A 24-year-old with moderate keratoconus, clear central cornea, Kmax 52 D, and contact lens intolerance is offered intrastromal corneal ring segment implantation. The PRIMARY goal of this procedure is to:

• A Halt enzymatic degradation of the stroma
• B Flatten and recentre the cone to improve corneal regularity ✓
• C Replace the need for any refractive correction permanently
• D Increase corneal sensitivity

Explanation

Intracorneal ring segments act by an arc-shortening effect: inserting PMMA segments into peripheral stromal channels flattens the central cornea and shifts the apex toward centre, improving topographic regularity and contact lens tolerance or spectacle acuity. They do not stop progression, so cross-linking remains necessary if the disease is actively progressing. Vision usually improves but many patients still need some optical correction, and the segments can be removed or exchanged.

Reference: Yanoff and Duker, Ophthalmology, 5th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.