Author’s Name(s): Winnie Yu, Marko Popovic, Ya-Ping Jin, Michael Baillargeon, Keith Gordon, Rajeev Muni 

Author’s Disclosure Block: Winnie Yu: none; Marko Popovic: Fighting Blindness Canada, PSI Foundation and Data Sciences Institute, University of Toronto; Ya-Ping Jin: Glaucoma Research Society of Canada and Data Sciences Institute, University of Toronto; Michael Baillargeon: none; Keith Gordon: none; Rajeev Muni: Consultant- Alcon, Apellis, AbbVie, Bayer, Bausch Health, Roche; Financial Support (to institution) - Alcon, AbbVie, Bayer, Novartis, Roche 

Abstract Body
Purpose: Routine eye exams by optometrists under the Ontario Health Insurance Plan (OHIP) were delisted in November 2004 for individuals aged 20-64 years who were otherwise healthy with no pre-existing eye conditions. This study aimed to assess the impact of delisting routine eye exams on the annual prevalence of common ocular conditions in adults 40-64 and 65+ years between 1997-2021. Study Design: Population-based, retrospective cohort study using health administrative data. Methods: Adults ≥40 years who were eligible for OHIP between 1997-2021 were included. OHIP diagnostic codes and fee codes submitted by ophthalmologists or optometrists were used to identify individuals with common ocular conditions, namely cataracts, retinopathies, glaucoma, and keratitis. Segmented linear regression was used to determine the change in prevalence before and after the delisting of eye exams. Linear regression models were used to derive the change (β coefficient) and prevalence trend over time. Results: Annual prevalence rates of adults aged 40-64 years with 1+ common ocular condition increased by 1.9% per year (p<0.0001) from 5.9% in 1997 to 19.6% in 2004. Since 2005, annual prevalence increased 0.2% per year (p<0.0001) to 21.0% in 2021. The number of additional individuals in this age group who could potentially have 1+ ocular condition and were not seen for an eye exam due to the delisting of routine eye exams was estimated to be 1.5 million (n=1,532,249) in 2021. Prevalence of cataracts was reported to be 2.1% in 1997 and 6.2% in 2021 (β=0.1, p<0.0001), retinopathies was 1.4% in 1997 and 7.8% in 2021 (β=0.2, p<0.0001), glaucoma was 2.1% in 1997 and 8.1% in 2021 (β=0.2, p<0.0001) whereas keratitis was 0.7% in 1997 and 6.5% in 2021 (β=0.2, p<0.0001). In adults aged 65+ years, prevalence of having a common ocular condition was 29.1% in 1997, which increased 5.1% per year (p<0.0001) to 2004 and continued to rise at 0.6% per year (p<0.0001) to 78.9% in 2021. In those aged 65+, the annual prevalence rates of cataracts increased from 20.0% in 1997 to 66.6% in 2021 (β=1.5, p <0.0001). Retinopathies also rose from 3.9% in 1997 to 34.8% in 2021 (β=1.3, p<0.0001), glaucoma was 7.3% in 1997 which increased to 31.1% in 2021 (β=1.0, p<0.0001) and keratitis increased from 1.3% in 1997 to 15.2% in 2021 (β=0.6, p<0.0001). Conclusions: Annual prevalence of common ocular conditions have significantly increased over time. However, the increase in having 1+ common ocular condition appeared to have slowed significantly in the cohort of adults aged 40-64 since 2005, with approximately 1.5 million Ontarians likely undetected with a common ocular condition. With improvements in diagnostic tools for early detection of various ocular conditions, this illustrates the impact that delisting eye exams on OHIP may have on the accessibility of early diagnosis and management of common ocular conditions.