Ankyloblepharon is a medical condition characterized by the partial or complete fusion of the upper and lower eyelids. This fusion involves the eyelid margins. While the eyelids themselves typically remain anatomically and functionally normal, the adhesion restricts the ability to fully open the eye. This condition can affect one or both eyes, presenting as a range from fine, thread-like connections to broader areas of fusion across the lid margins.
Causes of Fused Eyelids
Fused eyelids can be either congenital (present at birth) or acquired later in life due to external factors. Congenital ankyloblepharon arises from an incomplete separation of the eyelids during fetal development. Normally, eyelid margins fuse around the ninth week of gestation and begin to separate by the fifth fetal month, with complete separation usually occurring by the seventh month.
The most common congenital form is ankyloblepharon filiforme adnatum (AFA), which involves fine, thread-like bands of tissue connecting the upper and lower eyelid margins. While AFA can occur as an isolated condition, it is sometimes associated with broader genetic syndromes. These can include Hay-Wells syndrome (also known as ankyloblepharon-ectodermal defects-cleft lip/palate or AEC syndrome), which affects skin, hair, nails, and teeth, or popliteal pterygium syndrome, characterized by intercrural webbing of the lower limbs.
Acquired ankyloblepharon develops after birth. This type typically results from severe trauma, such as chemical burns, thermal burns, or physical injuries to the eye. Inflammatory conditions can also lead to acquired fusion, including severe forms of conjunctivitis, herpes simplex infections, or cicatrizing diseases like Stevens-Johnson syndrome and ocular cicatricial pemphigoid.
Treatment and Outlook
The standard approach for treating ankyloblepharon involves a surgical procedure performed by an ophthalmologist to separate the fused eyelids. For fine filamentous adhesions, such as those seen in ankyloblepharon filiforme adnatum, the bands can often be divided with simple tools like blunt scissors or a scalpel. This minor incision divides the connecting tissue, allowing the eyelids to open fully.
For more extensive or complete fusions, a more involved surgical separation and reconstruction of the lid margins may be necessary. Following the division of adhesions, care is taken to ensure the lid margins heal properly and remain separated. Early treatment is highly recommended, particularly in infants, to facilitate normal visual development and prevent potential complications.
Untreated ankyloblepharon, especially in early childhood, can lead to amblyopia, commonly known as “lazy eye,” because the restricted eyelid opening prevents proper visual stimulation. The outlook following surgical treatment is generally favorable, with most individuals achieving normal eyelid function and improved vision. While some fine adhesions may spontaneously resolve, surgical intervention is typically effective in resolving the condition and preventing long-term visual impairment.