Long-term LASIK findings indicate safety, efficacy

Issue: February 2003

ByJennifer Byrne

In 1991, Ioannis Pallikaris, MD, in Heraklion, Crete, was one of the first surgeons to use an excimer laser to ablate the cornea after cutting a flap with a microkeratome. Today, nearly a decade later, LASIK has proven to be a highly effective procedure and remains at the forefront of refractive surgery. In assessing LASIK outcomes over the brief history of the procedure, clinicians report largely favorable results.

“I would say that, overall, the eyes appear to be very healthy,” said Richard N. Baker, OD, a practitioner based in Houston who saw his first LASIK patient in 1992. “The patients who have a problem with LASIK tend to have problems primarily with night vision, residual refractive error and dry eye.”

Patient satisfaction

According to a survey conducted at the Emory Vision Correction Center, patient satisfaction post-LASIK is high. According to these “subjective results,” 93% of patients claim that they can easily recognize a friend across the street without glasses or contact lenses, while 57% never wear glasses or contact lenses. Another 30% of patients wear glasses or contact lenses for only some activities, such as reading or driving at night. In addition, 27% of patients had monovision.

The survey reported that 95% of the patients said that they are “satisfied or very satisfied, have met their goals for the surgery and would have the surgery again.”

Regression rates

One concern regarding LASIK outcomes is the possibility of regression. According to Nikos Astyrakakis, OD, an optician at the Vardinoyiannon Institute at the University of Crete, the rate of regression is proportional to the amount of attempted correction.

“With retrospective studies throughout the years, we have found that the regression rate was increased in patients with higher attempted correction (more than 7 D),” he said. “In these patients, a retreatment, after the lift of the previous flap, was performed when the refraction was stabilized (in the majority of patients, 6 months after the initial operation).”

Dr. Baker said he has seen no significant regression in his patients over the years. “Some patients have become more myopic over time,” he said, “but if we look at their corneal curvatures, I haven’t seen a trend that those patients have regressed.”

Corneal decompensation

In his years of monitoring LASIK, Dr. Astyrakakis said he has seen no cases of corneal decompensation. “All of our patients underwent a detailed preoperative examination to exclude patients with corneal dystrophies or a predisposition to post-LASIK corneal decompensation,” he added.

Dr. Baker agreed that corneal decompensation is not a complication he has observed in LASIK patients. “I have seen no cases where the cornea has decompensated,” he said. “That would be unexpected.”

Cases of ectasia

Dr. Astyrakakis discussed a retrospective study that was performed 3 years ago at the Vardinoyiannion Institute concerning the incidence of ectasia in LASIK patients.

In this study, the charts of all patients (2,873 eyes) who underwent LASIK surgery between May 1995 and April 1999 were reviewed. Sixteen patients (22 eyes, 0.77%) were found to have developed post-LASIK ectasia.

“No patient with attempted correction less than 8 D or residual corneal bed thickness of more than 325 mm experienced post-LASIK ectasia,” Dr. Astyrakakis said. “There was a statistically significant positive correlation between corneal residual bed thickness and increasing patient age.”

Dr. Astyrakakis said he and his colleagues treated these patients using Intacs (Addition Technology) with promising results (preliminary results were published in the Journal of Refractive Surgery, 2002;18:43-46).

Dr. Baker said he has also seen some degree of ectasia in LASIK patients, but added that this is not a common occurrence. “I have seen a few patients who have had ectasia when the rule for the remaining bed thickness has been violated,” he said. “But I have not seen it in patients who have had the standard treatment, where bed thickness was not violated.”

Other possible complications

Dr. Baker said bullous keratopathy and neuropathic keratitis are also scarce in LASIK patients. “I have not seen a single case of bullous keratopathy post-LASIK,” he said.

Dr. Astyrakakis reported similar findings regarding these anomalies. “Throughout all these years, we found no patient with post-LASIK neuropathic keratitis,” he said.

Dr. Baker maintained that night vision problems and dry eye are the most significant problems post-LASIK. “Because we have done a better job screening patients with dry eye preoperatively and have treated them appropriately, we have reduced or minimized these problems,” he said. “But I have found that these are the most common complaints.”

After nearly 10 years of seeing LASIK patients, Dr. Baker said he has had every indication that the procedure is safe and effective. “In general, the outcomes have been positive,” he said.

For Your Information:

Richard N. Baker, OD, FAAO, can be reached at 3900 Essex Lane, Houston, TX 77027; (713) 626-5544; fax: (713) 626-7744.

Nikos Astyrakakis, OD, is based at the Vardinoyiannion Institute, University of Crete. He can be reached at University of Crete School of Medicine, VEIC, Voutes GR 71110 Crete, Greece; (30) 81 0 371800 ; fax: (30) 81 0 394653; e-mail: nasty@med.uoc.gr.