Proliferative Sickle Cell Retinopathy
Proliferative sickle cell retinopathy (PSR) occurs most commonly with sickle cell hemoglobin C (SC), at a rate of approximately 33%. It occurs less commonly with sickle cell thalassemia (SThal), at a rate of approximately 14%. Sickle cell homozygote (SS) disease results in more systemic complications but has a very low incidence of proliferative retinopathy, approximately 3%. Proliferative retinopathy is rare with sickle cell trait (AS). The ocular complications result from ischemia secondary to infarction of the retinal tissue by means of arteriolar, precapillary arteriolar, capillary, or venular occlusions; they include retinal neovascularization, preretinal or vitreous hemorrhage, and tractional retinal detachment.
PSR has been classified into 5 stages based on the following pathogenetic sequence:
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Peripheral arteriolar occlusions (stage 1) lead to peripheral nonperfusion and
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peripheral arteriovenular anastomoses (stage 2), which are dilated, preexisting capillary channels.
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Preretinal sea fan neovascularization (stage 3) may occur at the posterior border of areas of nonperfusion and lead to
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vitreous hemorrhage (stage 4) and
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tractional retinal detachment (stage 5).
PSR is one of many retinal vascular diseases in which extraretinal fibrovascular proliferation occurs in response to retinal ischemia. Whereas the neovascularization in eyes with proliferative diabetic retinopathy (PDR) generally begins postequatorially, the neovascularization in PSR is located more peripherally (Fig 7-4). Another way in which PSR can be differentiated from PDR is that in PSR, spontaneous regression of the peripheral neovascularization by autoinfarction frequently occurs, resulting in a white sea fan neovascularization (Fig 7-5). Table 7-2 presents a differential diagnosis of peripheral retinal neovascularization.
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Elagouz M, Jyothi S, Gupta B, Sivaprasad S. Sickle cell disease and the eye: old and new concepts. Surv Ophthalmol. 2010;55(4):359–377.
Table 7-2 Differential Diagnosis of Peripheral Retinal Neovascularization
Excerpted from BCSC 2020-2021 series: Section 10 - Glaucoma. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.