Posters

Managing keratoconic ectasia with topography-guided, partial cornea regularization, in conjunction with high-fluence cross-linking (the Athens protocol), based on a 750Hz excimer laser platform

Poster Details

First Author: D.Alexopoulos GREECE

Co Author(s):    S. Al-Bayati   G. Asimellis   A. Kanellopoulos        

Abstract Details

Purpose:

To compare the safety and efficacy of topography - guided excimer laser normalization, combined with high-fluence CXL, in the management of keratoconus with the Athens Protocol (AP) employing a refractive excimer laser operating at 750Hz repetition rate.

Setting:

Laservision.gr Eye Institute, Athens, Greece

Methods:

Placido and/or combined Placido (Keratron)with Scheimpflug corneal imaging topography (Sirius 3D Scheimpflug Camera, CSO, Scandicci Firenze, Italy) was employed to plan partial thickness excimer laser ablation aiming to reduce anterior cornea irregularity, to be followed by high-fluence collagen cross-linking (AP procedure). The Schwind Amaris (Schwind eye-tech-solutions GmbH, Kleinostheim, Germany) excimer laser, running at a 750Hz repetition rate was employed to provide excimer laser ablation. 1)For CXL one of 2 methods were used:Pulsed (1 second on-off) high-fluence UVA was administered at 30mW/cm2 for 8 minutes for a total of 7.2 J/cm2 energy. 2) 18mW/cm2 CW for 6 min for 6.4J/cm2 50 consecutive keratoconic eyes were studied pre-operatively and 1, 3, 6, and 12-months postoperatively for visual acuity, keratometry, and anterior surface corneal indices. The one-year changes in visual acuity, keratometric, and anterior-surface topometric indices were monitored.

Results:

CDVA changed from 0.65 ± 0.23 to 0.84±0.20, K1 (flat keratometry) changed from 45.5±3.82D to 43.02±3.9, (-2.18 D flattening), and K2 (steep) changed from 48.70±4.06 D to 45.85±4.94 D, (-2.8 D flattening). The index of surface variance (KVf) was reduced to from an average of 25.6±10.9 μm to 13.5±8.7. For group B, the index of ISV was reduced to -18.35% and the index of IHD to -39.03%. These reductions indicate a less irregular corneal surface and a ‘flatter' cone.

Conclusions:

The Athens Protocol procedure applied with a 750Hz repetition rate excimer laser, demonstrates safe and notable refractive, keratometric and topometric results. The observed changes, as well as keratometric flattening and topometric improvement are suggestive of the overall postoperative improvements. FINANCIAL INTEREST: One of more of the authors... travel has been funded, fully or partially, by a company producing, developing or supplying the product or procedure presented