Outcome of Trabeculectomy in Phakic and Pseudophakic Eyes with Open Angle Glaucoma after Phacoemulsification: A retrospective Comparative Study

Background: Glaucoma is one of devastating eye disease with major complications up to blindness. Trabeculectomy is the standard surgical procedure for management of the disease. However, the success rate after previous phacoemulsification is not will addressed. 
The aim of the work: The current work aimed to evaluate the effect of prior phacoemulsification surgery on the outcome of trabeculectomy for primary open angle glaucoma.
Patients and Methods: This is a retrospective study, that included all patients who underwent trabeculectomy for primary open angle glaucoma from January, 1^st, 2017 till the end of December 2021. They were 36 phakic and 28 pseudophakic eyes.  The operative success at the end of the sixth postoperative month was the primary outcome and different complications were the secondary outcome. Other collected data were patient demographics, pre- and post-operative intraocular pressure [IOP] and best corrected visual acuity [BCVA] at 2 weeks, and 1, 3, and 6 postoperative months.
Results: The glaucoma was of primary open type among majority of patients [79.7%]. At one, three and six postoperative months, the IOP was significantly reduced among phakic than pseudophakic groups. But the BCVA did not differ between phakic and pseudophakic groups either preoperative or at the follow up periods. The surgical failure was reported among 14 eyes [21.9%] and significantly increased in pseudophakic than phakic groups [35.7% vs 11.1%, respectively]. Choroidal detachment was reported among 7 eyes [10.9%], hyphema in one eye [1.6%] and bleb leak in 3 eyes [4.7%]; and there was insignificant difference between phakic and pseudophakic groups. 
Conclusion: Previous phacoemulsification is associated with increased failure rate of trabeculectomy in patients with open angle glaucoma.