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New data show LTK stability
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WAILEA, Hawaii — The data on laser thermal keratoplasty (LTK) with the Sunrise Hyperion that were reviewed by the Ophthalmic Devices Panel of the Food and Drug Administration (FDA) do not reflect the latest LTK techniques or results, said Donald R. Sanders, MD, PhD.
“Because of the nature of the regulatory process,” Dr. Sanders said, “Sunrise could not emphasize at the panel meeting that the results of the FDA trial reflected a population that was largely undercorrected.” Dr. Sanders has reviewed all of the Sunrise clinical study data, including the data that was not submitted under the Hyperion premarket approval application.
Patients in the early clinical trials were treated using a method that resulted in undercorrection and the regression that concerned many FDA panel members.
Moreover, Dr. Sanders told Ocular Surgery News in an interview here at Hawaii 2000, information on regression of LTK effect was not presented in the context of other laser surgical procedures for hyperopia.
No comparison allowed
“FDA did not allow comparisons between LTK and excimer results,” Dr. Sanders said. “Sunrise could not show the regression curves for the peer reviewed studies of hyperopic PRK and LASIK, which demonstrated the same loss of effect with time.”
The results of LTK also were assessed by the panel based on data only up to the 24-month follow-up point, Dr. Sanders pointed out. Analysis of that data projected a diminishing effect over time, but the prediction was not borne out by the actual patient data at even 30 months (see graph, “Longevity of LTK”).
“Furthermore,” Dr. Sanders continued, “Sunrise could not show the results with 32-spot LTK since this technique modification was not being considered for approval. Thirty-two spot LTK can treat 2.25 D to 3.0 D of hyperopia, depending upon the patient’s age, using the same energy allowed in the 16-spot FDA study. Thirty-two spot LTK is also ‘temporary’ because the effect can be expected to completely regress – in 270 years,” using the same statistical models applied to the FDA study data.
For Your Information:
- Donald R. Sanders, MD, PhD, is associate professor of ophthalmology at the University of Illinois and director of the Center for Clinical Research, 180 W. Park Ave., Suite 150, Elmhurst IL 60126; (630) 530-9700; fax: (630) 530-1636. Dr. Sanders has no direct financial interest in any of the products mentioned in this article. He is a paid consultant for Sunrise Technologies.