PURPOSE
To evaluate the visual outcomes, predictability, and planarity of four types of 60-kHz femtosecond laser–assisted LASIK flaps: 90, 100, 110, and 120 µm.
METHODS
This randomized, prospective, interventional, comparative trial was performed at a tertiary care facility. Two hundred forty eyes with a calculated residual bed thickness >300 µm (at 120-µm flap thickness and subjective refraction) were randomized into four flap thickness groups to undergo femtosecond laser–assisted LASIK. Pre- and postoperative assessment included uncorrected visual acuity, best spectacle-corrected visual acuity (BSCVA), and refraction. Flap thickness was assessed by anterior segment optical coherence tomography on 28 points per flap at 1-month follow-up. Three new indices were devised to assess the predictability and planarity.
RESULTS
The baseline parameters were matched. Postoperative vision and refractive outcome were similar in the four groups (P>.05, analysis of variance). The achieved flap thickness was different at each measured point among the groups (P<.05) with standard deviations ranging from ±3.2 to ±7.3 µm. The predictability and planarity were satisfactory in all four groups, although the indices were slightly better in the 110-µm and 120-µm groups. No loss of BSCVA or flap complications occurred in the four groups.
CONCLUSIONS
The study demonstrated that all four flap thicknesses are relatively uniform in predictability and clinical outcomes. [J Refract Surg. 2010;26(6):392-402.]
AUTHORS
From Dr Agarwal Eye Hospital and Eye Research Centre, Chennai, India.
Dr Agarwal is a paid consultant for AMO and Bausch & Lomb. The remaining authors have no financial or proprietary interest in the materials presented herein.
The authors acknowledge Gautam Kumar, BOptom, for his help in coordinating postoperative follow-up.
Correspondence: Amar Agarwal, MS, FRCS, FRCOphth, Dr Agarwal Eye Hospital and Eye Research Centre, 19 Cathedral Rd, Chennai - 600 086, India. Tel: 91 44 2811 6233; Fax: 91 44 2811 5871; E-mail: dragarwal@vsnl.com
Received: February 2, 2009; Accepted: June 9, 2009
Posted online: August 3, 2009
doi:10.3928/1081597X-20090728-02
