Long-term follow-up of intraocular pressure after vitrectomy in eyes without preexisting glaucoma

Purpose: To identify whether vitrectomy is associated with an increased risk of elevated intraocular pressure (IOP) and to report the incidence of open-angle glaucoma after vitrectomy. Methods: In this retrospective case series of 234 consecutive patients without a history of glaucoma or diabetes undergoing primary unilateral vitrectomy for an idiopathic epiretinal membrane or macular hole with a minimum of 2 years follow-up, mean IOP in operative and fellow eyes were compared at baseline and multiple postoperative times. Eyes were also assessed for the development of open-angle glaucoma. Results: The mean baseline IOP was 14.91 mmHg, and the mean final IOP was 14.6 (P = 0.278) in the operative eyes. Linear regression analysis of IOP in operative eyes from baseline to the final visit found an increase of 0.000047 mmHg per year compared with ?0.00027 mmHg per year in the fellow eyes with no significant difference in the slope of the 2 regression lines (P = 0.27). Six vitrectomy eyes were diagnosed with new-onset openangle glaucoma during a mean follow-up of 4.4 years; however, only one was not also diagnosed with glaucoma or ocular hypertension in the fellow unoperated eye. Conclusion: Vitrectomy does not seem to be correlated with increased risk of IOP elevation or glaucoma development in comparison with fellow control eyes.