Rotational extraction of incarcerated iris (REII): a slit lamp technique to reduce incarcerated iris after nonpenetrating deep sclerectomy for glaucoma.

Abstract

Iris incarceration is a complication of glaucomafiltering surgery that often requires surgery. We describe a technique for reduction of incarcerated iris at the slit lamp, dubbed rotational extraction of incarcerated iris (REII). A retrospective analysis of visual function and intraocular pressure (IOP) was done in patients treated with REII after nonpenetrating deep sclerectomy. We retrospectively evaluated a cohort of patients who received REII for iris incarceration after nonpenetrating deep sclerectomy for glaucoma. IOP (applanation) and visual acuity (VA) were measured day-of, and 1, 3, 6, and 12months post-REII. Adverse events were recorded. Kaplan-Meier survival analysis was done with definitions of IOP control at 15, 18, and 21mmHg. Forty-one eyes of 41 patients were treated with REII. Median time to iris incarceration from glaucoma surgery was 50days (range 1-1906). Mean pre-REII IOP ± SD was 33.7 ± 14.1mmHg, which reduced to 11.5 ± 6.1mmHgday-of. LogMAR VA was 0.72 ± 0.8 log units at baseline and was unchanged at 12months (P = 0.53). Survival analysis demonstrated varying efficacy depending on the definition of success. 79.0 to 92.2% of eyes achieved IOP control immediately after REII, 39.5 to 71.1% at 1month, 26.3 to 52.6% at 3months, 21.1 to 44.3% at 6months, and 10.5 to 38.0% at 12months. Nearly half (47.4%) of eyes required a tube shunt by 12months. REII may be a safe, minimally invasive slit lamp procedure that can reduce incarcerated iris and delay more invasive intervention for 3-6months in most eyes.