When pancytopenia meets the retina: Bilateral central retinal vein occlusion in idiopathic aplastic anemia

Bilateral central retinal vein occlusion (CRVO) is rare and is most often associated with systemic disorders such as hematological malignancies, hyper-viscosity syndromes, or thrombophilic states.^1–3 Its occurrence in aplastic anemia is exceedingly uncommon.

A 50-year-old woman presented with sudden, painless diminution of vision in both eyes for five days. She also reported generalized weakness and intermittent low-grade fever for one month. There was no history of hypertension, diabetes mellitus, dyslipidemia, thromboembolic disease, connective tissue disorder, or use of medications known to predispose to thrombosis. Best-corrected visual acuity at presentation was 1/60 in the right eye and 2/60 in the left eye. Intraocular pressure was within normal limits bilaterally. Anterior segment examination revealed bilateral nuclear sclerosis, with no evidence of intraocular inflammation. Dilated fundus examination revealed diffuse flame-shaped retinal hemorrhages involving all four quadrants in both eyes, together with optic disc edema [Figure 1a and b]. Notably, the marked venous dilatation and tortuosity typically seen in hyper-viscosity-related CRVO were absent, and the retinal veins appeared attenuated and non-tortuous. Optical coherence tomography (OCT) of the macula was performed in both eyes and demonstrated no macular edema.

Close

Figure 1: (a) Color fundus photograph of the right eye showing diffuse flame-shaped retinal hemorrhages involving all four quadrants, with optic disc edema, consistent with central retinal vein occlusion (CRVO). (b) Color fundus photograph of the left eye demonstrating a symmetric hemorrhagic pattern, with optic disc edema.

Export to PPT

Because severe anemia and thrombocytopenia can themselves produce extensive retinal hemorrhages that may mimic a vein occlusion, a deliberate distinction was made between a true venous occlusive event and anemic (hemorrhagic) retinopathy. The acute and profound symmetric visual loss, the four-quadrant distribution of predominantly superficial (flame- shaped) hemorrhages, and the associated optic disc edema favored a bilateral venous occlusive process rather than purely anemia- and thrombocytopenia-related hemorrhages. The atypical absence of venous engorgement and tortuosity was attributed to the concurrent profound anemia and the consequent reduction in red cell mass and blood viscosity, which can mask the venous distension that characterizes hyper-viscosity-related CRVO. A provisional diagnosis of bilateral CRVO was therefore made, and a detailed systemic evaluation was initiated.

Given the bilateral and simultaneous presentation, the systemic work-up sought a unifying cause. The infective profile, hyper viscosity work-up, and autoimmune work-up—including the antiphospholipid antibody profile and protein C and protein S levels—were within normal limits. Complete blood count revealed pancytopenia (hemoglobin [ 6.2 g/dL], total leukocyte count [2.2× 10⁹/L], and platelet count [10 × 10⁹/L]), prompting a detailed hematological evaluation. Bone marrow examination confirmed marked hypocellularity, consistent with aplastic anemia.

After exclusion of hyper viscosity, thrombophilia, autoimmune, and infective etiologies, a final diagnosis of bilateral CRVO secondary to idiopathic aplastic anemia was made. As OCT demonstrated no macular edema in either eye, intravitreal pharmacotherapy was not indicated at presentation; the patient was started on topical 0.1% nepafenac one drop three times daily in both eyes and was counseled regarding the guarded visual prognosis. Should macular edema subsequently develop, intravitreal anti-vascular endothelial growth factor (VEGF) therapy—the preferred first-line agent for macular edema secondary to CRVO—was planned, with a sustained-release intravitreal dexamethasone implant considered as an alternative in view of the bilateral involvement and the anticipated difficulty with frequent follow-up in a systemically unwell patient. Priority was given to the management of the underlying bone marrow failure under hematology care. The patient was, however, subsequently lost to ophthalmic follow-up.

Although ocular manifestations of aplastic anemia commonly include retinal hemorrhages secondary to anemia and thrombocytopenia, bilateral CRVO is exceptionally rare.⁴ The principal diagnostic challenge in such patients is to differentiate a true venous occlusive event from anemic (hemorrhagic) retinopathy, in which profound anemia and thrombocytopenia produce widespread retinal hemorrhages without genuine venous occlusion. In the present case, the acuteness and severity of visual loss, together with optic disc edema, supported CRVO, whereas the atypical absence of venous tortuosity and engorgement is best explained by the reduced red cell mass and blood viscosity inherent to severe pancytopenia. Severe anemia-related retinal hypoxia, endothelial instability, and venous stasis, compounded by thrombocytopenia, were considered contributory mechanisms in the absence of hypercoagulable or hyper viscosity states.⁵

This photo essay emphasizes the importance of prompt systemic evaluation in patients presenting with bilateral retinal vein occlusion, as ocular findings may serve as the first clinical clue to underlying, potentially life-threatening bone marrow failure.