Morphology of the Trabecular Meshwork and Schlemm's Canal in Posner-Schlossman Syndrome

PURPOSE. The purpose of this study was to investigate trabecular meshwork (TM) and Schlemm's canal (SC) morphology in Posner-Schlossman syndrome (PSS). METHODS. Forty-five patients with PSS were recruited. TM thickness and length as well as SC area and diameter of both affected and fellow eyes were assessed using swept-source optical coherence tomography. RESULTS. TM thickness (108.24 +/- 28.29 mu m vs. 89.36 +/- 25.82 mu m, P = 0.014), SC area (6010.90 +/- 1287.54 mu m(2) vs. 5445.69 +/- 1368.89 mu m(2), P = 0.003), and SC diameter (239.38 +/- 60.17 mu m vs. 217.76 +/- 60.79 mu m, P = 0.010) were significantly greater in the affected eyes. Furthermore, TM thickness (113.32 +/- 30.03 mu m vs. 89.00 +/- 26.99 mu m, P = 0.046), SC area (6216.32 +/- 1267.87 mu m(2) vs. 5476.40 +/- 1390.15 mu m(2), P = 0.001), and SC diameter (246.82 +/- 64.12 vs. 212.53 +/- 64.29 mu m, P = 0.001) were significantly greater in the affected eyes than in the fellow eyes in the ocular hypertension (OHT) subgroup (affected eye with intraocular pressure [TOP] > 21 mm Hg). However, those differences were not noted in the ocular normal tension (ONT) subgroup (affected eye with IOP <= 21 mm Hg, all P > 0.05). CONCLUSIONS. TM edema might play a role in the IOP elevation in PSS. The edematous TM could make controlling IOP of the affected eyes difficult. When TM edema is relieved, IOP of the affected eyes can reduce to normal spontaneously or with IOP-lowing medications.