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

Abstract

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.