The Athens Protocol (Kanellopoulos): Topography-Guided PRK Combined with Accelerated CXL for Keratoconus

In virgin laser surgery, the laser aims to eliminate all refractive error. In the Athens Protocol, the excimer laser aims purely at Topographic Regularization:

$$\text{Target: } \mathbf{\text{Reduce Vertical Coma } (Z_3^{-1}) \text{ and Regularize Cone Axis}} \implies \mathbf{\text{Max Stromal Depth } \le 50\ \mu\text{m}}$$

By limiting excimer laser photoablation to a strict maximum of $45\text{ to } 50\ \mu\text{m}$, the procedure preserves precious structural corneal thickness, smoothing the peak of the cone while leaving adequate bed for cross-linking.

The Athens Protocol is executed in a single surgical session:

1. Step 1: Phototherapeutic Keratectomy (PTK, $50\ \mu\text{m}$): Laser-clears the epithelium smoothly over a $6.5\ \text{mm}$ zone.
2. Step 2: Topography-Guided PRK (T-CAT): Removes up to $45\ \mu\text{m}$ of stromal peak tissue based on topography elevation maps.
3. Step 3: Mitomycin-C 0.02% (20 seconds): Suppresses keratocyte myofibroblast scarring.
4. Step 4: Accelerated CXL ($10\ \text{mW/cm}^2 \times 10\ \text{minutes}$, or $30\ \text{mW/cm}^2 \times 3\ \text{minutes}$): Floods the smoothed bed with riboflavin and locks in structural stability permanently.

Ten-year published clinical data on over 1,000 eyes reveals that over $85\%$ of patients gain 3 to 6 lines of uncorrected Snellen acuity, transforming legally blind, contact-lens-intolerant keratoconic eyes into functional spectacle-corrected vision.