Ankyloblepharon is defined as adhesion of the edges of upper eyelid with the lower eyelid. The eyelids maintain their integrity and identity. The condition is usually congenital but may be acquired. In congenital ankyloblepharon, the fused eyelids fail to separate completely during development of embryo. Congenital ankyloblepharon is caused by developmental arrest leading to aberration in growth at either medial or lateral canthus. It may occur as a sporadic finding or in association with chromosomal/syndromic conditions.
Ankyloblepharon may be complete, partial, or interrupted. In interrupted form, known as ankyloblepharon filiforme adnatum (AFA), epithelial bands are present between the lower and upper eyelids. These fine extensile cords attaching lower and upper eyelids may be single or multiple. The cords decrease the palpebral fissure height and reduce excursion of eyelids. It is reported in trisomy 18. In autosomal dominant Hay-Well’s syndrome, ankyloblepharon may be associated with ectodermal dysplasia and cleft lip/palate. In partial ankyloblepharon, the horizontal palpebral fissure is shortened.
Ankyloblepharon filiforme adnatum is a form first described by Von Hasner in the year 1881.
Ankyloblepharon may also develop following
Garg Ashok, Rosen Emanuel, Mortensen Jes, Toukhy Essam El, Dhaliwal Ranjit S. Instant Clinical Diagnosis in Ophthalmology- Oculoplasty and Reconstructive Surgery. Jaypee Brothers Medical Publishers (P) Ltd 2008. P 8.
Insler MS, Helm CJ. Ankyloblepharon associated with systemic 5-fluorouracil treatment. Ann Ophthalmol. 1987;19(10): 374- 375.
Patients may have symptoms such as
There is epithelial fusion of the eyelid margins of the developing foetus at about 9th week of gestation. Complete separation usually does not occur until about 7th month of foetal life. Rarely, the lid margins may remain fused at birth, which results in ankyloblepharon. The exact mechanism is still not clear. The problem may be in the epithelium fusion stage, in which there is fusion of the mesoderm of the lid margin rather than purely the epithelium.
Ankyloblepharon may be an isolated sporadic malformation. It may also be associated with other malformations which are presumably inherited as an autosomal dominant condition in some cases and as an autosomal recessive condition in others.
Congenital ankyloblepharon may be associated with central nervous system and/or cardiac anomalies, cleft lip and/or palate and gastrointestinal abnormalities.
Various aetiologies for acquired ankyloblepharon have been described.
Diagnosis of ankyloblepharon is based on clinical features.
The eyelid margins are usually fused laterally, and less commonly medially. This condition may be associated with other developmental anomalies such as ptosis, microphthalmos, anophthalmos, or cleft lip. Lateral canthal angle may be displaced downward giving an anti-mongoloid appearance to the palpebral fissure. Lateral canthal tendon is lax or not developed so that there is significant laxity of the lower eyelids.
In ankyloblepharon filiforme adnatum, one or more narrow epithelial strands connect the central part of lower and upper eyelid margins. These vary in dimensions from 0.5 mm to 5 mm in width, and may range from 1 mm to 10 mm in length. The zone of attachment lies between the meibomian gland orifices and the eyelashes.
In total ankyloblepharon, lacrimal secretions may accumulate beneath the eyelids forming a fluid cyst.
Commonly, acquired ankyloblepharon is due to progressive conjunctival scarring resulting in fusion of the eyelids. Patients usually have a history of progressive scarring related to the primary disease. The eyelids show fusion from scar tissue.
Detailed ocular examination is performed including measurement of intraocular pressure. Any ocular features of hydrocephalus are noted.
Screening may be required to rule out any genetic disorder associated with ankyloblepharon.
Ankyloblepharon may be differentiated from
Management should be carried out under medical supervision.
Indications for therapy in cases of congenital and acquired cases of ankyloblepharon are similar. Presence of a significant central ankyloblepharon may occlude vision. In congenital type, it may potentially cause an occlusion type amblyopia. A significant nasal or temporal ankyloblepharon may restrict peripheral vision. Normal opening and closing of eyes may also be affected.
Management of ankyloblepharon is surgical and is indicated for improvement of visual field or for cosmetic reasons.
A potential contraindication to ankyloblepharon surgery is the problem of corneal exposure following release of marginal adhesions. This is significant in cases of ankyloblepharon developing after trauma, since other injuries such as damage to fifth and seventh intracranial nerve may be present. This is also true in similar cases with injury to cornea, lacrimal gland, decreased corneal sensitivity, decreased tear production, or lagophthalmos. Surgical procedures include
Therapeutic approach to congenital ankyloblepharon depends upon the type and extent of lid margin adhesions. Spontaneous resolution of very fine filaments may occur in some cases of ankyloblepharon filiforme adnatum (AFA).
Determine the cause of scarring in cases of acquired ankyloblepharon. Any associated inflammation must be treated first before resorting to any surgical therapy.
Visual prognosis is usually good if separation of eyelids is performed in timely manner.
Cosmetic appearance of the eyelids after separation of bands is usually very good in congenital ankyloblepharon.
The process of scarring may hamper the healing process following eyelid and corneal reconstructive surgery in cases of acquired ankyloblepharon.