Microphthalmia is the medical term applied to eyes that are significantly smaller than normal. In fact, the eyes may be so small that they are clinically undetectable in which case it is sometimes called 'clinical anophthalmia'. The condition may involve one or both eyes. It may occur by itself (isolated) but often, as in this syndrome, other anomalies and health problems are present in addition.
In microphthalmia 5, one or both eyes are abnormally small. Many eyes have small corneas (the windshields of the eye), cataracts, and malfunctioning of the retina with abnormal pigmentation and blood vessels. Sometimes the optic nerve is missing or abnormally small. Vision is usually impaired when the eye is too small and in extreme cases the eye is blind.
In this syndrome, the pituitary gland can be abnormal as well. This may result in a reduction of thyroid function and low amounts of growth hormone, sex hormones and cortisol. As a result some patients are short in stature and male genitalia can be underdeveloped. Other patients have other deformities of the brain with developmental delays and impaired cognitive function. A few patients have seizures as well. Muscle tone is reduced in some individuals and sometimes babies seem ‘floppy’.
This condition follows a vertical pattern of inheritance known as autosomal dominant inheritance. Children of parents with microphthalmia 5 have a 50% risk of inheriting the same condition although there is a wide range in the severity of signs and symptoms.
Pediatricians, ophthalmologists, and endocrinologists may collaborate on the diagnosis and treatment. There is no treatment for the malformed eye although visual functioning can be aided with low vision aids when it is subnormal. There is no treatment when blindness occurs. Hormonal deficiencies can sometimes be treated with supplementation. Special education can also be helpful in selected individuals with cognitive impairment