doubled in size for older eyes. For the Indonesian data, however, this age-related straylight increase was found to be fundamentally different from the published age model. This suggests that current normative curves for age-related straylight increase may not always be appropriate for non-European populations, and that the inter-individual straylight variations in young, healthy eyes may possibly be due to variations in lens opacities.

Impact of glaucoma, lens opacities, and cataract surgery on visual functioning and related quality of life: the Barbados Eye Studies.

PURPOSE: To determine the relationship of open-angle glaucoma (OAG) and lens opacities to visual functioning and related quality of life (QOL), by using the 25-item National Eye Institute Visual Function Questionnaire (NEI-VFQ-25) in a population of African origin. METHODS: The study included 962 black participants of the Barbados Eye Studies with known glaucoma, prior cataract surgery, visual acuity (VA)

Prevalence of pterygium and cataract in indigenous populations of the Brazilian Amazon rain forest.

PURPOSE: To compare the prevalence of pterygium and cataract in four indigenous populations of the Brazilian Amazonian rain forest (Arawak, Tukano, Maku, and Yanomami) with different ethnic and social behaviour backgrounds. METHODS: A cross-sectional pterygium and cataract survey was performed in 624 adult Indians of the Brazilian rain forest belonging to four different ethnic groups. The Indians were classified according to their social behaviour in two groups: Arawak and Tukano (group 1) and Maku and Yanomami (group 2). Slit-lamp biomicroscopy was employed to examine the entire sample. All subjects were classified as 1 or 0 according to the presence or absence pterygium and cataract. Sex and age were also recorded. RESULTS: chi(2)-tests revealed that the prevalence of pterygium and cataract differed significantly between groups 1 and 2. For pterygia: 36.6% (97/265) and 5.0% (18/359), respectively (chi(2)=101.2, P<0.0001), and for cataracts: 24.5% (65/265) and 13.7% (49/359) respectively (chi(2)=12.09, P=0.0005). Gender was not associated with pterygium (P=0.1326) and cataract (P=0.2263) in both groups. Elderly subjects showed a significantly higher prevalence of cataract (P<0.0001). The prevalence of pterygia did not increase with age (P=0.8079) in both groups. CONCLUSION: Indians of group 1 have higher prevalence of pterygia and cataract than Indians of group 2. Social behaviour, especially the rate of sun exposure, appears to be the main factor for the different rates of pterygium and cataract displayed by these indigenous people of the Brazilian rain forest.

[Cataract blindness in people 50 years old or older in a semirural area of northern Peru]. / Ceguera por catarata en personas mayores de 50 años en una zona semirrural del norte del Perú

OBJECTIVE: To determine the prevalence of blindness and of cataract blindness in persons 50 years of age or older in Piura and Tumbes, which are two departments in northern Peru, and to describe the coverage and quality of cataract surgery services in that area, and the barriers that prevent access to those services. METHODS: Systematic sampling of persons 50 years old or older was done in Piura and Tumbes between August 2002 and March 2003, with 80 clusters of 60 people each being selected. Of the 4 800 persons chosen, 4,782 of them were examined, using a survey instrument that gathered general information on each person, the results of the visual acuity test and the lens examination, and information on cataract surgery or why that surgery had not been done. Visual acuity (VA) testing was done with a Snellen optotype with the letter "E," with sizes of 20/60 and 20/200 at distances of 6 m and 3 m, respectively, with the person using the visual correction (glasses) available. When the VA was less than 20/60 in one of the eyes, vision was tested with pinhole glasses. RESULTS: The prevalence of bilateral blindness (VA < 20/400) due to cataract, adjusted by age and sex, was 2.1% (95% confidence interval (CI): 1.7% to 2.6%). Among the 193 persons with bilateral blindness due to any cause, cataract was the cause in 104 of them (53.9%). The prevalence of blindness due to cataract or other causes increased with age and was higher in women than in men. Only 25% of the persons studied who needed cataract surgery had had that done. The prevalence of bilateral VA less than 20/200 due to unoperated cataract was 6.3% (95% CI: 5.3% to 7.3%); only 12% of the persons with that level of visual deficiency had had cataract surgery. The VA of 26% of the eyes operated on for cataract was lower than 20/200. The reasons given by persons who needed cataract surgery but who had not had it included not being able to pay for the operation (28%), lack of knowledge concerning cataracts (25%), fear of the operation (23%), and fear of completely losing their sight (17%). CONCLUSIONS: Most of the cases of blindness and of serious deficiency in visual acuity in persons 50 years old or older in Piura and Tumbes are due to uncorrected refractive defects, especially cataracts. The high prevalence of bilateral blindness due to cataracts (2.1%) could be reduced with measures that facilitate access to appropriate treatment.

Risk factors for incident cortical and posterior subcapsular lens opacities in the Barbados Eye Studies.

OBJECTIVE: To evaluate risk factors for the 4-year incidence of cortical and posterior subcapsular (PSC) lens opacities. DESIGN: Population-based cohort study with 85% participation at 4-year follow-up. PARTICIPANTS: Three thousand one hundred ninety-three black participants of the Barbados Eye Studies, Barbados, West Indies, of whom 2040 and 2954 were free of cortical and PSC lens opacities, respectively, at baseline. METHODS: The standardized protocol at baseline and follow-up included an interview, anthropometric and blood pressure measurements, and ophthalmic measurements including slitlamp lens grading, fundus photography, and an ophthalmologic examination. Factors associated with incident cortical and PSC opacities (Lens Opacities Classification System II, > or =2) were evaluated by logistic regression. Main Outcome Measure Relative risks (RRs) with 95% confidence intervals. RESULTS: The 4-year incidence of cortical lens opacities was 22.2% (452/2040); the factors increasing risk were older age, female gender (RR = 1.3), low socioeconomic status (RR = 1.4), and a history of diabetes mellitus (RR = 2.4), while aspirin use was associated with a lower RR (RR = 0.2; 95% confidence interval, 0.1-0.8), a result based on small numbers. The 4-year incidence of PSC opacities was lower at 3.3% (97/2954), and risk also increased with age and a history of diabetes mellitus (RR = 2.9). A dose-response relationship was evident between incident opacities and increased levels of glycosylated hemoglobin at baseline, with the highest risk of cortical (RR = 3.60; 95% confidence interval, 2.23-5.81) and PSC (RR = 4.93; 95% confidence interval, 2.69-9.05) opacities at more than an 11.5% glycosylated hemoglobin level. CONCLUSIONS: Diabetes mellitus and hyperglycemia are major modifiable risk factors for the development of cortical and PSC lens opacities in this African-descent population with a high rate of diabetes mellitus. Prevention and improved control of diabetes mellitus are likely to reduce the burden of cataract. The finding of a reduced incidence of cortical lens opacities in aspirin users merits further investigation, given its potential for cataract prevention.

Nine-year incidence of lens opacities in the Barbados Eye Studies.

OBJECTIVE: To provide 9-year cumulative incidence of age-related lens opacities in a predominantly black population. DESIGN: Population-based cohort study, after 9 years of follow-up (n = 2793; 81% participation). MAIN OUTCOME MEASURES: Nine-year cumulative incidence and progression of lens opacities, by type, based on the Lens Opacities Classification System II at the slit lamp. RESULTS: Black participants had a higher 9-year incidence of overall lens changes than white participants (age- and gender-adjusted relative risk [RR], 1.8; 95% confidence interval [CI], 1.2-2.8), as well as of cortical opacities (RR, 3.2; 95% CI, 1.7-6.2). In black participants, incidence rates of any cortical and any nuclear opacities were 33.8% and 42.0%, respectively, and higher than for any posterior subcapsular (PSC) opacities (6.3%). The incidence increased with age for all 3 types, and women had a higher risk of cortical and nuclear opacities (P<0.05). Single cortical opacities were the most frequent type to develop by the 9-year follow-up (23.2%), followed by nuclear-only opacities (17.1%) and mixed opacities (15.3%). Progression rates of pre-existing opacities were 22.0% for cortical, 17.8% for nuclear, and 25.8% for PSC opacities. CONCLUSIONS: The 9-year follow-up of this cohort indicated a high incidence and progression of cortical and nuclear opacities, highlighting the public health importance of cataract in black populations.

The impact of visual impairment and eye disease on vision-related quality of life in a Mexican-American population: proyecto VER.

PURPOSE: To describe the relationship of visual acuity impairment and eye disease on vision-related quality of life, as measured by the 25-item National Eye Institute Visual Function Questionnaire (NEI-VFQ-25), in a cross-sectional, population-based study of older Hispanic persons living in Arizona. METHODS: A random sample of block groups with Hispanic residents in Nogales and Tucson, Arizona, were selected for study. Participants were interviewed at home with a questionnaire that included the NEI-VFQ-25, an instrument measuring vision-related quality of life. Acuity was obtained with Early Treatment Diabetic Retinopathy Study (ETDRS) charts and standard protocol. Cataract was determined by clinical examination, diabetic retinopathy was diagnosed on stereo fundus photographs, and glaucoma was diagnosed on the basis of clinical examination and visual field results. Analyses were done to determine the degree of association between subscale scores and acuity in the better-seeing eye, monocular visual impairment, and specific eye diseases, with adjustment for acuity. RESULTS: Of the 4774 participants in the study, 99.7% had completed questionnaires that were not completed by proxy. Participants with visual impairment had associated decrements in scores on all subscales, with a decrease in presenting acuity associated with a worse score (P < 0.05), after adjustment for demographic variables. Monocular impairment was also associated with lower scores in several subscales. In those with cataract, low acuity explained most of the low scores, but those with glaucoma or diabetic retinopathy had low scores independent of acuity. CONCLUSIONS: In this study of Mexican-American persons aged 40 or more, monocular impairment and better-eye acuity was associated with a decrease in most domains representing quality of life. Subjects with uncorrected refractive error, cataract, diabetic retinopathy, and glaucoma had associated decrements in quality of life, many not explained by loss of acuity. Further work on the specific measures of vision associated with reported decreases in quality of life, such as visual field or contrast sensitivity, is warranted.

Risk factors for incident nuclear opacities.

PURPOSE: To evaluate risk factors for the 4-year incidence of nuclear opacities. DESIGN: Population-based cohort study (85% participation at 4-year follow-up). PARTICIPANTS: Two thousand six hundred nine black participants of the Barbados Eye Studies, without any nuclear opacities at baseline. METHODS: Participants completed a standardized protocol at baseline and follow-up, including ophthalmic and other measurements, an interview, slit-lamp lens grading, fundus photography, and an ophthalmologic examination. Factors associated with the incidence of nuclear opacities (Lens Opacities Classification System II N > or = 2) were evaluated by logistic regression. MAIN OUTCOME MEASURE: Relative risks (RR) with 95% confidence intervals (95% CI). RESULTS: The 4-year incidence of nuclear opacities was 9.2% (241 of 2609) and increased greatly with age. Women were at significantly greater risk (RR = 1.8), as were persons with darker iris color (RR = 4.9), myopia (RR = 2.8), history of diabetes (RR = 1.6), leaner body mass (RR = 0.95 for each unit increase in body mass index [kg/m(2)]), and intraocular pressure (IOP)-lowering treatment (RR = 2.7), mainly with topical beta-blockers. Treated participants had a threefold RR of nuclear opacities (RR = 3.2; 95% CI, 1.6, 6.5) compared with those untreated and with IOP < or =21 mmHg. Among participants with IOP >21 mmHg, those receiving treatment (n = 33) had a fivefold RR (RR = 5.0; 95% CI, 1.7, 15.1) versus those who were untreated. The RR was similar for treated persons with and without open-angle glaucoma (RR = 3.1; 95% CI, 1.3, 7.4 and RR = 2.8; 95% CI, 0.9, 8.6 respectively) but was lower in persons with newly detected (and thus untreated) glaucoma at baseline (RR = 1.2; 95% CI, 0.6, 2.6) compared with those without open-angle glaucoma or treatment. CONCLUSIONS: The 4-year risk of nuclear opacities increased with age, female gender, darker iris color, myopia, diabetes, and leaner body mass, indicating similarities with other populations. The use of topical IOP-lowering medications tripled the RR of nuclear opacities in this study, an association that requires verification from clinical trials.

Prevalence and causes of visual impairment in The Barbados Eye Study.

OBJECTIVE: To determine the prevalence and causes of low vision and blindness in a predominantly black population. DESIGN: Population-based prevalence study of a simple random sample of Barbados-born citizens aged 40 to 84 years. PARTICIPANTS: Four thousand seven hundred nine persons (84% participation). METHODS: The standardized protocol included best-corrected visual acuity (with a Ferris-Bailey chart), automated perimetry, lens gradings (LOCS II), and an interview. Participants with visual acuity of worse than 20/30, other positive findings, and a 10% sample also had an ophthalmologic examination that evaluated the cause and extent of vision loss (resulting from that cause), if any. MAIN OUTCOME MEASURES: Low vision and blindness were defined as visual acuity in the better eye between 6/18 and 6/120 and visual acuity worse than 6/120, respectively (World Health Organization [WHO] criteria). RESULTS: Of the 4631 participants with complete examinations, 4314 (93%) reported their race as black, 184 (4%) reported their race as mixed (black and white), and 133 (3%) reported their race as white or other. Low vision was found in 5.9% of the black, 2.7% of the mixed, and 3.0% of white or other participants. Bilateral blindness was similar for black and mixed race participants (1.7% and 1.6%, respectively) and was not found in whites. Among black and mixed participants, the prevalence of low vision increased with age (from 0.3% at 40-49 years to 26.8% at 80 years or older). The prevalence of blindness was higher (P < 0.001) for men than women at each age group (0.5% versus 0.3% at ages 40-49 and 10.9% versus 7.3% at 80 years or more). Sixty percent of blindness was due to open-angle glaucoma and age-related cataract, each accounting for more than one fourth of cases. Other major causes were optic atrophy or neuropathy and macular and other retinal diseases. Few cases of blindness were due to diabetic retinopathy (1.4%), and none were due to age-related macular degeneration. CONCLUSIONS: Using the WHO criteria, prevalence of visual impairment was high in this African-origin population, particularly at older ages. Most blindness was due to open-angle glaucoma and cataract, with open-angle glaucoma causing a higher proportion of blindness than previously reported. The increased prevalence of blindness in men may be due to the increased male prevalence of glaucoma in this population and warrants further investigation. Results underline the need for blindness prevention programs, with emphasis on effective treatment of age-related cataract and enhancing strategies for early detection and treatment of open-angle glaucoma.

Lens opacities and mortality : the Barbados Eye Studies.

OBJECTIVE: To evaluate the association between cataract and mortality in a black population by type of opacity, which has not been documented previously. DESIGN: Population-based cohort study. PARTICIPANTS: The Barbados Incidence Study of Eye Diseases reexamined the Barbados Eye Study cohort, identified through a simple random sample of predominantly black Barbadian-born citizens, aged 40 to 84 years. Of those eligible, 85% (3427 participants) had a 4-year follow-up visit. METHODS: Baseline and follow-up visits included an interview, blood pressure and other measurements, and a detailed ophthalmologic examination with slit-lamp lens gradings (Lens Opacities Classification System [LOCS] II protocol). Mortality at follow-up was verified from Ministry of Health records. MAIN OUTCOME MEASURES: Lens opacities were defined by a LOCS II score of 2 or more. Opacity types were classified in two ways: (1) single (cortical-only, nuclear-only, and posterior subcapsular-only) and mixed opacities; and (2) any cortical, any nuclear, or any posterior subcapsular opacities. Information on dates and causes of death was obtained from death certificates. RESULTS: Cardiovascular disease was the principal cause of death in black participants (3.6%), followed by malignant neoplasms (1.4%). The cumulative 4-year mortality varied with lens types, increasing from 3.2% for those without cataract to 6.0% for cortical-only, 8.8% for nuclear-only, and 20.9% for mixed opacities. Persons with mixed opacities had a 1.6-fold increase in mortality, while controlling for other factors (age, male gender, diabetes, hypertension, obesity, cigarette smoking, cardiovascular disease, and family history of diabetes) in Cox proportional-hazards regression analyses. Persons with any nuclear opacities also had increased mortality (death rate ratio, 1.5). The death rate ratios increased with age, but peaked at age 60 to 69 years. Coexisting diabetes further increased mortality: people with mixed opacities and diabetes had a 2.7-fold increased risk of death. A trend toward increased mortality from neoplasms was observed for individuals with mixed opacities or with any nuclear opacities. CONCLUSIONS: Participants with mixed opacities or any nuclear opacities had increased 4-year mortality rates, with diabetes acting as an effect modifier. This study is the first to identify a relationship between type of cataract and mortality in an African-descent population.

Barreiras no acesso ao tratamento da catarata senil: aspectos socio-culturais / Barriers to the acess to senile cataract treatment: social and cultural aspects

Objetivo: Identificar características e percepçöes de indivíduos adultos, portadores de catarata senil, em relaçäo ao seu problema visual e dificuldades à assistência oftalmológica, para subsidiar o planejamento de açöes preventivas e assistenciais em oftalmologia direcionadas à comunidade. Tipo de Estudo: "Survey" descritivo. Local: Hospital das Clínicas da Faculdade de Medicina da Universidade de Säo Paulo (HCFMUSP), Brasil. Participantes: Portadores de catarata senil indentificados pelo "Projeto Catarata". Método: Aplicou-se um questionário por entrevista em amostra de conveniência. Resultados: Os entrevistados apresentaram as seguintes características: 46.0 por cento do sexo masculino, 54.0 por cento do sexo feminino, idades entre 50 e 93 anos (média de 70 anos); 87.0 por cento näo exerce atividades profissionais. Foram apontadas como causas da dificuldade visual a velhice (58.0 por cento), hereditariedade (25.5 por cento) e o uso dos olhos em atividades profissionais (24.5 por cento). Para 68.2 por cento a catarata era a causa da dificuldade visual. Contribuíram para a ausência de tratamento anterior a falta de recursos econômicos (41.5 por cento) e o medo de submeter-se à cirurgia (25.0 por cento). A maioria deles (81.5 por cento) confia na qualidade da cirurgia e 93.0 por cento acredita que a cirurgia irá curá-los. Com o tratamento, 70.5 por cento espera poder voltar a exercer atividades caseiras, 62.5 por cento ler jornais e revistas, 62.5 por cento ver televisäo, 51.5 por cento deambular sem ajuda, 47.0 por cento ler o letreiro do ônibus e 34.5 por cento voltar a trabalhar fora. Conclusöes: Para a reabilitaçäo de deficientes visuais cegos por catarata senil é necessário que, ao lado de se prover maior facilidade de acesso ao tratamento, sejam executados esforços educativos abordando causas e resultados do tratamento da catarata.