Refractive Outcome of Femtosecond Assisted Laser in situ Keratomileusis in 1564 cases of Myopia and Compound Myopic Astigmatism.

Objective: To determine the outcomes of Femtosecond Assisted Laser in situ Keratomileusis (Femto LASIK) on eyes with myopia and compound myopic astigmatism in terms of efficacy, safety, accuracy, predictability, and stability of the procedure.

Study Design: Quasi-experimental study. Place and Duration of the Study: Refractive Surgical Department, Armed Forces Institute of Ophthalmology (AFIO), Rawalpindi, Pakistan, from January 2014 to August 2019.

Methodology: Participants aged 18 years and above with upto -12D (dioptre of myopia, underwent preoperative detailed work-up with history, ocular examination, subjective refraction and assessment on topography, tomography, and aberrometry. Suitable candidates underwent Femto LASIK and were re-evaluated at 1st postoperative day, end of 1st week, 1 month, 3 months, 6 months and 1 year. Results were analysed and represented in form of standard graphs for refractive surgery.  Results: Postoperative UDVA (uncorrected distance visual acuity) of 20/40 was achieved in 99% of patients. Efficacy index was 1.02 + 0.15. Safety index was 1.04 + 0.199. None of the patients lost more than one line in postoperative CDVA (corrected distance visual acuity) when compared to preoperative CDVA. All the eyes (100%) were accurately treated within +1.0 DS of intended spherical equivalent (SEQ) range. Mean SEQ showed stability with 1% eyes recorded to have more than 0.5D change or more over 12 months.

Conclusion: Femto LASIK is an effective, safe, accurate, predictable, and stable procedure for correction of myopia and compound myopic astigmatism.

Key Words: Femtosecond, Laser in situ Keratomileusis, Refractive surgery, Myopia, Compound myopic astigmatism, Uncorrected distance visual acuity.