Corneal Ectasia · A Comprehensive Evaluation · Advanced Treatment & Surgery
Corneal Reshaping
After CXL has stabilized a keratoconic cornea, some patients continue to experience significant irregular astigmatism that limits best-corrected visual acuity or impairs contact lens tolerance. Corneal reshaping procedures aim to regularize the corneal surface — improving the quality of vision achievable with or without optical correction.
— Procedures
Advanced Corneal Reshaping
CAIRS
Corneal Allogenic Intrastromal Ring Segments (CAIRS)
Also known as CTAK (Corneal Tissue Addition Keratoplasty), curved ring segments of irradiated sterile corneal stromal tissue are implanted within the existing corneal stroma at approximately 70% depth, via femtosecond laser-created channels. They mechanically flatten and regularize the central corneal surface by redistributing the biomechanical forces within the stroma.
Indications: Moderate keratoconus with residual irregular astigmatism after CXL; patients unable to tolerate contact lenses due to lens instability on the irregular corneal surface. CAIRS may improve contact lens fit and may improve spectacle-corrected visual acuity. They are reversible and removable.
Limitations: CAIRS do not eliminate the need for contact lenses in most cases; they optimize the corneal surface to allow better optical correction. They are not appropriate for advanced scarring or corneas below adequate thickness thresholds.
TG-PRK with CXL
Topography-Guided PRK with Corneal Cross-linking
Improving vision with keratoconus often requires a two-fold approach: smoothing the irregular cornea and stopping the disease from progressing. We target both goals by pairing Topography-Guided PRK (a highly customized laser treatment) with Corneal Cross-Linking (CXL).
Depending on your specific corneal health, this is achieved through one of two approaches:
The Athens Protocol (Simultaneous Treatment): This all-in-one procedure simultaneously reshapes and strengthens the eye. First, using detailed 3D topographic maps, a customized laser (TG-PRK) gently smooths the steep, irregular areas of the cornea. Immediately after, accelerated CXL is applied to reinforce the cornea's structural integrity and halt further disease progression.
The TOPOLink Protocol (Staged Approach): This approach is designed for patients who have previously undergone CXL and have documented, long-term stability. Once we confirm the keratoconus is halted, TG-PRK is performed as a standalone procedure. It targets specific areas of steepening to reduce irregular astigmatism and improve functional, everyday vision.
Patient Candidacy and Safety While these protocols offer remarkable visual improvements, they are not appropriate for every patient. Because the laser reshaping process involves removing microscopic amounts of tissue, a rigorous assessment of your residual corneal thickness and overall eye health is required to ensure your eyes can safely and predictably accommodate these procedures.
The appropriate reshaping procedure depends on the degree of irregular astigmatism, residual corneal thickness, the extent of prior CXL, and whether the goal is to improve spectacle or contact lens correction, or to achieve acceptable unaided vision.
— Keratoconus
Corneal Surface Regularization after Stabilization — a customized treatment plan
Reshaping is considered only after CXL has achieved documented corneal stability. Dr. Hu evaluates topography, pachymetry, and contact lens tolerance before recommending any reshaping procedure.