Evaluation of Changes in Anterior Segment Morphology After Laser Iridotomy in Brazilian Eyes

Abstract

Abstract: : Purpose: To quantify changes in anterior segment morphology after laser iridotomy using gonioscopy and ultrassound biomicroscopy (UBM) and to perform UBM dark room provocative test after iridotomy. Methods:Prospective comparative observational case series that evaluated consecutive 21 fellow eyes of patients with acute primary angle closure glaucoma (APAC) and 23 eyes of newly diagnosed chronic primary angle closure glaucoma (CPACG) patients. None of the eyes could have more than 90^o of peripheral anterior synechiae. All subjects were submitted to indentation gonioscopy, A scan ultrasonography and UBM exam before and ten days after YAG laser peripheral iridotomy. UBM images were obtained under standard lighting and darkness condition at two predetermined angle location. The angle recess area (ARA) and angle opening distance (AOD) were analyzed using UBM Pro 2000 software. Results: Gonioscopic grading and AOD500, AOD250 and ARA values increased after laser iridotomy in both fellow eyes and CPACG eyes. Anteriorized ciliary processes were observed in 14 (66.67%) fellow eyes and 18 (78.26%) CPACG eyes. Under dark condition, there were 10 (47.62%) fellow eyes and 9 (39.13%) CPACG eyes that showed evidence of persistent appositional angle closure after laser iridotomy. Conclusions: In Brazilian fellow eyes and CPACG eyes, laser iridotomy produced a widening of the irido–corneal angle. However, the appositional angle closure observed in UBM dark room provocative test after iridotomy suggests the involvement of additional angle closure mechanisms in those eyes.

Keywords: anterior segment • ciliary body • clinical (human) or epidemiologic studies: prevalence/incidence