Clinical Characteristics and Outcomes of Malignant Glaucoma after Different Procedures Treated with Pars Plana Vitrectomy: A 10-Year Retrospective Study

Background and objectives: Despite established common risk factors, malignant glaucoma (MG) remains a rare condition with challenging management. We aimed to analyze differences in risk factors for MG after different surgeries and outcomes after pars plana vitrectomy (PPV). Materials and Methods: This retrospective study included cases of MG treated with PPV between January 2005 and December 2015 in the Department of Ophthalmology, Lithuanian University of Health Sciences, Kaunas, Lithuania. Results: A total of 39 cases were analyzed: 23 (59%) after cataract surgery, 13 (33.3%) after trabeculectomy, and 3 (7.7%) after other interventions. Characteristics among the groups did not differ. Intraocular lens refractive power was significantly higher in the cataract group, in which intraocular pressure (IOP) before MG was significantly greater in the affected eye. Normotension was achieved in 92.3%, and a normal anterior chamber in 75%. Additional measures included eye drops (n = 24), trabeculectomy (n = 5), bleb revision (n = 2), synechiotomy (n = 4), and cyclophotocoagulation (n = 1). The proportion of drop-free patients significantly increased after PPV compared with that before MG development (38.5% versus 15.4%). Complications were observed in 11 cases: choroidal detachments with spontaneous resolution (n = 2); retinal detachment (n = 1); constant mydriasis (n = 1), neovascular glaucoma (n = 1); obstruction of filtrating zone by iris (n = 1) and by blood clot (n = 1); posterior synechia formation causing IOP rise (n = 4 (all resolved after synechiotomy)). The cataract group experienced significantly fewer complications than the trabeculectomy group (17.4% vs. 53.8%, respectively). Conclusions: There were no differences in the risk of MG among the different surgeries. However, higher IOP in the predisposed eye (versus contra-lateral eye) could indicate additional risk of MG after cataract surgery. PPV afforded reliable treatment for MG and the possibility for glaucoma patients to discontinue topical treatment.