The eyelids are the primary protective structures of the eyes. In addition to being a physical barrier blocking out foreign particles and ultraviolet light, the eyelids also contain structures important for maintaining a smooth, clear tear film and healthy ocular surface. Eyelid anatomy is complex, and degeneration or dysfunction of its tissues may result in various eyelid disorders.
Eyelid ptosis occurs when the upper eyelid droops down over the eye. When the drooping is so severe as to obstruct the pupil and affect vision, surgery may be recommended to help raise the lid. In children, ptosis is often due to an underdeveloped eyelid-opening muscle. In adults, it is typically due to the muscle stretching out or separating from its normal position in the lid. This may be due to normal aging, prior injury to the eye or eyelid, or sometimes previous eye surgery.
Dermatochalasis is the condition of excess eyelid skin. In the upper eyelid, this excess skin may hang over the eyelashes and interfere with visual function. It may also cause a tired or fatigued appearance. Removal of this excess skin may improve visual function and provide a rejuvenated appearance. Often, dermatochalasis is accompanied by fat prolapse from the orbit that may also be removed at the time of surgery.
Ectropion occurs when the eyelid turns out and is no longer in contact with the eye. Symptoms include irritation, tearing, and discharge. Ectropion most commonly occurs from laxity or stretching of the part of the eyelid that attaches to the bone of the orbit. Medical treatment consists of lubrication. Tightening the tendon surgically can restore the eyelid position. In some cases, the eyelid may turn out due to a shortage of skin. In these instances, skin grafting may be necessary.
Entropion occurs when the eyelid turns in and causes the eyelashes and eyelid skin to chafe against the eye. This causes discomfort, watering, discharge, and redness. In the most common type of entropion, the eyelid tendon is lax and the muscle that pulls the eyelid down is separated from its normal attachment. Surgical repair can restore the normal eyelid position.
Cranial nerve 7 palsy
This condition occurs when the muscles on one side of the face become weak or paralyzed due to injury to the facial nerve. It may be the result of surgery in a certain part of the face, a tumor, or viral infection. When an underlying cause is not identifiable the condition is known as a Bell’s palsy. As part of the facial paralysis, the eyebrow on the affected side may droop, and the lower eyelid may turn out, away from the eye. In most cases, there is spontaneous improvement over months; treatment consists of frequent lubrication to prevent dryness of the exposed tissues. If spontaneous improvement does not occur and symptoms persist, surgery may be indicated to repair the malposition.
Blepharospasm is a condition that results in uncontrolled, involuntary spasm-like contractions of the muscles that close the eyelids. When moderate or severe, it interferes with vision by not allowing the individual to keep his or her eyes open long enough to function normally. In some cases, medical therapy may be helpful, but most patients require treatment with botulinum toxin injections to weaken the contracting muscles. Repeated treatments are usually required for symptom control.
Shingles is a reactivation of the virus that causes chicken pox (Varicella zoster). When an individual contracts chicken pox, the offending virus remains in the body even after the signs and symptoms of the rash are gone. Sometimes, this virus comes out of its dormant state and causes a painful rash of blisters on the skin in a sensory nerve distribution. When the rash occurs on the eyelids and/or nose, there is an increased chance that it may also affect the cornea (clear part of the eye) or even result in inflammation inside the eye (uveitis). Treatment with oral antivirals and eye drops if indicated hastens recovery.