Fluorescein assessment of a rigid gas-permeable trial lens shows a bright pool of dye centrally beneath the lens with minimal touch at the periphery. This pattern indicates:

• A A flat-fitting lens requiring a steeper base curve
• B A warped lens that must be replaced regardless of base curve
• C An ideal alignment fit requiring no change
• D A steep-fitting lens requiring a flatter base curve ✓

Explanation

With fluorescein, dye pools where the lens stands off from the cornea. Central pooling means the lens vaults over the corneal apex, that is a steep fit, and it will ride high, cause bubble formation and discomfort. Correction is a flatter (larger radius) base curve. In an alignment fit dye distributes thinly and evenly, while a flat fit shows central bearing with peripheral pooling. Recognising these patterns is a standard fitting skill examined in ophthalmology.

Reference: Khurana, Comprehensive Ophthalmology, 7th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.