While millions of LASIK procedures have been performed worldwide, the long-term stability and efficacy of LASIK for the treatment of hyperopia remain uncertain.
ParisWhile millions of LASIK procedures have been performed worldwide, the long-term stability and efficacy of LASIK for the treatment of hyperopia remain uncertain.
David O'Brart, MD, and colleagues from the St. Thomas' Hospital, London, conducted a retrospective investigation of 34 patients (49 eyes) (mean age, 50 years) who underwent LASIK with the Moria LSK One microkeratome (Moria) and the Summit SVS Apex Plus Excimer Laser (Alcon Laboratories), both of which are early-generation instruments. The mean preoperative spherical equivalent was 3.5 D and the mean follow-up period was 55 months (range, 49 to 62 months). All patients had a 6 mm optical zone and a blend zone of 1.5 mm.
Dr. O'Brart reported at the annual meeting of the European Society of Cataract and Refractive Surgeons that LASIK performed with a prototype system was moderately effective for the treatment of low degrees of hyperopia up to 3. D. The investigators found a hyperopic shift of 0.5 D after 5 years that was greater than what was expected considering the normal physiologic shift that occurs with aging. The same hyperopic shift was seen when patients were divided by age into those who were under 40 years and those who were over 40 years, suggesting that the hyperopic shift seen in the study was not a physiological response.
"There is a true physiological hyperopic shift of about 0.6 D that occurs every 10 years between ages 50 and 70 years. Therefore, some hyperopic shift is expected, but not as much as the 0.5 D observed in this study. The long-term stability of hyperopic LASIK refractive corrections is uncertain and requires further investigation," Dr. O'Brart commented.
The overall visual results of hyperopic LASIK were very good, with improved uncorrected visual acuity (UCVA) levels in the vast majority of the eyes. The best-corrected visual acuity (BCVA) remained unchanged in most eyes. Three eyes lost one line of vision over the 5 years of the follow-up; no eyes lost more than one line of best spectacle-corrected visual acuity (BSCVA). No serious complications such as ectasia developed as a result of the procedure.