Age-related changes in human corneal epithelial thickness measured with anterior segment optical coherence tomography

To measure corneal and limbal epithelial thickness (ET) in normal subjects and to evaluate its variation with age by using anterior segment optical coherence tomography (AS-OCT).

A total of 180 normal subjects (180 healthy eyes) were enrolled and divided into four groups according to age: A (0-20 years), B (21-40 years), C (41-60 years), and D (>60 years). Cornea and limbus were imaged with OCT. Corneal ET (CET) was obtained automatically by the built-in analysis software of the OCT system. Limbal ET (LET) in four quadrants was manually measured from OCT images.

Corneal ET of a central 2-mm diameter zone in groups A, B, C, and D were 53.4 ± 2.8 μm, 53.4 ± 2.7 μm, 53.2 ± 3.0 μm, and 52.9 ± 3.3 μm, respectively, N showing no significant change with aging. In the paracentral zone extending to 6-mm diameter, correlation analysis suggested that CET was inversely associated with age (P < 0.05). Limbal ET in the nasal and the temporal quadrants were similar and decreased with aging, the averages were 58.3 ± 8.1 μm, 54.1 ± 6.1 μm, 51.2 ± 6.1 μm, 51.6 ± 5.2 μm for groups A, B, C and D, respectively; while age seemed to have no effect on LET of the superior and the inferior quadrant.

The paracentral corneal epithelium, as well as the nasal and temporal limbal epithelium, became thinner with aging, while the central CET seemed to remain constant. Measurement with AS-OCT of the corneal and limbal ET could aid in clinical assessment and planning treatments of the cornea.