Sickle Cell Retinopathy: Sea Fan Staging

Master sickle cell retinopathy stages, sea fan neovascularization, genotype risks, screening, and treatment for eye care board exams.

Reviewed for accuracyAugust 1, 20263 min read

Warm-up

In proliferative sickle cell retinopathy, the characteristic peripheral retinal neovascular lesion is termed which of the following, based on its fan-like configuration?

Lesson

Sickle Cell Retinopathy in 30 Seconds

Sickle cell retinopathy is a peripheral ischemic vasculopathy caused by recurrent vaso-occlusion. Board questions test the progression from peripheral nonperfusion to sea fan neovascularization, then vitreous hemorrhage or tractional retinal detachment. Hemoglobin SC disease has a particularly high risk of proliferative disease.

Nonproliferative and Proliferative Stages

Sickle cell retinopathy progresses through nonproliferative and proliferative stages. Nonproliferative findings include salmon patch hemorrhages, iridescent spots, black sunbursts caused by retinal pigment epithelium hyperplasia following resolved intraretinal hemorrhage, and peripheral arteriovenous anastomoses. Proliferative sickle cell retinopathy features peripheral neovascularization in the characteristic sea fan configuration, most commonly in the temporal peripheral retina, which can lead to vitreous hemorrhage, tractional retinal detachment, and vision loss. The far periphery has poor collateral circulation and is relatively ischemic. Hemoglobin SC disease often causes more severe retinopathy than sickle cell anemia because higher hematocrit and blood viscosity promote peripheral vaso-occlusion despite milder systemic disease.

Goldberg Classification

Stage I: Peripheral arteriolar occlusions.
Stage II: Peripheral arteriovenous anastomoses.
Stage III: Neovascular proliferations, the sea fan stage. This is the critical treatment threshold because active neovascularization can bleed or cause traction. Sea fans may also auto-infarct and fibrose spontaneously, although new lesions may develop subsequently.
Stage IV: Vitreous hemorrhage.
Stage V: Tractional retinal detachment.

4 Facts Exams Always Ask

Hemoglobin SC disease and sickle beta thalassemia often cause more retinopathy than hemoglobin SS disease because relatively higher hematocrit and viscosity increase peripheral retinal vaso-occlusion.
Classic nonproliferative findings are salmon patch hemorrhages, which may leave iridescent spots, and black sunbursts caused by retinal pigment epithelium hyperplasia following resolved intraretinal hemorrhage.
Sector scatter laser photocoagulation directed at areas of peripheral nonperfusion is the standard treatment for active proliferative disease. Anti-vascular endothelial growth factor therapy is an adjunct in selected cases. Persistent vitreous hemorrhage and tractional retinal detachment may require pars plana vitrectomy.
All patients with sickle cell disease need periodic dilated fundus examination regardless of systemic severity. Wide-field imaging improves detection of peripheral disease, while fluorescein angiography helps identify leakage and active sea fans.

The Classic Trap

Do not assume milder systemic sickle cell disease means milder retinal disease. Hemoglobin SC disease and sickle beta thalassemia can have less systemic anemia yet greater risk of proliferative retinopathy than hemoglobin SS disease. Think retinal viscosity and peripheral ischemia, not overall systemic illness burden.

Clinical Pearl

A sea fan is not simply a peripheral vessel abnormality. It is pathologic neovascularization at the border of perfused and nonperfused retina. On fluorescein angiography, leakage distinguishes an active sea fan from an auto-infarcted, fibrotic lesion, which does not require treatment.

Check yourself

Checkpoint 1

Which hemoglobin genotype is most associated with severe proliferative sickle cell retinopathy despite milder systemic disease?

Checkpoint 2

At which Goldberg stage does active sea fan neovascularization appear, marking the threshold for treatment?

Clinical case

A 27-year-old patient with hemoglobin SC disease has no visual symptoms. Dilated examination shows a temporal peripheral sea fan with adjacent arteriovenous anastomoses. Wide-field fluorescein angiography shows leakage from the sea fan and extensive peripheral nonperfusion.

What finding on fluorescein angiography makes treatment of this sea fan urgent?

Explanation

Leakage from a sea fan on fluorescein angiography confirms active neovascularization rather than a spontaneously auto-infarcted fibrotic lesion. Active leaking sea fans are at risk of bleeding or causing traction, making retina-directed treatment generally indicated.

Case discussion

This is Goldberg Stage III proliferative sickle cell retinopathy. Leakage on fluorescein angiography confirms an active rather than auto-infarcted sea fan. Active leaking sea fans are at risk of progression to vitreous hemorrhage and tractional retinal detachment, so retina-directed treatment is generally indicated.

Sources & Reviewer Info

Reviewed by Vasilis Inglezis: Optometrist and Ocular Oncology Imaging Specialist, Ocular Oncology Center, Athens, Greece. Last updated August 1, 2026.

References

Goldberg MF. "Classification and pathogenesis of proliferative sickle retinopathy." American Journal of Ophthalmology. 1971;71(3):649-665. doi: 10.1016/0002-9394(71)90429-6.
Dinah C, Greystoke B, Mueller I, Talks J. "Action on Sickle Cell Retinopathy: The Time Is Now." Eye. 2022.
Downes SM, Hambleton IR, Chuang EL, Lois N, Serjeant GR, Bird AC. "Incidence and Natural History of Proliferative Sickle Cell Retinopathy." Ophthalmology. 2005.

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