Does Tube-Iris Touch Cause Anterior Chamber Inflammation in Patients with Ahmed Valve Implantation?

Abstract

Purpose : To evaluate whether significant anterior chamber inflammation and/or cystoid macular edema (CME) occurs in patients with tube-iris touch after Ahmed glaucoma valve (AGV) implantation.

Methods : This is a cross-sectional study. Patients aged ≥ 18 years old who underwent AGV implantation at least 3 months prior to the study were included. Patients with any uveitis, corneal haze, prior macular diseases or prior intraocular surgery (with the exception of cataract surgery) were excluded. Tube-iris touch was identified by slit lamp examination and confirmed with anterior segment optical coherence tomography. Anterior chamber (AC) inflammation was graded using Standardization of Uveitis Nomenclature classification. CME was evaluated using spectral domain OCT to measure central foveal thickness (CFT).

Results : 103 eyes (84 patients) were included. The tube was inserted into the anterior chamber in 33 eyes (32%) and the sulcus in 70 eyes (68%). Tube-iris touch was identified in 47 eyes: 10 shunts (21.3%) had anterior chamber placement and 37 (78.7%) had sulcus placement. Pigmented and inflammatory cells in the AC were found in 5 of 47 eyes (10.6%) with tube-iris touch and 3 of 56 eyes (5.4%) without tube-iris touch (P=0.34), presenting a non-significant difference in AC inflammation between the two groups. Mean CFT was 245 and 250 microns for the tube-iris touch and no tube-iris touch groups, respectively (P=0.60).

Conclusions : Tube-iris touch following AGV implantation is not associated with increased post-operative AC inflammation or cystoid macular edema regardless of whether the tube is placed in the anterior chamber or ciliary sulcus.

This is a 2021 ARVO Annual Meeting abstract.