Conjunctival sensitivity in pathological cases, with simultaneous measurement of corneal and lid margin sensitivity.

A total of 209 pathological eyes each had 17 localities tested for sensitivity (cornea, caruncle, upper and lower lid margins (centrally, medially and laterally), and corresponding localities on the palpebral conjunctiva, and upper and lower halves of the bulbar conjunctiva). Reduced conjunctival sensitivity is seen in pemphigoid (excluding the lid margin) in contact lens wearers, at sites of nerves transected during operation and in rare cases of infectious conjunctivitis. Isolated corneal hypaesthesia is seen in bacterial or fungal keratitis. In herpes, the hypaesthesia extends over the bulbar conjunctiva, in zoster, over wider areas (including the lid margin). The sensitivity is normal in keratoconjunctivitis sicca and chronic conjunctivitis. In neurological diseases the hyposensitivity could include the cornea, conjunctiva and lid margin. The conclusion is drawn that a study of the conjunctivo-corneal sensitivity can give differential diagnostic information, provided the normal sensitivity range is known. This has been set out in a Table in 10-year age groups.