Original article
Progression of visual field loss in untreated glaucoma patients and glaucoma suspects in st. lucia, west indies1, 2,

https://doi.org/10.1016/S0002-9394(02)01585-4Get rights and content

Abstract

PURPOSE: A 1986–1987 survey found 8.8% prevalence of open-angle glaucoma in the black population of St. Lucia, West Indies. This follow-up study assessed visual field loss progression in untreated glaucoma patients and glaucoma suspects 10 years later.

DESIGN: Cohort study.

METHODS: Subjects were 205 glaucoma patients and suspects; 1987 data included age, sex, visual acuity, and visual fields measured by automated threshold perimetry (Humphrey C 30-2 test), and 1997 data included intraocular pressure, visual acuity, and visual fields measured by the same test. Exclusion criteria included field unreliability, field improvement due to vision improvement, nonglaucomatous vision deterioration, glaucoma treatment since 1988, and scoring of a visual field as end stage in 1987. Visual fields were scored by algorithms for the Advanced Glaucoma Intervention Study (AGIS) and Collaborative Initial Glaucoma Treatment Study (CIGTS).

RESULTS: By AGIS criteria, 55% of 146 right eyes and 52% of 141 left eyes showed progression of visual field loss. In linear regressions, progression severity was unassociated with sex, intraocular pressure, or baseline visual field score, but was positively associated with age (P < .001, right; P = .002, left). The cumulative probability of reaching end stage in 10 years in at least one eye was approximately 16% by AGIS criteria. By CIGTS criteria, 73% of 146 right eyes and 72% of 141 left eyes progressed.

CONCLUSIONS: These data provide a unique opportunity to study progression of untreated glaucoma. The percentage of eyes showing visual field loss progression and the percentage reaching end stage were considerably higher than in studies of visual field progression in treated eyes.

Section snippets

Design

This is a cohort study of visual field progression in untreated glaucoma patients and glaucoma suspects identified from 1986 to 1987. Initially, we intended to compare visual field loss progression between treated and untreated subjects. However, in 1997, few subjects were under active treatment, in part because the infrastructure for subsidized glaucoma care had changed in 1988. We found that only a few patients had undergone surgery and only a few who could afford medications had continued to

Methods

A 1996 feasibility study demonstrated that the subjects’ medical records were available, and it was estimated that approximately 75% of the subjects in the 1986–1987 survey could be located. The survey was approved by the Institutional Review Board of Howard University School of Medicine, and all subjects signed an informed consent form before participating in any part of the study. Multiple attempts were made to contact each of the 364 subjects identified in the 1986–1987 survey as glaucoma

Results

Of the 410 eyes (205 patients) for which data were obtained, 59 right and 64 left eyes were excluded. The final sample consisted of 146 right and 141 left eyes of 155 subjects (47 men and 108 women). The mean age was 52.3 years, with a range of 26 to 85 years. The mean IOPs from the 1997 examination were 21.0 mm Hg (standard deviation [SD] = 4.3; range = 10–39) for right eyes and 21.0 mm Hg (SD = 4.2; range = 12–43) for left eyes. Of the 155 subjects, 81 (52%) had definite glaucomatous visual

Discussion

No standard for identifying progression of glaucomatous visual field loss has been agreed upon, and separating true progression from changes in visual fields due to learning effects, fatigue, and the long-term fluctuation inherent in the test is extremely difficult.6, 9, 11, 12, 13, 14, 15 For a definitive determination of progression, clinical trials often require that three successive fields show a definite change from baseline. In our study, the lack of repeated evaluation for a given

Acknowledgements

We thank the Ministry of Health of St. Lucia for its support, both for the initial survey and the present study. We also acknowledge and thank Zeiss Humphrey (Dublin, California, USA) for donation of the Humphrey Field Analyzer and the International Eye Foundation (Bethesda, Maryland, USA) for donation of the slit-lamp microscope. New World Medical, Inc. (Rancho Cucamanga, California, USA) responded to the problem of lack of adequate surgical treatment found in this study by sponsoring two of

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    This work was supported in part by a grant from the Glaucoma Research Foundation, San Francisco, California (O.K.), the Health Future Foundation, Omaha, Nebraska (M.R.W.), and grant NEI EY08208 from the National Eye Institute, National Institutes of Health, Bethesda, Maryland. (P.S.). This manuscript is abstracted from a thesis submitted by M.R.W. to the American Ophthalmological Society.

    1

    InternetAdvance publication at ajo.com May 7, 2002.

    2

    This study was conducted while the principal author was affiliated with the Jules Stein Eye Institute, University of California at Los Angeles and the Charles R. Drew University of Medicine and Science, Los Angeles, California.

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