Abstract
Purpose:
Previously, we demonstrated that intraocular pressure (IOP) altered according to the head position in lateral decubitus posture in healthy subjects. This study aimed to investigate the effects of different head positions in lateral decubitus posture on IOP in medically treated eyes with open-angle glaucoma (OAG).
Methods:
Twenty patients with bilateral open-angle glaucoma (OAG) who received only latanoprost for treatment were included in this prospective observational study. IOP was measured in both eyes using Icare Pro rebound tonometer in the sitting position and the recumbent positions including supine position, right lateral decubitus position (LDP), and left LDP. In right or left LDP, IOP measurements were taken with 3 different head positions (30° higher, 30° lower and parallel to the center of the thoracic vertebra) in a randomized sequence. The eye on the lower side in the LDP was termed the dependent eye. We compared the IOPs between the dependent and non-dependent eyes in the LDPs with different head positions. We also analyzed the differences in IOPs between the better-mean deviation (MD) eyes and worse-MD eyes in those postures.
Results:
IOP was higher in the dependent eyes than in the non-dependent eyes in LDP, regardless of the head position (all p< 0.05). Lower head position significantly increased the IOP of dependent eyes, compared with the neutral or higher head position in LDP. However, the amounts of IOP elevation seen during the changes of body posture or head position were not significantly different between the better-MD and worse-MD 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.