Variables affecting refractive outcome following LASIK for myopia

Abstract

Aim To investigate factors affecting refractive outcome following LASIK for myopia. Method Six hundred and seventy-four consecutive uncomplicated myopic LASIK surgeries, performed by a single surgeon, either using the Technolas 217 planoscan (n ¼ 372) or the NIDEK EC 5000 (n ¼ 302), were evaluated. Stratified random sampling was used to match the groups for refractive error, patient age, and gender. The final analysis included 302 patients from each treatment group. Conditions were identical for both surgeries, and pre-operative refractive errors were between À1.00 and À14.00 DS and oÀ1.50 DC. Refractive success was defined as À0.50 to þ 0.50 DS of the targeted refraction measured 3 months after surgery. A stepwise logistical regression analysis was used to determine variables associated with refractive failure. Results A successful refractive outcome was achieved in 78% (235/302) of surgeries using the Technolas laser and in 88% (266/302) using the NIDEK laser. Predictor variables for not achieving refractive success were pre-operative refractive error of above À5.00 DS, age more than 40 years, and surgery performed with the Technolas laser. Conclusion Both the Technolas 217 and the NIDEK EC-5000 excimer lasers achieve a successful refractive outcome in the majority of cases. However, patient and surgical factors can influence refractive outcome.

One-month Outcomes of Wavefront-guided LASIK for Low to Moderate Myopia With the VISX STAR S4 Laser in 32,569 Eyes

“…Some reports have found that age is a factor, with younger patients having better outcomes, but other studies have not found an association. 9,19,20 In addition, studies of the possible benefi t of femtosecond-created LASIK fl aps have shown both similar and improved outcomes compared to mechanical keratome-created fl aps. 4,[21][22][23][24] Given these mixed results, it is not known whether patients who did not attend the 1-month examination would have collectively done better, worse, or the same as the cohort who attended the 1-month examination.…”

A Microscopy Study of the Structural Features of Post-LASIK Human Corneas

“…Unfortunately, due to the limited information supplied to eye banks, most of the clinical details of the patient were unknown, but the results clearly demonstrate the lack of long-term wound healing at the flap margins and across the flap bed. It should however be noted the patient was 50 years old at the time of surgery and there is a significant trend for increased refractive failure with increasing patient age suggesting that stromal changes with age may have influenced post-operative healing [11], [12].…”

Laser in situ keratomileusis in 2012: a review

“…Visual outcome is similarly enhanced by matching the patient characteristics with the appropriate surgery. Several variables may influence this decision for the refractive surgeon, including magnitude of refractive error, corneal and ocular health and patient age …”

“…Several variables may influence this decision for the refractive surgeon, including magnitude of refractive error, corneal and ocular health and patient age. 16 Prior to proceeding with surgery, a comprehensive visual and ocular assessment is vital to assess the suitability of the procedure. Patients who routinely wear contact lenses must have them out for a minimum period: three days for soft contact lenses and three weeks for gas-permeable or hard contact lenses.…”