Characteristics of corneal aberration in patients with bilateral keratoconus and unilateral corneal Vogt's striae

To assess the corneal high-order aberration (HOA) and its correlation with corneal morphological parameters in patients with bilateral keratoconus (KCN) and unilateral Vogt's striae.

A total of 168 eyes of 84 patients with KCN, whose corneas had definite signs of unilateral Vogt's striae, were enrolled. Corneal HOA and morphological parameters were measured using Pentacam HR.

The corneal morphological parameters between KCN eyes with and without Vogt's striae were evidently different (P<0.001). The 3^rd coma 90°, 4^th spherical aberration, 5^th coma 90°, root-mean-square (RMS) (total), and RMS (HOA) in the front, back surfaces and total cornea in KCN eyes with Vogt's striae were significantly higher than those in KCN eyes without Vogt's striae (P<0.001). In KCN eyes with Vogt's striae, the 3^rd coma 90° and 4^th spherical aberration in the front surface and total cornea were negatively correlated with flat keratometry value (K1), steep keratometry value (K2), mean keratometry value (Km), maximum keratometry value (Kmax), anterior corneal elevation (ACE), and posterior corneal elevation (PCE; P<0.05). The 3^rd coma 90°, 4^th spherical aberration in back surface and RMS (total), RMS (HOA) in the front, back surfaces, total cornea were positively correlated with K1, K2, Km, Kmax, ACE, and PCE (P<0.05).

Corneal HOA especially vertical coma and spherical aberration may increase when Vogt's striae appeared in KCN eyes. The scale of increase is significantly related with changes in corneal shapes.