A Prospective Analysis of Nerve Fiber Layer and Macular Changes After Pars Plana Vitrectomy

Since the introduction of vitrectomy in 1971, this procedure has become the third most frequently performed ophthalmic surgery. Approximately 225,000 vitrectomies are performed annually in the United States and indications continue to expand. Known long-term complications of vitrectomy are relatively few and include retinal detachment and cataract formation. Although much has been written in the literature concerning acute rises in intraocular pressure (IOP) in the immediate postoperative period, there is surprisingly little information on long term IOP outcomes after vitrectomy. A recent report by Chang given at the LXII (62) Edward Jackson Memorial Lecture hypothesized a causal relationship between vitrectomy and open-angle glaucoma (OAG) via oxidative stress exacerbated by removal of the crystalline lens. A second report by Luk and colleagues reported similar conclusions in a modified cohort. Both studies, were retrospective in nature and did not perform baseline evaluations to exclude pre-existing glaucoma. Furthermore neither study accounted for natural history. Finally, our analysis has not reproduced similar results.

The primary purpose of this study is to analyze the full spectrum of optic nerve and macular changes between vitrectomized study eyes and their non-vitrectomized fellow eyes to control for natural history. Baseline evaluations will include examination by fellowship trained retina and glaucoma specialists, fundus photography, autofluorescence, optical coherence tomography (macula and optic nerve) and automated visual field testing. At 3 month then annually for 5 years after vitrectomy surgery, the cohort will undergo similar evaluation.