Endothelial Cell Density and Contrast Sensitivity in Patientsafter Deep Lamellar Keratoplasty

Abstract

Abstract: : Purpose:Deep Lamellar Keratoplasty (DLK) has made resurgence in recent years for the treatment of corneal pathology in eyes with healthy endothelium. Preservation of patients own endothelium has the obvious advantage of protection from endothelial rejection. There is, however, theoretical risk of damage to the endothelium at the time of surgery due to manipulation of the thin posterior lamella containing the endothelium. This study looks at the endothelial cell density following DLK and presents results of contrast sensitivity and glare testing in these patients. Methods:All patients having DLK at our institute were included in the study. Primary pathology, pre and postoperative visual acuity, refractive errors and complications were recorded. Endothelial cell density was measured using a non contact specular microscope. Contrast sensitivity was tested using the Pelli–Robson chart and effect of glare on contrast sensitivity was measured using Brightness Acuity Tester. Results:To date 21 eyes of 20 patients have been reviewed. There were 14 (70%) males and 6(30%) females. Mean age was 36 years (range, 16 – 68 years) with a mean follow up of 7 months (range, 3 – 18 months). Primary pathology consisted of 13 (62%) eyes with keratoconus, and 8 (38%) eyes with corneal scars of various other causes. Visual acuity was ≤6/36 in 85% of eyes preoperatively. All eyes had improved vision postoperatively with 85% achieving ≥6/9 best correct vision. Mean spherical error and astigmatism at last follow up was 2.9 and 2.7 diopters respectively. Complications included perforations (19%) and post operative iris atrophy and lens opacity (14%). No rejection episodes have been seen to date. Mean endothelial cell density was 2553/mm² at last follow up. Mean contrast sensitivity was 0.75 and the mean glare effect was 0.025 which represents no dropped lines in contrast sensitivity. Conclusions:DLK can achieve excellent results for visual rehabilitation in this group of patients. Refractive errors and astigmatism are comparable to penetrating keratoplasty. Endothelial cell count postoperatively is encouraging as is the absence of rejection episodes. The lamellar interface does not appear to significantly affect contrast sensitivity or cause a glare effect.

Keywords: cornea: clinical science • cornea: endothelium • keratoconus