Body mass index, peripheral corneal thickness and anterior chamber depth in young European adults - A pilot study

Abstract

Purpose: To assess the relationship of body mass index (BMI) and the corneal thickness profile in normal white European individuals.

Methods: For this pilot study, 63 eyes of 63 healthy subjects were assessed. Following completion of an ocular and general health questionnaire body height and weight were measured and the BMI calculated. Ocular assessments included habitual visual acuity, slit-lamp biomicroscopy, and optical coherence tomography. Non-contact specular microscopy was performed to rule out corneal endotheliopathy. Scheimpflug photography (Pentacam) was used to assess central, mid-peripheral and peripheral corneal thickness as well as anterior chamber depth (ACD) at eleven locations nominally 1 mm apart along the horizontal meridian. Two consecutive Scheimpflug scans were performed and the mean value used for analyses. Descriptive statistics were generated. The association between BMI, corneal thickness and ACD at central as well as off-center locations was assessed using univariate regression analyses. The coefficient of correlation (r) was calculated.

Results: The mean [SD] age was 27 [7] years. Mean body height and body weight were 1.69 [0.08] meters and 64.6 [11.4] kilograms respectively, the mean BMI was 22.7 [3.1]. Mean central corneal thickness was 558 [33] micrometers (µm). Corneal thickness increased progressively and asymmetrically from the corneal center to the periphery with a significantly greater thickness at all nasal locations as compared to the respective temporal sites (P<0.001, related samples t-test). Temporal corneal thickness 5 mm away from the center was 772 [50] µm and the corresponding nasal thickness was about 6 % greater (823 [53] µm). While central corneal thickness was independent of BMI (P = 0.241; r = -0.15), temporal corneal thickness at 4 mm (P = 0.026; r = -0.28) and 5 mm (P = 0.012; r = -0.31) was inversely associated with BMI. Anterior chamber depth averaged 3.03 [0.35] mm and was independent of BMI P>0.05).

Conclusions: For this cohort of young, healthy white European adults with normal-weight average BMI, peripheral corneal thickness was inversely related to BMI. The findings suggest the possibility of a different corneal thickness profile in individuals with above-average BMI. Further studies on the relationship between BMI, obesity and corneal parameters are indicated.

Keywords: 479 cornea: clinical science • 733 topography • 574 keratoconus