Small palpebral fissures at or below 2nd standard deviations of the 3rd percentile. Flattened or smooth philtrum is measured using lip-philtrum guide.

Compensating for anesthesia-induced lagophthalmos and adjusting the palpebral fissure increased the predictability of eyelid height after surgery for pediatric congenital ptosis, a study found ...

The mean height of the vertical palpebral fissure in patients with congenital ptosis and aponeurotic ptosis were 6.5 mm (range 5–9 mm) and 6.1 mm (3–9 mm), respectively.

About 1 week after surgery, the palpebral fissure widened and gradually became apparent to yield a good shape. The cosmetic results were acceptable to most of the patients.