Transitory Haze in Surface Ablation, Epithelial Flap Retention

Determinants of early onset haze were retrospectively explored in patients who had been undergone laser-assisted sub-epithelial keratectomy (LASEK) in a private eye clinic. The technique included creating an epithelial flap following 20 seconds exposure to 20% alcohol. ‘Optimized’ ablation profile was used by Allegretto laser (Wavelight Technologie). Following repositioning of the flap, a single-brand bandage contact lens was used. For eyes with a spherical equivalent of more than 3 diopters, intraoperative mitomycin C (MMC) was used for 20-30 seconds. Patients were visited at day 1, day 4, week 3, month 3, month 6, and year 1 postoperatively. Candidates included 130 patients (260 eyes), of whom 62% were female. Mean age was 29.0±10 years and baseline range of spherical equivalent was -11.50 to +5.75 (absolute mean 3.50) diopters. The epithelial flap was lost in 36 eyes (28%). Transitory haze was observed in 29 cases (21.5%), all of which had retained their epithelial flap; none of the epithelial flap lost eyes showed haze (P<0.004). Gender, age, MMC usage, and pre-existing astigmatism were not associated with transitory haze (P-values: 0.652, 0.575, 0.815, and 0.248 respectively). Haze was resolved in all of the eyes. No case of classic haze was noted. Contrary to the current concept that the epithelial flap acts as a biologic contact lens and controls wound healing in surface ablation,1,2 in the current series, loss of epithelial flap seems to have had a protective effect in (transitory) haze formation.