Abstract
Abstract: :
Purpose: Develop an experimental animal model of LASIK and assess pharmacological modulation of cornel transparency with an objective method. Methods: 32 adult hens were cared follow ARVO guidelines, underwent LASIK surgery (right eyes) and were divided in 4 groups with different post–operative treatment: A– no treatment; B– carboxymethyl chitosan 0.5%; C– carmellose sodium 0.5%; D– fluorometholone 0.20%. Left eyes from group A were used as control (no surgery, no drugs): group E. Masked treatments were applied for 10 days. Surgical procedure: animals were anesthetised (intramuscular and topical) and corneal flaps were created with a special microkeratome (60 µm plate). Stromal photoablation was performed with a 193nm excimer laser, programmed for –4D. Surgical outcome and follow up was performed 1, 15 and 30 days after surgery, with a surgical microscope, and haze was clinically evaluated (grade 0–4). Day 30, animals were euthanasized, corneas were carefully excised and corneal transmittance was objectively assessed with an experimental scatterometer. Corneal tissue was fixed for light microscopy study. Results: Surgical outcome shows intra–operative (12.5%) and postoperative (18.7%) complications and these animals were excluded from the study. Haze was not clinically detected in the 22 eyes (68.7%) that finished the study. The higher corneal transmittance value was found in group E and lower in group B. Statistically significance difference was not found between groups B, C and D (treated groups) but significance difference (P < 0.05) was found between groups B, C comparing that with group E. Conclusions: an experimental animal model of LASIK was developed and was used to assess pharmacological modulation of corneal transparency, which was evaluated with an objective method. Corneal transparency shows no differences between treated groups.
Keywords: refractive surgery: LASIK • cornea: stroma and keratocytes • refractive surgery: complications