Cornea plana 2

Cornea Plana 2 (CNA2) is a rare genetic disorder affecting the cornea, the clear, dome-shaped surface that covers the front of the eye. This condition is characterized by a flattened cornea, which can lead to reduced visual acuity. Cornea Plana 2 is distinct from Cornea Plana 1 in its genetic cause and inheritance pattern.

Etiology

Cornea Plana 2 is caused by mutations in the KERA gene, which encodes for keratocan, a protein that is crucial for the maintenance of corneal structure and transparency. The mutations lead to a deficiency or dysfunction of keratocan, resulting in the abnormal development of the cornea.

Genetics

The condition is inherited in an Autosomal Recessive manner. This means that an individual must inherit two copies of the mutated gene, one from each parent, to be affected by the disorder. Parents of an individual with Cornea Plana 2 typically do not show symptoms of the condition but are carriers of the mutation.

Symptoms

The primary symptom of Cornea Plana 2 is a significantly flattened cornea, which can lead to:

• Reduced visual acuity
• Astigmatism
• Hyperopia (farsightedness)
• Possible nystagmus (involuntary eye movement)

Diagnosis

Diagnosis of Cornea Plana 2 involves a comprehensive eye examination, including:

• Measurement of corneal curvature
• Visual acuity tests
• Examination of the eye's anterior segment using slit lamp microscopy

Genetic testing can confirm the presence of mutations in the KERA gene.

Treatment

There is no cure for Cornea Plana 2, and treatment focuses on managing symptoms and improving visual function. Options may include:

• Prescription glasses or contact lenses to correct refractive errors
• In severe cases, corneal transplantation may be considered

Prognosis

The prognosis for individuals with Cornea Plana 2 varies. While the condition can significantly impact visual acuity, appropriate corrective measures, such as glasses or contact lenses, can help improve vision. Regular follow-up with an ophthalmologist is essential to monitor the condition and adjust treatment as necessary.

See Also

• Corneal dystrophy
• Genetic disorder
• Eye examination