Experimental and clinical investigation of efficiency and ablation profiles of new solid-state deep-ultraviolet laser...

To investigate the efficiency and ablation profiles of a newly developed, all-solid-state laser platform.

Experimental investigations performed at Katana Technologies GmbH, Kleinmachnow, Germany, and clinical study, at the Ophthalmology Clinic, University of Messina, Messina, Italy.

Experimental studies were performed on poly(methyl methacrylate) (PMMA) and in porcine eyes using an all-solid-state, Q-switched, frequency-shifted laser (LaserSoft, Katana Technologies GmbH) with a Gaussian spot with a diameter of 0.2 mm in the target plane, a peak fluence of 350 mJ/cm2, and a repetition rate of 1 kHz. The ablation profiles were determined using a profile meter (MicroProf, Fries Research and Technology GmbH), corneal topography was analyzed with a TMS 2N (Tomey Inc.), and corneal thickness was measured with an ultrasound pachymeter (DGH Technology). In the clinical study, 9 human eyes were treated with photorefractive keratectomy. The mean outcome measures were uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), corneal topography, and corneal transparency. The follow-up was 1 month for all eyes and 3 months for 4 eyes. Safety, efficacy, and predictability were evaluated.

Smooth profiles were found in the PMMA and the porcine eyes. The topographic maps showed central steepening after the hyperopic ablation and slight central flattening of the surface after the myopic treatment. No eye lost lines of BSCVA; the UCVA improved in all eyes. All eyes were within +/-1.00 diopter (D) of emmetropia, and 89% were within +/-0.50 D.

The efficacy of the ablation was good, with the profile meter results confirmed by the topographic measurements.