Changes in retinal oxygen saturation, choroidal thickness, and retinal nerve fibre layer.

Objective: To investigate the changes of retinal oxygen saturation (Sat O2) concentrations, choroidal thickness (CT), and retinal nerve fibre layer (RNFL) in eyes with trabeculectomy-required acute primary angle closure (APAC).
Design: Prospective, longitudinal study.
Participants: Twenty-three eyes with trabeculectomy-required APAC were recruited.
Methods: Retinal oximetry was performed at postoperative day one and again at approximately 1 month. CT and the RNFL were tested on the same day. A paired t test and Pearson correlation were used for analysis.
Results: Mean Sat O2 increased in retinal arterioles from 88.74% ± 14.36% at postoperative day 1 to 96.61% ± 18.42% at 1 month (p = 0.049). The mean diameter of the arterioles was statistically different between postoperative day 1 and 1 month (p = 0.044), as was the mean diameter of the venules (p = 0.027). APAC eyes at postoperative 1 month had a thinner mean CT, compared with day 1 (p = 0.002). No significant difference was found in the RNFL between postoperative day 1 and 1 month (p > 0.05). The Sat O2 in retinal arterioles correlated with the mean diameter of the arterioles at postoperative day 1 (r = -0.482, p = 0.020) and at 1 month (r = -0.463, p = 0.026). No significant correlation was found between retinal Sat O2 and other parameters.
Conclusions: Increased Sat O2 in retinal arterioles, changed vessel diameter, and thinner CT from postoperative day 1 to 1 month suggest gradual recovery from APAC. However, the different pathophysiologies for APAC still need further study to prove.
(Copyright © 2015 Canadian Ophthalmological Society. Published by Elsevier Inc. All rights reserved.)