Sickle Cell and Retinopathy

Having sickle cell can also affect the eyes. The small blood vessels can become blocked during a crisis because of the abnormally shaped red blood cells, resulting in inflammation and decreased oxygen supply. The blockage can develop in any part of the eye, but the retina is where it occurs most often. When the retina becomes damaged, it can lead to sickle cell retinopathy.

This retinopathy causes thinning of the retina and the growth of abnormal blood vessel. the retina is in the back of the eye, containing cells called photoreceptors that sense light entering the eye. Those photoreceptors convert light into electrical signals that are sent to the brain via the optic nerve so they can be interpreted as images.  As a result, damage to the retina may develop slowly or suddenly causing vision loss and permanent blindness. So, one may not experience any symptoms, but some may especially in the early stages of the condition, however as the retinopathy progresses, these symptoms may arise:

1. Floaters: Patients may see small, dark specks or spots drifting in their field of vision. These floaters are caused by the accumulation of blood cells or vitreous debris within the eye.

2. Blurred vision: A reduction in visual acuity or clarity can occur as a result of retinal damage or swelling.

3. Visual field loss: Some patients may experience a loss of peripheral vision or "tunnel vision" due to damage in the peripheral retina.

4. Flashes of light: Patients might see sudden flashes of light, typically in their peripheral vision, which can be an indication of retinal traction or detachment.

5. Sudden vision loss: In severe cases, individuals may experience sudden, painless vision loss due to complications such as vitreous hemorrhage or retinal detachment.

Sickle cell retinopathy can present in various forms and severity levels. The Goldberg (1971) classification system is widely used to categorize the condition into five distinct stages, each reflecting the progression and severity of the disease:

1. Stage 1 - Peripheral arteriolar occlusions: This initial stage is characterized by the blockage of small blood vessels (arterioles) in the peripheral retina. The occlusions may be difficult to detect and typically cause no symptoms.

2. Stage 2 - Peripheral arteriovenous anastomoses: As the disease progresses, new blood vessels begin to form in response to the blocked arterioles. These new vessels create abnormal connections between arteries and veins (anastomoses) in the peripheral retina.

3. Stage 3 - Neovascular proliferation: During this stage, the abnormal blood vessels proliferate and form a network known as "sea fan" neovascularization. These fragile vessels are prone to leakage and bleeding, which can lead to vision problems.

4. Stage 4 - Vitreous hemorrhage: The fragile new blood vessels can rupture and bleed into the vitreous humor, the clear gel-like substance that fills the space between the lens and the retina. A vitreous hemorrhage can cause sudden vision loss or floaters (small spots or cobweb-like shapes) in the visual field.

5. Stage 5 - Retinal detachment: The most severe stage, retinal detachment occurs when scar tissue from the bleeding and neovascularization pulls the retina away from its normal position. This detachment can lead to severe vision loss or even blindness if not treated promptly.

Treatment 

Currently, there is no cure for sickle cell anemia, but there are treatments that can help decrease the risk of complications and symptoms.

To help protect vision, it is important for people with sickle cell anemia to have regular eye exams. To identifying any changes in vision early may help decrease the risk of vision loss.

When sickle cell retinopathy is identified, the type of treatment recommended may depend on the extent of symptoms and damage to the retina. Possible treatment includes:

1.     Laser treatment: If a large area of blood vessels is blocked, laser treatment can help decrease further development of abnormal blood vessels.

2.     Medications: Certain medications are available that prevent the formation of additional abnormal blood vessels. The drugs are injected directly into the eye.

3.     Surgery: If the condition becomes serious and the retina detaches, surgery is needed to prevent blindness.

Reference

http://www.kadrmaseyecare.com/eye-health--care-blog/sickle-cell-anemia-and-vision-national-sickle-cell-month

Goldberg, F. (1971) Classification and pathogenesis of proliferative sickle retinopathy. Am J Ophthalmol. 71:649–665. doi: 10.1016/0002-9394(71)90429-6. [PubMed] [CrossRef] [Google Scholar]