Isolated congenital alacrima is a rare disorder characterized by a lack of tears. It is caused by a deficiency in the lacrimal glands, which are responsible for producing tears. Symptoms of this disorder include dry eyes, eye irritation, and a feeling of sand in the eyes. In some cases, the eyes may become red and swollen. Treatment typically involves artificial tears and lubricating eye drops.

The primary symptom of isolated congenital alacrima is a lack of tears. Other symptoms may include dry eyes, eye irritation, redness, and sensitivity to light. In some cases, the eyes may appear sunken or have a bluish tint. In severe cases, the eyes may become infected due to the lack of tears.

Isolated congenital alacrima is a rare disorder caused by a genetic mutation. The exact cause of the mutation is unknown, but it is believed to be caused by a combination of genetic and environmental factors. Possible causes include:

1. Mutations in the lacrimal gland-specific transcription factor gene (TFEB).

2. Mutations in the lacrimal gland-specific transcription factor gene (TFEB) and other genes involved in the development of the lacrimal gland.

3. Mutations in the genes involved in the production of tears.

4. Mutations in the genes involved in the regulation of tear production.

5. Environmental factors, such as exposure to certain chemicals or radiation.

The treatment for isolated congenital alacrima is typically focused on managing the symptoms. This may include artificial tears to help lubricate the eyes, antibiotics to prevent infection, and punctal occlusion to help keep the tears in the eye. In some cases, surgery may be recommended to help increase tear production.

The exact cause of isolated congenital alacrima is unknown. However, some risk factors may include:

- Genetic mutations: Mutations in the TAC3, TAC3R, and CHST6 genes have been linked to isolated congenital alacrima.

- Family history: Isolated congenital alacrima may be inherited in an autosomal recessive pattern, which means both parents must carry the gene mutation for a child to be affected.

- Environmental factors: Exposure to certain environmental toxins, such as lead, may increase the risk of developing isolated congenital alacrima.

Unfortunately, there is no cure for isolated congenital alacrima. However, there are medications that can help to improve tear production and reduce the symptoms of dry eye. These medications include artificial tears, cyclosporine, and tacrolimus. Additionally, punctal plugs can be used to help retain the tears on the surface of the eye.