Opto-functional results in keratoconus patients after intrastromal keratoplasty

Abstract

Analysis of quantitative and qualitative characteristics of vision in patients with stage II and III keratoconus who underwent intrastromal allokeratoplasty. The study included 15 patients (15 eyes) with stage II-III KC (Amsler-Krumeich classification) aged 17 to 38 years old (28.8±6.2). All patients underwent intrastromal keratoplasty with implantation of an allograft in the form of a wide incomplete ring. The following parameters were assessed before and 6 months after surgery: distance VA with and without correction, near VA with and without correction, VA with glare effect, high-order aberrations (HOA), thickness of the tear film lipid layer, spatial contrast sensitivity (SCS) under photopic and mesopic conditions with light filters, reading speed. VA without correction increased from 0.15 to 0.7; with correction from 0.35 to 0.7. The glare effect with varying degrees of illumination did not affect VA either before or after surgery. Statistically significant changes were observed when comparing the aberrations «coma», «spherical», «trefoil» before and after the intervention, they became inverted. The thickness of the tear film lipid layer did not change significantly when comparing pre- and postoperative data. The use of light filters (orange, yellow) did not lead to significant changes in the VA and SCS under photopic and mesopic conditions. The use of a wide intrastromal allograft to correct deformity and stabilize the cornea in keratoconus improves the patients' quality of vision and visual performance.