In keratoconus with progression and corneal thickness less than 50 microns, which treatment is indicated?

• A. Corneal cross-linking (CXL)
• B. Penetrating keratoplasty
• C. Orthokeratology only
• D. Topical antibiotics

Answer: (A)

In progressive keratoconus, the main objective is to stop further ectasia and preserve vision. Corneal collagen cross-linking accomplishes this by creating additional chemical bonds between collagen fibrils, increasing corneal stiffness and slowing or halting progression. Even with a very thin cornea, cross-linking is pursued because it targets the underlying disease process rather than just correcting refractive error; there are specialized protocols to make CXL feasible in thinner corneas, aiming to stabilize the cornea instead of moving straight to transplant.

Penetrating keratoplasty would be considered if the ectasia had progressed to the point of significant scarring or vision loss not amenable to other therapies, but it is more invasive with graft rejection risks. Orthokeratology is not a treatment to halt keratoconus progression and can be problematic in a ectatic cornea. Topical antibiotics do not address the ectatic disease at all.

Therefore, corneal cross-linking is the indicated approach to stop progression in this scenario.