Effect of age on anterior chamber angle configuration in Asians determined by anterior segment optical coherence tomography; clinic-based study

Abstract

Purpose: To evaluate the distribution of anterior chamber angle (ACA) parameters and to assess association of these parameters with age in Asian subjects.

Methods: Four hundred and thirty-nine consecutive Korean subjects aged from 30 to 89 were enrolled from a university clinic. All participants were scanned using anterior segment optical coherence tomography (AS-OCT, Visante, version 2.0). We measured ACA parameters such as anterior chamber depth (ACD), angle opening distance at 500 and 750μm (AOD(500,750) ), angle recess area at 500 and 750μm (ARA(500,750) ), trabecular iris space area at 500 and 750μm (TISA(500,750) ), and determined age-related changes in these parameters with use of a linear mixed effect model that adjusted for gender, axial length, intraocular pressure, and keratometry data. Slopes of ACA parameters as a function of age were determined. For various AS-OCT parameters, the normalized slope was calculated by dividing the slope by the mean value.

Results: All analysed ACA parameters decreased with age in both nasal and temporal quadrants. Axial length and keratometry data were significant covariates for ACA changes. The slopes of ACD were -0.02396mm/year, AOD(500) , ARA(500) , and TISA(500) measured at the temporal angle were -0.00634mm/year, -0.0019mm(2) /year, and -0.00177mm(2) /year, respectively. There was no age-dependent difference in central corneal thickness (p value; 0.4597) Based on the normalized slopes, the AOD showed the steepest slope at both temporal and nasal sectors.

Conclusion: All ACA parameters assessed by AS-OCT, which accounted for other ocular biometric parameters, showed significant negative slopes with increasing age. These results should be considered when assessing changes in the anterior chamber over time.