Abstract
Purpose :
To estimate the prevalence of glaucoma in Canada based on data from Frequency Doubling Technology Perimetry (FDT), optic nerve vertical cup-to-disc ratio (CDR), intraocular pressure (IOP) and use of glaucoma eye drops.
Methods :
The study included 2,612 randomly selected Canadians aged 40-79 taking part in the 2016-2019 Canadian Health Measures Survey. Data from self-report and ocular exams for glaucoma were analyzed. Participants who failed FDT and had a CDR≥0.7 were considered to have definite glaucoma. Those with only a failed FDT, only a CDR≥0.7, only IOP>21 mmHg, or those with ‘normal’ values of FDT, CDR, and IOP but used glaucoma eye drops, were considered glaucoma suspects. Participants who passed FDT, had CDR<0.7, IOP≤21 mmHg, and did not use glaucoma eye drops were deemed as not having glaucoma. Survey weights were used in all analyses.
Results :
Based on self-reports, an estimate of 421,800 Canadians aged 40-79 had glaucoma, representing a prevalence of 2.5% (95% confidence interval [CI] 1.7%-3.3%). The prevalence was higher in Canadians aged 65-79 (5.0%) vs those aged 40-64 (1.6%), in people with less than secondary school graduation (5.0%) vs those with secondary school graduation (2.0%) or higher (2.3%), and in individuals who visited an ophthalmologist/optometrist in the past 12 months (10.0%) vs those that did not (1.4%). Less than half (44.0%) of the self-reported glaucoma individuals used glaucoma eye drops.
Based on ocular exams, there were 71,000 Canadians with definite glaucoma and an additional 1.7 million Canadians labeled as glaucoma suspects. Corresponding prevalence was 0.7% (95% CI 0.3%-1.1%) and 16.3% (95% CI 13.2%-19.4%), respectively.
Of the glaucoma suspects, 44.3% had ocular hypertension (OHT, mean IOP 22.8 mmHg). Only 3% of OHT individuals used glaucoma eye drops. IOP≥28 mmHg was found in 2.4% of OHT individuals and none of them were on glaucoma eye drops.
About 40% (37.5%, or 26,625) of Canadians with exam-determined definite glaucoma were unaware they had glaucoma.
Conclusions :
Among Canadians aged 40-79, the prevalence of glaucoma was 2.5% by self-reports and 0.7% by clinical exams. Exams identified 1/6 Canadians as glaucoma suspects requiring further exams to clarify a glaucoma diagnosis. Few Canadians with OHT used glaucoma eye drops, including those with IOP≥28 mmHg. Nearly 40% of Canadians with exam-determined definite glaucoma were unaware of their glaucoma status.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.