Long Term Incidence Rate of Glaucoma after Pars Plana Vitrectomy

ABSTRACT

PURPOSE: To evaluate the incidence rate of postoperative glaucoma after pars plana vitrectomy (PPV) and to compare incidence rate of glaucoma between phakic and pseudophakic eyes. METHODS: Retrospective chart review of patients who underwent PPV between January 2007 and May 2014. The outcome measure was the presence or absence of postoperative glaucoma, defined as definitive loss of neuro-retinal rim defect on fundus exam or showing glaucomatous change on a visual field test that warranted maintenance of ocular hypotensive therapy. RESULTS: There were 333 patients average age 57.09 +/- 13.43 included this study. Patients were followed for an average of 56.23 +/- 10.85 months. There was no significant difference in mean intra ocular pressure (IOP) between the vitretomized eyes with unoperative eyes, except in mean IOP at one day postoperatively (p = 0.012). In unoperative eyes, 10 of 315 (3.1%) were newly diagnosed as postoperative glaucoma. For the vitrectomized eyes, 69 of the 351 (19.6%) were newly diagnosed as postoperative glaucoma. There was a significant difference in incidence rate of glaucoma between the two groups (p < 0.001, chi-square test). There was a significantly higher IOP in glaucoma eyes compared with normal eyes (p < 0.001, Repeated Measures Analysis of variance [RM-ANOVA]). A possible risk factor for the development of glaucoma after PPV was cataract surgery (p = 0.0497, chi-square test). CONCLUSIONS: The incidence of glaucoma in patients with PPV is higher than in normal eyes. The incidence seems to increase particularly in those who have a pesudophakic eye. Patients who underwent PPV, especially in the pseudophakic state, need to have their IOP monitored carefully and managed properly by an ophthalmologist.