BOSTON — LASIK surgery is safe and somewhat more effective in patients younger than 25 years than in older patients, according to a retrospective analysis of more than 5000 eyes.
"Statistically better outcomes in all evaluated metrics were seen for younger, appropriately selected patients," said investigator Ronald Rebenitsch, MD, from Durrie Vision in Overland Park, Kansas.
He presented the study results here at the American Society of Cataract and Refractive Surgery 2014 Symposium.
Younger age presents a host of logical safety concerns to ophthalmologists in terms of LASIK surgery, Dr. Rebenitsch explained.
"Younger patients tend to be more likely to use contact lenses and sleep in their contacts, for instance, so it makes sense to ask about functionality," he said. "Is it safe, stable, and effective to enhance these patients if they need it?"
To answer those questions, Dr. Rebenitsch and his colleagues conducted a retrospective chart review of patients who underwent LASIK surgery with primary sub-Bowman's keratomileusis in 1 or both eyes from 2007 to 2013.
Preoperative refractions in the study population ranged from –10 to +6 diopters of sphere and from 0 to –6 diopters of cylinder.
Enhancement rates after surgery in 4755 eyes ranged from 3.7% in patients 17 to 25 years of age, 4.3% in patients 26 to 35 years, 6.6% in patients 36 to 45 years, to 15.8% in patients 46 to 50 years (P < .0001).
"This surprised us," Dr. Rebenitsch said. "Anecdotally, we expected the younger patients to do well, but not this well."
"Initially it was more of a dichotomous comparison, but as we looked at the data further, it became clear that there was an exponential increase in the enhancement rate that was statistically significant."
Refractive outcomes, defined as stability at 3 months, were available for 1944 patients and 3024 eyes; 20/20 monocular vision was consistent, at about 97%, in all age groups.
"This also surprised us," Dr. Rebenitsch said.
For refractive outcomes of 20/15 vision, rates ranged from a high of 79.4% in patients 17 to 25 years, to 78.9% in patients 25 to 35 years, 73.0% in patients 36 to 45 years, and 64.7% in patients 46 years and older.
When the researchers evaluated rates of epithelial ingrowth after enhancement, they found significantly lower rates in younger patients.
In 693 eyes from 481 patients, epithelial ingrowth was 0.0% in patients 17 to 25 years, 2.0% in patients 25 to 35 years, 3.3% in patients 36 to 45 years, and 7.2% in patients 46 years and older (P = .023).
"This was exciting. We found that patients in the youngest age group actually had 0% epithelial ingrowth after flap enhancement; the rate increased as the patients got older," Dr. Rebenitsch reported.
"Overall, younger patients did significantly better after LASIK surgery than older patients," he concluded. "They had better vision, lower enhancement rates, and fewer complications if an enhancement was needed."
"This was a retrospective study, so a prospective longitudinal study is needed," Dr. Rebenitsch said. "But these findings allow us to talk about the safety profile with these patients, as well as the potential economic and functional benefit they might get from this."
This study offered some valuable insights on patient safety with LASIK, said session moderator Ronald Krueger, MD, MSE, an ophthalmologist from the Cole Eye Institute at the Cleveland Clinic.
"It was the runner-up for the best paper of the session," he told Medscape Medical News. "It pointed out important points to consider with the age of patients having LASIK."
Dr. Krueger explained that refinements of the procedure, such as "modern Femto flaps, are reducing the risk of epithelial ingrowth."
"In my own analysis of 1600 eyes over the past 3 years, we had none with significant ingrowth using the WaveLight platform — this included all age groups," he said.
Dr. Rebenitsch has disclosed no relevant financial relationships. His coauthors report relationships with Alcon and Ziemer Ophthalmics. Dr. Krueger is a consultant with Alcon.
American Society of Cataract and Refractive Surgery (ASCRS) 2014 Symposium. Presented April 27, 2014.
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Cite this: LASIK Effective, Safe in Patients Under 25 - Medscape - May 09, 2014.