■ Atlas of Eyelid Malpositions
INTRODUCTION Ankyloblepharon is a condition where the eyelid margins are fused together to varying degrees. In congenital ankyloblepharon the fused eyelids fail to completely separate during embryogenesis. It can occur as a sporadic isolated finding or in association with diverse chromosomal and syndromic conditions characterized by failure of separation of apposed tissues suggesting a common defect in the mechanisms that regulate tissue fusion. It has also been associated with trisomy 18. The condition may be complete, partial, or interrupted. In the latter, called ankyloblepharon filiforme, multiple epithelial bands are present between the upper and lower lid margins. More commonly, in partial ankyloblepharon, the horizontal palpebral fissure is shortened. Ankyloblepahron can also be seen following trauma, chemical burs, cicatrizing diseases such as Stevens-Johnson syndrome or cicatricial ocular phemphigoid, or inflammations such as ulcerative blepharitis or herpes simplex.