Ocular biometrics help predict progression of primary angle closure disease
17 Mar 2022
Use of ocular biometric measurements can stratify patients with early angle closure at risk for more severe disease, according to a study.
Moreover, anterior segment optical coherence tomography (OCT) measurements of biometric parameters describing the angle and iris predict the progression from primary angle closure suspect (PACS) to primary angle closure (PAC) or acute angle closure (AAC), while gonioscopy grades do not.
Overall, 643 mainland Chinese with untreated PACS were included in this prospective, observational study. They underwent baseline clinical examinations, including gonioscopy, anterior segment OCT imaging, and A-scan ultrasound biometry as part of the Zhongsan Angle Closure Prevention trial.
PACS was characterized as an inability to visualize pigmented trabecular meshwork in two or more quadrants based on static gonioscopy. PAC was defined as development of intraocular pressure >24 mm Hg or peripheral anterior synechiae. Progression referred to the development of PAC or an AAC attack.
The authors developed multivariable logistic regression models to assess biometric risk factors for progression.
Of the 643 untreated eyes analysed, 609 were nonprogressors and 34 progressors. The multivariable model with continuous parameters showed that narrower horizontal angle opening distance of 500 μm 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 significantly correlated with progression (area under the receiver operating characteristic curve [AUC], 0.73).
On the other hand, smaller cumulative gonioscopy score showed no association with progression (OR, 1.03 per 1-modified Shaffer grade decrease; p=0.85) when replacing horizontal AOD500 in the multivariable model.
A separate multivariable model with categorical parameters showed higher odds of progression (AUC, 0.72) among participants in the lowest quartile of horizontal AOD500 (OR, 3.10; p=0.002) and IC (OR, 2.48; p=0.014) measurements and those aged ≥59 years (OR, 2.68; p=0.01) at baseline.