Break up time test is done for:

# Break up time test is done for:

a. Sjogren’s syndrome

b. Scleroderma

c. Myasthenia gravis

d. Guillian barre syndrome

The correct answer is a. Sjogren's syndrome.

Tear break-up time (TBUT) also known as tear film break-up time (TFBUT) is the time taken for the first dry spot to appear on the cornea after a complete blink. TFBUT measurement is an easy and fast method used to assess the stability of tear film. It is a standard diagnostic procedure in the dry eye clinics. 

Tear film break-up time is abnormal in several conditions like aqueous tear deficiency, keratoconjunctivitis sicca, mucin deficiency, and meibomian gland disorders. Evaporative dryness can also be seen in conditions like lagophthalmos, proptosis, Parkinson's disease, computer vision syndrome, contact lens use, drugs (antihistamines, beta blockers, antispasmodics, diuretics) and vitamin A deficiency, amongst others.