Summary about Disease
Meesmann corneal dystrophy (MECD) is a rare, inherited eye disorder that affects the cornea, the clear front part of the eye. It is characterized by tiny, bubble-like cysts in the epithelium, the outermost layer of the cornea. These cysts typically appear in early childhood and can cause varying degrees of discomfort and visual disturbances. It usually progresses slowly and rarely causes severe vision loss.
Symptoms
Tiny, clear cysts visible on the cornea (best seen with a slit lamp microscope)
Foreign body sensation (feeling like something is in the eye)
Photophobia (sensitivity to light)
Blurred vision
Tearing
Eye pain or discomfort
Erosion or rupture of the cysts, leading to increased discomfort
Causes
Meesmann corneal dystrophy is caused by mutations in the genes encoding the corneal keratins K12 and K3. These keratins are structural proteins crucial for maintaining the integrity of the corneal epithelium. Mutations in either the KRT12 or *KRT3* gene can disrupt the formation of these proteins, leading to the characteristic corneal abnormalities. MECD is inherited in an autosomal dominant pattern, meaning that only one copy of the mutated gene is needed to cause the disorder.
Medicine Used
There is no specific cure for Meesmann corneal dystrophy. Treatment focuses on managing the symptoms and improving visual comfort. Treatments may include:
Lubricating eye drops and ointments: To relieve dryness and foreign body sensation.
Bandage contact lenses: To protect the cornea and promote healing.
Debridement: Removal of damaged or loose epithelial cells.
Phototherapeutic keratectomy (PTK): A laser procedure to remove the superficial layer of the cornea and smooth the surface.
Corneal transplant (rarely): In severe cases where other treatments are ineffective.
Is Communicable
No, Meesmann corneal dystrophy is not communicable. It is a genetic disorder caused by inherited gene mutations. It cannot be spread from person to person through contact or other means.
Precautions
There are no specific precautions to prevent acquiring Meesmann corneal dystrophy since it is a genetic condition. Genetic counseling and testing can be helpful for individuals with a family history of MECD who are planning to have children. Precautions for managing the condition:
Protect eyes from bright light and glare.
Use lubricating eye drops regularly.
Avoid rubbing the eyes.
Follow your doctor's instructions carefully.
How long does an outbreak last?
Meesmann corneal dystrophy is not characterized by outbreaks. It's a chronic condition with symptoms that can fluctuate in intensity over time. Erosion or rupture of corneal cysts can cause temporary exacerbation of symptoms, but these are not outbreaks in the typical sense of an infectious disease.
How is it diagnosed?
Meesmann corneal dystrophy is typically diagnosed through a comprehensive eye exam by an ophthalmologist. The diagnosis usually involves:
Slit-lamp examination: A detailed examination of the cornea to identify the characteristic microcysts.
Review of medical history: Including family history of corneal dystrophies.
Corneal topography: Mapping the surface of the cornea to assess its shape.
Genetic testing: To confirm the diagnosis by identifying mutations in the KRT3 or *KRT12* gene (although not always necessary for diagnosis).
Timeline of Symptoms
Early childhood: Microcysts typically appear in the corneal epithelium.
Childhood/Adolescence: Symptoms may be mild or absent initially. Some individuals may experience occasional discomfort or blurred vision.
Adulthood: Symptoms tend to become more noticeable, including foreign body sensation, photophobia, and blurred vision. The severity of symptoms can vary greatly among individuals.
Progression: The condition typically progresses slowly over time. While symptoms may fluctuate, significant vision loss is rare.
Important Considerations
Genetic Counseling: Individuals with MECD or a family history of the condition should consider genetic counseling to understand the inheritance pattern and risks of passing the gene on to their children.
Regular Eye Exams: Regular follow-up with an ophthalmologist is essential to monitor the progression of the disease and manage symptoms effectively.
Symptom Management: Focus should be placed on managing symptoms to maintain visual comfort and quality of life.
Variability: The severity of symptoms can vary widely among individuals with MECD, even within the same family.
Differential Diagnosis: MECD should be distinguished from other corneal dystrophies and conditions that can cause similar symptoms.