Results of 193-nm excimer laser photorefractive keratectomy for severe myopia

Objective To evaluate the therapeutic effects of 193 nm excimer laser photorefractive keratectomy(PRK)for severe myopia.Methods Eighty nine eyes(48 patients) of severe myopia(rang:-10.00~-25.00D)were treated by multiple zone photorefractive keratectomy with a Keracor 116 excimer laser.The therapeutic effects and the refractive stability were investigated in 12 month follow up study.Results After one year,3.48%(12 of eyes)attained visual acuity of 1.0 or better,19.10%(17 of eyes)were 0.5 to 0.8 and 67.42% of the eyes≤0.4,96.63% of the eyes improved or their best corrected visual acuity did not change,whereas 3.37% lost at least one line.Corneal haze was observed to be severe After one month,and diminished considerably after 6th and 12 month.After one year no haze could be seen in 88.76% ,32.69% were within ±1.00D and 46.31% in ±2.00D.SAI,SRI and Sim K values had a significant change( P 0.001) one month after PRK,and no change occured( P 0.05) 3~12 months after PRK.Conclusion These date show that excimer PRK for treatment of severe myopia is an effective and safe refractive surgery,but it's predictability is not satisfactory.The treated pattern should be improved.