Iris abnormalities may influence the efficacy and filtration strategies of Posner-Schlossman syndrome: a retrospective study involving trabeculectomy, ExPRESS and Ahmed valve implants.

PURPOSE

To evaluate and compare the one-year efficacy and influencing factors of different filtration surgeries on Posner-Schlossman syndrome (PSS) patients.

METHODS

A retrospective study enrolling 91 PSS patients who underwent filtering surgeries and were followed for at least one year. Unilateral PSS was diagnosed as recurrent attacks of mild, unilateral, non-granulomatous anterior uveitis, elevated intraocular pressure (IOP), keratic precipitates (KPs) on the corneal endothelium, open angle, no posterior synechia, and no inflammatory lesions in the posterior segment; the IOP and anterior segment returned to normal between attacks. Medical histories and thorough ocular examination results were collected. Trabeculectomy and ExPRESS were chosen as the first line and AGV was considered for those under high risk of fibrosis. Follow-up data, mainly IOP, best-corrected visual acuity (BCVA), and anterior segment manifestations at the 1st week, 6th month, and 12th month were generated and analyzed. Iris abnormalities were determined by depigmentation or atrophic changes on the anterior segment photograph. Complete surgical success was defined as 5 mmHg < IOP ≤ 21 mmHg without IOP-lowering drug or needle revision; qualified surgical success was defined as 5 mmHg < IOP ≤ 21 mmHg with IOP-lowering drugs or needle revisions. Survival analysis was performed to obtain the success rates.

RESULTS

At the 12th month, the complete surgical success rate of trabeculectomy (N = 54), ExPRESS (N = 23), and AGV group (N = 14) was 58.97% (95%CI 46.91-77.09%), 84.21% (95%CI 68.33-100.87%), and 100%; the qualified success rate was 71.79% (95%CI 62.46-88.34%), 89.47% (95%CI 77.07-103.33%), and 100%, respectively. Patients undergoing trabeculectomy experienced the largest decline of BCVA (from 0.58±0.46 to 1.01±0.51, P < .05); the trabeculectomy group endured the highest IOP (20.84±9.92 mmHg) compared to ExPRESS (14.51±2.86 mmHg, P < .05) and AGV group (13.17±3.32 mmHg, P < .05). At the 12th month, in the ExPRESS group, patients with iris abnormalities had higher IOP than the normal ones (15.65±2.05 mmHg, 12.93±3.17 mmHg, P < .05). ExPRESS helped patients with iris abnormalities maintain lower IOP than trabeculectomy (15.65±2.05 mmHg, 22.52±10.67 mmHg, P < .05). Three patients developed hypotony at the 3rd month (1 in ExPRESS and 2 in trabeculectomy group).

CONCLUSION

AGV and ExPRESS performed better than trabeculectomy in PSS patients in terms of IOP and success rate. Iris abnormalities might influence the postoperative IOP and this may be valuable in guiding filtration strategies.

TRIAL REGISTRATION

Chinese Clinical Trial Registry (No. ChiCTR1800017532, date: 2018/08/02).