Exogenous oestrogen exposure,female reproductive factors and the long‐term incidence of cataract: the Blue Mountains Eye Study

Acta Ophthalmol. 2010: 88: 773–778

Abstract.

Purpose: To assess the association between exogenous oestrogen exposure, female reproductive factors and the long‐term incidence of cataract. Methods: People aged 49+ years living in a defined geographic region were invited to participate in this prospective population‐based survey. Of 2072 women (83% of those eligible) who were examined during 1992–1994 at baseline, around 75% of survivors were re‐examined at 5‐ and 10‐year follow‐up visits. Lens photographs were assessed using the Wisconsin Cataract Grading System by masked graders. An interviewer‐administered questionnaire was used at each visit to collect information on female reproductive factors and the use of the oral contraceptive pill and postmenopausal hormone replacement therapy. Results: After adjusting for age, smoking, socioeconomic status, steroid use, hypertension and diabetes, ever having used the oral contraceptive pill had a mild protective effect against incident cortical cataract (odds ratio 0.70, 95% confidence interval 0.50–0.98). However, hormone replacement therapy, age at menarche, age at menopause, duration of exposure to endogenous oestrogen, parity and type of menopause were not found to have significant associations with the incidence of any type of cataract or cataract surgery. Conclusion: Apart from a weak protective association of oral contraceptive pill use and the development of cortical cataract, we found no significant longitudinal associations between exogenous oestrogen exposure, female reproductive factors and the long‐term incidence of cataract in this older population‐based cohort.     

白内障手术与血糖关系探讨

目的：探讨白内障手术与血糖关系,以防治术后糖尿病及其并发症。方法：应用日立７１５０全自动生化检测仪测定１８６例白内障患者手术前后空腹血粮,并加以比较。结果：正常组６３％术后血糖升高。平均为１．８８ｍｍｏｌ／１;糖量异常组５６％术后血糖升高,平均为１．５６ｍｍｏｌ／１;糖尿病组７３％术后血糖升高,平均为４．１６ｍｍｏｌ／１。结论：白内障患者６４％术后血糖应激性升高,均值为２．２２ｍｍｏｌ／Ｌ,糖尿病     

Lower nasal distribution of cortical cataract: the Blue Mountains Eye Study

Previous reports have indicated that cortical cataract commences in the lower nasal lens, possibly due to sunlight exposure because of the shallow brow temporally. The present study aimed to assess the lens sector distribution of cortical cataract in a population. The Blue Mountains Eye Study assessed 3654 residents aged 49–97years; 3270 phakic subjects had retroillumination lens photographs graded using the Wisconsin method, which divides the lens into eight radial sectors with a grid overlay. Graders estimated percentage of cortical opacity in each sector. The lower nasal area consistently had the greatest opacity, a pattern present at each age and similar in both sexes, despite the 20% greater cortical cataract in women. The mean area of lens cortex involved by opacities in the lower nasal hemisphere was four fold greater than in the upper temporal hemisphere at each age. The lower nasal distribution was highly symmetrical when both eyes were affected. When > 20% of the lower nasal lens quadrant had cortical opacity, 88% of bilaterally affected subjects had cortical cataract in the same quadrant of the fellow eye. The lower nasal distribution may indicate a role for sunlight in the aetiology of cortical cataract, which could be considered when examining other cortical cataract risk factors, such as diabetes, vascular disease and hormonal factors in women.     

Diabetes,fasting blood glucose and age-related cataract: the Blue Mountains Eye Study

AIMS. To examine the relationship between diabetes and the presence of cortical, nuclear and posterior subcapsular (PSC) cataract in a defined older population, while controlling for known cataract risk factors. METHODS. Slit-lamp and retroillumination lens photographs were taken on 3654 participants attending the population-based Blue Mountains Eye Study during 1992-94. Masked grading of the photographs was performed using the Wisconsin Cataract Grading System. RESULTS. 217 subjects (5.9% of the population) had previously diagnosed diabetes and 66 (1.8%) had diabetes diagnosed from fasting blood glucose measurements. Cortical cataract, PSC and past cataract surgery were associated with known diabetes in age-sex adjusted models. However, only PSC (odds ratio (OR) 1.8, 95% confidence interval (CI) 1.0-3.1) and past cataract surgery (OR 2.5, CI 1.5-4.2) remained statistically significantly associated with diabetes after further adjustment for other known cataract risk factors. Increasing therapy, as an index of diabetes severity (oral or insulin treatment, compared to treatment by diet alone), was associated with a markedly increased risk of PSC (OR 5.4). CONCLUSIONS. These findings support previous research showing that diabetes has a harmful effect on the lens. The markedly increased risk for PSC may also have been reflected in the association found between diabetes and past cataract surgery. Contrary to findings from the Beaver Dam Eye Study, we found only a weak association with cortical cataract, which was not statistically significant after adjusting for other known cataract risk factors.     

Intermediate- and longer-term visual outcomes after cataract surgery: the Blue Mountains Eye Study

Background: Limited data are available on long‐term cataract surgical outcomes. We aimed to compare intermediate‐term (up to 5 years) and longer‐term (5–10 years) post‐surgery visual outcomes in an older Australian population. Design: Population‐based cohort. Participants: Persons aged 49+ years, living in the Blue Mountains area, west of Sydney. Methods: Of 3654 baseline participants of Blue Mountains Eye Study, 75% of survivors were seen at each of the 5‐ and 10‐year follow‐up visits; 90 participants (130 eyes) underwent incident cataract surgery during the first 5 years and returned to both follow‐up visits. Main Outcome Measures: Changes in visual acuity over time, and ocular conditions affecting visual acuity. Results: After the first (intermediate‐term) follow‐up period, 33/128 eyes (26%) had presenting visual acuity <6/12. Similarly, after the second (longer‐term) period, 27/119 eyes (23%) had presenting visual acuity <6/12. Uncorrected refractive error accounted for 22/33 eyes (66%) with reduced presenting visual acuity at the intermediate term and for 16/27 eyes (59%) at the longer‐term follow‐up visits. Of 10 eyes with reduced best‐corrected visual acuity after longer term, five (50%) were attributed to posterior capsular opacification. Of 115 eyes with refractive error data, 82 (71%) and 70 (61%) were emmetropic, at the intermediate‐term and longer‐term visits, respectively. Conclusion: Over a longer term post cataract surgery, three quarters of eyes achieved presenting visual acuity ≥6/12 and nearly two‐thirds achieved emmetropia. Uncorrected refractive error and posterior capsular opacification were the main causes of poor vision in operated eyes, a finding emphasizing the need for ongoing eye care services post cataract surgery.     

Socioeconomic status and incident cataract surgery: the Blue Mountains Eye Study

The aim of this study was to assess whether socioeconomic status influenced the incidence of cataract surgery in a defined population of older Australians. The Blue Mountains Eye Study examined 3654 residents during 1992-1994, then 2334 survivors (75.1%)during 1997-1999. Interviewers collected information on principal occupation, which was analysed using Australian Bureau of Statistics categories (stratified into four groups) and the Daniel Occupational Prestige Scale. Cataract surgical history was confirmed at both visits from clinical examinations. There were no statistically significant associations for any of the occupational categories with the 5-year incidence of cataract surgery. In summary, this study could not confirm any major socioeconomic associations with incident cataract surgery, supporting the view that cataract surgery is largely patient driven and that its primary incentive is patient benefit.     

Refractive changes following cataract surgery: the Blue Mountains Eye Study

This study aimed to assess refractive changes following cataract surgery in subjects attending the Blue Mountains Eye Study baseline examinations in 1992-1994 (3654 residents aged 49+ years),with 2335 (75.1%) survivors re-examined after 5 years. Participants underwent a standardized subjective refraction. History of cataract surgery was confirmed at examination and lens photograph grading. During follow up, 151 persons had cataract surgery (60 bilateral, 91 unilateral). After exclusions, data from 198 eyes(93 right, 105 left) were analysed. The proportions of eyes achieving postoperative spherical equivalent refraction (SER) -0.25 to +0.25 D, -0.50 to +0.50 D, -0.75 to +0.75 D and -1.00 to +1.00 D,were 32%, 44%, 60% and 74%,respectively. The magnitude and direction of refractive changes following cataract surgery were related to the preoperative refraction. Myopic eyes had a hyperopic shift (mean +2.76 D),hyperopic eyes a myopic shift (mean -1.77 D) and emmetropic eyes recorded little change (mean -0.13 D). Astigmatism (> or = 1.00 D cylinder) increased slightly postoperatively, from 47% to 56%, mostly 'against the rule' but with less oblique astigmatism. These findings indicate satisfactory refractive outcomes following current cataract surgery in a random older population.     

Five year incidence of cataract surgery: the Blue Mountains Eye Study

AIMS: To assess the 5 year incidence of cataract surgery in an older population based prospective cohort. METHODS: 5 Year prospective follow up of the population based Blue Mountains Eye Study (BMES) performed in 1992. The follow up study examined 2335 survivors (75.1%) of the 3654 baseline participants. Baseline and 5 year slit lamp and retroillumination lens photographs were graded for presence of cortical, nuclear, or posterior subcapsular cataract using the Wisconsin cataract grading method and cataract surgery was documented from the history and the clinical examination. RESULTS: An overall cataract surgery rate of 5.7% in first or both eyes was documented. The incidence was 0.3% in people aged 49-54 years at baseline, 1.7% for ages 55-64 years, 7.9% for ages 65 to 74 years, and 17.4% in people aged 75 years or older. The rate of surgery in first or both eyes was 6.0% in women and 5.2% in men, age adjusted p = 0.66. Bilateral cataract surgery was performed during follow up on 2.7% of participants, while 43.1% of unilateral phakic cases had second eye surgery. Presence of any posterior subcapsular (PSC) cataract, either alone or in combination with other cataract types, was the most likely type of cataract at baseline to be associated with incident cataract surgery. Baseline age was the most important non-ocular variable predicting incident cataract surgery. CONCLUSIONS: This study has documented age specific rates for 5 year incident cataract surgery in an older community. The finding of relatively similar incidence rates and ocular predictors of cataract surgery to those reported by the Beaver Dam Eye Study, Wisconsin, United States, is of interest, given previous documented similarities between these two populations.     

Extended long‐term outcomes of cataract surgery

Purpose: To longitudinally report the changes in visual acuity (VA) and subjective visual function, 10 years after cataract surgery. Methods: This population‐based prospective study reviewed 335 patients (85% of survivors) who underwent cataract surgery during a 1‐year period in 1997–98, 289 of whom were also re‐examined. The patients underwent a routine eye examination and answered the same visual function questionnaire (VF‐14), preoperatively, 4 months postoperatively, 5 years and 10 years after surgery. Results: Ten years after surgery, the best corrected VA (BCVA) of the operated eye had deteriorated to a median of 0.06 (logMAR) (Snellen acuity: 20/23) from 0.046 (logMAR) (20/22) postoperatively (p = 0.001). More than two‐thirds of the patients had <0.1 logMAR units worsening of BCVA compared with postoperatively. Approximately half of the patients had no deterioration in subjective visual function, and 77% had 10 points decline or less. Twelve per cent of the patients (42/335) had a worsening of more than 30 points. Effect size was calculated for the VF‐14 total score at all three occasions of follow‐up after surgery and was largest approximately 4 months postoperatively. Long‐time follow‐up of 10 years shows still moderate effect size. Conclusion: These results confirm the effectiveness of cataract extraction, offering good long‐term visual rehabilitation for the majority of the patients. The most common cause for large functional loss after 10 years is age‐related macular degeneration.     

Five-year cumulative incidence and progression of epiretinal membranes: the Blue Mountains Eye Study

PURPOSE: To describe the 5-year cumulative incidence and change in epiretinal membranes in a defined older Australian population. DESIGN: Population-based cohort study. PARTICIPANTS: Three thousand six hundred fifty-four persons 49 years of age or older, living in the Blue Mountains area, west of Sydney, Australia, participated in the baseline survey during 1992 to 1994. The cohort was reexamined after 5 years in 1997 to 1999. Excluding persons (543) who died since the baseline, 75% of survivors (n = 2335) attended the follow-up examination. METHODS: All participants underwent a detailed eye examination, including stereo retinal photography. Epiretinal membranes were diagnosed from grading of baseline and 5-year retinal photographs. MAIN OUTCOME MEASURES: Epiretinal membranes were classified as either preretinal macular fibrosis (PMF), with retinal folds, or as a less severe form, termed cellophane macular reflex (CMR), without retinal folds. The incidence of epiretinal membranes was determined if either lesion was found in eyes with no preexisting epiretinal membrane at baseline. Progression was defined if the area of involvement increased by more than 25%, regression if it decreased by more than 25%, and stable if it changed by less than 25%. RESULTS: Epiretinal membranes developed in the first eye of 108 of 2030 participants who had no sign of this condition in either eye at baseline, 5.3%, 95% confidence interval (CI) 4.4 to 6.4. Five-year cumulative incidence rates for PMF and CMR were 1.5% and 3.8%, respectively. Of those participants with epiretinal membranes in one eye at baseline, 18 of 133 (13.5%) developed this sign in their second eye after 5 years. New epiretinal membranes (mostly CMR) occurred in 15 of 165 subjects (9.1%; CI, 5.2-14.6) who had undergone cataract surgery since the Blue Mountains Eye Study I. This rate was significantly higher than in the nonsurgical group, 92 of 1861 (4.9%; CI, 4.0-6.0) of whom developed epiretinal membranes. Progression from CMR to PMF was observed in 17 of 183 eyes (9.3%). Existing epiretinal membranes progressed, regressed, or remained stable in 28.6%, 25.7%, and 38.8% of eyes, respectively. CONCLUSIONS: This study has documented the 5-year cumulative incidence and the natural history of epiretinal membranes in an older population.     

Refractive status and the 5-year incidence of age-related maculopathy: the Blue Mountains Eye Study

This study aimed to assess the longitudinal association between refraction and 5-year incident age-related maculopathy (ARM) in the Blue Mountains Eye Study population. The dataset included 3654 participants aged 49+ (82.4% of eligible) examined at baseline (1992-1994), and 2335 (75.1% of survivors) examined after 5 years. Retinal photograph grading followed the International ARM Classification. Incident ARM was assessed using a side-by-side comparison. Refraction was performed using autorefraction with subjective refinement. Spherical equivalent was calculated from spherical plus half the cylindrical power. After adjusting for age, sex and smoking, no association was found between baseline spherical equivalent and 5-year incident late or early ARM. Hyperopic right eyes had slightly higher incident rates for late (0.8%) and early (6.3%) ARM, compared with myopic (0.4% and 4.1%, respectively) or emmetropic (0.5% and 5.0%, respectively) right eyes. After multivariable adjustment, this study found no significant association between hyperopia and the 5-year incidence of late or early ARM. Left eyes or the combined data from both eyes had similar findings.     

Cardiovascular disease,vascular risk factors and the incidence of cataract and cataract surgery: The Blue Mountains Eye Study

PURPOSE To assess whether an association exists between cardiovascular disease, vascular risk factors and incident cataract and cataract surgery. METHODS The Blue Mountains Eye Study examined 3654 participants =49 years of age during 1992–4, then 2335 survivors (75.1%) after five years. Trained interviewers administered a vascular history questionnaire; height, weight and blood pressure were measured. Lens photographs from both examinations were graded for presence of cortical, nuclear or posterior subcapsular cataract. RESULTS Obesity (body mass index =30kg/m 2 ) was significantly associated with increased incidence of both cortical [odds ratio (OR) 1.6, 95% confidence interval (CI) 1.2–2.2] and posterior subcapsular cataract (OR 2.1, CI 1.2–3.7). Hypertensive participants using medication and aged less than 65 years at baseline had a higher incidence of posterior subcapsular cataract (OR 3.4, 95% CI 1.3–8.4) than normotensive subjects. A history of angina was associated with higher cataract surgery incidence (OR 2.1, 95% CI 1.3–3.5). CONCLUSIONS These longitudinal data provide some evidence supporting a relationship between cardiovascular disease, vascular risk factors and incident cataract and cataract surgery. The findings confirm a number of associations previously documented in cross-sectional data.