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.     

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.     

Pseudoexfoliation in southern India: the Andhra Pradesh Eye Disease Study

PURPOSE: To report the prevalence of pseudoexfoliation (PXF) and its associations with ocular diseases in a south Indian population. METHODS: This was a population-based, cross-sectional epidemiologic study 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 underwent a comprehensive ophthalmic evaluation. PXF was diagnosed on slit lamp biomicroscopy by the presence of white dandruff-like material in the pupillary margin, on the trabecular meshwork, and/or on the anterior lens capsule of one or both eyes. RESULTS: The age-gender-area-adjusted overall prevalence of PXF was 0.69% (95% CI: 0.53-0.86). The prevalence of PXF increased with increasing age: 3.01% (95% CI: 2.45-3.80), in those 40 years of age or older, and 6.28% (95% CI: 4.80-7.76), in those 60 years of age or older. The prevalence of PXF was significantly higher among people whose occupation involved outdoor activities (adjusted odds ratio [OR], 2.14; 95% CI: 1.10-4.16). After adjustment for age, the prevalence of PXF was significantly higher in those with nuclear cataract (adjusted OR, 2.00; 95% CI: 1.13-3.54). PXF was significantly associated with blindness (adjusted OR, 2.19; 95% CI: 1.16-4.13). Fifteen (20.5%; 95% CI: 11.20-29.80) of those with PXF were blind, with age-adjusted relative risk (RR) = 4.25 (95% CI: 4.01-4.51). Unilateral blindness (41.2%; 95% CI: 29.81-52.39) and visual impairment (45.21%; 95% CI: 34.29-57.13) were also more common with PXF. Four subjects (5.5%; 95% CI: 0.27-10.2) of those with PXF had glaucoma. The prevalence of PXF in those with glaucoma was 4.2%; (95% CI: 0.17-8.23). In general linear models, the estimated mean +/- SE of IOP with glaucoma and PXF was 24.14 +/- 1.41 mm Hg and was 18.94 +/- 0.26 mm Hg with glaucoma in the absence of PXF; the difference was statistically significant (P < 0.0001). CONCLUSIONS: The association of PXF with blindness and aging has public health implications for India. This is especially so considering the burden of cataract with aging and the association of PXF with cataract as well as complications of cataract surgery. The diagnosis of PXF may also be important in the management of glaucoma in this population.     

Changing trends in the prevalence of blindness and visual impairment in a rural district of India: Systematic observations over a decade

Context : Globally, limited data are available on changing trends of blindness from a single region. Aims : To report the changing trends in the prevalence of blindness, visual impairment (VI), and visual outcomes of cataract surgery in a rural district of Andhra Pradesh, India, over period of one decade. Settings and Design : Rural setting; cross-sectional study. Materials and Methods : Using a validated Rapid Assessment of Cataract Surgical Services (RACSS) method, population-based, cross-sectional survey was done in a rural district in the state of Andhra Pradesh, India. Two-stage sampling procedure was used to select participants ≥50 years of age. Further, a comparative analysis was done with participants ≥50 years from the previously concluded Andhra Pradesh Eye Disease Study (APEDS) study, who belonged to the same district. Statistical Analysis : Done using 11 th version of Stata. Results : Using RACSS, 2160/2300 (93.9%) participants were examined as compared with the APEDS dataset (n=521). Age and sex adjusted prevalence of blindness in RACSS and APEDS was 8% (95% CI, 6.9-9.1%) and 11% (95% CI, 8.3-13.7%), while that of VI was 13.6% (95% CI, 12.2-15.1%) and 40.3% (95% CI, 36.1-44.5%), respectively. Cataract was the major cause of blindness in both the studies. There was a significant reduction in blindness following cataract surgery as observed through RACSS (17.3%; 95% CI, 13.5-21.8%) compared with APEDS (34%; 95% CI, 20.9-49.3%). Conclusion : There was a significant reduction in prevalence of blindness and VI in this rural district of India over a decade.     

Risk factors for age related cataract in a rural population of southern India: the Aravind Comprehensive Eye Study

AIM: To determine risk factors for lens opacities and age related cataract in an older rural population of southern India. METHODS: A cross sectional population based study of 5150 people aged 40 years and above from 50 clusters from three districts in southern India. The lens was graded and classified after dilation using LOCS III system at the slit lamp for cataract. Definite cataract was defined as nuclear opalescence >/=3.0 and/or cortical cataract >/=3.0 and/or PSC >/=2.0. RESULTS: Definite cataracts were found in 2449 (47.5%) of 5150 subjects and the prevalence of cataract increased with age. The age adjusted prevalence of cataract was significantly lower in males (p = 0.0002). Demographic risk factors-increasing age and illiteracy-were common for the three subtypes of cataract; females were more likely to have cortical cataracts and nuclear cataracts. Additionally, nuclear cataracts were associated with moderate smoking (OR:1.28, 95% CI:1.01 to 1.64), lean body mass indices (OR: 1.37, 95% CI: 1.17 to 1.59) and higher waist to hip ratios (OR: 0.67, 95% CI: 0.54 to 0.82); cortical cataracts with hypertension (OR: 1.39 95% CI:1.11 to 1.72), pseudoexfoliation (OR:1.53,95% CI:1.17 to 2.01), and moderate to heavy smoking; and posterior subcapsular cataracts with diabetes (OR:1.55, 95% CI:1.12 to 2.15), lean body mass (OR:1.32, 95% CI:1.11 to 1.57), and high waist to hip ratios (OR: 0.77, 95% CI: 0.62 to 0.94). CONCLUSIONS: Risk factors for age related cataract in this population do not appear to be different from those reported in other populations. Further studies are required to identify the reason for the high prevalence of age related cataract and to understand better the role of each risk factor for cataractogenesis in this population.     

Dietary and lifestyle risk factors associated with age-related macular degeneration: A hospital based study

Aim:

To establish the frequency, associations and risk factors for age-related macular degeneration (AMD) in hospital population of South India.

Materials and Methods:

In this cross-sectional hospital based study, 3549 subjects (2090 men and 1459 women) above 45 years of age were screened randomly for AMD. Participants underwent ocular evaluation and were interviewed for lifestyle variables and dietary intake of carotenoids by structured food frequency questionnaire. AMD was defined according to the international classifications and grading system.

Results:

Either form of AMD was detected in 77 (2.2%) participants. Of which, early and late AMD was present in 63 (1.8%) and 14 (0.4%) subjects, respectively. Binary logistic analysis showed that the incidence of AMD was significantly higher with increasing age (Odds ratio [OR] 1.17; 95% CI 1.13-1.22) and diabetes (OR 3.97; 95% CI 2.11-7.46). However, AMD was significant among heavy cigarette smokers (OR 5.58; 95% CI 0.88-7.51) and alcoholics (OR 4.85; 95% CI 2.45-12.22). Dietary lutein/zeaxanthin (L/Z) and β-carotene intake were associated (P < 0.001) with the reduction in risk for AMD, with an OR of 0.38 and 0.65, respectively.

Conclusions:

Higher dietary intake of carotenoids, especially L/Z, was associated with lower risk for AMD. Risk of AMD is higher with increasing age and was prevalent among subjects with diabetes. Cessation of smoking and alcohol may reduce the risk of AMD in this population.     

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.     

Awareness of eye donation in an urban population in India.

PURPOSE: Awareness of eye donation and willingness to pledge eyes for donation was assessed in the urban population of Hyderabad, India, where corneal blindness is a significant problem. METHODS: A total of 2522 subjects of all ages, representative of the Hyderabad population, participated in the Andhra Pradesh Eye Disease Study. Subjects >15 years old were interviewed regarding awareness of eye donation and willingness to pledge eyes for donation. RESULTS: Age-gender-adjusted prevalence of awareness of eye donation was 73.8% (95% CI: 66.5-81.0%) but only 1.9% (95% CI: 0.16-3.66%) had pledged eyes. With multivariate analysis, significantly less awareness of eye donation was found in illiterate subjects (OR 0.1; 95% CI: 0.1-0.14), subjects > or =70 years old (OR 0.3; 95% CI: 0.2-0.6), subjects of lower socio-economic status (OR 0.4; 95% CI: 0.3-0.6), females (OR 0.6; 95% CI: 0.5-0.8) and Muslims (OR 0.7; 95% CI: 0.6-0.9). Media was the major source of information about eye donation. Of those aware of eye donation, 44.9% were willing to pledge eyes. Willingness to pledge eyes for donation was significantly lower in Muslims (OR 0.18; 95% CI: 0.13-0.24) than in Hindus and in subjects > or =60years old (OR 0.3; 95% CI: 0.2-0.5). CONCLUSIONS: These data show that although only a few had pledged eyes there is enough potential in this population for obtaining many more corneas for transplantation. The information about distribution and demographic associations of awareness and willingness for eye donation could help in developing strategies to increase procurement of corneas for dealing with corneal blindness.     

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.     

Population based assessment of uveitis in an urban population in southern India

AIM: To assess the prevalence of active and inactive uveitis unrelated to previous surgery or trauma in an urban population in southern India. METHODS: As part of the Andhra Pradesh Eye Disease Study, 2522 subjects (85.4% of those eligible), a sample representative of the population of Hyderabad city in southern India, underwent interview and detailed dilated eye examination. Presence of sequelae of uveitis without current active inflammation was defined as inactive uveitis. RESULTS: Unequivocal evidence of active or inactive uveitis unrelated to previous surgery or trauma was present in 21 subjects, an age-sex adjusted prevalence of 0.73% (95% confidence interval (CI) 0.44-1.14%). Active uveitis was present in eight subjects, an age-sex adjusted prevalence of 0.37% (95% CI 0. 19-0.70), of which 0.06% was anterior, 0.25% intermediate, and 0.06% posterior. The 0.36% (95% CI 0.17-0.68%) prevalence of inactive uveitis included macular chorioretinitis scars (0.26%), anterior (0. 07%) and previous vasculitis involving the whole eye (0.03%). The prevalence of visual impairment due to uveitis of less than 6/18 in at least one eye was 0.27%, less than 6/60 in at least one eye was 0. 16%, and less than 6/60 in both eyes was 0.03%. CONCLUSION: These population based cross sectional data give an estimate of the prevalence of various types of uveitis in this urban population in India. Active or past uveitis that might need treatment at some stage was present in one of every 140 people in this population.     

Cardiovascular risk factors and age-related macular degeneration: the Los Angeles Latino Eye Study

PURPOSE: To assess the association of cardiovascular risk factors and ocular perfusion pressure with early and advanced age-related macular degeneration (AMD) in Latinos. DESIGN: Population-based, cross-sectional study. METHODS: Data were collected from a population-based sample of self-identified adult Latinos using standardized protocols for assessing blood pressure and intraocular pressure (IOP) measurement and stereoscopic macular photography. Hypertension was defined as either a history of hypertension or systolic blood pressure (SBP) > 140 mm Hg +/- diastolic blood pressure (DBP) > or = 85 mm Hg. Ocular perfusion pressure (OPP) was defined as the difference between mean arterial blood pressure and IOP. AMD was diagnosed from photographic grading by masked trained graders. Logistic regression was used to assess associations. RESULTS: Gradable retinal photographs were available in 5,875 participants. After adjusting for age, gender, and cigarette smoking, higher DBP and uncontrolled diastolic hypertension were associated with exudative AMD (odds ratio [OR], 1.8; 95% confidence interval [CI], 1.1 to 2.8; and OR, 3.3; CI, 1.2 to 9.3, respectively). Higher OPP was associated with a decreased risk of geographic atrophy (GA) (OR, 0.4 per 10 mm Hg; CI, 0.3 to 0.5). Low pulse pressure was associated with a lower risk of exudative AMD (OR, 0.2; CI, 0.1 to 0.6). Obesity was associated with increased retinal pigment (OR, 1.6; CI, 1.0 to 2.3). CONCLUSIONS: These data suggest that in Latinos cardiovascular risk factors may play a role in advanced AMD. Given that Latinos have a high prevalence of cardiovascular risk factors, an intervention aimed at reducing these risk factors may also have a beneficial impact on the risk of having early and advanced AMD.     

Smoking and the risk of dry eye: a Meta-analysis

AIM: To collect the evidence to estimate the correlation between smoking and the incidence of dry eye. METHODS: The PubMed, EMBASE, the Cochrane Central Register of Controlled Trials (CENTRAL, last issue), CBM (Chinese BioMedical Literature Database), and CNKI (China National Knowledge Infrastructure/Chinese Academic Journals full-text Database) were searched for eligible studies published from January 1964 to December 2015 to investigate the association of smoking with the risk of dry eye. The odds ratio (OR) and 95% confidence interval (CI) were summarized and calculated. The extracted studies were pooled by the fixed-effects model or a random-effects model. RESULTS: Two cohort studies and eight cross-sectional surveys were included in our Meta-analysis. There was no statistically significant relationship between current (OR=1.32; 95% CI: 0.99-1.76; P=0.055) or ever smoking (OR=1.12; 95% CI: 0.98-1.28; P=0.107) and the risk of dry eye among the studies, even when age and gender were adjusted (OR=1.16; 95% CI: 0.83-1.64; P=0.383). In the sensitivity analysis in which only general population were included, the association was significant between smoking and dry eye (OR=1.50; 95% CI: 1.08-2.09; P=0.016). CONCLUSION: This Meta-analysis suggests that smoking may associate with the risk of dry eye in general population.     

Population-based assessment of refractive error in India: the Andhra Pradesh eye disease study

Purpose: To assess the prevalence, distribution, and demographic associations of refractive error in the population of the southern Indian state of Andhra Pradesh. Methods: From 94 clusters in one urban and three rural areas of Andhra Pradesh, 11 786 persons of all ages were sampled using a stratified, random, cluster, systematic sampling strategy in the Andhra Pradesh Eye Disease Study, a population‐based cross‐sectional study. A total of 10 293 people underwent an interview and detailed dilated eye examination. Refraction was performed by ophthalmic personnel trained in the study procedures. Objective refraction under cycloplegia was assessed for participants ≤ 15 years of age and subjective refraction for those > 15 years of age. Myopia was defined as spherical equivalent worse than ‐0.50 D and hyperopia as spherical equivalent worse than +0.50 D. Results: In the participants ≤ 15 years of age, the prevalence of myopia was 3.19% (95% confidence interval [CI] 2.24?4.13%) and of hyperopia was 62.62% (95% CI 57.10?68.13%). In this age group, myopia increased with increasing age and was more prevalent in the urban study area, and hyperopia prevalence was greater in the participants < 10 years of age. In participants > 15 years of age, the prevalence of myopia was 19.45% (95% CI 17.88?21.02%) and of hyperopia was 8.38% (95% CI 6.91?9.85%). Myopia and hyperopia increased with increasing age. Myopia was more common in males, those with education higher than class 12, those with nuclear cataract, and those living in rural study areas. Hyperopia was more common in females, those with any level of formal education, and those living in the urban area and in the well‐off rural study area. Conclusions: There is significant refractive error in this population. These data on the distribution and associations of refractive error can be useful for the planning of refractive eye‐care services.     

Associations of cardiovascular disease and its risk factors with age-related macular degeneration: the POLA study

The POLA study (June 1995 through July 1997) is a population-based study on cataract and age-related macular degeneration (AMD) and their risk factors in 2584 residents of Séte (South of France), aged 60--95 years. Classification of AMD was performed on 50 degrees fundus photographs, according to an international classification. The presence of cardiovascular disease and its risk factors was determined by interviewer-based questionnaire, clinical examination (anthropometry, blood pressure) and fasting plasma measurements. Using a logistic model adjusted for age and gender, late AMD was not significantly associated with a history of cardiovascular disease, diabetes, use of hypocholesterolemic drugs, hypertension, blood pressure or plasma lipids. Obese subjects (body mass index greater than 30 kg/m( 2)) had a 2.29-fold (95% confidence interval (CI): 1.00--5.23) and 1.54-fold (CI: 1.05--2.26) increased risk of late AMD and pigmentary abnormalities in comparison with lean subjects. Finally, the risk of soft drusen was decreased in those subjects with a history of cardiovascular disease (odds-ratio (OR) = 0.72, CI: 0.54--0.97), and increased with increasing levels of HDL-cholesterol (OR = 1.52, CI: 1.14--2.02). None of these results were modified by further adjustments for smoking, educational level and plasma alpha-tocopherol. These results need to be confirmed by other studies, which ideally should be longitudinal and prospective.     

Elevated serum homocysteine, low serum vitamin B12, folate, and age-related macular degeneration: the Blue Mountains Eye Study

PURPOSE: To assess associations between increased serum homocysteine, low vitamin B12, low folate, and age-related macular degeneration (AMD). DESIGN: Population-based, cross-sectional analysis. METHODS: Serum homocysteine, vitamin B12, and folate were measured in 2,335 participants of the Blue Mountains Eye Study second survey. AMD detected from retinal photographs included atrophic or neovascular lesions. RESULTS: After adjusting for age, gender, and smoking in logistic regression models, homocysteine >15 micromol/l was associated with an increased likelihood of AMD in participants aged <75 years (odds ratio [OR] 3.21, 95% confidence interval [95% CI] 1.09 to 9.43). A similar association was found for vitamin B12 <125 pmol/l (OR 2.30, 95% CI 1.08 to 4.89) among all participants. In participants with homocysteine < or =15 micromol/l, low serum B12 was associated with nearly four-fold higher odds of AMD (OR 3.74, 95% CI 1.06 to 13.24). Folate was not statistically significantly associated with AMD. CONCLUSIONS: Increased homocysteine and low vitamin B12 were independently associated with an increased risk of AMD in this study population.     

Smoking and age related macular degeneration: the number of pack years of cigarette smoking is a major determinant of risk for both geographic atrophy and choroidal neovascularisation

BACKGROUND/AIMS: There is evidence that smoking is a risk factor for age related macular degeneration (AMD). However, not all studies have demonstrated this association and several key questions about the role of smoking in AMD have still to be determined. The aim of this study was to further investigate this relation for both choroidal neovascularisation (CNV) and geographic atrophy (GA). METHODS: To investigate the relation between smoking and the risk of developing age related macular degeneration (AMD) in white people, 435 cases with end stage AMD were compared with 280 controls. All subjects had graded stereoscopic colour fundus photography and AMD was defined as the presence of GA or CNV. Smoking history was assessed using multiple parameters in a detailed questionnaire. RESULTS: Comparison of current and former smokers with non-smokers was consistent with smoking being a risk factor for AMD but did not reach statistical significance. There was a strong association between AMD and pack years of cigarette smoking (p = 0.002), the odds ratio increasing with the amount smoked; for subjects with more than 40 pack years of smoking the odds ratio was 2.75 (95% CI 1.22 to 6.20) compared with non-smokers. Both types of AMD showed a similar relation; smoking more than 40 pack years of cigarettes was associated with an odds ratio of 3.43 (95% CI 1.28 to 9.20) for GA and 2.49 (95% CI 1.06 to 5.82) for CNV. Stopping smoking was associated with reduced odds of AMD and the risk in those who had not smoked for over 20 years was comparable to non-smokers. The risk profile was similar for males and females. Passive smoking exposure was associated with an increased risk of AMD (OR 1.87; 95% CI 1.03 to 3.40) in non-smokers. CONCLUSIONS: The authors have demonstrated a strong association between the risk of both GA and CNV and pack years of cigarette smoking. This provides support for a causal relation between smoking and AMD. They also show an increased risk for AMD in non-smokers exposed to passive smoking. Stopping smoking appears to reduce the risk of developing AMD.     

Blindness in the Indian state of Andhra Pradesh

PURPOSE: To determine the current prevalence and causes of blindness in the Indian state of Andhra Pradesh to assess if blindness has decreased since the last survey of 1986-1989. METHODS: A population-based epidemiology study, using a stratified, random, cluster, systematic sampling strategy, was conducted in the state of Andhra Pradesh in India. Participants of all ages (n = 10,293), 87.3% of the 11,786 eligible, from 94 clusters in one urban and three rural areas representative of the population of Andhra Pradesh, underwent interview and a detailed dilated ocular evaluation by trained professionals. Blindness was defined as presenting distance visual acuity < 6/60 or central visual field < 20(o) in the better eye. RESULTS: Two hundred seventy-five participants were blind, a prevalence of 1.84% (95% confidence interval, 1.49%-2.19%) when adjusted for the age, sex, and urban-rural distribution of the population in 2000. The causes of this blindness were easily treatable in 60.3% (cataract, 44%; refractive error, 16.3%). Preventable corneal disease, glaucoma, complications of cataract surgery, and amblyopia caused another 19% of the blindness. Blindness was more likely with increasing age and decreasing socioeconomic status, and in female subjects and in rural areas. Among the 76 million population of Andhra Pradesh, 714,400 are estimated to have cataract-related blindness (615,600 cataract, 53,200 cataract surgery-related complications, 45,600 aphakia), and 228,000 refractive error-related blindness (159,600 myopia, 22,800 hyperopia, 45,600 refractive error-related amblyopia). If 95% of the cataract and refractive error blindness in Andhra Pradesh had been treated effectively, 3.4 and 7.4 million blind-person-years, respectively, could have been prevented. If 90% of the blindness due to preventable corneal disease and glaucoma had been prevented, another 2.7 million blind-person-years could have been prevented. CONCLUSIONS: The prevalence of blindness in this Indian state has increased from 1.5% in the late 1980s to 1.84% currently, as against the target of the National Program for Control of Blindness to reduce the prevalence to 0.3% by 2000. The number of people with cataract-related blindness has not reduced even with the eye care policy focus on cataract. Reduction of blindness in India will require strategies that are more effective than those that have been pursued so far.     

中国陕西省农村年龄相关性黄斑变性流行病学调查

目的：调查中国陕西省农村≥40岁人群年龄相关性黄斑变性（AMD）的患病率及相关危险因素。 方法：2003-07／12,采用整体随机分层抽样法在陕西省洋县、靖边县及富平县调查8500人,其中≥40岁人群3500人,所有受检人员均进行标准问卷调查及详细的眼科检查。应用直接检眼镜散瞳后检查眼底,根据国际AMD分级系统将AMD分为地图状萎缩性年龄相关黄斑变性（GA）和新生血管性年龄相关性黄斑变性（NV）。 结果：≥40岁人群中有2835人完成了相关检查,受检率为81．00％。此受检人群中AMD总患病率（95％CI）为3．00％（2．42,3．71）,其中NV患病率为1．45％（1．05,1．98）,GA患病率为1．55％（1．14,2．10）。通过多因素logistic回归分析显示AMD患病率随着年龄的增长而显著增加（P〈0．001）。在年龄组时AMD患病率为0．47％,80-年龄组时AMD患病率上升至11．90％。NV患病率从40～49年龄组的0．28％上升至80-年龄组的4．76％,GA患病率从40～49年龄组的0．19％上升至80-年龄组的7．14％。各类型AMD患病率在性别上均未见显著差异。在此人群中除年龄为AMD的危险因素外,吸烟也是各类型AMD的重要危险因素。 结论：中国陕西省农村≥40岁人群中AMD患病率低于中国国内其他报道。年龄与吸烟是各类型AMD的重要危险因素。     

Risk Factors for Progression of Early Age-Related Macular Degeneration in Koreans

Purpose: To identify risk factors for the progression of early age-related macular degeneration (AMD) in Koreans.

Methods: This study was conducted at a health-screening center and followed a prospective cohort study design. Of 10,890 participants older than 50 years, 318 (2.92%) presented with early AMD. Among these 318 participants, we re-examined 172 participants after a mean duration of 4.4 years. Progression was defined by the Age-Related Eye Disease Study (AREDS) simplified AMD severity scale. Multivariable logistic regression was used to examine associations between AMD progression and baseline physical, demographic, behavioral, and ocular characteristics.

Results: Of the 172 participants with early AMD who were re-examined, 34 (19.8%) had progression. Multivariable analyses revealed that current smoking (odds ratio, OR, 7.0, 95% confidence interval, CI, 1.4–34.4, adjusted for age, alcohol consumption, body mass index, BMI, blood pressure, BP, total cholesterol, and high density lipoprotein, HDL, cholesterol) and hypertension (OR 10.3, 95% CI 1.9–55.7, adjusted for age, smoking status, alcohol consumption, BMI, total cholesterol, and HDL cholesterol) were independently associated with progression of early AMD. Additionally, the presence of a central drusen lesion within one-third disc diameter of the macula (age-adjusted OR 4.8, 95% CI 1.3–17.6) and 20 or more drusen (age adjusted OR 7.8, 95% CI 2.5–24.0) were independently associated with progression of early AMD.

Conclusion: Current smoking, hypertension, central drusen location, and increasing number of drusen were associated with an increased risk of early AMD progression in Koreans.     

Prevalence and risk factors associated with dry eye symptoms: a population based study in Indonesia

AIM: To determine the prevalence and identify associated risk factors for dry eye syndrome in a population in Sumatra, Indonesia. METHODS: A one stage cluster sampling procedure was conducted to randomly select 100 households in each of the five rural villages and one provincial town of the Riau province, Indonesia, from April to June 2001. Interviewers collected demographic, lifestyle, and medical data from 1058 participants aged 21 years or over. Symptoms of dry eye were assessed using a six item validated questionnaire. Presence of one or more of the six dry eye symptoms often or all the time was analysed. Presence of pterygium was documented. RESULTS: Prevalence of one or more of the six dry eye symptoms often or all the time adjusted for age was 27.5% (95% confidence interval (CI) 24.8 to 30.2). After adjusting for all significant variables, independent risk factors for dry eye were pterygium (p<0.001, multivariate odds ratio (OR) 1.8; 95% CI 1.4 to 2.5) and a history of current cigarette smoking (p=0.05, multivariate OR 1.5; 95% CI 1.0 to 2.2). CONCLUSIONS: This population based study provides prevalence rates of dry eye symptoms in a tropical developing nation. From our findings, pterygium is a possible independent risk factor for dry eye symptoms.