Time spent in lateral sleep position and asymmetry in glaucoma

Purpose. To explore sleep position in asymmetric primary open-angle glaucoma (POAG) with a focus on low pressure glaucoma (LPG). Methods. Sleep laboratory videos of 54 POAG patients were examined for lateral sleep. Then, 29 LPG patients (intraocular pressure [IOP] < 22 mm Hg) with an intereye visual field index (VFI) asymmetry of more than 5% continuously recorded their sleep position at home for 2 nights by using a portable device. Correlations were sought between sleep position, visual field (VF), and retinal nerve fiber layer (RNFL) symmetry as well as ocular biometric data and positional IOP changes. Finally, an expanded data set of 178 POAG patients (63 LPG and 115 high pressure glaucoma [HPG; IOP ≥ 22 mm Hg]) was used to correlate VF and the RNFL symmetry to the self-assessed sleep position collected in a survey. Results. In the video analysis, patients spent 19% ± 2% (mean ± SEM) more time sleeping on one side than on the other. Right-sided sleep was preferred. Right-sided sleep was 1.6 times more common in continuously recorded home data and correlated to an asymmetric VF that was worse in the left eye (b = −0.422, P = 0.002). Pulse amplitude of left eyes was lower in the right decubitus position (P = 0.02). In the expanded survey, 73% of LPG and 58% of HPG patients slept asymmetrically. Right-sided sleepers had a worse RNFL symmetry score. Conclusions. Asymmetric sleep behavior is common. Right-sided sleep was preferred and correlated with a lower VFI on the left.