This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Cornea and sclera, Subject name: Ophthalmology
To prevent keratoconus what is used - 
Select and explain. 
A. Antibiotics, B. Cycloplegics, C. Glasses, D. None
D: None
Answer: D: None 
Explanation: Treatment of keratoconusFalling vision may not be corrected by glasses due to irregular astigmatism. Contact lenses (rigid gas permiable) usually improve the vision in early cases. In later stages penetrating keratoplasty may be required. Intacs, the intracorneal ring segments, are repoed to be useful in early cases.Reference:Comprehensive ophthalmology,AK Khurana,4th edition,page no.120