Congenital Absence of the Eye (Anophthalmia and Microphthalmia)

Congenital Absence of the Eye

Congenital absence of the eye refers to the condition where the entire eye or part of the eye tissues are missing from birth. There are different classifications and terminologies based on the amount of tissue present and its function.

Anophthalmia

Anophthalmia is a condition where one or both eyes are completely undeveloped at birth. This occurs due to a disruption in the formation of the eye during embryonic development in the mother's womb. Anophthalmia is a rare condition, and in these cases, there is no visual function. It may also be associated with other genetic or developmental abnormalities.

Microphthalmia

Microphthalmia is characterized by one or both eyes being abnormally small. In some cases, the eye may appear almost absent due to its small size, but some eye tissue remains. Even when the elements of the eye appear intact, microphthalmic eyes are usually disorganized and non-functional; vision may either be absent or extremely limited. Microphthalmia can occur alone or as part of a syndrome associated with other birth defects.

Causes of Congenital Absence of the Eye

The exact cause of congenital eye absence is unknown, but risk factors may include genetic mutations, chromosomal abnormalities, maternal vitamin A deficiency, infections during pregnancy (such as rubella, toxoplasmosis),medications (such as isotretinoin for acne treatment, thalidomide, a now-banned skin medication),or exposure to harmful substances (such as X-rays, radiation, pesticides).

Diagnosis of Congenital Absence of the Eye

The diagnoses of anophthalmia and microphthalmia are typically made through ultrasound evaluations during pregnancy. After birth, the absence of the eye or its small or abnormal structure is visually detected during a general evaluation. For a more detailed assessment, imaging techniques such as ultrasound, computed tomography (CT),magnetic resonance imaging (MRI),and genetic testing may be employed.

Treatment of Anophthalmia and Microphthalmia

The development of the eye, periocular tissues, and the orbit (bone tissue and surrounding soft tissues) depends on the growth of the eyeball and its ability to synchronize the growth of surrounding tissues.

If the eyeball does not grow, the other tissues of the eye, eyelids, and the bony structure of the orbit also fail to develop, making it impossible to fit a prosthesis properly. To allow these tissues to grow, the use of special implants (conformers) that gradually increase in size and make contact with the bones is the most ideal treatment method. This approach allows the growth of the eyelid and orbital tissues up to the age of 3-4 years, and after this, a permanent volume can be achieved with a dermis-fat graft taken from the patient. At the age of 4-5 years, the patient can move on to the stage of fitting a healthy prosthesis.

In treatment, some expanding systems placed surgically into the socket are also used. However, these more expensive, invasive techniques, which require surgery and do not show significantly better results than the other method, have had some success in certain infants. Yet, they have not become an ideal treatment option for everyone.

Through a patient and persistent treatment process, cosmetic improvement, healthy orbital expansion, and the fitting of a prosthesis can be achieved in many patients.

Which Doctor Should Be Consulted for Anophthalmia and Microphthalmia?

The management of these conditions typically requires a multidisciplinary approach involving ophthalmologists, oculoplastic surgeons, genetic specialists, and other specialists as needed. Treatment should begin immediately after birth and continue persistently at regular intervals. In cases where the bone volume has not been established and treatment has been delayed (after 2-3 years),it is not possible to create volume with the techniques mentioned. Therefore, early consultation and treatment are crucial for the successful management of these conditions.