Coats disease: Year of the Zebra 2024

Coats disease is a rare eye disorder that causes abnormal development of the blood vessels in the retina. The retina is a layer of tissue at the back of the eye that contains specialized cells called photoreceptors. These photoreceptor cells are sensitive to light and convert it into electrical signals, which are then sent to the brain for visual processing.

In Coats disease, the blood vessels that supply the retina become dilated or enlarged, leading to the formation of retinal telangiectasias, which are the key manifestation of the disorder. These blood vessels are more fragile and prone to leakage, which can result in the accumulation of fluid beneath the retina.

Usually, Coats disease affects young individuals, more commonly those assigned male at birth, and it typically only affects one eye. The exact cause is unknown, but it may be related to mutations in the NDP gene, which codes for a protein involved in the vascular development of the retina.

Alright, now symptoms of Coats disease generally begin in childhood or adolescence and can include blurry vision, loss of visual acuity, and strabismus, or misalignment of the eyes. Most often, vision problems are related to retinal detachment, which is when the retina peels away from its underlying layer of support tissue, resulting in degeneration of the photoreceptors and, eventually, vision loss. Retinal detachment is generally painless, and is often accompanied by flashes or “floaters” in the affected individual’s vision.

When the retina detaches, it can also disrupt the normal structure of the eye, causing the pupil to appear white or yellow instead of black. This occurs because the detached retina reflects light differently, leading to leukocoria or a “white pupil”.