Received 27 March 2007; received in revised form 18 June 2007; accepted 9 July 2007. published online 27 September 2007.
Purpose
To investigate the efficacy and safety of LASIK over a 5-year postoperative period.
Design
Observational case series.
Participants
We examined 779 eyes in 402 patients with myopia or myopic astigmatism who underwent LASIK to correct their refractive errors and received regular postoperative assessments for 5 years.
Methods
Postoperative examinations were performed 1 day; 1 week; 1, 3, and 6 months; and 1, 2, 3, 4, and 5 years after LASIK surgery.
Main Outcome Measures
We evaluated changes in uncorrected visual acuity (UCVA) (logarithm of the minimum angle of resolution [logMAR]), manifest refraction, best-corrected visual acuity (BCVA) (logMAR), intraocular pressure, corneal thickness, corneal endothelial cell counts, and complications.
Results
Preoperative UCVA of 1.27 improved to −0.03 at 1 day after surgery and −0.08 at 1 month and revealed minimal but significant decreases thereafter. Postoperative manifest refraction was also improved by surgery, showing minimal but significant regression after 1 year. Final BCVA loss was seen in 10 eyes of 7 patients; in 7 cases, there were obvious reasons such as the progression of cataracts in 3 eyes, epithelial disintegrity due to dry eye in 2 eyes, irregular astigmatism due to flap striae in 1 eye, and age-related macular dystrophy in 1 eye. Intraocular pressure and corneal thickness decreased by 4.0 mmHg and 76.9 μm, respectively, due to surgery, but remained stable throughout the follow-up period. Corneal endothelial cell counts (2689.0±232.9 cells/mm2 before surgery) showed a statistically significant decrease at 5 years after surgery (2658.0±183.1 cells/mm2; 1.2% loss for 5 years), likely within the range due to physiological age-related loss. No serious, vision-threatening, irreversible complication such as keratectasia or progressive endothelial cell loss was observed.
Conclusion
LASIK surgery is an effective and safe procedure for correcting myopia/myopic astigmatism as long as inclusion and exclusion criteria are strictly respected. However, minimal regression occurred during the 5-year investigative period.
2Department of Ophthalmology, School of Medicine, Keio University, Tokyo, Japan.
Correspondence and reprint requests to Naoko Kato, MD, PhD, Department of Ophthalmology, School of Medicine, Keio University, Shinanomachi 35, Shinjuku-ku, Tokyo 160-8582, Japan.
Manuscript no. 2007-417.
Drs Kato and Toda contributed equally to the work.
ABSTRACT