Abstract
Purpose :
To determine the pattern of epithelial thickness profile distribution in a healthy Mexican population, using a map measuring 9 mm in diameter with spectral domain optical coherence tomography (SD-OCT) Schwind MS-39.
Methods :
We performed a cross-sectional study in which we measured the central corneal thickness (CCT), and epithelial thickness (CET) mapping in the 3mm (central), 6mm (paracentral) and 9mm (mid-peripheral) zones. 4 Specific regions of ET (superior, inferior, nasal, temporal) were studied. 92 healthy eyes of 46 adults aged between 21 - 49 years were evaluated using the Schwind MS-39 spectral domain optical coherence tomographer. Exclusion criteria included subjects with keratoconus, previous eye surgery, glaucoma, use of contact lens and irregular corneas.
Results :
The average CET was 52.21mm with a SD of ±3.28, it was thinner in the central 3mm zone (51.1± 3.4) than in the paracentral (52.49± 3.2) and midperipheral (54.34±3.8). We found that male CET (53.07 ± 3) was thicker than female (51.87 ± 3.34) CET but without significant difference found (p=0.14), the only statistically significant difference between sex was found in the paracentral zone (6mm) in which the ET was thicker in males than in females in the 4 regions studied (inferior p=0.015, nasal p= 0.023, superior p=0.003, temporal p=0.01). We looked for a difference in ET in the 3 studied zones using age as a variable but found no statistical difference (p= 0.29 for CET). The superior quadrant was found to be thinnest (50.8mm-3mm, 51.28-6mm, 49.45-9mm) compared to the inferior (51.7mm-3mm, 52.84mm-6mm, 54.21mm -9mm) which was thickest (p=0.001, p= 0.00, p= 0.00). The CCT was significantly thicker in females than in males, using Mann Whitney test the average CCT in females was 552.86mm and in males 519 mm (p=0.00).
Conclusions :
This comprehensive study in healthy Mexican population using MS-39 Schwind SD-OCT to map the corneal epithelium thickness distribution showed us that CET was 52.21 ±3.28 mm. We found no difference according to age or eye in the ET profile in the 36 zones examined. The superior quadrant was found to be thinnest when compared to the other 3 quadrants, which was statistically significant, when compared to the inferior quadrant. This provides us with a normative database for ET profile in the studied population.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.