97th DOG Annual Meeting 1999
DIODE LASER THERMOKERATOPLASTY FOR HYPEROPIA CORRECTION - RESULTS OF A TWO-CENTER STUDY
M. Derse, T. Bende, B. Wannke, B. Mathys, B. Jean
Since 2 years, the continuous wave (cw) diode laser (1.9µm) is available offering an optimized laser-tissue-interaction when compared to pulsed infrared lasers. Thus, an increase in the amount of hyperopia correction and a better stability can be expected.
Patients & Methods: Over 100 eyes have been treated using the Rodenstock LTK 1.9 Diodenlaser (Rodenstock Instr., Ottobrunn) by means of a contact applications handpiece to correct hyperopia. The patients with natural hyperopia and secondary hyperopia after refractive myopia correction were included. The range of preoperative hyperopia was +0.75 to +6.5 D. Patients were 21 to 62 years old. The procedure was performed following a standardized protocol using either one or two rings with 8 coagulations each. The coagulation diameter (CD) of the central ring was varied between 6 and 9 mm depending on the amount of preoperatively measured hyperopia.
Results: At present the results of 42 eyes can be reported. The follow-up is 6 to 30 months. The achieved hyperopia correction is dependent upon the CD. The refractive change was measured between 0.75 D and 4.5 D. For a 6 mm CD the average correction was 3.5 D and for a 7 mm CD it was 2.5 D on the average. Stability of the refraction could be observed between 3 to 6 months postoperatively. Eyes with secondary hyperopia after PRK showed higher corrections when using the same surgical parameters. No loss of more than one line in best-corrected visual acuity could be observed.
Conclusion: Diode laser thermokeratoplasty is a minimal invasive procedure for hyperopia correction. Up to now it does not show the known regression of pulsed infrared lasers. It is an alternative treatment to Hyperopia-PRK or LASIK avoiding the risk of central corneal scarring.
DEOS, Univ. Eye Hospital Tuebingen Dept. I, Derendinger Str. 41, D-72072 Tuebingen