Elsevier

Ophthalmology

Volume 109, Issue 7, July 2002, Pages 1303-1308
Ophthalmology

Risk factors for incident nuclear opacities☆

https://doi.org/10.1016/S0161-6420(02)01094-1Get rights and content

Abstract

Purpose

To evaluate risk factors for the 4-year incidence of nuclear opacities.

Design

Population-based cohort study (85% participation at 4-year follow-up).

Participants

Two thousand six hundred nine black participants of the Barbados Eye Studies, without any nuclear opacities at baseline.

Methods

Participants completed a standardized protocol at baseline and follow-up, including ophthalmic and other measurements, an interview, slit-lamp lens grading, fundus photography, and an ophthalmologic examination. Factors associated with the incidence of nuclear opacities (Lens Opacities Classification System II N ≥ 2) were evaluated by logistic regression.

Main outcome measure

Relative risks (RR) with 95% confidence intervals (95% CI).

Results

The 4-year incidence of nuclear opacities was 9.2% (241 of 2609) and increased greatly with age. Women were at significantly greater risk (RR = 1.8), as were persons with darker iris color (RR = 4.9), myopia (RR = 2.8), history of diabetes (RR = 1.6), leaner body mass (RR = 0.95 for each unit increase in body mass index [kg/m2]), and intraocular pressure (IOP)-lowering treatment (RR = 2.7), mainly with topical β-blockers. Treated participants had a threefold RR of nuclear opacities (RR = 3.2; 95% CI, 1.6, 6.5) compared with those untreated and with IOP ≤21 mmHg. Among participants with IOP >21 mmHg, those receiving treatment (n = 33) had a fivefold RR (RR = 5.0; 95% CI, 1.7, 15.1) versus those who were untreated. The RR was similar for treated persons with and without open-angle glaucoma (RR = 3.1; 95% CI, 1.3, 7.4 and RR = 2.8; 95% CI, 0.9, 8.6 respectively) but was lower in persons with newly detected (and thus untreated) glaucoma at baseline (RR = 1.2; 95% CI, 0.6, 2.6) compared with those without open-angle glaucoma or treatment.

Conclusions

The 4-year risk of nuclear opacities increased with age, female gender, darker iris color, myopia, diabetes, and leaner body mass, indicating similarities with other populations. The use of topical IOP-lowering medications tripled the RR of nuclear opacities in this study, an association that requires verification from clinical trials.

Section snippets

Material and methods

The Barbados Eye Studies (1998–1992), funded by the National Eye Institute, investigated the prevalence, incidence, and risk factors for major causes of visual loss among a black population.4, 13 The studies were based on a simple random sample of Barbados residents, 40 to 84 years old (84% participation),13 who originated from the same areas of West Africa as African Americans.14 After informed consent was obtained from all participants, 4631 persons completed examinations at the study site;

Results

Of the 3427 persons who participated in BISED, 3193 (93%) reported their race as black. As described previously,12 2609 of the black participants had no nuclear opacities at baseline, with a mean age of 54.7 (standard deviation, 10.1) years; 58% were female. Among those at risk, 9.2% (241 of 2609) developed nuclear opacities after 4 years of follow-up. Table 1 presents incidence according to baseline characteristics. Incidence was greater in older persons, such that the group with incident

Discussion

After 4 years of follow-up, this cohort study found that the incidence of nuclear opacities was 9.2% and increased with age, female gender, darker iris color, myopia, diabetes, and leaner body mass Table 1, Table 2, thus supporting the view that risk factors in this black population are similar to those seen in other populations. Results also suggest that topical IOP-lowering treatment (primarily β-blockers in combination with other drugs) increases the RR Table 3, Table 4. These medications

Conclusions

This longitudinal study was the first to provide incidence-based data on the risk of nuclear opacities in a black population, as far as we know. In addition to age, the results confirmed previous findings from other populations, such as the increased risk of women and persons with darker iris color, myopia, diabetes, and leaner body mass. Results also suggest that topical treatment to reduce IOP may increase the risk of nuclear opacities. Confirmation is needed from clinical trials of

Coordinating center

Stony Brook University, Stony Brook, New York: M. C. Leske, MD, MPH; Barbara Nemesure, PhD; Suh-Yuh Wu, MA; Leslie Hyman, PhD; Xiaowei Li, PhD; Shu-Hong Xie, MS; Lixin Jiang, MS; Kasthuri Sarma, Melinda Santoro, Koumudi Manthani.

Data collection center

Ministry of Health, Bridgetown, Barbados, West Indies: Anthea M. S. Connell, FRCS, FRCOphth; Anselm Hennis, MRCP(UK), PhD; Ann Bannister, MB, BS, DO; Muthu A. Thangaraj, MB, BS, DO; Coreen Barrow, Patricia Basdeo, Kim Bayley, Anthanette Holder.

Fundus photography reading center

The Johns Hopkins

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    Supported by grants EY07625 and EY07617 from the National Eye Institute, Bethesda, Maryland.

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