This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Ophthalmology
Tear lysozyme levels are decreased in: 
Select and explain. 
A. Keratoconjunctivitis sicca, B. Stevens Johnson syndrome, C. Ocular pemphigoid, D. All of the above
A: Keratoconjunctivitis sicca
Answer: A: Keratoconjunctivitis sicca 
Explanation: Ans. Keratoconjunctivitis sicca