Bietti's Crystalline Dystrophy

Also known as Bietti’s crystalline corneoretinal dystrophy, Bietti’s crystalline dystrophy is an inherited condition that affects the eyes. Bietti’s crystalline dystrophy is named after an Italian ophthalmologist, the first to describe the condition in 1936.

Bietti’s crystalline dystrophy is a rare condition and tends to affect people with Asian heritage more commonly than other ethnicities. It tends to cause symptoms to develop when people reach their twenties or thirties.

What are the causes of Bietti’s crystalline dystrophy?

Bietti’s crystalline dystrophy is an inherited condition which is passed on from parents to a child. The condition is autosomal recessive, meaning that a child must inherit one faulty gene from both parents to develop Bietti’s crystalline dystrophy. If a child inherits a faulty gene from a single parent they are likely a carrier of the condition – so if they then have a child they can only pass on the condition if their partner also has a faulty gene, the child then inheriting the gene from both parents. Research shows that the gene for Bietti’s crystalline dystrophy is located in chromosome number 4. Within the chromosome there is a multitude of different genes and scientists have worked to determine which specific genes are linked to Bietti’s crystalline dystrophy. In 2004 researchers identified the gene for the condition and named it CYP4V2.

Symptoms of Bietti’s crystalline dystrophy

Symptoms of Bietti’s crystalline dystrophy include the development of crystals at the cornea of the eyes, the formation of yellow drops in the region of the retina and gradual degeneration of the retina, choroids and choriocapillaries (this is known as atrophy). Atrophy can contribute to a gradual loss of vision, problems seeing during the night and a gradual restriction in your field of vision. This is mainly concerned with peripheral vision, which tends to become increasingly hampered as the retina degenerates.

It is possible for crystals to develop in the lymphocytes (commonly known as white blood cells), but there is no evidence to suggest that people with Bietti’s crystalline dystrophy suffer any other effects or symptoms aside from vision problems.

Treating Bietti’s crystalline dystrophy

There is currently no cure for Bietti’s syndrome and no specific treatments that can be used to improve or prevent symptoms. However, researchers are hopeful that they will be able to find effective treatments in the future.

What is the prognosis for people with Bietti’s crystalline dystrophy?

The outlook depends on the individual and some peoples’ symptoms develop much quicker than others. But this is a progressive condition and it is likely that it will take some time for symptoms to develop to a stage in which significant loss of vision is experienced. Most people start to develop symptoms between the ages of 20 or 30.