Ocular Biometric Characteristics in Preoperative Diagnosis of Acute Angle Closure With and Without Zonular Laxity

Abstract

Précis: Biometric parameters, including binocular difference of anterior chamber depth (ACD), lens vault (LV) in affected eyes, and binocular difference of the LV, had high efficiency in diagnosing acute angle closure (AAC) with zonular laxity. Purpose: To investigate the ocular biometric characteristics of eyes with AAC with zonular laxity to further explore the sensitive parameters for preoperative diagnosis. Methods: This study included 50 patients with AAC with zonular laxity and 54 patients with AAC without zonular laxity. Demographic data, ocular examination results, and biometric parameters on ultrasound biomicroscopy images were compared between the affected and fellow eyes in 2 groups. Parameters significant in the multiple linear regression model were included in a regression equation and the diagnostic efficiency was evaluated by area under the curve. Results: In patients with AAC with zonular laxity, the binocular difference of central ACD, LV in affected eyes, and binocular difference of the LV were significantly larger than those in patients without zonular laxity respectively and these three parameters were all significant in multiple linear regression analysis (all P<0.001). The area under the curve of binocular difference of ACD, LV in affected eyes, and binocular difference of LV were 0.972, 0.796, and 0.855, respectively, with the cutoff values of 0.23, 1.28, and 0.19 mm. The regression equation containing these three parameters was: ln (P/(1-P))=-4.322 + 1.222 [LV in affected eyes (mm)] + 3.657 [binocular difference of LV (mm)] + 6.542 [binocular difference of ACD (mm)], with the accuracy of prediction reaching 94.05%. Conclusion: Binocular difference of ACD, LV in affected eyes, and binocular difference of LV had high efficiency in diagnosing AAC with zonular laxity.