<prompt> A 62 year old woman with keratoconjunctivitis sicca is most likely to demonstrate corneal staining in which location?Superior thirdMiddle third interpalpebralInferior thirdDiffuse over entire cornea  <response>: Rose Bengal staining is a very useful test for detecting even mild cases of Kerato conjuctivitis sicca .Depending upon the severity of Kerato conjunctivitis sicca three staining patterns A, B and C have been described: C pattern represents mild or early cases with fine punctate stains in th.e interpalpebral area; B the moderate cases with extensive staining; and A the severe cases with confluent staining of conjunctiva and cornea. Thus the women is most likely to demonstrate staining in interpalpebral area. 