# When the Air Gets Thin, and the Blood Gets Thick: Choroidal Hemangioma in High-Altitude Polycythemia

## TL;DR

A rare case of choroidal hemangioma is reported in a soldier at high altitude, showing how hypoxia and blood thickening may worsen this eye condition.

## Contribution

Highlights a novel association between high-altitude polycythemia and choroidal hemangioma.

## Key findings

- Choroidal hemangioma was diagnosed in a patient with high-altitude polycythemia.
- Therapeutic phlebotomy and aflibercept injection improved the patient's condition.
- Chronic hypoxia may contribute to choroidal vascular changes.

## Abstract

Choroidal hemangioma is a rare benign vascular tumor that can cause visual impairment due to associated subretinal fluid. Systemic factors influencing its presentation and activity are not well-understood. We report a unique case of choroidal hemangioma diagnosed in a patient who developed high-altitude polycythemia, highlighting the possible role of systemic hypoxia and blood hyperviscosity in aggravating choroidal vascular tumors. A 36-year-old male soldier, posted at an altitude of approximately 16,300 feet, presented with painless diminution of vision in the right eye. Fundus examination revealed an orange-red, elevated lesion located superior to the optic disc, approximately two disc diameters in size, with subretinal fluid extending to the fovea, suggestive of choroidal hemangioma. Hematological work-up revealed hemoglobin 18.8 g/dL and hematocrit 60.6%, consistent with high-altitude polycythemia. The serum erythropoietin level was normal, while the JAK 2 mutation and antinuclear antibody (ANA) were negative. Lipid profile demonstrated hypertriglyceridemia (525 mg/dL) and elevated very low-density lipoprotein (VLDL) (105 mg/dL). The patient underwent three sessions of therapeutic phlebotomy, following which the hemoglobin decreased to 16.6 g/dL. The patient also received a single intravitreal Eylea (aflibercept) injection, following which the subretinal fluid subsided significantly. The patient was subsequently advised to avoid future high-altitude exposure after his hematocrit normalized and visual acuity improved. Awareness of systemic contributory factors is important in the evaluation and management of choroidal vascular tumors. Choroidal hemangioma in the setting of high-altitude polycythemia is rare. Chronic hypoxia-induced hyperviscosity may contribute to vascular dilation and permeability changes within the choroid. Recognition of this association is crucial for timely diagnosis and effective management of choroidal hemangioma to preserve vision.