Which disease is associated with a type 2 hypersensitivity reaction and causes conjunctival scarring?

• A. Ocular Rosacea
• B. Allergic conjunctivitis
• C. Ocular Cicatricial Pemphigoid
• D. Meibomian gland dysfunction

Answer: (C)

Conjunctival scarring due to an antibody‑mediated attack fits a type II hypersensitivity pattern. In this response, IgG or IgM antibodies target antigens at the cell surface or basement membrane, triggering complement and inflammatory damage that leads to tissue injury rather than immune complexes circulating in the blood. In the eye, the classic example is ocular cicatricial pemphigoid (autoimmune mucous membrane pemphigoid), where autoantibodies react against basement membrane components like BP180 and BP230. This causes separation of the conjunctival epithelium from the underlying tissue, chronic inflammation, and scarring that results in forniceal shortening and symblepharon, with potential vision loss.

Ocular rosacea involves chronic eyelid inflammation without a primary antibody‑mediated attack on the conjunctival basement membrane. Allergic conjunctivitis is a type I hypersensitivity reaction driven by IgE to environmental allergens and typically lacks scarring. Meibomian gland dysfunction is a glands‑related, nonimmune condition that alters tear film, not a primary autoimmune scarring process.