Structural and Optical Corneal Alterations in Inactive Herpetic Keratitis: A Quantitative Tomographic Analysis

To quantitatively characterize the structural and optical changes in the cornea in inactive herpetic keratitis and, secondarily, to evaluate whether these parameters vary according to lesion location and depth of vascularization.

This prospective cross-sectional study included 37 patients with unilateral inactive stromal and epithelial herpetic keratitis. Affected eyes were compared with contralateral healthy eyes. Corneal tomography was used to assess corneal thickness, epithelial and stromal profiles, anterior and posterior elevation, and higher-order aberrations (HOAs). Lesions were classified by location and vascularization depth.

Affected eyes showed significantly worse visual acuity, increased astigmatism, and greater corneal irregularity (all p < 0.001). Stromal thinning, epithelial thickening, increased anterior elevation, and altered posterior elevation were observed at lesion sites (p = 0.044, p < 0.001, p < 0.001, p = 0.015; respectively). Total HOAs and higher-order RMS components were significantly elevated (p < 0.001), while vertical coma and spherical aberration coefficients differed significantly between affected and fellow eyes (p = 0.024 and p = 0.008, respectively). No significant differences in structural or optical parameters were observed among vascularization depth subgroups. Spherical aberration differed significantly among lesion-location subgroups (p = 0.039), with a significant difference between the central and paracentral groups after Bonferroni correction (adjusted p = 0.034).

Inactive herpetic keratitis is associated with structural and optical alterations beyond stromal opacity. Tomographic and wavefront analysis may improve understanding of visual impairment and support individualized management.