Corneal Scheimpflug Densitometry Following Photorefractive Keratectomy in Myopic Eyes.

Abstract

To evaluate the modification of corneal optical densitometry following photorefractive keratectomy (PRK) using Scheimpflug topography. Corneal densitometry (0 to 100 grayscale units [GSU]), pachymetry, and keratometry were evaluated using a rotating Scheimpflug camera (Pentacam HR; Oculus Optikgeräte, GmbH, Wetzlar, Germany) at baseline and 1 and 3 months following PRK in myopic patients. Subjective refraction, uncorrected distance visual acuity, corrected distance visual acuity, and corneal haze (0 to 4 on common subjective scale) were evaluated preoperatively at baseline, 1 month, and 3 months. The study included 75 eyes (38 right eyes, 37 left). The preoperative mean spherical equivalent and cylinder were -2.28 ± 1.24 and 0.92 ± 0.65 diopters (D), respectively. Maximal corneal densitometry (central 4 mm) was 27.44 ± 1.93 GSU at baseline. At 1 month postoperatively, corneal haze with a mean clinical grade of 0.54 ± 0.45 (P < .0001) was observed, associated with corneal densitometry increased to 29.69 ± 5.16 GSU (P > .05). At 3 months postoperatively, mean clinical haze decreased to 0.11 ± 0.24 (P < .0001) and was associated with a significant decrease (P < .0001) in maximal densitometry (25.13 ± 3.42 GSU). Corneal densitometry could represent a useful objective measurement of postoperative mild corneal haze and aid in the rating and follow-up of refractive surgery. [J Refract Surg. 2016;32(11):788-791.].