Effect of collagen implants in the reduction of high astigmatism induced by penetrating keratoplasty.

PURPOSE: To evaluate the insertion of EagleVision collagen plugs as spacers between corneal relaxing incisions to correct significant residual astigmatism after penetrating keratoplasty (PKP). SETTING: Ambulatory Clinic of the Department of Ophthalmology, Rhode Island Hospital, and Rhode Island Eye Institute, Providence, Rhode Island, USA. METHODS: This study comprised 8 patients meeting the following criteria: had previous PKP, had at least 5.0 diopters of residual keratometric astigmatism with all the sutures removed, were free from eye infection, and were at least 21 years old. All 8 patients had unilateral high astigmatism after PKP. Four eyes were randomly assigned to the control group of astigmatic keratectomy (AK) incisions without the collagen implants and 4 eyes to the experimental group of AK incisions with collagen implants. RESULTS: Best corrected visual acuity 1 day, 3 weeks, and 1, 2, and 6 months after AK showed decreased astigmatism in all the patients who had the relaxing incisions. The amount of astigmatism was lower in patients who received AK incisions with collagen implants (P < .28). Minimal adverse effects were noted. CONCLUSION: Implanting a biocompatible material into AK incisions to correct post-PKP astigmatism appears to be safe and may enhance astigmatic correction.

Preservation of vision through Weiss ring after dense vitreous hemorrhage.

PURPOSE: To report an unusual case of retained vision through a Weiss ring in the setting of dense vitreous hemorrhage. METHOD: Case report of a 55-year-old woman with a 23-year history of type 1 diabetes mellitus who presented with new onset of blurred vision in the left eye as a result of a dense vitreous hemorrhage. RESULTS: The patient had received full scatter laser photocoagulation for proliferative diabetic retinopathy in the right eye several years earlier and reported previous resolving episodes of vitreous hemorrhage in the left eye. Best-corrected visual acuity in the left eye was hand motions at 3 feet. However, with careful head positioning visual acuity improved to 20/40 through a small clear central island. Examination of the left fundus showed a dense vitreous hemorrhage with a clear, mobile opening in the posterior hyaloid corresponding to the Weiss ring. The retina could be partially visualized only through the area of the Weiss ring. CONCLUSIONS: This unusual case demonstrates the anatomical relationship between the posterior hyaloid and Weiss ring.

Cataracts, bilateral macular holes, and rhegmatogenous retinal detachment induced by lightning.

PURPOSE: To report ocular injuries, including a unilateral rhegmatogenous retinal detachment, induced by lightning. METHOD: Case report. A 30-year-old man was injured by lightning. RESULTS: The patient developed a severe decrease in visual acuity in both eyes, an afferent pupillary defect in his left eye, bilateral cataracts, posterior vitreous detachments, macular holes, and an inferotemporal retinal detachment with an associated flap retinal tear in his left eye. CONCLUSIONS: This is a case of bilateral cataracts, posterior vitreous detachments, macular holes, and a unilateral retinal detachment associated with lightning. We postulate that the heating of the retinal surface, the concussive forces on the eye, and a sudden lateral contraction of the attached vitreous resulted in bilateral posterior vitreous detachments and a unilateral peripheral retinal break.

Expression of fibronectin isoforms in rat cornea after an epithelial-scrape wound.

The polymerase chain reaction (PCR) technique was used to analyze the presence or absence of the EIIIB and V region fibronectin (FN) mRNA isoforms, generated by alternative splicing of the FN primary mRNA transcript during epithelial wound healing, in a rat cornea wound model. A central 4mm area of the cornea was denuded of epithelium. At 5, 15, 30, 45 minutes, 1, 2, 4, 8, 24, 48 hours, and 4 days post-wounding, the rats were euthanized and a 6mm diameter full thickness corneal biopsy was performed. cDNA was synthesized from extracted RNA, and specific FN sequences were amplified by PCR as directed by different sets of 5' and 3' primers specific for the alternatively spliced EIIIB and V region domains. Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) mRNA expression was used to normalize the data. PCR products were analyzed by agarose gel electrophoresis and the identity of the bands were confirmed by direct nucleotide sequencing. The alternatively-spliced EIIIB and all three alternatively spliced isoforms of V domain FN mRNA were observed post-wounding. Similarly, in normal tissue, EIIIB and all three V region alternatively spliced FN isoforms were expressed. These findings suggest that in situ synthesis of cellular associated EIIIB FN and FN V domain may play a role in corneal wound healing.