A 10-year-old boy with advanced vernal keratoconjunctivitis and giant papillary hypertrophy of the upper tarsal conjunctiva develops a horizontally oval, white, shield-shaped plaque firmly adherent to the tarsal surface. Histopathological examination of this plaque would show deposition of:

• A Collagen type II produced by metaplastic epithelium
• B Amyloid derived from immunoglobulin light chains
• C Calcium hydroxyapatite crystals
• D Fibrin mixed with eosinophil granule proteins such as major basic protein ✓

Explanation

The shield ulcer plaque of severe VKC is composed of fibrin entangled with eosinophil-derived toxic granule proteins, chiefly major basic protein, which impair re-epithelialisation and keep the defect from closing. This composition explains why simple lubrication fails and why debridement of the plaque is often required for healing. Calcium deposition belongs to band keratopathy, not the shield ulcer.

Reference: Kanski's Clinical Ophthalmology, 9th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.