Purpose:
It is known that increased intra-abdominal pressure increases intraocular pressure (IOP). It is unknown whether enlarged abdominal circumference (AC) or elevated body mass index (BMI) is associated with elevated IOP during a normal slit lamp exam. We sought to investigate the relationship between AC and BMI with changes in IOP during a normal exam.
Methods:
Baseline patient characteristics and IOP measurements were recorded on consecutively enrolled patients. Applanation tonometry was used to measure IOP in each eye at both reclined and normal slit lamp position. An average IOP between each eye was recorded for each position. Univariate and linear regression statistics were used to determine the relationship between BMI, AC, and IOP.
Results:
Sixty-six consecutive patients were examined, with a mean age of 55 yrs. Baseline BMI and AC measurements were 32.6 + 7.7 kg/m2 and 103.6 + 19.4 cm respectfully. Starting at a BMI of 21.4 kg/m2, each one-unit increase in BMI was associated with 0.07 mm Hg increase in IOP while in the slit lamp position (p = 0.005, 95% CI 0.022, 0.121). Although not statistically significant, every 1-cm increase in abdominal circumference was associated with a 0.02 mmHg increase in IOP (p = 0.14, 95% CI -0.005, 0.358).
Conclusions:
Elevated BMI is associated with increased IOP in the sitting position. This suggests that significantly obese patients may have falsely elevated slit lamp pressures. Further study into the etiology of this relationship is warranted.
Keywords: intraocular pressure • anterior segment • clinical (human) or epidemiologic studies: systems/equipment/techniques