The effect of phacoemulsification on late bleb failure or intraocular pressure in patients with glaucoma: a systematic review

The purpose of our systematic review is to document the adverse events that follow phacoemulsification in eyes with trabeculectomy due to glaucoma and to determine whether phacoemulsification jeopardizes the survival of the trabeculectomy. Our research was based on English- and non-English-language articles obtained using the Medline, Embase, Web of Science and Scopus databases. Additional studies were identified by searching bibliographies in the British Library and abstracts presented at the Association for Research in Vision and Ophthalmology annual meetings. Search terms included randomized controlled trial, controlled clinical trial, random allocation, double-blind method, matched studies and trabeculectomy failure, glaucoma-filtering operation failure, bleb failure and cataract surgery or phacoemulsification. Only prospective or retrospective matched studies testing the survival of a trabeculectomy alone versus clear corneal phacoemulsification after a trabeculectomy in patients with glaucoma were included. Data were independently extracted by two authors using predefined data fields. PubMed yielded 152 results, Scopus 235, Embase 222, and Web of Science (science citation index) 216. We read the abstracts of all the trials, and after reading the full text of 31 studies, we decided that 13 studies should be comprehensively evaluated. Current evidence does not allow us to draw safe conclusions on the scientific question so far.