Corneal collagen cross-linking to stop corneal ectasia exacerbated by radial keratotomy.
OBJECTIVE
To assess the efficacy of riboflavin ultraviolet A (UV-A) corneal collagen cross-linking in the management of keratoconic corneal ectasia exacerbated by radial keratotomy (RK).


METHODS
A patient with progressive corneal ectasia and hyperopic shift, occurring 10 years after RK performed in the left eye, was treated with riboflavin UV-A corneal collagen cross-linking according to the Siena protocol: Pilocarpin 0.1% drop (1 hour before), lidocaine 4% drops 15 minutes before, mechanical scraping of epithelium (9-mm-diameter area), preirradiation stromal soaking for 10 minutes in riboflavin 0.1%-dextrane 20% (Ricrolin; Sooft Italy) applied every 2 minutes, and 30 minutes of total exposure (6 steps of 5 minutes) to solid-state UV-A illuminator (Caporossi, Baiocchi, Mazzotta Vega X linker; CSO Opthalmics, Florence, Italy), energy delivered 3 mW/cm, and irradiated area 9 mm in diameter.


RESULTS
After the operation, uncorrected visual acuity and best spectacle-corrected visual acuity improved from 0.2 to 0.6 and from 0.3 to 0.8 Snellen lines, respectively, in a 12-month follow-up. Improved topographical K readings and corneal symmetry index were also recorded starting from the first postoperative month and continuing thereafter. No adverse effects were recorded after treatment.


CONCLUSIONS
Riboflavin UV-A-induced corneal cross-linking seems to be a promising surgical option in the management of unstable corneal ectasia exacerbated by RK, particularly in eyes with preexisting keratoconus. A large cohort and longer follow-up are needed to determine its long-term efficacy in this clinical setting.
Mazzotta
Cosimo
C
Department of Ophthalmology, Siena University, Italy. cgmazzotta@libero.it
Baiocchi
Stefano
S
Denaro
Rosario
R
Tosi
Gian Marco
GM
Caporossi
Tomaso
T
D000328:Adult; D003094:Collagen / Q000378:metabolism* / Q000528:radiation effects*; D003315:Cornea / Q000378:metabolism*; D003316:Corneal Diseases / Q000150:complications / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology; D004108:Dilatation, Pathologic / Q000188:drug therapy; D005139:Eyeglasses; D006801:Humans; D007640:Keratoconus / Q000150:complications; D007646:Keratotomy, Radial / Q000009:adverse effects*; D008297:Male; D010778:Photochemotherapy; D017319:Photosensitizing Agents / Q000627:therapeutic use*; D012256:Riboflavin / Q000627:therapeutic use*; D014466:Ultraviolet Rays; D014792:Visual Acuity / Q000187:drug effects / Q000528:radiation effects
D017319:Photosensitizing Agents; D003094:Collagen; D012256:Riboflavin