Journal - American Intra-Ocular Implant Society最新文献

To study the effectiveness of the neodymium:YAG laser for secondary posterior capsulotomy, 100 limbal needle-knife discissions were compared to 100 YAG discissions. After a one-year follow-up, the “post-knife” and “post-YAG” visual acuities were compared to (1) the prediscission vision, and (2) the best vision achieved following cataract surgery prior to posterior capsule opacification. Additional comparisons rated the relative “success” of the two procedures in producing improved visual acuity. When compared to best post-cataract vision, the results at one year showed knife discission to be a success in 94.6% of all cases; the YAG, in 80% of all cases. When patients with preexisting pathology were eliminated from the comparison (there was a higher percentage of preexisting pathology in the YAG group), the knife discissions were successful in 98.5% of the cases, the YAG in 84.6%. The patients in the knife group also recovered their best visual acuity more promptly and completely than did those in the YAG group and had a lower incidence of complications.

The first use of a new irrigation/aspiration tip resulted in a posterior capsular rupture. Scanning electron microscopy of the tip revealed burrs on the aspiration portion of the tip, as well as poor finishing around the irrigation ports.

A method is described for determining the power of an intraocular lens (IOL) within the eye by measuring the horizontal dimension of the corneal reflected image (Purkinje-Sanson I) and the anterior IOL reflected image (Purkinje-Sanson III) as seen through a standard slitlamp with a target positioned 68 mm anterior to the focal plane of the biomicroscope. The horizontal K-reading (at 180°) and the anterior chamber depth are the two other parameters necessary to calculate the exact power of the IOL. Seven tables that use these four measurements have been provided, eliminating the need for complex calculations. To determine the accuracy of this technique, ten implanted IOLs ranging from 9 diopters (D) to 27 D were chosen and their powers calculated; these calculated values were then compared to the actual IOL powers. The largest error was 0.5 D and the average error was 0.17 D.

We present the pathologic and scanning electron microscopic findings from 44 semiflexible, all polymethylmethacrylate, anterior chamber intraocular lenses (IOLs). These IOLs, which have round, small diameter, closed loops were removed following a variety of complications, including uveitis and/or the uveitis-glaucomahyphema syndrome, secondary glaucoma, pseudophakic bullous keratopathy, cystoid macular edema, erosion into uveal tissue (with and without oval pupil), and iris neovascularization. Over 200,000 of these lens styles have been implanted. Even though the number of these IOLs accessioned in our laboratory is small, we feel this analysis documents some of the problems that may be encountered with this IOL design. Many of the complications documented in our series resulted in severe visual loss. In addition to tissue damage that appeared secondary to the mechanical tissue-to-implant interface, other causes of complications included variations in surgical technique, implantation into eyes with preexisting disease (including eyes that had undergone previous surgery), and damage to tissue that occurred during IOL removal.

A technique using the Meditec OPL-3 YAG laser for anterior capsulotomy just prior to planned extracapsular cataract surgery is presented. A review of 1,108 cases showed this technique to have a low complication rate. Compared to conventional anterior capsulotomies, it is the author's opinion that this method gives increased operative control, shortens time in the operating room, and is a help with in-the-bag intraocular lens placement.

An irrigation/aspiration (I/A) system for cortex removal has been developed. It consists of an I/A cannula, connecting silicone tube, a handle with an aspiration cut-off device for the silicone tube, and an aspirating device. The aspirating pressure is produced by a fixed syringe, the cylinder of which is pulled by a weight. In addition, the aspirating system can be equipped with a small battery-operated pump. The aspiration cut-off device located in the handle enables aspiration with one hand so the other hand is free for another instrument. Flushing back, if necessary, is possible.

We studied the effects of the Nd:YAG laser on the blood-aqueous barrier following photodisruption of the anterior capsule, posterior capsule, and mid-vitreous of the albino rabbit eye with fluorophotometric techniques using albumin-bound fluorescein. After photodisruption of the anterior capsule, fluorescence appeared in the anterior chamber at 30 minutes, peaked at two hours, and decreased almost to baseline values by 24 hours. No fluorescence was noted at any time in contralateral control eyes or in eyes receiving photodisruption of the posterior capsule or mid-vitreous.