Corneal densitometry in bilateral keratoconus patients with unilateral corneal Vogt's striae: a contralateral eye study.

Abstract

To investigate corneal densitometry and correlations with corneal morphological parameters in patients with bilateral keratoconus (KC) with unilateral Vogt's striae. This prospective contralateral study enrolled 112 patients (224 eyes) with evident KC characteristics (corneal topography with asymmetric bow-tie pattern, inferior steepening), and at least one KC sign (conical protrusion of the cornea at the apex, corneal stromal thinning, Fleischer ring, Vogt's striae) on slit-lamp examination. Corneal densitometry and morphological parameters were measured using Pentacam HR. The mean age was 23.93 ± 6.81years. Fifty-two (23.22%), 111 (49.55%), and 61 (27.23%) eyes were in mild, moderate, and severe groups, respectively. Corneal densitometry values of the anterior 0-2mm and 2-6mm, intermediate 0-2mm and 2-6mm, posterior 2-6mm, and total cornea 2-6mm were significantly higher in eyes with Vogt's striae (P < 0.05), whereas those of the anterior 6-10mm, posterior 0-2mm, and total cornea 6-10mm were significantly lower in eyes with Vogt's striae (P < 0.05). Anterior 0-2mm and total cornea 2-6mm corneal densitometry values were positively correlated with anterior K1 (A-K1), K2 (A-K2), Km (A-Km), Kmax (A-Kmax), anterior corneal elevation, and posterior corneal elevation (P < 0.05), and negatively correlated with central corneal thickness and thinnest corneal thickness in eyes with Vogt's striae (P < 0.05). A-K2, A-Km, and A-Kmax were significantly correlated with the densitometry values of the anterior 0-2mm and intermediate 0-2mm in eyes without Vogt's striae (P < 0.05). Vogt's striae mainly occur on the anterior and intermediate layers during KC progression.