Articoli Scientifici di Oftalmologia

Argomento : 2

Comparison of Corneal Epithelial and Stromal Thickness Distributions between Eyes with Keratoconus and Healthy Eyes with Corneal Astigmatism $2.0 D

Abstract

Purpose: To identify corneal epithelial- and stromal-thickness distribution patterns in keratoconus using spectral-domain

optical coherence tomography (SD-OCT).

Patients and Methods: We analyzed SD-OCT findings in 20 confirmed cases of keratoconus (group 1) and in 20 healthy

subjects with corneal astigmatism $2 D (group 2). Epithelial and stromal thicknesses were measured at 11 strategic

locations along the steepest and flattest meridians, previously located by corneal topography. Vertical mirrored symmetry

superimposition was used in the statistical analysis.

Results: The mean maximum keratometry measurements in groups 1 and 2 were 47.962.9 D (range, 41.8–52.8) and

45.661.1 D (range, 42.3–47.5), respectively, with mean corneal cylinders of 3.362.2 D (range, 0.5–9.5) and 3.661.2 D (range,

2.0–6.4), respectively. The mean epithelial thickness along the steepest meridian in group 1 was the lowest (37.464.4 mm) at

1.2 mm inferotemporally and the highest (59.364.4 mm) at 1.4 mm supranasally from the corneal vertex. There was only a

small deviation in thickness along the steepest meridian in group 2, as well as along the flattest meridians in both groups.

The stromal thickness distribution in the two groups was similar to the epithelial, while the stromal thickness was generally

lower in group 1 than in group 2.

Conclusions: SD-OCT provides details about the distribution of corneal epithelial and stromal thicknesses. The epithelium

and stroma in keratoconic eyes were thinner inferotemporally and thicker supranasally compared with control eyes. The

distribution pattern was more distinct in epithelium than in stroma. This finding may help improve the early diagnosis of

keratoconus.

Trial Registration: ClinicalTrials.gov NCT02023619