Differential Diagnosis for Small Persistent Dark "Spots" in Peripheral Vision

Single Most Likely Diagnosis

• Floaters: Small, dark spots that appear to float in front of the eyes are most commonly due to floaters. These are tiny clumps of cells that form in the vitreous, the clear jelly-like substance that fills the inside of the eye. They are particularly noticeable when looking at something bright, like the sky on a sunny day, and are very common, especially in people who are nearsighted or have had cataract surgery.

Other Likely Diagnoses

• Migraines: Some people experience visual auras during migraines, which can include small, dark spots in the peripheral vision. These spots can be part of a larger visual disturbance that may include zigzag patterns or blind spots.
• Dry Eye Syndrome: While not typically causing dark spots, severe dry eye can lead to visual disturbances, including the perception of spots or floaters due to irregularities on the surface of the eye.
• Posterior Vitreous Detachment (PVD): As people age, the vitreous gel can shrink and pull away from the retina, a condition known as posterior vitreous detachment. This can cause new floaters and is a common condition, especially in older adults.

Do Not Miss Diagnoses

• Retinal Detachment: Although less common, a retinal detachment can cause sudden flashes of light and an increase in eye floaters. It is a medical emergency that requires immediate attention to prevent permanent vision loss.
• Diabetic Retinopathy: In people with diabetes, high blood sugar levels can damage the blood vessels in the retina, leading to diabetic retinopathy. This condition can cause spots or floaters due to bleeding or fluid leakage in the retina.
• Malignant Hypertension: Severe high blood pressure can cause changes in the blood vessels of the retina, leading to visual disturbances, including spots or floaters.

Rare Diagnoses

• Ocular Lymphoma: A rare type of cancer that can affect the eyes, ocular lymphoma can cause a variety of symptoms, including floaters or spots in the vision.
• Vitreous Hemorrhage: Bleeding into the vitreous gel can cause sudden vision loss and the appearance of dark spots or floaters. This is often associated with diabetes, trauma, or retinal tears.
• Choroidal Melanoma: A type of eye cancer that develops in the choroid, the pigmented layer beneath the retina. It can cause visual disturbances, including the perception of dark spots, though this is less common.