Outcome of peripheral iridotomy in subjects with uveitis

Peripheral iridotomy (PI) may be required in subjects with uveitis to manage iris bombe, seclusio pupillae and primary angle closure glaucoma. The aim of this study was to identify risk factors for failure of both laser and surgical PIs in patients with uveitis and determine survival durations.

Retrospective study of subjects with a history of uveitis undergoing yttrium-aluminium-garnet (YAG) laser or surgical PI at Auckland District Health Board over an 11-year period. Failure of PI was defined as loss of patency or recurrence of iris bombe. A mixed effects shared frailty model was constructed with PI nested within eyes nested within patients, to examine time to failure.

131 PIs were performed in 52 eyes of 39 subjects during the study period (111 YAG PIs and 20 surgical PIs). Median age at time of PI was 46.6 years and 60.5% of subjects were female. HLAB27 positive uveitis was the most common diagnosis (25.6% of subjects). Median survival time was 70 days for YAG PI and 11.0 years for surgical PI. On multivariate analysis, younger age at time of PI (HR 0.933, p<0.001) and iris bombe (HR 2.180, p=0.046) were associated with risk of failure. Surgical PI was associated with a lower risk of failure (HR 0.151, p<0.001) compared with YAG PI. Glaucoma developed in 19 eyes (36.5%), of which 13 required glaucoma surgery.

Surgical PI had longer survival than YAG PI, and should be considered in subjects presenting with iris bombe and in young subjects with uveitis.