Comparison of Anterior Chamber Depth of Normal and Keratoconus Eyes Using Scheimpflug Photography

Objectives: To compare the corneal anterior chamber depth (ACD) adjusted by age and sex in normal and keratoconus eyes. Methods: Scheimpflug photography with the Oculus Pentacam was used to measure the ACD of 162 normal and 41 keratoconus patients. Results: Univariate analysis showed that the mean ACD of 162 normal subjects (3.18 +/- 0.32 mm) was borderline significantly less than in 41 keratoconus patients (3.28 +/- 0.40 mm; P=0.079). However, we found that sex (P=0.001) and age (P<0.001) are significantly related to ACD in all patients. Women with normal eyes had a significantly lower mean ACD (3.13 +/- 0.34 mm) than men (3.27 +/- 0.28 mm, P=0.008). Women with keratoconus eyes also had a lower mean ACD (3.16 +/- 0.39 mm) than men with keratoconus (3.42 +/- 0.36 min, P=0.032). Bivariate regression showed that with each additional year of aging, the ACD was decreased by an average of 0.012 mm in a normal eye (P<0.001) and by 0.014 mm in a keratoconus eye (P<0.001). Regression analysis showed that sex (P=0.003), age (P<0.001), and keratoconus (P=0.003) are all significant variables for determining ACD. After adjusting for age and sex, keratoconus eyes had a significantly higher mean ACD (3.34 +/- 0.34 mm) than normal eyes (3.18 +/- 0.28 mm) (P=0.003). Conclusions: Sex, age, and keratoconus are all significant variables for ACD. After adjusting for age, keratoconus eyes of both genders had a significantly higher ACD than normal eyes of both genders. Women showed lower mean ACID than men in both normal and keratoconus eyes.