Do age-related macular degeneration and cardiovascular disease share common antecedents?

Age-related macular degeneration (AMD) is the leading cause of irreversible vision loss and blindness in elderly Americans. The etiology of this condition remains unknown and treatment options are limited. Some epidemiological findings point to a cardiovascular risk profile among persons with AMD. Documented risk factors for cardiovascular disease (such as age, smoking, hypertension, hypercholesterolemia, post-menopausal estrogen use, diabetes, and dietary intake of fats, alcohol and antioxidants) have also been associated with AMD in some studies. This raises the possibility that the causal pathways for cardiovascular disease and AMD may share similar risk factors. Future research on this hypothesis could lead to important insights into etiologic factors for AMD. Research could also identify modifiable risk factors and suggest new treatment options which could prevent AMD, slow its progression, or reduce visual loss. Susceptible individuals could then be targeted for improved health promotion and disease prevention measures for this disabling and highly prevalent disorder.

Evaluation of the Best disease gene in patients with age-related macular degeneration and other maculopathies

Vitelliform macular dystrophy (VMD2, Best disease, MIM153700) is an early onset, autosomal, dominant macular degeneration characterized by the deposition of lipofuscin-like material within and below the retinal pigment epithelium (RPE); it is associated with degeneration of the RPE and overlying photoreceptors. Recently, we cloned the gene bestrophin, which is responsible for the disease, and identified a number of causative mutations in families with VMD2. Here, we report that the analysis of bestrophin in a collection of 259 age-related macular degeneration (AMD) patients provides evidence that mutations in the Best disease gene do not play a significant role in the predisposition of individuals to AMD. However, our results suggest that, in addition to Best disease, mutations within the bestrophin gene could be responsible for other forms of maculopathy with phenotypic characteristics similar to Best disease and for other diseases not included in the VMD category.

Clinical course of macular holes: the Eye Disease Case-Control Study

OBJECTIVE

To describe the clinical course of affected and unaffected eyes in patients with idiopathic macular holes.

PATIENTS

Prospective study of patients with macular holes enrolled in the Eye Disease Case-Control Study.

MAIN OUTCOME MEASURES

The best-corrected visual acuity at follow-up was compared with that at baseline. Changes in the macular holes, including increases in size or spontaneous regression, were assessed. The rates of development of new macular holes in fellow unaffected eyes were estimated.

RESULTS

Of the 198 patients examined at baseline, 28 (14.1%) died before reevaluation. Of those who survived, 122 (71.8%) had a follow-up examination. Approximately 34% (34.4%) of all eyes with macular holes had an increase in the size of the macular hole. Forty-five percent of eyes had a decrease in visual acuity of 2 or more lines and 27.8%, of 3 or more lines; 40.9% remained stable, with a gain or loss of fewer than 2 lines. The rate of development of a new macular hole during follow-up in fellow eyes that were unaffected at baseline was 4.3% for 3 or fewer years of follow-up, 6.5% for 4 to 5 years of follow-up, and 7.1% for 6 or more years of follow-up. Spontaneous regression of the macular hole occurred in 3 (8.6%) of 35 patients with a follow-up interval of 6 or more years, whereas no regression occurred in patients with a shorter follow-up.

CONCLUSIONS

The visual acuity of 45.0% of eyes with macular holes deteriorated by 2 or more lines during follow-up. The rate of development of macular holes in unaffected fellow eyes was low.

Risk factors for hemiretinal vein occlusion: comparison with risk factors for central and branch retinal vein occlusion: the eye disease case-control study

OBJECTIVE

Possible risk factors for hemiretinal vein occlusion were identified and compared with risk factor profiles for central and branch retinal vein occlusion.

DESIGN

The design was a multicenter case-control study.

METHODS

The authors identified 79 patients with hemiretinal vein occlusion (HRVO), 258 patients with central retinal vein occlusion (CRVO), 270 patients with branch retinal vein occlusion (BRVO), and 1142 control subjects at 5 clinical centers. Risk factor data were obtained through interviews, clinical examinations, and laboratory analyses of blood specimens.

RESULTS

Systemic hypertension and history of diabetes mellitus were associated with increased risk of HRVO. Risk of CRVO increased with history of diabetes, systemic hypertension, and higher erythrocyte sedimentation rate (females only); risk of CRVO decreased with increasing amounts of physical activity and increasing amounts of alcohol consumption. Systemic hypertension, higher body mass index, and higher alpha2-globulin levels were associated with increased risk of BRVO, whereas higher high-density lipoprotein levels and increasing levels of alcohol consumption were associated with decreased risk of BRVO. Glaucoma history was associated with all three types of retinal vein occlusion.

CONCLUSION

Patients presenting with retinal vein occlusion should be evaluated for cardiovascular disease, diabetes, and glaucoma.

The rate of mitochondrial 12S rRNA gene evolution is similar in freshwater turtles and marsupials

Assertions that the "conventional" rate of mitochondrial DNA (mtDNA) evolution is reduced in poikilotherms in general and turtles in particular were tested for side-necked turtles (Pleurodira: Chelidae). Homologous data sets of mitochondrial 12S rRNA gene sequences were used to compare the average divergence between the Australian and South American species for two Gondwanan groups: the chelid turtles and the marsupials. The mean nucleotide divergences between continental groups for both the turtles and the marsupials are remarkably similar. These data suggest that the rate of evolution of mitochondrial 12S rRNA gene is not substantially slower in turtles than in the homeothermic marsupials.

Cancer incidence after retinoblastoma. Radiation dose and sarcoma risk

CONTEXT

There is a substantial risk of a second cancer for persons with hereditary retinoblastoma, which is enhanced by radiotherapy.

OBJECTIVE

To examine long-term risk of new primary cancers in survivors of childhood retinoblastoma and quantify the role of radiotherapy in sarcoma development.

DESIGN

Cohort incidence study of patients with retinoblastoma followed for a median of 20 years, and nested case-control study of a radiation dose-response relationship for bone and soft tissue sarcomas.

SETTING/PARTICIPANTS

A total of 1604 patients with retinoblastoma who survived at least 1 year after diagnosis, identified from hospital records in Massachusetts and New York during 1914 to 1984.

RESULTS

Incidence of subsequent cancers was statistically significantly elevated only in the 961 patients with hereditary retinoblastoma, in whom 190 cancers were diagnosed, vs 6.3 expected in the general population (relative risk [RR], 30 [95% confidence interval, 26-47]). Cumulative incidence (+/-SE) of a second cancer at 50 years after diagnosis was 51.0% (+/-6.2%) for hereditary retinoblastoma, and 5.0% (+/-3.0%) for nonhereditary retinoblastoma. All 114 sarcomas of diverse histologic types occurred in patients with hereditary retinoblastoma. For soft tissue sarcomas, the RRs showed a stepwise increase at all dose categories, and were statistically significant at 10 to 29.9 Gy and 30 to 59.9 Gy. A radiation risk for all sarcomas combined was evident at doses above 5 Gy, rising to 10.7-fold at doses of 60 Gy or greater (P<.05).

CONCLUSIONS

Genetic predisposition has a substantial impact on risk of subsequent cancers in retinoblastoma patients, which is further increased by radiation treatment. A radiation dose-response relationship is demonstrated for all sarcomas and, for the first time in humans, for soft tissue sarcomas. Retinoblastoma patients should be examined for new cancers and followed into later life to determine whether their extraordinary cancer risk extends to common cancers of adulthood.

Mutation of the Stargardt disease gene (ABCR) in age-related macular degeneration

Age-related macular degeneration (AMD) is the leading cause of severe central visual impairment among the elderly and is associated both with environmental factors such as smoking and with genetic factors. Here, 167 unrelated AMD patients were screened for alterations in ABCR, a gene that encodes a retinal rod photoreceptor protein and is defective in Stargardt disease, a common hereditary form of macular dystrophy. Thirteen different AMD-associated alterations, both deletions and amino acid substitutions, were found in one allele of ABCR in 26 patients (16%). Identification of ABCR alterations will permit presymptomatic testing of high-risk individuals and may lead to earlier diagnosis of AMD and to new strategies for prevention and therapy.

Phenotypic heterogeneity in families with age-related macular degeneration

PURPOSE

To evaluate the ophthalmic phenotype in families with three or more individuals who have age-related maculopathy.

METHODS

Eight families were identified at academic centers in Massachusetts and North Carolina. Macular findings were graded based on a modification of the grading system used in the Age-Related Eye Disease Study (AREDS).

RESULTS

All families had at least three members with stage 3 (extensive drusen change) or higher maculopathy in at least one eye, and six families had at least two members with advanced maculopathy (stage 4, geographic atrophy of the retinal pigment epithelium, or stage 5, exudative maculopathy). Both stages 4 and 5 maculopathy were observed among different individuals in four families. Individuals with stage 3 maculopathy were members of families with more advanced maculopathy (six families) and were of similar age as more severely affected family members but tended to be older than those with stage 2.

CONCLUSION

The phenotypic appearance of the macula in families with multiple affected individuals is heterogeneous and representative of the spectrum of macular findings typically associated with age-related maculopathy.

Phosphatidylcholine-fatty acid membranes: effects of headgroup hydration on the phase behaviour and structural parameters of the gel and inverse hexagonal (H(II)) phases

The phase behaviour and structural parameters of a homologous series of saturated diacyl phosphatidylcholine/fatty acid 1:2 (mol/mol) mixtures having chain lengths from C12 to C20 were studied by X-ray diffraction and calorimetry, as a function of water content. The chain-melting transition temperatures of the 1:2 PC/FA mixtures are found to be largely independent of the degree of hydration. For all chain lengths, the tilted L(beta') and rippled P(beta') gel phases of the pure PC component are replaced by an untilted L(beta) gel phase in the 1:2 PC/FA mixtures. This gel phase swells considerably upon hydration, with a limiting water layer thickness in the range 18-24 A, depending on the chain length. However, unlike pure phospholipid systems, the lateral chain packing within the gel phase bilayers is essentially identical in both the dry and the fully hydrated states. The fluid bilayer L(alpha) phase is suppressed in the 1:2 mixtures, being replaced by inverse non-lamellar phases for all chain lengths greater than C12, and at all levels of hydration. For chain lengths of C16 and greater, the inverse hexagonal H(II) phase is formed directly upon chain melting, at all water contents. For the shorter chain length mixtures, the behaviour is more complex, with the H(II) phase forming at low hydration, but with bicontinuous cubic phases appearing at higher levels of hydration. The implications of these surprising results are explored, in terms of the effective hydrophilicity of the associated PC and FA headgroups and the packing within the interfacial region. We suggest that the presence of the fatty acids significantly alters the lateral stress profile across the lipid monolayer in the fluid state, compared to that of the corresponding pure PC system, such that inverse phases, where the interface bends towards the water, become strongly favoured. Furthermore, for short chain lengths, packing constraints favour the formation of phases with negative interfacial Gaussian curvature, such as the bicontinuous cubic phases, rather than the H(II) phase, which has more severe chain packing frustration.

Exclusion of TIMP3 as a candidate locus in age-related macular degeneration

PURPOSE

Age-related macular degeneration (AMD) is a genetically complex disorder. Tissue inhibitor of metalloproteinases-3 (TIMP3) on chromosome 22 has been identified as a gene that is mutated in Sosby's fundus dystrophy, an autosomal-dominant macular dystrophy that phenotypically resembles AMD. The purpose of this study was to determine whether TIMP3 is a major susceptibility gene for the AMD phenotype.

METHODS

Thirty-eight multiplex families with AMD were identified in Massachusetts and North Carolina. The macular findings were graded according to a modification of the grading system used in the Age-Related Eye Disease Study, and persons with extensive intermediate drusen, any large drusen, geographic atrophy, or evidence of exudative maculopathy were coded as affected for the purpose of the analysis. Linkage analysis was performed using both model-dependent (lod score) and model-independent (sibpair) methods. For the lod score analysis, both autosomal-dominant as well as recessive low penetrance "affecteds only" analyses were examined. Three markers, D22S280, D22S529, and D225268, linked tightly and flanking the TIMP3 locus, were chosen for the analysis. Association studies were performed by examining one randomly chosen affected person per family and comparing the patients with AMD with a series of age, gender, and ethnically matched control subjects with no known history of AMD.

RESULTS

Lod score analysis excluded linkage in these data for an approximately 10-cm interval surrounding the TIMP3 gene for all models tested. In addition, no significant findings were observed with either the sibpair or the association study.

CONCLUSIONS

No evidence of linkage or association or both was found between AMD and TIMP3 in these 38 families. These data suggest that although clinically similar, the genetic defect in Sorsby's fundus dystrophy is of a different cause than the majority of the genetic causes of AMD.

Familial aggregation of age-related maculopathy

PURPOSE

To determine whether age-related maculopathy aggregates in families by evaluating whether its prevalence is higher among relatives of case subjects with age-related maculopathy compared with relatives of control subjects without age-related maculopathy.

METHODS

Individuals with (n = 119) and without (n = 72) age-related maculopathy were identified. First-degree relatives of case and control probands (parents, siblings, or offspring) 40 years of age or older were asked whether they had ever been diagnosed with macular degeneration. Medical records of 177 case and 146 control relatives confirmed the presence or absence of age-related maculopathy.

RESULTS

The prevalence of medical-record confirmed age-related maculopathy was significantly higher among first-degree relatives of case probands (23.7%) compared with first-degree relatives of control probands (11.6%) with an age- and sex-adjusted odds ratio (OR), 2.4; 95% confidence interval (CI), 1.2 to 4.7; P = .013. Relatives of 78 case probands with exudative disease had a significantly higher prevalence of maculopathy (26.9%) compared with relatives of the 72 unaffected control probands (11.6%) (adjusted OR, 3.1; 95% CI, 1.5 to 6.7; P = .003), whereas the prevalence of age-related maculopathy among relatives of 41 probands with dry maculopathy (19.2%) was slightly but not significantly higher (adjusted OR, 1.5; 95% CI, 0.6 to 3.7; P = .36).

CONCLUSIONS

The prevalence of age-related maculopathy among first-degree relatives of subjects with age-related maculopathy, particularly with exudative disease, is greater than among first-degree relatives of subjects without this disease. Results suggest that macular degeneration has a familial component and that genetic or shared environmental factors, or both, contribute to its development.

Phylogenetic relationships of chelid turtles (Pleurodira: Chelidae) based on mitochondrial 12S rRNA gene sequence variation

Conflicting phylogenies have been proposed for the Chelidae (Testudines: Pleurodira), a family of side-necked turtles found only in Australasia and South America. Sequence data from the mitochondrial 12S rRNA gene were used to test these phylogenies. In total, 411 nucleotides were sequenced for each of 16 chelid species, including all 11 recognized chelid genera and, as outgroups, 5 genera of Pelomedusidae (Testudines: Pleurodira). Analyses using parsimony and neighbor joining algorithms strongly support the division of Australian Chelidae into the three monophyletic groups initially suggested by Burbidge et al. (1974; Copeia 2: 392-409): Chelodina (bootstrap value 99%), the Emydura group (87%), and Pseudemydura. The analyses suggest that the Australian chelids are a monophyletic lineage (64%), with the Australian long-necked turtles, Chelodina, more closely related to the Australian short-necked chelids than to the long-necked South American species. These relationships are in contrast to those of Gaffney (1977; Am. Mus. Novitates 2620: 1-28). The species of Australian long-necked chelids consistently form a monophyletic clade, with Chelodina longicollis and Chelodina oblonga as sister taxa. The data failed to resolve relationships among the Australian short-necked taxa: Emydura, the Elseya latisternum group, the Elseya dentata group, Rheodytes, and Elusor. Unlike Gaffney (1977), we find some weak support (58%) for Pseudemydura as the closest relative of the other Australian short-necked taxa. With the exception of Hydromedusa, the South American taxa are monophyletic and the subgenera of Phrynops are paraphyletic.

A prospective study of cigarette smoking and age-related macular degeneration in women

OBJECTIVE

To evaluate the relationship between cigarette smoking and incidence of age-related macular degeneration (AMD) among women.

DESIGN

Prospective cohort study with 12 years of follow-up (1980 to 1992), in which information on smoking habits was updated every 2 years.

SETTING

Eleven states throughout the United States.

PARTICIPANTS

A total of 31 843 registered nurses enrolled in the Nurses' Health Study who were aged 50 to 59 years in 1980 and did not report a diagnosis of cancer or AMD at the beginning of the study. Additional women entered the analytic cohort as they reached 50 years of age.

MAIN OUTCOME MEASURE

Incidence of AMD with visual loss.

RESULTS

During 556 338 person-years of follow-up, 215 women were newly diagnosed as having AMD. After adjusting for other risk factors for AMD, women who currently smoked 25 or more cigarettes per day had a relative risk (RR) of AMD of 2.4 (95% confidence interval [CI], 1.4-4.0) compared with women who never smoked. Past smokers of this amount also had a 2-fold increased risk (RR=2.0; 95% CI, 1.2-3.4) relative to never smokers. Compared with current smokers, little reduction in risk was suggested even after quitting smoking for 15 or more years. Risk of AMD also increased with an increasing number of pack-years smoked (P for trend <.001); among women who smoked for 65 or more pack-years, the risk was 2.4 times the risk of never smokers (95% CI, 1.5-3.8). Analyses of dry and exudative types of AMD and other alternative definitions of AMD revealed similar results.

CONCLUSIONS

Cigarette smoking is an independent and avoidable risk factor for AMD among women. Because AMD is the most common cause of severe visual impairment among the elderly and treatment is not available or is ineffective for most patients, reducing the risk of this disease is another important reason to avoid smoking.

Freeze fracture electron microscopy of lyotropic lipid systems: quantitative analysis of the inverse micellar cubic phase of space group Fd3m (Q227)

An inverse micellar cubic phase of cubic aspect 15 formed by dioleoylglycerol/dioleoylphosphatidylcholine mixtures has been studied by freeze fracture electron microscopy. The structure was well preserved after freezing samples which had been hydrated either in pure water or in 30 vol% aqueous glycerol solutions. Electron microscopy images of high quality and resolution have been obtained. Four types of fracture planes, perpendicular to the [111], [110], [311] and [100] crystallographic axes, were identified by optical diffraction of the images from selected areas of the replicas. This is the largest number of different fracture planes yet observed in any lipid mesophase by electron microscopy. These planes are also perpendicular to the directions of the lowest order, and most intense reflections in the X-ray patterns from this cubic phase. The images were filtered using correlation averaging techniques, and they revealed the presence of mirror planes, which establishes that the space group is Fd3m (Q227) rather than Fd3. The interpretation of the images was aided by the novel use of standard deviation (s.d.) information obtained from the averaging procedures. The results are easily interpreted with the structure model deduced from X-ray diffraction and consisting of a complex packing of two different sizes of quasi-spherical inverse micelles located at positions (a) and (d) of the Fd3m unit cell. The results also show clearly that the fracture pathways always coincide with the regions of high CH3 concentration, located between the crystallographic planes containing the larger inverse micelles located at positions (a).

Decision-making in the treatment of subfoveal neovascularization in age-related macular degeneration. An analysis from the patient's perspective

BACKGROUND

The clinical management of subfoveal neovascularization in age-related macular degeneration remains controversial. Large multicenter clinical trials recommend laser photocoagulation for certain subfoveal membranes, but many ophthalmologists are reluctant to treat patients with such lesions because a substantial initial visual loss may be induced by the treatment itself. Despite these controversies in management, the attitude of patients toward treatment of these lesions has not been assessed systematically.

METHODS

In this article, a newly designed survey containing five hypothetical clinical scenarios was given to 68 patients with age-related macular degeneration to measure their relative preferences for the potential long-term benefits of laser photocoagulation compared with the immediate visual loss induced by laser therapy.

RESULTS

This pilot study reveals a strong preference by these patients for laser intervention, despite the risk of immediate visual loss. On all five questions, the laser treatment outcome was preferred over the natural course of the disease.

CONCLUSION

Ophthalmologists, when making clinical recommendations to patients with subfoveal exudative macular degeneration, may wish to consider the results of this survey, which suggest a substantial patient preference for laser treatment versus no intervention.

Serum zinc and serum lipid profiles in 778 adults

There has been increasing use of high-dosage zinc supplementation in the population, in particular as a potential treatment for age-related macular degeneration. We examined the relationship between fasting serum zinc and serum lipid levels in 778 adults, aged 22 to 80 years, who were control subjects in a multicenter, clinic-based case-control study. The samples were taken during 1987 to 1990, a time when vitamin/mineral supplementation was becoming increasingly common. We found that higher serum zinc levels, most notably those above the highest quintile, were associated with higher levels of total serum cholesterol, low-density-lipoprotein cholesterol, and triglycerides. No significant trend was noted for high-density-lipoprotein cholesterol. Previous studies demonstrated that high-dosage zinc supplements raise serum zinc levels. The possibility that use of such supplements can adversely affect serum lipid profiles suggests that chronic ingestion of such supplements should not be done without adequate medical supervision.

Prediction of visual function after cataract surgery. A prospectively validated model

OBJECTIVE

To develop a model to predict visual functional improvement after cataract extraction with intraocular lens implantation based on preoperative data.

DESIGN

A prospective study with serial evaluations of visual function preoperatively and at 3 and 12 months after surgery.

SETTING

The General Eye Service of the Massachusetts Eye and Ear Infirmary. Boston, Mass, and 33 ophthalmology practices in Boston.

PATIENTS

Patients (N = 426; ages, > or = 65 years) who were undergoing cataract surgery.

METHODS

Twelve-month improvement in visual function was measured by using the Activities of Daily Vision Scale (ADVS). Ordinal logistic regression was used to identify correlates of improved ADVS scores in 281 patients (derivative set). Potential factors included the preoperative visual acuity, preoperative ADVS score, four chronic ocular diseases, eight medical conditions, and demographic characteristics. Five predictors were identified and used to construct a prediction rule. The accuracy of the prediction rule was evaluated in an independent group of 145 patients (validation set).

RESULTS

Postoperatively, 40% of the 281 patients in the derivative set had substantial improvement in their ADVS scores, and 53 (19%) had some improvement. Predictors of improvement included younger age (P < .001), a poorer preoperative ADVS score (P < .001), posterior subcapsular cataract (P = .09), and absence of age-related cataract (P = .09), and absence of age-related macular degeneration (P = .07) and/or diabetes (P = .006). When applied to the independent sample of 145 patients, these five characteristics classified the patients into three groups in which the probabilities of substantial improvement were 85%, 34%, and 3%, thus verifying the discriminatory power of the prediction rule.

CONCLUSIONS

Preoperative data can identify patients who are likely to have improvements in visual function after cataract surgery. Such findings may be useful in the selection of patients for this high-volume procedure.

Improved visual function and attenuation of declines in health-related quality of life after cataract extraction

OBJECTIVE

To measure the effect of cataract extraction and lens implantation on elderly persons' health-related quality of life and on their ability to perform visual activities.

DESIGN

Evaluations of health status were conducted preoperatively and at 3 and 12 months after surgery on patients scheduled for cataract extraction.

SETTING

Patients were enrolled from the General Eye Service of the Massachusetts Eye and Ear Infirmary and 33 Boston practices.

PATIENTS

The cohort consisted of 464 patients aged 65 years or older who were identified from the surgical schedule of the Massachusetts Eye and Ear Infirmary. At 3 to 12 months after surgery, 458 (99%) of the participants were successfully contacted. Health-related quality of life data were available for 419 (90%) to assess changes after surgery.

MAIN OUTCOME MEASURES

Ophthalmologic examinations were performed preoperatively and during the follow-up period. The Activities of Daily Vision Scale (ADVS) and the Medical Outcomes Study 36-item short from (SF-36) were administered before surgery and at 3 and 12 months postoperatively to assess changes in health status.

RESULTS

At 12 months after surgery, 95% of patients had improved Snellen visual acuity, 80% had improved ADVS scores, but only 36% had improved SF-36 physical functioning. Average scores on seven of eight SF-36 subscales worsened at 12 months. Patients with improved ADVS scores had significantly smaller declines across all SF-36 dimensions except for role limitations due to emotional problems.

CONCLUSION

Improved visual function after cataract surgery was associated with better health-related quality of life, suggesting that age-related declines in health may be attenuated by improvements in visual function.

Confirmation of self-reported cataract in the Physicians' Health Study

Large-scale prospective studies of disease development often rely on self-reported data. To assess the accuracy of self-reports of cataract, we compared the self-reports with medical record data obtained from diagnosing ophthalmologists and optometrists for participants in the Physicians' Health Study, a randomized trial of aspirin and beta-carotene among 22,071 male U.S. physicians aged 40-84 years. A report of cataract, defined as a positive response to a question about whether cataract had ever been diagnosed in either eye and the date of diagnosis, was found to be a very good indicator of lens opacification but was not a good indicator of an incident, age-related opacity that reduced visual acuity. These results indicate that in large prospective studies of clinically significant cataract, where examination of all study participants is not feasible and self-reported data are used, additional documentation to supplement the self-reports should be obtained and strict diagnostic criteria applied to minimize the likely effects of misclassification.

The use of vitamin supplements and the risk of cataract among US male physicians

OBJECTIVES

The purpose of this study was to examine prospectively the association between reported use of vitamin supplements and risk of cataract and cataract extraction.

METHODS

The study population consisted of 17,744 participants in the Physicians' Health Study, a randomized trial of aspirin therapy and beta-carotene among US male physicians 40 to 84 years of age in 1982 who did not report cataract at baseline and provided complete information about vitamin supplementation and other risk factors for cataract. Self-reports of cataract and cataract extraction were confirmed by medical record review.

RESULTS

During 60 months of follow-up, there were 370 incident cataracts and 109 cataract extractions. In comparison with physicians who did not use any supplements, those who took only multivitamins had a relative risk of cataract of 0.73 after adjustment for other risk factors. For cataract extraction, the corresponding relative risk was 0.79. Use of vitamin C and/or E supplements alone was not associated with a reduced risk of cataract, but the size of this subgroup was small.

CONCLUSIONS

These data suggest that men who took multivitamin supplements tended to experience a decreased risk of cataract and support the need for rigorous testing of this hypothesis in large-scale randomized trials in men and women.

A prospective study of alcohol consumption and risk of cataract

The role of alcohol as a determinant of age-related cataract is largely unexplored, although a possible influence has been suggested by previous retrospective and cross-sectional studies. We used the prospective data base of the Physicians' Health Study to examine the association between alcohol consumption and incidence of cataract as well as cataract extraction among U.S. male physicians. Participants in the Physicians' Health Study, a randomized trial of aspirin and beta-carotene among 22,071 male physicians 40-84 years of age at entry in 1982, were included in these analyses if they did not report cataract at baseline and if they provided information about alcohol consumption and other cataract risk factors. A total of 17,824 physicians satisfied these criteria. An incident cataract was defined as a self-report confirmed by medical record review, first diagnosed after randomization, with an age-related cause, and responsible for a reduction in best corrected visual acuity to 20/30 or worse. During 88,565 person-years of follow-up, 371 participants had a confirmed incident cataract and 110 underwent cataract extraction. Compared to physicians consuming alcohol less than once per month, daily consumers of alcohol had an age-adjusted relative risk (RR) of cataract of 1.31 (95% confidence interval [CI] = 0.95, 1.81). For posterior subcapsular (PSC) cataract, the most disabling subtype in terms of vision loss, the RR was 1.38 (95% CI = 0.84, 2.27); for PSC cataract extraction, the RR was 1.43 (95% CI = 0.71, 2.88).(ABSTRACT TRUNCATED AT 250 WORDS)