Effect of Various Body and Head Positions on Intraocular Pressure in Cataract Patients With Limited Mobility.

Purpose: To assess the impact of various body and head positions on intraocular pressure (IOP) in cataract patients aged over 40 years with limited mobility. Methods: This cross-sectional study was conducted between August and December 2023 at Aier Eye Hospital of Wuhan University. The IOP was measured using a handheld tonometer (iCare IC200 rebound tonometer) in various head positions (forward, tilted left, and tilted right) and body positions: supine, semirecumbent, sitting, and prone. Results: In the supine position, the IOP measurements for the head positioned forward, right, and left were (13.80 ± 3.62) mmHg, (14.25 ± 3.66) mmHg, and (13.78 ± 3.40) mmHg, respectively. In the semirecumbent position, the corresponding IOPs were (12.08 ± 3.34) mmHg, (12.12 ± 3.22) mmHg, and (12.04 ± 3.38) mmHg. In the sitting position, the IOPs were recorded as (11.73 ± 3.29) mmHg, (11.73 ± 3.22) mmHg, and (11.59 ± 3.17) mmHg. Lastly, in the prone position, the IOPs were (14.19 ± 3.73) mmHg, (14.42 ± 3.93) mmHg, and (14.74 ± 3.81) mmHg, respectively. In each position group, there was no statistically significant difference in IOP among the three head positions. Regardless of the head position, the IOP is lowest in the sitting position, followed by semirecumbent and supine positions, with the prone position having the highest IOP. The analyses revealed that central corneal thickness (CCT) was correlated with an IOP value (p < 0.05) when patients were in different positions. Conclusion: IOP is influenced by body position. As the body transitions from upright to horizontal, IOP tends to increase. The position of the head, however, has no effect on IOP.