Abstract:AIM: To compare the fluctuating characteristics, mean value and peak value of intraocular pressure (IOP) between medically and surgically controlled eyes in patients with primary open angle glaucoma (POAG) based on a 12-hour daytime diurnal curve (12-DDC) and water drinking test (WDT). Additionally, this study evaluated the consistency of 12-DDC outcomes measured on two separate days. METHODS: This was a cross-sectional observational study. Eligible POAG patients with unilateral medically and contralateral surgically controlled IOP via functional augmented trabeculectomy bleb were enrolled. Diurnal IOP was detected every 3h from 8:00 a.m. to 8:00 p.m. over two consecutive days to establish the 12-DDC. The WDT was performed subsequent to the completion of diurnal IOP measurement. RESULTS: A total of 21 POAG patients were included, with a mean age of 65.5±7.3y, predominantly male (n=17, 81.0%), and of Malay ethnicity (n=13, 61.9%). The medically controlled eyes exhibited significantly greater diurnal IOP fluctuation (4.6±1.7 mm Hg) compared with surgically controlled eyes (3.0±1.5 mm Hg, P=0.005). Similarly, the peak IOP derived from WDT was significantly higher in medically controlled eyes (19.6±4.1 mm Hg) than in surgical counterparts (11.2±3.4 mm Hg, P<0.001). A strong and significant positive correlation was identified between peak IOP values of 12-DDC and WDT. For surgically controlled eyes, 12-DDC measurements obtained on two different days showed excellent consistency at all corresponding time points, with Kappa values ranging from 0.88 to 0.95. CONCLUSION: Under the condition of consistent physiological background affecting IOP circadian variation in the same individual, surgically controlled eyes demonstrate a superior IOP profile with lower fluctuation and peak IOP compared with medically controlled eyes in POAG patients.
