Effect of different head positions in lateral decubitus posture on intraocular pressure in treated patients with open-angle glaucoma

Purpose To investigate the effects of different head positions in the lateral decubitus posture on intraocular pressure (IOP) in medically treated patients with open-angle glaucoma (OAG). Design Prospective observational study. Methods setting: Institutional. participants: Twenty patients with bilateral OAG who received only latanoprost as treatment. observation procedures: IOP was measured using an ICare Pro tonometer in the sitting, supine, right, and left lateral decubitus posture. In lateral decubitus posture, IOP measurements were taken with 3 different head positions (30 degrees higher than, 30 degrees lower than, and parallel to the center of the thoracic vertebra) in a randomized sequence. main outcome measures: Comparison of the IOPs between the dependent (lower-sided) and nondependent eyes in the lateral decubitus postures with different head positions. We also analyzed the differences in IOPs between the better and worse eyes. Results IOP was higher in the dependent eyes than in the nondependent eyes in lateral decubitus posture, regardless of the head position (all P <.05). Lower head position increased the IOP of dependent eyes, compared with the neutral or higher head position. However, the amounts of IOP elevation seen during the changes of body posture or head position were not significantly different between the better and worse eyes. Conclusions Low head position elevates IOP of the dependent eyes of medically treated OAG patients compared with neutral head position in the lateral decubitus posture. Adjustment of the height of a pillow may help mitigate IOP elevations resulting from lying on the side with a low or no pillow in glaucoma patients.