Intraocular Pressure Variations in Postural Changes: Comparison between Obese and Non-Obese Controls

Background: Comparing intraocular pressure (IOP) changes (ΔIOP) between obese subjects and non-obese controls in relation to different positions: standing, sitting, supine. Methods: the IOP was measured in both obese patients and non-obese controls groups with Tono-Pen AVIA in different positions following this sequence: after 5 min (5′) in the standing position, sitting, supine, supine after 5 min (supine 5′) and immediately after standing. ΔIOP values obtained comparing all positions were, therefore, evaluated. Results: 92 eyes of 46 obese subjects aged between 18 and 59 years (mean 38.07 ± 11.51 years) and of a Body Mass Index (BMI) between 31.84 and 60.65 (mean 41.84 ± 7.05) were evaluated. A total of 48 eyes of 24 non-obese controls aged between 23 and 55 (mean 35.21 ± 11.96 years) and of a BMI between 18.20 and 26.79 (mean 21.04 ± 2.36) were also recruited. In obese subjects, there were statistically significant differences between the IOP in the supine position and the supine positions 5′ with all other IOP measurements (p < 0.05). There were statistically significant differences between ΔIOP in both supine positions and prolonged standing positions obtained by obese subjects and non-obese controls (p < 0.05). Conclusions: In obese subjects, there is a statistically significant increase in IOP in the supine positions that is significantly greater than the non-obese population. BMI is weakly correlated with IOP and ΔIOP in postural changes.