Biometric factors associated with acute primary angle closure: A comparison of the affected and eyes with a similar short axial length

Abstract

Purpose : A short axial length is a major risk for acute angle closure. However, not all eyes with a short axial length experience acute attack. The purpose of this study was to clarify the difference in the biometric factors of the anterior segment in acute primary angle closure eyes and eyes with a similar short axial length.

Methods :
This retrospective study was carried out at the Department of Ophthalmology of Tsukazaki Hospital in Himeji, Japan. Anterior segment optical coherence tomography (AS-OCT) CASIA (Tomey Corporation, Nagoya, Japan) was used to examine 27 eyes of 27 patients with acute angle closure (A group), and 49 axial length- and age-adjusted eyes of 49 subjects with a short axial length (S group). After measuring the axial length, refractive error, corneal curvature, central corneal thickness, anterior chamber depth, angle opening distance 500 (AOD500), lens vault, anterior chamber width, and the perpendicular distance between the horizontal line joining the two scleral spurs and the back side of central cornea (anterior chamber height), multivariate regression analyses were performed to determine the factors predicting acute angle closure.

Results : The axial length (average: A group vs. S group: 22.80 vs. 22.39 mm) and refractive error (1.12 vs. 1.05 D) showed no significant differences. The corneal curvature (7.61 vs. 7.41 mm), central corneal thickness (579 vs. 521 µm), and lens vault (1.12 vs. 0.56 mm) of the A group were larger than in the S group. The anterior chamber depth (1.53 vs. 2.53 mm), AOD500 (0.09 vs. 0.37 mm), anterior chamber width (11.00 vs. 11.20 mm), and anterior chamber height (2.64 vs. 3.08 mm) of the A group were smaller than in the S group (p<0.05). The anterior chamber depth and AOD500 were selected as predictive factors for acute angle glaucoma (p<0.01, R² = 1.0).

Conclusions : Acute angle closure eyes have a crowed anterior segment compared to eyes with a similar short axial length without acute attack. A shallow anterior chamber and small AOD500 were found to be associated with acute angle closure in short-axial-length eyes.

This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.