Aqueous humour dynamics in uveitic eyes

Abstract Purpose To investigate aqueous humor dynamics in uveitic eyes Design A cross-sectional study Participants Patients with recurrent(≥3 attacks) anterior uveitis(now quiescent) and being treated for glaucoma or OHT(group-1), previous recurrent anterior uveitis(≥3 attacks) without glaucoma or OHT(group-2), and normal subjects with no ocular problems and IOP Methods Patients had one-off measurements. Group-1 patients who were on anti-hypertensives, were washed out for a 4-week period, prior to their study measurements. Main outcome measure Tonographic outflow facility, aqueous flow rate and uveoscleral outflow. Results One hundred and one patients were screened between February 2014 and February 2017. Nine patients did not meet the inclusion criteria. Groups-1 and-3 each included 30 patients, and group-2 included 32 patients. The mean IOP was higher in the group-1 compared to the others(25±10.2(group-1) vs 16±2.7(group-2) vs 16±2.2mmHg(group-3), p The tonographic outflow facility was lower in group-1 compared to the others(0.18±0.1(group-1) vs 0.25±0.1(group-2) vs 0.27±0.1μl/min/mmHg(group-3), p=0.005). However, aqueous flow rate was not statistically different(2.47±0.9(group-1) vs 2.13±0.9(group-2) vs 2.25±0.7μl/min(group-3), p=0.3). There was also no significant difference in calculated uveoscleral outflow. Conclusion This is the first aqueous humor dynamic study in patients with uveitic glaucoma/OHT and recurrent anterior uveitis compared with age-matched controls. We have demonstrated that the elevated IOP seen in the uveitic glaucoma/OHT eyes (3-6 attacks), was due to reduced tonographic outflow facility. The aqueous humor flow rate was not detectibly different nor did the calculated uveoscleral outflow demonstrated any discernible difference. However, the exact mechanism remains to be elucidated.