Stability of simultaneous topography-guided photorefractive keratectomy and riboflavin/UVA cross-linking for progressive keratoconus: case reports.
OBJECTIVE
To follow the stability of a simultaneously delivered therapy that corrects aberrations and stiffens the corneal collagen of eyes with progressive keratoconus.


METHODS
Two patients with progressive keratoconus underwent partial treatment (70% cylinder and sphere up to 50-μm central depth) with topographic customized photorefractive keratectomy (PRK) using the T-CAT module of the ALLEGRETTO WAVE Eye-Q excimer laser (Alcon Laboratories Inc), and then immediate corneal collagen cross-linking (CXL) with riboflavin 0.1% drops every 2 minutes while exposed to mean 365-nm ultraviolet A (UVA) light at 3.0 mW/cm² for 30 minutes (the Athens Protocol). Pre- and postoperative evaluations included manifest and cycloplegic refraction, Scheimpflug corneal tomography and pachymetry, and slit-lamp examination of corneal clarity with a minimum follow-up of 30 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 reduced the astigmatism and aberrations, allowing for successful soft contact lens wear at 3 months. Follow-up at 13, 19, 30, and 36 months showed progressive reduction of refractive myopia and keratometric power. In the second case, laser treatment led to a near emmetropic refraction with an uncorrected visual acuity of 20/20 at 3 months, which remained unchanged at 21 and 30 months postoperative.


CONCLUSIONS
Partial topography-guided PRK followed by riboflavin/UVA CXL is a safe and effective therapy that halts the progression of keratoectasia and reduces the spherocylindrical refraction and aberrations to improve the visual function of patients with progressive keratoconus. Stability and progressive improvement over time is observed, although limitations may exist for steeper and thinner corneas.
Krueger
Ronald R
RR
Cole Eye Institute, Cleveland Clinic Foundation, Cleveland, Ohio 44195, USA. krueger@ccf.org
Kanellopoulos
A John
AJ
D003094:Collagen / Q000378:metabolism; D003131:Combined Modality Therapy; D003319:Corneal Stroma / Q000378:metabolism; D019781:Corneal Topography; D003432:Cross-Linking Reagents / Q000627:therapeutic use*; D005500:Follow-Up Studies; D006801:Humans; D007640:Keratoconus / Q000188:drug therapy / Q000503:physiopathology / Q000601:surgery / Q000628:therapy*; D054018:Lasers, Excimer / Q000627:therapeutic use; D008297:Male; D018903:Photorefractive Keratectomy / Q000379:methods*; D017319:Photosensitizing Agents / Q000627:therapeutic use*; D012029:Refraction, Ocular / Q000502:physiology; D012256:Riboflavin / Q000627:therapeutic use*; D014466:Ultraviolet Rays; D014792:Visual Acuity / Q000502:physiology; D055815:Young Adult
D003432:Cross-Linking Reagents; D017319:Photosensitizing Agents; D003094:Collagen; D012256:Riboflavin