Purpose
To investigate the effect of CPAP on IOP fluctuations associated with changes from wake to sleep (W/S) and sleep to wake (S/W) in patients both with and without POAG suffering from OSAS, measured by continuous recording using a CLS.
Methods
In this single-center, prospective, exploratory, open-label study, POAG and non-POAG patients with moderate to severe OSAS underwent continuous 24-hour IOP recording using Triggerfish® (Sensimed AG, Lausanne, Switzerland) in 2 sessions, 7 days apart, in the same eye. W/S and S/W slopes for CLS were computed by fitting linear regression to measurements from 1 hour before transition to 1 hour after. Slopes reported are changes in millivolts/hour. Effect sizes were computed by Cohen’s d.
Results
We analyzed 8 OSAS patients, 4 with and 4 without POAG (mean age 64.3±7.8 years, 75% men). With CPAP, W/S slope for both groups was similar (44.4±34.8 and 42.2±40.7, respectively). Without CPAP, the W/S slope increased to 52.3±26.4 for POAG eyes, and decreased to 35.8±43.0 for non-POAG eyes (Fig 1). Thus the effect size of the difference between the groups when not using CPAP was 0.46 and only 0.06 when using CPAP, W/S slope becoming more moderate with CPAP in POAG and the reverse in non-POAG. Similarly, the S/W slope was more moderate in POAG with CPAP than without (-15.5±10.4 vs -24.4±29.1); in non-POAG the difference was once again reversed (with CPAP -36.1±21.1 and without -9.1±40.9 (Fig 2). The effect size of the difference between the groups without CPAP was 0.43 and with CPAP was 1.24. All slopes were in the expected direction (positive for W/S , indicating an increase in CLS IOP fluctuations; and visa versa for S/W).
Conclusions
POAG patients with CPAP had a slower increase of IOP going from W/S and a slower decrease going from S/W than without CPAP. A larger trial is warranted to substantiate the beneficial effects of CPAP in POAG patients with OSAS.
Keywords: 568 intraocular pressure •
477 contact lens