A 12 month prospective contralateral study to compare Ultrathin 90 Micron and 120 Micron LASIK flap using the IntraLase 150 kHz femtosecond laser

Session Details

Session Title: LASIK

Session Date/Time: Monday 12/09/2016 | 08:00-10:30

Paper Time: 08:18

Venue: Hall C3

First Author: : D.Mathur INDIA

Co Author(s): :    R. Dutta   N. Shroff                 

Abstract Details

Purpose:

To evaluate and compare the effect of an ultrathin 90 micron and 120 micron flap on visual function, safety and efficacy, residual cylinder, flap stability, contrast sensitivity and overall patient satisfaction after femtosecond LASIK for moderate to high myopia.

Setting:

Cornea & Refractive Service, Shroff Eye Centre, A-9, Kailash Colony, New Delhi - 110048, India.

Methods:

396 eyes of 198 patients with myopia of -2.25 to -8.75 D (Mean -3.26±1.73) and astigmatism of -0.25 to -3.75 D (Mean -1.92±0.78) underwent LASIK with IntraLase iFS150 laser and Star S4 IR Excimer Laser (AMO). One eye of each patient was randomized to undergo a 120 micron flap and the other eye a 90 micron flap. The patients were followed for 12 months after surgery. The flap thickness was measured by anterior segment OCT at day-7, day-30 and day-90. The primary outcome measures compared were flap complications, UCVA, residual cylinder, predictability, contrast sensitivity and overall patient satisfaction.

Results:

At day-30 90.8% (120µ) versus 92.1% (90µ) achieved 20/20 or better UCVA (p=.235). At day-30 mean spherical equivalent was +0.13±0.56 D (120µ) and +0.12±0.48 D (90µ) (p=.377), and mean residual cylinder was 0.28±0.27 D (120µ) and 0.29±0.25 D (90µ) (p=.569). Mean logmarUCVA on day-7 was -0.01±0.15 (120µ) and 0.07±0.21 (90µ) (p=.023). Parameters were comparable at 12-months. Mean flap thickness standard deviation was stable and comparable in both groups. OBL formation occurred in 4 eyes (2.02%) (120µ) and 16 eyes (8.08%) (90µ) (p<.001). Contrast sensitivity was better in the 90µgroup at 1-month. At 12-months, patient satisfaction was high in both groups.

Conclusions:

No long term difference in visual outcome in both groups. Both treatments were safe, effective and predictable with high reproducibility of flap creation. The 120 micron group showed faster and better visual recovery in the early post-operative period. The 90 micron group showed slower visual recovery with improved contrast sensitivity at 3, 6 and 12 months with high patient satisfaction and more patient benefit with thinner corneas.

Financial Disclosure:

NONE