Abstract
Abstract: :
Purpose:To investigate the usefulness of ablation depth (AD) and AD/CT (ablation depth / corneal thickness) ratio to predict corneal haze in post-LASEK (laser-assisted sub-epithelial keratectomy) patients. Methods:Seventy-seven eyes in 42 were treated for refractive error by LASEK procedure with a Ladarvision 4000 excimer laser. 18% alcohol solution was used to help create epithelial flaps. Patients were followed up to 1 year. Corneas were assessed by 2 evaluators under a slit-lamp biomicroscope with broad tangential illumination. The relative scale was quantitated in the following manner: 0 (clear), 0.5+ (trace), 1+ (mild), 2+ (moderate) and 3+ (marked). Results:The mean of pre-op spherical equivalence was –5.35D (+4.88D to –12D), AD 86.66 µm (21.2 µm to 185.3 µm) and AD/CT ratio 0.16 (0.04 to 0.36). Of 77 eyes, 30 eyes with AD more than 100 µm and AD/CT ratio 0.18 or more developed 1+ or more corneal haze. Among 47 eyes with AD less than 100 µm and AD/CT ratio less than 0.18, only one eye (AD = 73.2 µm, AD/CT ratio = 0.14) developed 1+ to 2+ haze and rest of them had only clinical insignificant haze (0 to 0.5+). Conclusion:Ablation depth and AD/CT ratio are useful factors to predict corneal haze in post-LASEK patients. AD more than 100 µm or AD/CT ratio more than 0.18 suggests that patients have a high risk of developing clinically significant haze (1+ or more) after LASEK.
Keywords: 545 refractive surgery: complications • 369 cornea: clinical science • 549 refractive surgery: other technologies