Effect of Demographic Variables on the Regional Corneal Pachymetry

The measurement of corneal thickness by corneal pachymetry provides valuable information in the setting of corneal disease; however, spectral-domain optical coherence tomography (SD-OCT)-based assessment of different corneal sectors has been scarce in Pakistan.

We aimed to obtain a whole-corneal thickness map using SD-OCT and to evaluate its correlation with age, sex, and axial length.

Our study included 214 subjects with healthy corneas; each eye was scanned with an SD-OCT covering a 9-mm diameter, and reproducibility was evaluated in a subset of 50 participants by means of an identical scan protocol repeated by 2 different OCT operators.

Our analysis revealed corneal thickness to be thinnest inferotemporally whereas thickest in the superior and superonasal quadrants. No statistically significant differences could be detected between male and female participants with respect to corneal thickness, age, intraocular pressure, axial length, and refractive errors. However, we identified a significant negative correlation between age and corneal thickness in all corneal sections, excluding the inner and middle superior, inner superonasal, and inner and middle superotemporal quadrants. Conversely, the correlation between axial length and corneal thickness was found to be positive in the central region (P = 0.03, R = 0.149), the outer inferotemporal quadrant (P = 0.012, R = 0.171), throughout the temporal quadrant (P = 0.024, R = 0.154 for inner; P = 0.025, R = 0.153 for middle; P = 0.006, R = 0.186 for outer), and in the inner superotemporal quadrant (P = 0.018, R = 0.162).

Different corneal sectors may interact heterogeneously with patient-related characteristics. This may provide incentive to evaluate whole-corneal thickness as a distinct parameter for clinical identification of disease processes.