Mutational screening of VSX1, SPARC, SOD1, LOX, and TIMP3 in keratoconus.

PURPOSE: To evaluate the involvement of Visual System Homeobox 1 (VSX1), Secreted Protein Acidic and Rich in Cysteine (SPARC), Superoxide Dismutase 1 (SOD1), Lysyl Oxidase (LOX), and Tissue Inhibitor of Metalloproteinase 3 (TIMP3) in sporadic and familial keratoconus. METHODS: Mutational analysis of the five genes was performed by sequencing and fragment analysis in a large cohort of 302 Italian patients, with a diagnosis of keratoconus based on clinical examination and corneal topography. The variants identified in VSX1 and SPARC were also assessed in the available relatives of the probands. RESULTS: A novel mutation p.G239R and previously reported mutations were found in VSX1. Novel and already reported variants were identified in SPARC and SOD1, whose pathogenic significance has not been established. No pathogenic variants have been identified in LOX and TIMP3. CONCLUSIONS: Molecular analysis of the five genes in a cohort of 225 sporadic and 77 familial keratoconus cases confirms the possible pathogenic role of VSX1 though in a small number of patients; a possible involvement of LOX and TIMP3 could be excluded; and the role played by SOD1 and SPARC in determining the disease as not been definitively clarified. Further studies are required to identify other important genetic factors involved in the pathogenesis and progression of the disease that in the authors' opinion, and according with several authors, should be considered as a complex disease.

A new transepithelial phototherapeutic keratectomy mode using the NIDEK CXIII excimer laser.

PURPOSE: To evaluate epithelial healing, postoperative pain, and best spectacle-corrected visual acuity (BSCVA) after transepithelial photorefractive keratectomy (PRK) performed with a new phototherapeutic keratectomy (PTK) mode using the NIDEK CXIII excimer laser. METHODS: Fifteen eyes from 10 patients with myopia underwent transepithelial PRK using a multistage program to perform PTK followed by PRK. The PTK incorporated Flex Scan, which accounts for the loss of radial ablation efficiency on the peripheral cornea. The epithelium was removed with the excimer laser by monitoring the disappearance of blue fluorescence during the ablation. Epithelial healing was evaluated by taking slit-lamp photographs every 24 hours until complete reepithelialization. Postoperative pain was measured according to the Faces Pain Rating Scale. All outcomes are reported for 3 months postoperatively. Haze was graded by two ophthalmologists, each masked to the other's result. RESULTS: Mean reepithelialization took 3.50+/-0.85 days, mean pain score was 3.00+/-1.20, and BSCVA was 20/20 for 9 eyes, 20/30 for 3 eyes, and 20/40 for 3 eyes. All patients had haze below grade 2. CONCLUSIONS: The outcomes of the preliminary study show that the incorporation of the Flex Scan algorithm in the PTK mode is as safe and effective as conventional PTK algorithms. The primary advantage of this new PTK mode may be more consistent epithelial removal. Additional studies are needed to determine long-term outcomes.

Arcuate keratotomy for high postoperative keratoplasty astigmatism performed with the intralase femtosecond laser.

PURPOSE: To evaluate the refractive and keratometric effect of arcuate keratotomy performed using the IntraLase femtosecond laser (Abbott Medical Optics) in patients with high postoperative keratoplasty astigmatism. METHODS: Nine eyes of nine patients (mean age 45 +/- 7.5 years; mean spherical equivalent refraction -2.50 +/- 3.60 diopters [D]) who had undergone a penetrating keratoplasty were considered. The subjective refraction was measured, and corneal thickness and keratometric parameters were calculated by the Pentacam (Oculus Optikgeräte). All uncomplicated surgeries were performed with the IntraLase femtosecond laser. Paired 70 degrees arc length incisions were performed at 80% depth of the corneal thickness. The mean optical zone was 5.9 mm. The side cut was 90 degrees. All incisions were performed in the graft itself. Mean change in best spectacle-corrected visual acuity (BSCVA), refractive and keratometric astigmatism, and spherical equivalent refraction was evaluated. Follow-up was 3 months. Refractive and keratometric data were analyzed using vector analysis as described by Alpins. A paired Student t test was used to compare preoperative and 3-month postoperative data. A P value <.05 was considered significant. RESULTS: Mean preoperative BSCVA was 20/30, increasing to 20/25 postoperatively (P > .05). The mean refractive astigmatism decreased by 6.00 D (P < .05), whereas the mean keratometric value decreased by 4.60 D (P < .05). The mean spherical equivalent refraction did not change significantly. The surgical vectors in the refractive and keratometric analysis were calculated, showing good predictability. CONCLUSIONS: Arcuate keratotomy performed with the IntraLase femtosecond laser could be an effective, safe, and relatively predictable treatment of high postoperative keratoplasty astigmatism.