The effect of lateral decubitus position on nocturnal intraocular pressure over a habitual 24-hour period in healthy adults

• Published in: PloS one Vol. 9; no. 11; p. e113590
• Main Authors: Hao, Jie, Zhen, Yi, Wang, Hao, Yang, Diya, Wang, Ningli
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 25.11.2014; Public Library of Science (PLoS)
• Subjects: Adults; Diurnal; Eye; Female; Glaucoma; Healthy Volunteers; Heart rate; Hospitals; Humans; Intraocular Pressure; Laboratories; Male; Measurement methods; Medicine and Health Sciences; Middle Aged; Nocturnal; Patient Positioning; Position measurement; Posture; Pressure; Pressure effects; Sitting position; Sleep; Statistical analysis; Statistical significance; Studies; Supine position; Tonometry, Ocular; Beijing China; China; Japan
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0113590

To investigate the effect of lateral decubitus position (LDP) on nocturnal intraocular pressure (IOP) and the effect of LDP on 24-hour habitual IOP pattern in healthy subjects. Intraocular pressure was measured every 2-hours using an Accupen Applanation Tonometer (Accutome, USA). During the diurnal period (7:30 am, 9:30 am, 11:30 am, 1:30 pm, 3:30 pm, 5:30 pm, 7:30 pm, and 9:30 pm), IOP was measured in the sitting position under bright light (500-1000 lux) after the subjects had been seated for 5 min. The nocturnal IOP was measured in the supine position, right LDP, and left LDP, with randomized sequences, under dim light (<10 lux) at 11:30 pm, 1:30 am, 3:30 am, and 5:30 am. The subjects were awakened and maintained each position for 5 min before the measurement. The 24-hour habitual IOP patterns were obtained according to the nocturnal position (supine, right LDP and left LDP) for either eye. P<0.05 was considered to be significant. Nineteen healthy subjects were included with a mean age of 51.3±5.8 years. During the nocturnal period, a significant IOP difference was found between the dependent eye (the eye on the lower side) of LDP and the supine position, but not for all the nocturnal time points. Over a 24-hour period, the effect of LDP on habitual IOP pattern was not statistically significant, although the mean nocturnal IOP and the diurnal-nocturnal IOP change for the right and the left eye in the LDP pattern was slightly higher than that in the sitting-supine pattern. Significant nocturnal IOP differences existed between the dependent eye and the supine, but did not occur consistently for all time points. Over a 24-hour period, the effect of LDP on habitual IOP pattern was not statistically significant in healthy subjects.