Refractive surgery regression in the longer term
Older patients more prone to regression after LASIK but not after LASEK
A 20-year review comparing the time to retreatment in eyes undergoing LASIK and LASEK suggests that regression occurs earlier in older patients’ eyes after LASIK but not after LASEK, said Ciara E Byrne MBBS, Mater Private Hospital, Dublin, Ireland.
“Laser refractive corneal surgery provides an effective treatment option for myopia. Over the past decade, techniques have improved resulting in safer and more successful outcomes. Retreatment remains a complication despite a decrease in rates,” Ms Byrne told the ASCRS Virtual Meeting 2020.
The study reviewed the medical records of all cases of regression requiring retreatment following laser in situ keratomileusis (LASIK) or laser-assisted subepithelial keratectomy (LASEK) from 1998 to 2018 in the Mater Private Hospital, Dublin, Ireland.
The mean age of patients at initial treatment was 31.9 years. Nearly half, 48%, reported an occupation that was categorised as likely to involve high-intensity computer use. The analysis of spherical equivalent, astigmatism and visual acuity included 269 eyes of 198 patients. Patients were excluded if they were myopic in one eye and hyperopic in the other eye or if they had undergone LASIK on one eye and LASEK on the other.
The analysis showed no significant difference between LASIK and LASEK in terms of time to retreatment, which was 55.6 months on average overall in this study cohort. As in previous research reported by the same group, the analysis showed no significant difference between LASIK and LASEK in terms of the effect of high refractive error on regression associated with retreatments.
The mean cylindrical value preoperatively in those treated with LASEK was -0.73D. The mean cylindrical value for those treated with LASIK was -0.86D. Prior to retreatment, mean cylinder value was -0.42D in the LASEK group and -0.54D for those treated with LASIK.
A linear regression analysis, with months to retreatment in the first eye as the outcome variable and age as the explanatory variable, showed that age was not signiﬁcantly associated with months to retreatment In the LASEK group, but it was in the LASIK group. When the researchers analysed the sexes separately, they found the same association between age and LASIK but not between age and LASEK. They also found that gender did not influence regression rate with either technique.
“Our study does not demonstrate a difference in time to regression between LASIK and LASEK refractive surgery. Further study with a larger patient population would be beneficial in accurately evaluating the relationship between age and LASEK refractive surgery,” Ms Byrne added.