What is A patient with ptosis, upper 4mm of cornea is covered by upper eyelid. Grade of ptosis is- and explain in detail?
*In unilateral cases of ptosis, difference between the veical height of palpebral fissures of the two sides indicates the degree of ptosis. *In bilateral cases it can be determined by measuring the amount of cornea covered by the upper eyelid and then subtracting 2mm. *Depending upon its amount the ptosis is graded as:- *Mild : 2mm *Moderate : 3mm *Severe : 4mm *In this question, 4mm of cornea is covered by upper eyelid. Subtracting 2mm from this means there is 2mm of ptosis, i.e. mild grade. Ref: Khurana 7th/e p.395