Effect of Prior Phacoemulsification Surgery in Trabeculectomy Surgery Outcomes

Sónia Torres-Costa,1 António Benevides Melo,1,2 Sérgio Estrela-Silva,1,2 Fernando Falcão-Reis,1,2 João Barbosa-Breda1– 4 1Department of Ophthalmology, Centro Hospitalar e Universitário São João, Porto, Portugal; 2Department of Surgery and Physiology, Faculty of Medicine, University of Porto, Porto, Portugal; 3UnIC@RISE, Faculty of Medicine of the University of Porto, Porto, Portugal; 4Research Group Ophthalmology, Department of Neurosciences, KU Leuven, Leuven, BelgiumCorrespondence: Sónia Torres-CostaOphthalmology Department, Centro Hospitalar Universitário de São João, Alameda Professor Hernani Monteiro, Porto, 4200, Portugal, Tel +351 225 512 100, Fax +351 225 025 766, Email sonia.torres.costa@gmail.comPurpose: To evaluate whether previous clear-cornea phacoemulsification surgery affects the surgical outcomes of trabeculectomy in open-angle glaucoma (OAG).Methods: We performed a retrospective cohort study, which included 82 patients with OAG that underwent trabeculectomy between January 1, 2010, and December 31, 2017. The primary outcome was the probability of surgical failure. Failure was defined as IOP > 21 mmHg or reduced < 20% from baseline, IOP ≤ 5 mmHg in three consecutive visits, need for further glaucoma surgery, phthisis or loss of light perception vision due to glaucoma.Results: Eighty-two eyes (58 phakic and 24 pseudophakic) were included. Phakic group patients were younger than those in the pseudophakic group, 65.8 ± 11.7 vs 76.2 ± 7.9 years (p < 0.001). The most common type of glaucoma was primary OAG [59% (n = 34) phakic vs 63% (n = 15) pseudophakic], followed by exfoliative and pigmentary glaucomas. The mean preoperative IOP was not significantly different between groups nor was the number of preoperative hypotensive medications. The rate of surgical failure was not significantly different between groups at year 1 [17% (n = 10) phakic vs 29% (n = 7) pseudophakic; p = 0.361] nor at year 2 [28% (n = 16) phakic vs 46% (n = 11) pseudophakic; p = 0.110]. No significant differences were observed regarding the postoperative IOP or any secondary outcome measures at year 1 or 2.Conclusion: Previous clear-cornea phacoemulsification surgery does not lead to statistically significant differences in the rate of trabeculectomy failure. Despite not being significant, clinically relevant differences were observed between groups. Future studies with a larger sample and/or randomized are needed to clarify this association.Keywords: trabeculectomy, phacoemulsification, surgical failure, intraocular pressure