Study provides insight on long-term outcomes after hyperopic LASIK

By Cheryl Guttman Krader

Las Vegas-Hyperopic LASIK (H-LASIK) has limited predictability and declining efficacy during long-term follow-up, but its safety remains good and patient satisfaction stays high, said Reena Mahendra Dave, MD.

Dr. Dave, Guy’s and St. Thomas’ Hospital, London, reported findings from an analysis of data collected for 33 eyes of 19 patients evaluated at a mean of 16.5 years after H-LASIK.

The mean age at time of correction was 51.6 years (range 34 to 60 years), mean preoperative spherical equivalent (SEQ) was +3.73 D (range +1.25 to +6.5 D), and minimum follow-up was 15 years, said Dr. Dave at the 2015 meeting of the American Academy of Ophthalmology.

The results showed mean hyperopic SEQ increased significantly between 1, 5, and 16.5 years (mean +0.28 versus +0.84 versus +1.74 D); at 16.5 years, only 24% of eyes were ±1.0 D and only 6% were ±0.5 D. Mean SEQ increased similarly over time in eyes with lower versus higher power corrections (< +3.0 versus >+3.5 D).

However, the annual rate of refractive change was greater in the first 5 years than between 5 and 16.5 years, and in an age-based analysis, the hyperopic increase in SEQ was less in older (>53 years) than in younger (<52 years) age patients, although the difference between the two subgroups was not statistically significant.

The increase in hyperopic SEQ also translated into declining efficacy as the efficacy index decreased from 0.98 at 1 year to 0.5 at 16.5 years.

Nevertheless, 89% of patients were happy and 75% said they would recommend LASIK to family and friends.

The safety index at 16.5 years was 1.09. Five eyes had undergone cataract surgery, but there were no late complications, including no evidence of ectasia based on topographic analysis, Dr. Dave noted.

The refractive changes between 5 and 16.5 years reflect an expected age-related hyperopic shift, but it was found that keratometry values remained stable over time, which suggests that the hyperopic drift after H-LASIK is probably due to physiological lenticular changes rather than regression at the level of the cornea.

Keeping in mind the development of visually significant cataract and that the hyperopic increase in SEQ was less in the older age patients, it appears that time and advancing age may mask any hyperopic drift, Dr. Dave added.

Dr. Dave noted that while H-LASIK was first performed about 20 years ago, the longest term studies only include follow-up to 5 years.

The 19 patients included in the study were treated between 1998 and 1999 and returned after recall for a complete ophthalmic examination. They were part of a total cohort of 52 patients who had undergone H-LASIK. There were no significant differences between the 19 evaluated patients and those who did not return with respect to mean age, preoperative spherical equivalent preoperative cylinder, attempted correction, or achieved refractive correction at 12 months.