Abstract
Purpose :
Iris incarceration as a complication of glaucoma filtering surgery generally requires surgical intervention. We describe a novel technique for removal of incarcerated iris and restoration of bleb filtering capacity that can be safely performed at the slit lamp, dubbed rotational extraction of incarcerated iris (REII). A retrospective analysis of visual function and intraocular pressure (IOP) control was done in eyes treated with REII.
Methods :
The patient is positioned at a securely locked slit lamp with two assistants. One drop of 0.5% proparacaine hydrochloride ophthalmic solution is administered to the affected eye. The eye is cleansed with betadine 5% sterile ophthalmic prep solution. Using sterile technique, 0.7mL of carbachol 0.01% intraocular solution is drawn into a 30G needle. With the bevel facing up, the needle is bent to 45° before inserting it using the dominant hand (at 11:00 or 2:00) tangentially into the anterior chamber (AC) via a peripheral corneal approach. 0.2mL carbachol is injected into the AC before the needle engages the iris over the zonule near the incarceration site. The needle is rotated downward using the cornea as a fulcrum, freeing the iris. Then the remaining 0.5mL carbachol is injected into the AC.
We retrospectively evaluated all patients who received REII between 1/1/2015 and 1/1/2021. IOP (Goldman applanation tonometry) and LogMAR visual acuity (VA) were measured at the time of REII, and at 1 month and 3 months post-procedure. Paired, two tailed t-tests with Bonferroni correction were used for all comparisons using Microsoft Excel (Redmond, Washington, USA).
Results :
Forty-one eyes (46% left) of 41 patients (44% female, mean age±SD 64.7±10.7) were treated with REII. Median time to iris incarceration from surgery date was 50 days (range 1- 1906). Mean pre-REII IOP±SD was 33.1±14.4 mmHg, which reduced to 11.4±6.0 mmHg (66% reduction) day-of procedure (P<0.01) and remained reduced to 14.6±7.2 mmHg (56%, P<0.01) and 18.6±9.0 mmHg (44%, P<0.01) at 1 and 3 months, respectively. LogMAR VA was 0.78±0.8 log units at baseline, was unchanged at 1 month (0.70±0.8 log units, P=0.14), and improved at 3 months (0.50±0.6 log units, P<0.01).
Conclusions :
Iris incarceration can be effectively managed at the slit lamp by REII, which can restore bleb filtering capacity and provide sustained reduction in IOP.
This is a 2021 ARVO Annual Meeting abstract.