A population based case-control study of cataract and inhaled corticosteroids

BACKGROUND/AIMS: Exposure to systemic corticosteroid use is known to be associated with a risk of cataract. Whether low doses of inhaled corticosteroids are associated with an increased risk of cataract is not known. This study was undertaken to quantify the risk of cataract associated with the use of inhaled corticosteroids and assess whether there is a dose-response relation. METHODS: A population based case-control study based on the General Practice Research Database in the United Kingdom. 15 479 people with cataract and 15 479 controls were matched for age, sex, practice, and observation period. RESULTS: The crude odds ratio for the association between any recorded exposure to inhaled corticosteroids and cataract was 1.58 (95% CI 1.46 to 1.71), reduced to 1.10 (95% CI 1.00 to 1.20) after adjustment for systemic corticosteroid exposure and consultation rate. There was a dose-response relation, the adjusted odds ratio rising from 0.99 (95% CI 0.87 to 1.13) at daily doses up to 400 micro g to 1.69 (95% CI 1.17 to 2.43) for daily doses greater than 1600 micro g. The association was also stronger with increasing duration of use. CONCLUSION: Higher doses and longer duration of exposure to inhaled corticosteroids are associated with an increased risk of cataract. The lowest doses compatible with good control of airways disease should be used. The risk of cataract associated with high doses of inhaled corticosteroids needs to be more widely appreciated.     

Nutrient patterns and risk of cataract: a case-control study

AIM: To assess the relation between nutrient patterns and cataract risk. METHODS: This is a hospital-based case-control study with 97 cataract patients and 198 matched controls. Dietary consumption was collected through a valid food frequency questionnaire (FFQ). Nutrient patterns were detected by applying factor analysis. Unconditional logistic regression models were used to estimate odds ratio (ORs) and 95%CIs. RESULTS: We extracted 5 main nutrient patterns. Factor 1 included niacin, thiamin, carbohydrates, protein, zinc, vitamin B6 and sodium (sodium pattern). Factor 2 was characterized by oleic acid, monounsaturated fats, polyunsaturated fats, linoleic acid, trans fatty acid, linolenic acid, vitamin E and saturated fats (fatty acid pattern). The third factor represented high intake of vitamin B12, vitamin D, cholesterol and calcium (mixed pattern). The 4th pattern was high in intake of beta and alpha carotene, vitamin A and vitamin C (antioxidant pattern). Finally, the 5th pattern loaded heavily on docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) (omega-3 pattern). In crude and multivariate analysis, the sodium pattern was associated with increased risk of cataract (OR=1.97, 95%CI: 1.09-3.96). The fatty acid pattern elevated the risk of cataract (OR=1.94, 95%CI: 1.1-3.86). Antioxidant pattern was associated with a significant 79% reduced risk (2nd category compared with the 1st). Omega-3 pattern was significantly negatively associated with risk of cataract (P=0.04). CONCLUSION: These findings imply that nutrient patterns reflecting a combined consumption of nutrients might be important in the etiology of cataract. Additional studies with more efficient designs are warranted to confirm our findings.     

Casteldaccia eye study: prevalence of cataract in the adult and elderly population of a Mediterranean town

Prevalence of cataract was studied in a population based survey performed in adults aged 40 years or more living in Casteldaccia, a small Sicilian town. Lens opacities of moderate or severe grade (type II or worse, according to the Lens Opacity Classification System II) were found at the following rates: nuclear opalescence in 18.5%, cortical cataract in 12.9%, posterior subcapsular cataract in 10.8%. All these types of cataract were much more frequent in the elderly population and were about 1.5 times more common in women than in men. Late cataract was found in about 1/3 of subjects aged 60 to 69 years, in 2/3 of subjects aged 70 or more, but rarely under 60 years of age. However, early cataract was rather common among younger subjects. Cataracts causing a reduction of visual acuity under 0.7 in the worst eye were found in 4%, 8.7% and 21.5% respectively in the three age groups ranging from 40 to 49, 50 to 59 and 60 to 69 years and in 54.4% of subjects 70 years old or over.     

Hormone replacement therapy and cataract: a population-based case-control study

PURPOSE: Laboratory studies have suggested that hormone replacement therapy (HRT) may protect against the development of cataract, but epidemiological studies in humans have thus far been inconclusive. The aim of this study was to assess the association between hormone replacement therapy and cataract. METHODS: Population-based case-control study using data from the General Practice Research Database in the UK. Participants were 10 000 women aged 45 years and over with diagnosed cataract and 10 000 controls matched on age, general practice, and calendar period. RESULTS: The crude odds ratio for the association between cataract and ever-use of oestrogen-only hormone replacement therapy was 1.13 (95% CI 0.99-1.29). This reduced to 0.81 (95% CI 0.71-0.94) after adjustment for consultation rate. Similarly, the crude odds ratio for the association between cataract and ever-use of a formulation containing oestrogen and progestogen was 1.18 (95% CI 1.01-1.39), reducing to 0.86 (95% CI 0.72-1.02) after adjustment for consultation rate. CONCLUSIONS: Oestrogen-only and oestrogen-progestogen hormone replacement therapies are associated with a small reduced risk of cataract. This data adds to the growing body of evidence on the effects of HRT on health. All potential benefits and risks of this therapy should be taken into account when considering its use.     

Role of Mediterranean diet, tropical vegetables rich in antioxidants, and sunlight exposure in blindness, cataract and glaucoma among African type 2 diabetics

AIM: To assess whether regular Mediterranean diet and regular intake of vegetables may reduce the risk of blindness, cataract, and glaucoma in these type 2 diabetics. METHODS: A cross-sectional design was carried out among known black diabetics admitted at the diabetic clinics of Kinshasa, between October 2008 and March 2009. The Mediterranean-style dietary score (MSDPS) was used to characterize a Mediterranean-style dietary pattern in the study population using the Harvard semi quantitative FFQ adapted for Africa. RESULTS: Five hundred Type 2 diabetic patients were included in this study (48% of males; 40% aged ≥60 years). There was a significant association between blindness, cataract and aging; between blindness (P<0.05), cataract (P<0.05), glaucoma (P<0.05), and physical inactivity; between blindness (P<0.05), cataract (P<0.0001), glaucoma (P<0.01) and high SES, and a very significant association between blindness (P<0.0001), cataract (P<0.0001), glaucoma (P<0.0001) and exposure to sunlight. There was also a significant association between blindness, glaucoma, and male sex. Regular intake of Mediterranean diet, Brassica Rapa, beans, Abelmoschus, Musa acuminata reduced significantly the risk of blindness, cataract and glaucoma. CONCLUSION: Regular intake of Mediterranean diet, Brassica Rapa, beans, Abelmoschus, and Musa acuminata may significantly reduce the risk of blindness or its major causes among type 2 diabetes mellitus in Africa.     

Risk factors for secondary cataract: a case-control study with multivariate analysis

AIM: A retrospective case-control study was initiated to determine the risk factors for the development of posterior capsule opacification. Subjects and methods: 100 cases of patients with secondary cataract treated by YAG laser capsulotomy were compared with 100 controls (patients who had cataract surgery not complicated with a secondary cataract). The posterior capsule was examined by the biomicroscope. A 1-to-1 matched case-control study was designed by stratifying inclusions on the basis of age, sex, and delay. We studied the risk factors related to the patient, the primary cataract, the surgical technique, the surgeon's skill, and intraoperative and postoperative complications. All the lenses were biconvex and all-PMMA with the same design. Statistical analysis was done in 3 steps: a univariate analysis, then a bivariate analysis using chi-square and the Student tests and finally, we performed a multivariate analysis with a logistic regression. The significance level for type I error rate was fixed at 5%. RESULTS: The average age was 61.6 years. The mean delay was 32.7 months for cases and 34.5 months for controls. The bivariate analysis identified nine risk factors: corneal opacities (p=0.031), absence of a posterior chamber lens p=10(- 4)), the can opener anterior capsulotomy (p=0.003), ciliary sulcus fixation of the lens p=0.030), a large optic diameter of 7mm p=10(- 5)) and (t=0.002), poor intraoperative pupillary dilatation (p=0.003), a less experienced surgeon (p=3.10(- 4)), postoperative inflammation (p=0.021), and persistence of residual cortical material (p=0.002). The multivariate analysis selected five principal factors: absence of a posterior chamber lens, an optic diameter of 7mm, poor intraoperative pupillary dilatation, a less skilled surgeon, and persistence of cortical material. CONCLUSION: This case-control study reveals some of the risk factors previously identified and may contribute to the determination of methods for prevention of secondary cataract. The new intraocular lenses and pharmacological agents would lead to better results.     

Risk factors of acute endophthalmitis after cataract extraction: a case-control study in Asian eyes

AIM: To describe risk factors of acute endophthalmitis after cataract extraction in an Asian population. METHODS: A retrospective, case-control study. Cases (n = 34) were patients with acute endophthalmitis presenting within 6 weeks after cataract surgery. Three controls per case (n = 102) were randomly selected from the cataract surgery list matched on the date of operation of cases. RESULTS: Few risk factors were identified. In multivariable analysis, endophthalmitis was associated with silicone intraocular lens (odds ratio 5.1, 95% confidence intervals, 1.2 to 21.6, compared to poly(methylmethacrylate) lens) and posterior capsular rupture during surgery (odds ratio 20.9, 95% confidence intervals 2.3 to 187.9). CONCLUSION: Silicone intraocular lens and rupture of the posterior capsule are risk factors of acute endophthalmitis after cataract surgery.     

A case-control study of cataract in Oxfordshire: some risk factors.

Three hundred patients with cataract and 609 control subjects with the same age-sex distribution were interviewed in a study of cataract in Oxfordshire, England. The risks associated with severe diarrhoea, glaucoma, and work on a military base have been demonstrated. Population attributable risks were calculated for those and other risk factors.     

Reducing the risk for endophthalmitis after cataract surgery: population-based nested case-control study: endophthalmitis population study of Western Australia sixth report

PURPOSE: To characterize operative and nonoperative risks for the potentially blinding complication of endophthalmitis after cataract surgery. SETTING: Ophthalmology services for the whole state of Western Australia. METHODS: This retrospective population-based nested case-control study in Western Australia covered the period between 1980 and 2000. For each of the 205 cases of endophthalmitis, 4 time-matched controls were randomly selected from all cataract operations performed in the state. Conditional logistic regression was used to estimate multivariate adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for the risk factors of interest. RESULTS: Wound location, suturing the wound, and type of cataract operation did not affect the risk for postoperative endophthalmitis. Antibiotic prophylaxis reduced the risk, but only if given as a subconjunctival injection (OR, 0.46; 95% CI, 0.29-0.70). The risk for endophthalmitis was greater with same-day surgery (OR, 2.27; 95% CI, 1.52-3.41) than with admission the day before surgery. A concurrent eyelid procedure was a substantial risk. Surgeons within 2 years of obtaining specialist qualifications were more likely to have a case of endophthalmitis, although this was partly the result of more posterior capsule breaches. Posterior capsule breach increased the risk when it occurred in private hospitals (OR, 13.57; 95% CI, 4.00-45.99), but not in public hospitals. CONCLUSIONS: Nonoperative as well as operative factors are important in the prevention of endophthalmitis. Subconjunctival injection of antibiotics appears to be beneficial for endophthalmitis prophylaxis. The model showed that active risk management strategies designed to optimize hospitalization and chemoprophylaxis may reduce the incidence of endophthalmitis by up to 81%.     

Presumed infectious endophthalmitis following cataract surgery in the UK: a case-control study of risk factors

AIMS: To study risk factors for presumed infectious endophthalmitis complicating cataract surgery in the United Kingdom. METHODS: Two hundred and fourteen clinically diagnosed patients with presumed infectious endophthalmitis were compared with 445 control patients throughout the United Kingdom in a prospective case-control study. The cases were identified through the British Ophthalmological Surveillance Unit reporting card system. Control patients undergoing cataract surgery from 13 'control centres' throughout the United Kingdom were selected randomly. Risk factors were identified by univariate and multivariate logistic regression analyses. Pertinent variables relating to the cataract extraction procedure, antimicrobial prophylaxis, ophthalmic and medical history were analysed with regard to postoperative infection. RESULTS: Statistically significant risk factors in the multivariate model included inpatient cataract surgery (P=0.001), surgery in dedicated eye theatres (P<0.001), consultant grade surgeon (compared to registrar) (P=0.001), posterior capsule tear during cataract surgery (P=0.001). The use of face masks by the scrub nurse and surgeon during cataract surgery (P<0.001) and the administration of subconjunctival antibiotics at the end of surgery (P<0.001) were protective against postoperative infection. CONCLUSIONS: In order to minimise the risk of postoperative endophthalmitis we would recommend the wearing of face masks by the surgeon and scrub nurse during cataract surgery and subconjunctival antibiotics at the end of surgery.     

老年性白内障危险因素病例对照研究

目的 探讨可能引起老年性白内障的危险因素。为制定预防白内障提供依据。方法 采用1：1病例对照研究方法对合肥市及定远县50对老年性白内障及对照进行多变量多指标测量,研究因素采条件Logistic回归单因素和多因素分析。结果 单因素分析结果发现居住在农村及小城市高中及中专文化程度（OR=13.33,95%CI=1.78-40.86)、吸烟（OR=1.23,95%CI=1.03-2.29)、饮酒（OR=1.65,95%CI=1.04-4.33)、高血压（OR=1.25,95%CI=1.11-1.46)、胆固醇（OR=1.37,95%CI=1.05-1.79)及紫外线（OR=2.06,95%CI=1.84-4.34)、腹泻引起营养不良（OR=2.87,95%CI=1.80-5.31)及类固醇等药（OR=1.51,95%CI=1.16-2.04)可能是白内障发病的危险因素,维生素（OR=0.66,95%CI=0.45-0.94),阿斯匹林（OR=0.93,95%CI=0.74-1.16)及谷光甘肽（OR=0.58,95%CI=0.38-0.85)可能是保护因子,条件Logistic回归逐步法进行分析显示高血压年限,降压药种类、腹泻引起营养不良、维生素、谷光甘肽和胆固醇等6个因素进入方程。结论 老年性白内障的发病与多种因素有关。合肥市和定远县两地白内障发病的危险因素基本具有其它地区人群共同的特点外,还有有别与其它地区人种的自身特点。     

The role of sunlight in human cataract formation

This review summarizes and integrates new findings concerning the role of near-ultraviolet radiation, as is present in sunlight and common artificial light sources, in stimulating human and animal cataract formation. Epidemiological and basic research studies are summarized and critical statements concerning them are offered. Although certain questions still remain unanswered, the evidence that near-UV radiation does stimulate cataract formation is very strong. Avoidance of excessive exposure to near-ultraviolet light and the use of protective lenses that filter it out are suggested to prevent the enhancement of human cataract formation by near-UV light.     

Impact of cataract surgery on car driving: a population based study in Sweden

AIMS—To investigate the outcome of cataract surgery on the patients' self estimation of visual function while driving. Furthermore, the benefit of surgery to the car driving population was determined.
METHODS—A total of 208 consecutive patients (211 cases) with driving licences, who underwent cataract surgery with intraocular lenses, were studied prospectively using self administered questionnaires. Their self estimated degree of visual functional problems while driving were analysed before and after surgery.
RESULTS—Visual problems while driving declined from 82% preoperatively to 5% after surgery. Remaining visual problems with the operated eye were present in only seven patients. Problems in estimating distance while driving decreased from 37% before surgery to 6% after surgery. Twenty three per cent of the patients drove with a visual acuity below the requirements for driving in Sweden before surgery and only 4% after surgery. There was no correlation between the degree of visual problems while driving and visual acuity before surgery.
CONCLUSION—The car driving population greatly benefited from cataract surgery in terms of subjectively improved visual function and distance estimation while driving. Functional visual problems while driving should be considered as an indication for cataract surgery. These findings also indicated that the second eye should be operated on, if necessary, to achieve optimal ability to estimate distance and give best possible road safety.

     

The association between pinguecula, sunlight and cataract

The pathology and epidemiology of pinguecula suggest that it is due to exposure to sunlight. There is some epidemiological and laboratory evidence that sunlight is an etiological factor in cataract so that it would be expected that the two conditions--pinguecula and cataract--would occur together more frequently than by chance. In a series of patients requiring cataract extraction pinguecula did not occur more frequently than in sex- and and aged-matched controls. Although there was a correlation between an outdoor working environment and the incidence of pinguecula there was no such correlation with cataract. It is concluded that direct exposure of the eye to sunlight did not seem to be a factor in the development of age-related cataract in this population.     

Association between sunlight exposure and risk of age-related macular degeneration: a meta-analysis

Background

A substantial number of epidemiological studies have investigated the possible associations between sunlight exposure and Age-related Macular Degeneration (AMD), but the results from studies are inconsistent. The aim of this meta-analysis was to evaluate the association between sunlight exposure and the risk of AMD.

Methods

Relevant studies were searched using databases including PubMed, EMBASE, and Web of Science database. Two authors independently extracted data and assessed study quality. The random-effects model was used to calculate the pooled covariates-adjusted odds ratio (OR). Subgroup analyses based on study design, stage of AMD, method of exposure assessment, and study latitude were carried out. The heterogeneity across the studies was tested, as was publication bias.

Results

Fourteen eligible studies including 43,934 individuals based on the inclusion criteria were analyzed. The pooled OR for sunlight exposure and AMD was 1.10 (95% CI?=?0.98–1.23). In addition, similar insignificant results were observed in further subgroup analyses based on stage of AMD, method of exposure assessment, and study latitude. Sun-avoidance behavior did not decrease the risk of AMD (OR?=?1.12, 95% CI?=?0.76–1.67). Moderate heterogeneity was observed in most of analyses.

Conclusion

The results indicate that sunlight exposure may not be associated with increased risk of AMD based on current published data.

     

Use of traditional cooking fuels and the risk of young adult cataract in rural Bangladesh: a hospital-based case-control study

Background

This study aimed to investigate the independent relationship between the use of various traditional biomass cooking fuels and the occurrence of cataract in young adults in rural Bangladesh.

Methods

A hospital-based age- and sex-matched case-control study incorporating two control groups was conducted. Cases were cataract patients aged 18 and 49 years diagnosed on the basis of any opacity of the crystalline lens or its capsule and visual acuity poorer than 6/18 on the Log Mar Visual Acuity Chart in either eye, or who had a pseudophakic lens as a result of cataract surgery within the previous 5 years. Non-eye-disease (NE) controls were selected from patients from ENT or Orthopaedics departments and non-cataract eye-disease (NC) controls from the Ophthalmology department. Data pertaining to history of exposure to various cooking fuels and to established risk factors for cataract were obtained by face-to-face interview and analyzed using conditional logistic regression.

Results

Clean fuels were used by only 4% of subjects. A majority of males (64-80% depending on group) had never cooked, while the rest had used biomass cooking fuels, mainly wood/dry leaves, with only 6 having used rice straw and/or cow dung. All females of each group had used wood/dry leaves for cooking. Close to half had also used rice straw and/or cow dung. Among females, after controlling for family history of cataract and education and combining the two control groups, case status was shown to be significantly related to lifetime exposure to rice straw, fitted as a trend variable coded as never, ≤ median of all exposed, > median of all exposed (OR = 1.52, 95%CI 1.04-2.22), but not to lifetime exposure to wood/dry leaves. Case status among females showed an inverse association with ever use of cow dung as a cooking fuel (OR 0.43, 95%CI 0.22-0.81).

Conclusions

In this population, where cooking is almost exclusively done using biomass fuels, cases of young adult cataract among females were more likely to have had an increased lifetime exposure to cooking with rice straw fuel and not to have cooked using cow dung fuel. There is a possibility that these apparent associations could have been the result of uncontrolled founding, for instance by wealth. The nature of the associations, therefore, needs to be further investigated.     

Testing time for the sunlight hypothesis of cataract

The proceedings of a 2-day workshop on the role of sunlight in cataract formation have provided an opportunity to assess the importance of this widely discussed risk factor. There seems to be no role in nuclear cataract, and any role in cortical or posterior subcapsular cataract is scarcely measurable.