Visian toric implantable collamer lens for correction of compound myopic astigmatism.

PURPOSE: To assess the safety, efficacy, predictability, and stability of a toric posterior chamber phakic intraocular lens for the correction of myopia with astigmatism. METHODS: A non-randomized, retrospective analysis of 63 eyes of 36 patients with a minimum follow-up of 6 months was performed. The STAAR Toric Implantable Collamer Lens (TICL) was implanted under topical anesthesia through a 3-mm temporal clear corneal incision. Mean preoperative spherical equivalent refraction was -10.71+/-3.55 diopters (D). Median preoperative best spectacle-corrected visual acuity (BSCVA) was 20/25, with a mean sphere of -8.78 D (range: -2.50 to -16.50 D) and mean cylinder of 3.60 D (range: 1.25 to 7.00 D). Postoperative parameters were analyzed at different time points, and vector analysis was performed to calculate surgically induced astigmatism. RESULTS: Fifty-nine (93.6%) eyes had a spherical equivalent refraction within +/-1.00 D and 52 (82.5%) eyes were within +/-0.50 D of emmetropia. Median postoperative uncorrected visual acuity was 20/25 and BSCVA was 20/20. Preoperative keratometric astigmatism was 1.99@178.2 vs 1.82@178.6 postoperative keratometric astigmatism, most likely due to the surgical incision. Preoperative refractive astigmatism was 2.17@93 whereas postoperatively it reduced to 0.38@99.6. No eye lost 2 or more lines of Snellen BSCVA. Twenty-two (34.9%) eyes gained 2 or more Snellen lines of vision. Preoperatively, 45 (71.4%) eyes had a BSCVA of 20/30 or better, whereas 60 (95.2%) eyes were within this range of BSCVA after surgery. The TICL demonstrated good rotational stability in this study. CONCLUSIONS: Implantation of the STAAR TICL was an effective, predictable, and safe method for correction of high myopia and myopic astigmatism as shown in this retrospective observational series.

Comparative study of ablation profiles of six different excimer lasers.

PURPOSE: To compare the morphological features of photorefractive ablations produced by six different excimer lasers. METHODS: A spherocylindrical photoablation (-2.00 -2.00 x 90 degrees; 6-mm optical zone) was performed on regular fluence plates with six excimer lasers: Bausch & Lomb Technolas 217C, Schwind Esiris, Kera Technology Isobeam D200, Ladarvision 4000, Zeiss Meditec MEL 70 G-Scan, and Visx Star S3. Morphometric analysis of the fluence plates provided superficial measurements of the ablated areas. RESULTS: Two areas were identified visually: a central area with a complete ablation of the metallic surface layer and a surrounding area with a partial ablation. The dimensions of the ablated areas were highly variable in the lasers tested. The major differences appeared in the total ablated area (ranging from 38.55 mm2 [Schwind] to 81.94 mm2 [Bausch & Lomb] and in the peripheral to total area ratio (ranging from 36.95% [Schwind] to 59.51% [Ladarvision]). CONCLUSION: Large differences appeared in the superficial dimensions and contours of the ablations produced by different excimer lasers for the treatment tested in this study. It remains unknown how these different ablation patterns induce the same optical correction, but we assume that the depth of the ablation compensates for the differences in the surface extension of the ablated areas.

Silicone posterior chamber phakic intraocular lens dislocated into the vitreous cavity.

PURPOSE: To report two highly myopic patients with silicone posterior chamber phakic intraocular lenses (Phakic Refractive Lens; CIBA Vision, Duluth, Ga) that luxated into the vitreous cavity without history of ocular trauma. METHODS: Two patients with posterior chamber phakic intraocular lenses (PIOLs) that luxated into the vitreous cavity of the right eye were examined. Each eye underwent pars plana vitrectomy and removal of the posterior chamber PIOL under retrobulbar anesthesia. RESULTS: Both patients were treated successfully. In the first patient, the posterior chamber PIOL luxated into the anterior vitreous cavity whereas in the second patient, the posterior chamber PIOL lay on the posterior pole. No ocular complications developed postoperatively. CONCLUSION: Luxation into the vitreous cavity is a rare, but potentially severe complication of posterior chamber PIOL refractive surgery in highly myopic eyes. Successful management includes pars plana vitrectomy and removal of the posterior chamber PIOL.