Risk of glaucoma after vitreoretinal surgery - Findings from a population-based cohort study

Purpose To investigate the association between different types of vitrectomy and risk of different types of glaucoma and to determine the effect of systemic medication and diabetes status on this risk. Methods A population-based nested case-control study included individuals of age >= 18 years who had undergone single vitrectomy, vitrectomy with retinal procedure, or combined phaco-vitrectomy between 2001 and 2010. End of follow-up was 2017. Odds ratio (OR) for the development of glaucoma after different types of vitrectomy and 95% confidence interval (CI) were based on conditional logistic regression models. For every glaucoma case, five controls were matched by age, sex, start of follow-up year, and hospital district. Results The cohort (n = 37 687), of which 52.8% was female, consisted of 6552 individuals diagnosed with glaucoma and 31 135 controls matched by age, sex, and hospital district. Vitrectomy was performed on 103 eyes in the glaucoma group and 158 eyes in the control group. As regards the risk of any glaucoma, the risk was lowest in eyes that underwent combined phaco-vitrectomy (OR: 2.7, 95% CI: 1.8-4.1), followed by single vitrectomy (OR: 3.15, 95% CI: 2.1-4.8), and highest in eyes that underwent vitrectomy with retinal procedure (OR: 4.5, 95% CI: 2.7-7.4). Diabetes had no effect (OR: 0.96, 95% CI: 0.92-1.01), but 5-year systemic statin use slightly decreased glaucoma risk (OR: 0.86, 95% CI: 0.77-0.97). Conclusions Vitreoretinal surgery was associated with an increased glaucoma risk; the risk being related to the complexity of vitrectomy. Long-term systemic statin therapy may decrease glaucoma risk, while diabetes had no association.