The new modified STARE-X EVO protocol for keratoconus: two years' results of full customised transepithelial ablation and pachymetry-guided accelerated cross-linking

Session Details

Session Title: Corneal Cross-Linking

Session Date/Time: Monday 16/09/2019 | 16:00-18:00

Paper Time: 16:30

Venue: South 5

First Author: : M.Rechichi ITALY

Co Author(s): :    C. Mazzotta   F. Marco   A. Meduri   V. Romano   D. Borroni   M. Zagari              

Abstract Details

Purpose:

To evaluate the changes in refractive outcomes, corneal aberrations, and biomechanics after selective transepithelial topography-guided photorefractive keratectomy with dynamic cyclotorsion control (DCC) centred on cone apex and guided by epithelial mapping and combined with pachymetry-guided accelerated corneal collagen cross-linking (ACXL) based on residual stromal thickness.

Setting:

Multi-centre retrospective study conducted by three surgical centres: Centro Polispecialistico Mediterraneo, Sellia Marina, Italy, Poliambulatorio Centro Europeo, Acicastello, Italy, Siena Crosslinking Center, Siena, Italy.

Methods:

100 eyes were treated. Examinations included measurement of UDVA, CDVA, corneal tomography and corneal wavefront aberrometry pre-op and at months 1, 3, 6, 12, and 24. The platform was a Schwind Amaris 750s platform linked with Scheimpflug tomography and KXL (Avedro) parameters were: optic zone < 6 mm, oct-guided epithelium removal, stromal ablation depht ≤ 50 micron. The treatment was shifted toward the cone apex at 1 mm from corneal vertex measured on topography then CXL was performed using 15 mw/5.4J pulsed 2:1 if RST > 450 micron and 30 mw/7.2J if RST < 400 micron.

Results:

Pre-op corneal thinnest point measured by OCT was 418 µm (range 398- 461 µm). Mean follow-up time was 24 ± 5 months. No intraoperative complications were observed. Corneal demarcation line was observed in all cases after one month after (range 190 to 250 µm). After 24 months UDVA improved in both group from 0.85 Logmar to 0.65 and BDVA significantly improved from 0.35 Logmar to 0.12. Average gain in visual acuity was 2.2 lines. Kmax flattening of more than 3 diopter occurred in 100%. The HOAs RMS and coma also demonstrated a statistically significant decrease.

Conclusions:

The new Stare X EVO protocol was effective for corneal reshaping in patients with significant ectasia in which spectacle correction is unable to correct high irregular astigmatism and a comfortable contact lens fitting sometimes is hard to reach. The topoguided apex-centred ablation and epithelial map-guided epithelial trend removal improved the efficiency of original protocol reducing stromal ablation on the apex and outside corneal area. The following CXL treatment will be forced to be focused mainly on corneal ectasic area inducing a localised long term flattening.

Financial Disclosure:

None