Visumax Femtosecod and MEL90 Excimer Laser Outcome in Mild, Moderate and High Myopic Astigmatism: Six Months Follow-up

Background: Myopia is the most common refractive disorders worldwide. There is progressive demand for myopia correction. The popularity of techniques and the machines is based on the outcome of surgery regarding visual acuity, recovery time and stability of refraction. Aim of Study: To evaluate the efficacy, safety, predictability, and visual outcome of visumax femtosecond laser and Mel 90 excimer laser for correction of mild, moderate and high myopic astigmatism through six months follow-up. Patients and Methods: Patients divided into three groups each group has 50 eyes based on refractive errors into mild myopia with SER up to -3.00 D, moderate myopia with SER –3.00 up to –6.00 D and high myopia with SER more than –6.00 up to –9.00 D. All patients selected based on specific criteria and evaluated properly. Preoperative UDVA & CDVA, central corneal thickness, pentacam, wave front, flap thickness and postoperative residual stromal bed thickness, postoperative UDVA one month, three months and six months and the residual SER were recorded. All patients operated using same machines, the visumax femtosecond laser for flap creation and Mel 90 excimer laser for ablation. Results: Preoperative mean SER were –2.19 – 0.60, –4.54 – 0.87, –7.94 – 0.84 D for mild, moderate and high myopia consecutively. The mean UDVA six months post surgery were –0.09 – 0.05, –0.05 – 0.06, –0.01 – 0.03 Log MAR for mild, moderate and high myopia groups. The mean preoperative central corneal thicknesses were 547.38 – 20.59, 541.30 – 18.22 and 555.92 – 9.78 micron for the three groups consequently. The mean postoperative residual stromal bed thicknesses were 407.52 – 19.85, 359.12 – 15.41 and 313.60 – 15.81 micron for the three groups consecutively. Conclusion: Visumax femtosecond laser and MEL90 lasik ablation has a high safety and predictability in the three groups. The refraction was stable tell the six month follow-up. The visual outcome and refraction were better in mild to moderate myopia than in high myopia. HOAs were higher in high myopia group compared to the other two groups. The triple A algorithm has a minimal ablation depth and low aberrations.