Continuous-wave diode laserthermokeratoplasty: First clinical experience in blind human eyes

Purpose:To evaluate the safety and stability of laser thermokeratoplasty (LTK) with a continuous-wave diode laser in blind human 'eyes and to optimize parameters for a study in sighted eyes.Setting:Department of Ophthalmology, Medical University Lübeck; GermanyMethods:A continuous-wave diode laser was set to emit radiation with a wavelength of 1.854 μm (Group 1, n = 4) or 1.870 μm (Group 2, n = 4) and 100 to 160 mW power for 10 seconds. A focusing handpiece was coupled with an application mask and fixed by partial vacuum to the conjunctiva or cornea. The radiation was focused into the corneal stroma between 400 and 600 μm in Group 1 and set to 1000 μm in Group 2. Eight (Group 1, single ring) or 16 (Group 2, double ring) coagulations were applied.Results:The refractive change increased with-higher laser, power and smaller ring diameters. Two rings of coagulations provided higher and more stable refractive changes of up to 5.66 diopters (D) than a single ring. The refractive effect stabilized between 3 and 6 months postoperatively. At 1 year, mean, refractive change was +0.99 D ± 0.39 (SD) in Group 1 and +2.32 ± 224 D in Group 2 Extensive endothelial damage occurred in Group 1 but was minimal in Group: 2.Conclusions:Diode LTK was used to treat hyperople safely and effectively Regression occurred mainly in the first 3 postoperative months. With a wavelength of 1.870 μm, corneal endothelial damage was limited.