OBJECTIVE MEASUREMENT OF CORNEAL LIGHT-SCATTERING AFTER EXCIMER-LASERKERATECTOMY

Purpose: To obtain objective measurements of corneal light scattering after excimer laser keratectomy, and to evaluate the relation of light scattering to clinical haze grading and visual acuity. Methods: The a uthors measured best-corrected visual acuity, subjective clinical haze grade, and corneal light-scattering index in patients undergoing phot orefractive keratectomy (PRK) (n = 26) and phototherapeutic keratectom y (n = 8), preoperatively and postoperatively at 1, 3, 6, 9, and 12 mo nths or later. Corneal light scattering was correlated with visual acu ity and clinical haze grade. Results: Corneal light scattering increas ed after PRK and was reduced after phototherapeutic keratectomy. Corne al light-scattering index showed a stronger positive correlation with logMAR visual acuity (r = 0.57) than clinical haze grading (r = 0.34). Corneal light-scattering index (P < 0.05 at I and 3 months) and clini cal haze grading (P < 0.05 at 6, 9, and 12 months) were significantly higher in eyes undergoing PRK with ablation depths of more than 80 mu m. Conclusions: Excimer laser surgery affects corneal light scattering . Ablations with depths greater than 80 mu m produce significantly hig her levels of haze than those less than 80 mu m. Objective measurement of corneal light scattering may be useful in monitoring the outcome o f excimer keratectomy.