Long-term results of excimer laser procedure to correct astigmatic refractive errors.

BACKGROUND: The aim of this study was to evaluate long-term efficacy, safety, stability, and predictability of photorefractive keratectomy (PRK) as treatment of astigmatism. MATERIAL/METHODS: Ninety-four eyes of 52 patients, treated with PRK for compound myopic astigmatism, compound hyperopic astigmatism, and mixed astigmatism were studied during a 36-month period. Main outcome measures were uncorrected and best-corrected visual acuity (UCVA, BCVA), refraction, and corneal transparency. Astigmatism correction was analyzed by a power vector method. RESULTS: In myopic astigmatism group (42 eyes), postoperative UCVA was 20/40 or better in 100% of eyes, 20/25 or better in 38 eyes out of 42 (90.5%), and 20/20 or better in 25/42 eyes (59.5%). No eye lost lines of the BCVA, 40/42 (95.2%) eyes had refraction within ± 1D and 37/42 (88.1%) within ± 0.50 D. In the hyperopic astigmatism group (28 eyes), the UCVA was 20/40 or better in 100% of eyes, 20/25 or better in 26/28 eyes (92.8%), and 20/20 or better in 24/28 eyes (85.7%); 1/28 eyes (3.6%) lost 1 line of the BCVA, 23/28 eyes (82.1%) were within ± 1D, and 21/28 (75%) were within ± 0.50D. In the mixed astigmatism group (24 eyes), the UCVA was 20/40 or better in 100% of eyes, 20/25 or better in 22/24 eyes (91.7%) and 20/20 in 15/24 (62.5%) eyes. No eye lost lines of BCVA, 23/24 eyes (95.8%) were within 1.0 D, and 20/24 eyes (83.3%) were within 0.50 D of defocus refraction. Power vector analysis showed a significant reduction of blurring strength in all examined groups. CONCLUSIONS: PRK is a safe and effective procedure for correction of all types of astigmatism, with good stability and efficacy at 3-year follow-up.

Contact lens wearing and chronic cigarette smoking positively correlate with TGF-ß1 and VEGF tear levels and impaired corneal wound healing after photorefractive keratectomy.

PURPOSE: To study the correlation of gender, contact lens (CL) wearing, chronic drinking and chronic smoking with wound healing cytokine levels and corneal recovery after photorefractive keratectomy (PRK). MATERIALS AND METHODS: One hundred and twenty-eight age-matched patients (180 eyes) undergoing PRK were enrolled. PDGF, EGF, VEGF, HGF and TGF-ß(1) protein levels were measured in tears by enzyme-linked immunosorbent assay either preoperatively or 2, 7 and 15 days after PRK. Patients were seen between one day and five days postoperatively for the evaluation of epithelial healing. Delayed re-epithelialization was defined as healing after day 5. All patients were followed for haze formation for a minimum of three months. RESULTS: All cytokines increased significantly during the first two postoperative days (p < 0.001). PDGF, EGF, HGF decreased to the preoperative levels by day 7, whereas TGF-ß1 and VEGF remained elevated over the entire period of observation of 15 days, although to a lesser extent than the second day after surgery, in CL-wearers and smokers, respectively (p < 0.01). The Pearson correlation analysis showed that: (i) CL-wearing positively correlated with TGF-ß1 amounts, while chronic smoking positively correlated with VEGF production; (ii) CL-wearing and TGF-ß1 amount were found to be associated with early haze formation, whereas chronic smoking and VEGF level with delayed re-epithelialization. No association was found between gender or alcohol consumption and cytokine levels or wound healing. CONCLUSIONS: Our findings highlight for the first time the important role that cigarette smoking and CL wearing may have in altering the tear cytokine network and impairing corneal epithelial wound repair after surgical injury.

One year outcome of manual alcohol-assisted removal of Salzmann's nodular degeneration.

BACKGROUND: To analyze visual and refractive modifications and corneal topography changes in a patient treated for bilateral advanced Salzmann's nodular degeneration (SND). METHODS: A forty-three-year-old man with bilateral advanced SND underwent manual, alcohol-assisted removal of the altered layer. Visual acuity, refraction, corneal topography and corneal aberrations were examined before and after the treatment after 7 days and 1, 6 and 12 months. RESULTS: The uncorrected visual acuity changed from 0.1 to 1.0 in both eyes. Refraction changed from sphere +3.00 and cylinder +4.50 x 180 degrees in the right eye and sphere +6 and cylinder +4.0 x 170 degrees in the left eye to bilateral emetropia. Corneal topography recovered from an extremely flat profile to a normal shape and it was unvaried during the follow-up period. Main topographic indices, highly altered before the treatment, normalized and were normal at control examinations. The quality of vision improved significantly with reduction of high-order aberrations from RMS of 5,07 microm to 0,66 microm in the right eye and RMS of 4,89 microm to 0,57 microm in the left eye respectively. CONCLUSIONS: Salzmann nodules produce an impressive central corneal flattening with high hyperopic refractive error and significant increment of corneal aberrations. After manual removal of the altered layer, the visual and refractive recovery, corneal topography and aberrometry normalization were immediate and stable during the observational period.

One-year clinical results of photorefractive keratectomy with a solid-state laser for refractive surgery.

PURPOSE: To investigate the safety, efficacy, and stability of photorefractive keratectomy (PRK) performed with a newly developed solid-state laser after 1-year follow-up. METHODS: The all-solid-state, Q-switched, frequency-shifted laser (LaserSoft; Katana Technologies, Berlin, Germany) with a Gaussian spot diameter of 0.2 mm and repetition rate of 1 kHz was used. Eleven eyes of six patients were treated with PRK. The mean outcome measures were uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), corneal topography, and corneal transparency. All patients were evaluated at 1, 3, 6, and 12 months postoperatively. RESULTS: At 12-month follow-up no eye lost lines of BSCVA and UCVA improved in all eyes. All eyes were within +/- 1.00 diopters (D) and 8 (73%) eyes were within +/- 0.50 D of emmetropia. CONCLUSIONS: Clinical results at 1 year were promising, with good safety, efficacy, and stability of the visual and refractive outcome.