Abstract
Purpose: :
To introduce a simultaneously delivered therapy that both corrects aberrations and stiffens the corneal collagen of eyes with progressive keratoconus.
Methods: :
Two patients with progressive keratoconus underwent partial treatment with topographic customized photorefractive keratectomy (PRK) in the worse eye, and then were immediately cross-linked with riboflavin 0.1% drops every 5 minutes while exposed to 365 nm ultraviolet (UVA) light at 3.0 mW/cm2 for 30 minutes. Pre and postoperative testing included manifest and cycloplegic refraction, corneal topography, pachymetry and slit lamp examination of corneal clarity with followup at 3, 6 and 12 months.
Results: :
Both treated eyes experienced rapid healing of the epithelial surface within 5 days and progressive improvement of vision. In the first case, partial treatment primarily reduced the astigmatism and aberrations, leading to a residual myopic refraction which allowed for successful wear of a soft contact lens. In the second case, laser treatment led to a near emmetropic refraction with an uncorrected visual acuity of 20/20 at 3 months and beyond. In both cases, the outcome remained stable with no shift in refraction or topography over the first postop year.
Conclusions: :
Topo-guided PRK followed by riboflavin/UVA cross-linking is a safe and effective therapy that both halts the progression of keratoectasia and significantly reduces the spherocylindrical refraction and aberrations to improve the visual function of patients with progressive keratoconus.
Keywords: keratoconus • refractive surgery • cornea: stroma and keratocytes