Changes in Anterior Chamber Volume, Depth and Angle After ProphylacticLaser Peripheral Iridotomy in Patients With Primary Angle-closure Suspect

This study aims to assess changes in anterior chamber parameters after prophylactic laser peripheral iridotomy (LPI) in patients with primary angle-closure suspect (PACS).

Subjects and Methods:

 In this study, 43 patients (86 eyes) with PACS (Mean age: 55.16±9.14 years) participated. The anterior chamber parameters including anterior chamber volume (ACV), anterior chamber angle (ACA) and central anterior chamber depth (CACD) were extracted from the Pentacam map at 0-180° meridian before and one month after prophylactic LPI.

The only parameter that had a significant increase after LPI was ACV, which increased from 99.26±19.57 mm3 to 113.09±19.712 mm3 after LPI (P<0.001). The relationship between age and ACV changes after LPI was statistically significant (P=0.014), indicating that the increase of age is associated with the increased of ACV after LPI. The relationship of ACV and ACD with their initial values was statistically significant, such that with the increase of the initial values of ACV and ACD, their changes decrease. Due to the lack of significant increase in CACD after LPI, the relationship between its changes after LPI and its initial value cannot be relied upon.

ACV is the only anterior chamber parameter that changes significantly after prophylactic LPI. This parameter can be used as a measurable scale to evaluate and monitor the eyes of patients with PACS. Among the PACS cases, older patients and patients with lower initial ACV have greater increase of ACV after LPI