Although ptosis correction using posterior approach conjunctivomullerectomy has short downtime, the patient refuses to take any chances for fear of lid swelling during the Chinese New Year. As a temporary measure, she is given topical phenylephrine to be used 3hourly. The pictures below shows the result before and after topical application of 2.5% phenylephrine.
a. Left ptosis; b. After application of 2.5% phenylephrine to the left eye.
2.5% phenylephrine (mydrifin)
Phenylephrine causes lid retraction by stimulating contraction of the Muller's muscle. It has a duration of action of about 3 hours and when taken four times a day should keep the eyelid open during the waking hours. The main unwanted side effects are moderate pupil dilatation which may cause glaring and the risk of precipitating acute angle glaucoma in susceptible patients. The risk of acute angle glaucoma is minimal in patients who have had cataract surgery.
Diagrams showing the effect of topical phenylephrine. By contracting
the Muller's muscle, phenylephrine can open the eye by between 2 to 3 mm.