An 11-year-old African American female presents for evaluation of traction of the macula OS. Medical history was remarkable for sickle cell at birth and both of her parents had sickle cell trait. BCVA was 20/20 OD 20/30+ OS. Preliminaries, intraocular pressure and slit lamp examination were all unremarkable. Dilated fundus exam of right eye was unremarkable. Dilated fundus exam of left eye revealed the presence of a thick fibrotic tissue in the macula that radiated towards the optic nerve (fig 1).
The superotemporal peripheral view of the left eye also revealed neovascularization associated with a pre-retinal hemorrhage and tortuous arteriovenous anastomosis (Fig 2). Regressed fibrovascular areas were also denoted (Fig 2) in the left eye. SDOCT of the right eye revealed mild temporal retinal thinning (fig 3). Left eye SDOCT revealed an increased retinal thickness with associated traction, correlating to the fibrotic macular tissue (Fig 3).
Wide field fluorescein angiography (UWFA) of the right eye revealed areas of nonperfusion temporally and inferotemporal (fig 4).
UWFA of the left eye reveled superior temporal peripheral leakage as well as, areas of nonperfusion temporally and inferotemporally (fig 4). Given the young age of the patient, the good VA and the invasive treatment option, a decision was made to closely observe for potential regression. Patient was also asked to continue care with her pediatrician. At the 2 month follow up, the neovascularization of the left eye, as well as the macular fibrotic tissue had shown extensive regression with visual acuity improvement to 20/20 (fig 5).
Sickle Cell Disease (SCD)
In the USA, SCD has a predilection for African Americans. It is a hereditary group of hemoglobinopathies characterized by sickling hemoglobin, leading to decrease oxygen and blood flow, as well as disruption in the normal blood flow. Under certain conditions, such as acidosis or hypoxia, the anomalous hemoglobin results in hemolysis and vaso-occlusive events, resulting in a host of ocular and systemic manifestations linked to specific genetic variants.
Sickle Cell disease is comprised of four genetic variants. (1) Sickle cell anemia (SS), which has the highest systemic complications. (2) Sickle cell C disease (SC), which carries the highest risk towards ocular complications. (1) Sickle trait (AS) which is often not associated with ocular manifestations (4) Sickle cell Thalassemia (S-Thal) which although the rarest variant, can lead to ocular complications.
Sickle cell retinopathy (SCR), like diabetes, has non-proliferative and proliferative stages. The non-proliferative stage (non-PSCR) is characterized by intraretinal hemorrhage known as salmon-patch. Over time the hemorrhage reabsorbed, leaving refractile deposits along with migration of the retinal pigment epithelium (Black Sunburst lesion). Proliferative sickle cell retinopathy (PSCR) is divided into 5 stages (Goldberg classification). These stages include (1) peripheral arteriolar occlusion (2) peripheral arteriovenous anastomosis (3) sea-fan neovascularization (4) vitreous hemorrhage and (5) tractional retinal detachment. Other posterior segment signs may include but are not limited to, retinal vascular occlusive diseases, angioid streaks and dark without pressure.
Diagnostic Modalities
Common diagnostic modalities used in the assessment of SCR include, fundus photography, SDOCT and UWFA. SDOCT is particularly useful in assessing inner retinal thinning temporal to the fovea, representing area of ischemia (such as in our case). On the other hand, UWFA is useful in revealing areas of nonperfusion along with active neovascularization, especially in the periphery. The peripheral retina yields the highest propensity for the manifestation of SCR.
Management
There are various management approaches for SCR. The non-proliferative stage of the disease is often monitored closely for progression toward PSCR. Treatment options are usually reserved for PSCR, implemented for the active stage of PSCR (stages 3-5). Laser photocoagulation and anti-VEGF injections have proven to be an effective treatment option for PSCR. While vitreoretinal surgery is often reserved for unresolving vitreous hemorrhage and/or tractional RD. Although treatment is often initiated in PSCR, monitoring closely for peripheral non visually threating neovascularization may be a management option in some cases. Neovascularization associated with PSCR has shown spontaneous regression, such as the in the case presented. Yet, reports have also revealed several untreated cases who have progressed, resulting in vision loss. Regardless, close follow up is crucial.
SCR is a common ocular condition in patients with known SCD. Dilated fundus examination is recommended for children (ages 9-13) with known SCD. Ultra-wide imagining, including UWFA, may be especially valuable in this disease. Of note, although dark without pressure is a common benign retinal finding, it may be associated with sickle cell disease in black or Caribbean patient. Any patient who is suspected to have SCD should be screened with complete blood count (CBC), sickledex, peripheral blood smear and plasma hemoglobin electrophoresis.
