Natural History of Optic Disc With Physiologic Large Cup: Incidence, Predictors of Glaucoma Conversion After Minimum 10-Year Follow-up

Abstract

To investigate the natural history of optic disc with physiologic large cup (PLC) (ie, vertical cup/disc ratio [VCDR] ≥0.6 without retinal nerve fiber layer defect) and the risk factors for glaucoma conversion. Observational retrospective cohort study. Subjects who underwent a health screening examination at Seoul National University Hospital Healthcare System Gangnam Center from 2003 to 2010 (n=76,030) were involved. The prevalence of PLC in the cohort was analyzed. The incidence rate of glaucoma conversion was estimated per 100 person-years among cases with a follow-up period longer than 10 years. Multivariate Cox proportional hazards regression was used to identify ocular and systemic factors associated with glaucoma conversion. Among 74,617 eligible subjects, 3569 subjects (4.8%) had PLC. Of those with a follow-up period longer than 10 years (n=859), the incidence rate of glaucoma conversion was 0.95 per 100 person-years. A total of 12.1% of PLC eyes progressed to glaucoma after 8.7 ± 3.9 years (range, 2.0-16.5 years). Higher VCDR (adjusted hazard ratio [aHR]=4.36; 95% CI=2.675-7.103), violation of the inferior superior nasal temporal neuroretinal rim thickness rule (aHR=1.86; 95% CI=1.057-3.258), presence of retinal arterial sclerosis (aHR=1.63; 95% CI=1.040-2.550), and lower total bilirubin level (aHR=0.58; 95% CI=0.340-0.991) were associated with glaucoma development. This study identified the prevalence of PLC as well as the incidence rate of glaucoma conversion and the risk factors for glaucoma development in PLC eyes. The natural history of PLC may help clinicians to better understand its risk factors and the specific management needs of their patients.