For a study, researchers sought to determine the baseline ocular biometric risk variables for progression from the primary angle-closure suspect (PACS) to primary angle closure (PAC) or acute angle closure (AAC). There were 643 people with untreated PACS. As part of the Zhongshan Angle Closure Prevention (ZAP) Trial, participants had baseline clinical exams like gonioscopy, anterior segment OCT (AS-OCT) imaging, and A-scan ultrasound biometry. Based on static gonioscopy, a primary angle-closure suspicion was characterized as an inability to observe pigmented trabecular meshwork in two or more quadrants. Primary angle-closure was characterized as an increase in intraocular pressure exceeding 24 mmHg or the formation of peripheral anterior synechiae. The development of a PAC or an AAC attack was termed progression. To investigate biometric risk variables for progression, multivariable logistic regression models were built.
About 643 untreated eyes (609 nonprogressors, 34 progressors) from 643 people were studied. A narrower horizontal angle opening distance of 500 m from the scleral spur (AOD500; odds ratio [OR], 1.10 per 0.01-mm decrease; P=0.03), flatter horizontal iris curvature (IC; OR, 1.96 per 0.1-mm decrease; P=0.01), and older age (OR, 1.11 per 1-year increase; P=0.01) at baseline were significantly associated with progression in a multivariable model with continuous parameters (area under the curve [AUC] the receiver operating characteristic, 0.73). When horizontal AOD500 was replaced in the multivariable model, a lower cumulative gonioscopy score was not linked with progression (OR, 1.03 per 1-modified Shaffer grade drop; P=0.85). Participants in the lowest quartile of horizontal AOD500 (OR, 3.10; P=0.002) and IC (OR, 2.48; P=0.014) readings, as well as those aged 59 or older (OR, 2.68; P=0.01) at baseline, had a greater risk of advancement in a separate multivariable model including categorical parameters (AUC, 0.72). Patients with early angle closure can be risk-stratified for more severe illness using ocular biometric data. Anterior segment OCT measures of biometric factors defining the angle and iris, but not gonioscopy grades, were indicative of progression from PACS to PAC or AAC.
Reference:www.aaojournal.org/article/S0161-6420(21)00746-6/fulltext
