Accepted 1 May 2002.

This is an 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. (see D below for a questioning of this conclusion)

a Creighton University School of Medicine, Omaha, Nebraska, USA (M.R.W., O.K., G.H., D.C.)
b Georgetown University School of Medicine, Washington, DC, USA (C.L.C.)
c University of California, San Diego, School of Medicine, San Diego, California, USA (P.S.)
d Devers Eye Institute, Portland, Oregon, USA (C.A.J.)
e Ingenix Pharmaceuticals, Grass Lake, Michigan, USA (C.E.)

Corresponding Author Information Reprint requests to M. Roy Wilson, MD, School of Medicine, Creighton University, 2500 California Plaza, Omaha, NE 68178; fax: (402)280-4027, USA

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.

-------------- The following by MRC -----------

Summary by MRC --

(A) in 10 years, 55% of the untreated patients showed progression. Progression was not associated with intraocular pressure or baseline field score -- but it was associated with age. The probablility of reaching end-stage in 10 years was 16% (in those that progressed?)

(B) In other words -- progression went from zero % / year to 1.6 % / year. The median was presumably .8% / year progression.

(C) So, assuming I have glaucoma, and I go untreated, I should expect to lose 16% of my vision in 20 years. That does not worry me, because I am now 75.

(D) Their singular conclusion is not supported by data in this report -- because they did not consider treated eyes. Their generalization would only be warranted if they showed the “treated” data.

Robert N. Weinreb, MDa Corresponding Author
David S. Friedman, MD, MPHb, Robert D. Fechtner, MDc, George A. Cioffi, MDd, Anne L. Coleman, MD, PhDe, Christopher A. Girkin, MD, MSPHf, Jeffrey M. Liebmann, MDg, Kuldev Singh, MD, MPHh, M.Roy Wilson, MD, MSi, Richard Wilson, MDj, William B. Kannel, MD, MPHk

Accepted 27 April 2004. published online 24 August 2004.

This is an Abstract

Purpose: To develop a model for estimating the global risk of disease progression in patients with ocular hypertension and to calculate the “number-needed-to-treat” (NNT) to prevent progression to blindness as an aid to practitioners in clinical decision making.

Design: Development of a mathematical model for estimating risk of glaucoma progression.

Methods: Population-based studies of patients with ocular hypertension and glaucoma were reviewed by a panel of glaucoma specialists. Measures of disease progression risks derived from three long-term studies and assumptions based on the available data were used to estimate the risk of progression from ocular hypertension to glaucoma and glaucoma to unilateral blindness for untreated and treated patients over a 15-year period. Using these estimates, the NNT (1/absolute risk reduction on treatment) to prevent unilateral blindness in one patient with ocular hypertension was calculated.

Results: In untreated patients, the estimated risk of progression from ocular hypertension to unilateral blindness was 1.5% to 10.5% and in treated patients, the estimated risk of progression was 0.3% to 2.4% over 15 years. From these estimates, between 12 and 83 patients with ocular hypertension will require treatment to prevent one patient from progressing to unilateral blindness over a 15-year period.

Conclusion: Global risk assessment that incorporates all available data plays a vital role in managing patients with ocular hypertension. A more precise understanding of long-term vision loss should be factored into decisions pertaining to the initiation of glaucoma therapy. Undoubtedly, these estimates will evolve and change with the availability of new population-based epidemiologic information and improvements in multivariable model testing.

------------The following by MRC --------------------------------
In other words ---
(A) The chances of any one person being saved from blindness in 15 years by treatment is about 2% (one person out of 50).
(B) Untreated patients progress at the average rate of 6 % over 15 years [(1.5 +10.5) / 2 = 6] which equals .4% / year.

Paul P. Leea, John W. Waltb, Lisa C. Rosenblattc, Lisa R. Siegartelc, Lee S. Stern Corresponding Author, Glaucoma Care Study Group

Accepted 30 July 2007. Published online 04 September 2007.

Purpose: To evaluate whether greater intraocular pressure (IOP) variation between visits was associated with higher likelihood of glaucoma progression.

Design: Cohort study.

Methods: A five-year minimum of data (June 1, 1990 through January 22, 2002) was collected on 151 patients (302 eyes) from 12 United States specialty centers. A post hoc analysis of visual field (VF) progression, glaucoma medication, intraocular pressure (IOP), and other ocular data was conducted for two nonmutually exclusive cohorts based on retrospective data abstracted well after actual patient visits. Mean IOP and standard deviations (SD) were calculated before treatment (medication or surgery) or progression, whichever occurred first, and before progression regardless of treatment. IOP variables were assessed in a univariate fashion; Cox proportional hazards models evaluated glaucoma progression as an outcome measure and IOP SD as a main predictor, controlling for covariates.

Results: In cohort 1 (55 patients; 84 eyes), mean age was 63 years (range, 37 to 85 years), 58% were female, and 19% of eyes underwent VF progression. In cohort 2 (129 patients; 251 eyes), mean age was 66 years (range, 19 to 88 years), 55% were female, and 27% of eyes underwent VF progression. Mean IOP was 16.5 mm Hg (IOP SD, 2.0 mm Hg), and 16.4 mm Hg (IOP SD, 2.7 mm Hg) in cohorts 1 and 2, respectively. Controlling for age, mean IOP, VF stage, and other covariates, each unit increase in IOP SD resulted in a 4.2 times and 5.5 times higher risk of glaucoma progression for cohort 1 (95% confidence interval [CI], 1.3 to 12.9) and cohort 2 (95% CI, 3.4 to 9.1), respectively.

Conclusions: IOP variability is an important predictor of glaucoma progression; SD is a convenient measure of variability to assess glaucoma progression risk.

---------------- below this line by Martin Carbone ---------------------

Summary by MRC --

(A) This study involved patients who underwent treatment (medication or surgery). 19 to 27% of the patients underwent progression (presumably over 5 years?). That is approximately a 4.6 % progression / year. Compare this aproximately 4.6 % / year to the previous test in column 2 in this report -- which appears to show about .4 % / year for untreated patients????

(B) If that is correct -- treatment significantly increases ( > x 10 ) the rate of progression.

(C) The test in column 1 of this table shows less than 1% progression / year for untreated patients. Once again, this study suggests treatment increases progression when compared to the study in column 1.

(D) Both B and C above contradict this study's conclusion