Posters

Advanced procedure in accelerated pulsed CXL for keratoconus

Poster Details

First Author: R. Fasciani ITALY

Co Author(s):    E. Zampulla   O. Caporossi   A. Caporossi              

Abstract Details

Purpose:

The amount of cross-linked cornea achieved by conventional CXL and Accelerated CXL have been directly evaluated and measured in vivo in humans by the detection of demarcation line (DL). Various studies have demonstrated significant difference in the depth of DL among the conventional and accelerated Cross Linking protocols. We present a new protocols of epithelium off CXL using pulsed light accelerated CXL and the results of demarcation line evaluation.

Setting:

Institute of Ophthalmology, Catholic University of “Sacro Cuore”, A. Gemelli Policlinic Foundation, Rome

Methods:

Seventeen eyes of 16 patients with progressive keratoconus (mean age 21.8 years ± 6,8SD ) affected by progressive keratoconus were submitted to Pulsed Accelerated epi-off (PA) CXL procedure with a disposable solution of Riboflavin 0.1% and using 30 mW/cm2 Avedro KXL I for a total of 15 minutes of UV A irradiantion in pulsed mode (2 second on – 1 second off). This intensity corresponds to a total dose energy of 7.2 J. High resolution acquisition of AC OCT were used to evaluate the depth of demarcation line of the treated corneas in each patients at 30 days after treatments.

Results:

No persistent early side effects were observed after the new protocol of PA CXL procedure except an early and transient stromal oedema. AC OCT evaluation shown a mean maximum depth of demarcation line at about 343 µm ± 30,23 SD (range 288/406µm) at the central cornea and 286,8 µm ± 40,44 SD in the paracentral area of the keratoconus. The AC OCT scans showed well the higher and uniform density of the corneal stroma above the demarcation line in all the treated patients.

Conclusions:

the depth reached by accelerated CXL is considerably less than conventional epi-off CXL. Oxygen supplementation during the procedure, making a pulsed illumination, may increase the amount of crosslinked corneal stroma. If the penetration of the treatment is inversely proportional to UV-A power and directly proportional to exposure time, increasing exposure time augments the treatment penetration and photo-oxidative effects. Using our PA CXL protocols with 2 minutes of UV A emission and 1 minutes of beam off, the AC OCT evaluation shown a result in DL depth that seems to be very similar to those observed in the conventional epi-off CXL.

Financial Disclosure:

NONE