Blepharoptosis, or ptosis, refers to the drooping or downward displacement of the upper eyelid. The levator muscle, its aponeurosis, and the superior tarsal muscle are responsible for upper eyelid resting position and elevation. When these structures are compromised, the resultant depressed eyelid position can reduce the amount of light entering the eye, thereby degrading visual acuity. In pseudoptosis, aberrant structural relationships of the intact globe, bony, and soft-tissue attachments may cause secondary eyelid abnormalities.
Congenital myogenic, acquired aponeurotic, and involutional forms of ptosis represent the most common causes of ptosis among children and adults.[1]Thakker MM, Rubin PA. Mechanisms of acquired blepharoptosis. Ophthalmol Clin North Am. 2002;12:101-111.
http://www.ncbi.nlm.nih.gov/pubmed/12064073?tool=bestpractice.com
[2]Bodker FS, Olson JJ, Putterman AM. Acquired blepharoptosis secondary to essential blepharospasm. Ophthalmic Surg. 1993;24:546-550.
http://www.ncbi.nlm.nih.gov/pubmed/8233320?tool=bestpractice.com
Adults may be affected by associated involutional changes to the facial soft tissues that exacerbate or mask signs of ptosis. The vast majority of patients with ptosis do not present to an ophthalmologist or an oculoplastic surgeon for evaluation and treatment. Of those who do, their symptoms include headache, brow ache, and decreased visual acuity and visual field. Visual acuity improves with manual elevation of the eyelid and facial soft tissues. Superior visual field loss is most common. However, central vision can also be adversely affected. Any acute onset of ptosis, especially with other ocular or orbital symptoms, justifies further investigation with ophthalmological consultation.[3]Anderson RL, Nowinski TS. The five-flap technique for blepharophimosis. Arch Ophthalmol. 1989;107:448-452.
http://www.ncbi.nlm.nih.gov/pubmed/2923572?tool=bestpractice.com
[Figure caption and citation for the preceding image starts]: Sagittal view of eyelid anatomyFrom the collection of Dr Allen Putterman [Citation ends].
[Figure caption and citation for the preceding image starts]: Bilateral, asymmetric, congenital myogenic ptosis (note poor left upper eyelid crease)From the collection of Dr Allen Putterman [Citation ends].
[Figure caption and citation for the preceding image starts]: Bilateral, asymmetric, congenital myogenic ptosis in downgaze (note subtle left upper eyelid lag and asymmetric upper eyelid creases)From the collection of Dr Allen Putterman [Citation ends].
[Figure caption and citation for the preceding image starts]: Bilateral, asymmetric, acquired aponeurotic and involutional ptosisFrom the collection of Dr Allen Putterman [Citation ends].
[Figure caption and citation for the preceding image starts]: Bilateral, asymmetric, acquired aponeurotic and involutional ptosis in downgazeFrom the collection of Dr Allen Putterman [Citation ends].