A choroidal hemangioma is a non-cancerous tumor composed of abnormal blood vessels. This growth is located in the choroid, a blood vessel-rich layer situated between the retina and the sclera, the white part of the eye. The tumor is benign, meaning it does not spread, and its presence is sometimes compared to a birthmark inside the eye. The exact cause is not fully understood, but it is considered a congenital condition present from birth. The primary concern is its potential to affect sight, so management focuses on preserving vision.
Types and Associated Conditions
Choroidal hemangiomas are classified into two main types: circumscribed and diffuse. The distinction is based on the tumor’s structure and if it is an isolated finding or part of a broader medical condition.
The more common type is the circumscribed choroidal hemangioma. This form appears as a solitary, well-defined, orange-red mass, typically located in the posterior part of the eye. These tumors are generally isolated and not linked to any other systemic health issues. Circumscribed hemangiomas are diagnosed in adults between their third and sixth decades of life, usually when they begin to cause visual symptoms.
In contrast, the diffuse choroidal hemangioma is more spread out and lacks clear borders. This type involves a larger portion of the choroid, giving the back of the eye a distinctive reddish appearance often described as a “tomato-ketchup fundus.” A diffuse hemangioma is almost always associated with Sturge-Weber syndrome, a congenital disorder that can also involve port-wine birthmarks on the face and neurological issues. This form may not cause vision problems until later in childhood or adolescence.
Symptoms and Complications
Many choroidal hemangiomas, particularly small, circumscribed ones, are asymptomatic and may only be discovered during a routine dilated eye exam. When symptoms do occur, they are not caused by the tumor invading the retina, but by its secondary effects. The primary cause of symptoms is fluid leakage from the hemangioma’s abnormal blood vessels.
This fluid, called subretinal fluid, can accumulate underneath the retina, causing it to swell or even detach from the back of the eye. This condition is known as an exudative retinal detachment. When the fluid affects the macula, the central part of the retina responsible for sharp, detailed vision, the visual consequences are most pronounced. Patients might experience:
- Blurred or distorted vision, where straight lines appear wavy (metamorphopsia)
- The perception of flashing lights (photopsia)
- The appearance of floaters in the field of vision
- The development of a blind spot (scotoma)
The Diagnosis Process
The diagnosis of a choroidal hemangioma often begins during a comprehensive eye examination. Through a dilated pupil, an ophthalmologist may spot a reddish-orange mass on the choroid that suggests a hemangioma. While this observation is a first step, a definitive diagnosis requires specialized imaging tests to confirm the tumor’s identity and rule out other conditions.
Ocular ultrasound is a non-invasive procedure that uses sound waves to create images of the eye’s internal structures. An A-scan measures the tumor’s high internal reflectivity due to its dense vascular structure, while a B-scan provides a two-dimensional view of its dome-like shape and thickness.
Optical coherence tomography (OCT) is a high-resolution imaging technique that provides a cross-sectional view of the retinal layers. An OCT scan can precisely show the presence and amount of subretinal fluid or swelling within the retina, which helps explain a patient’s visual symptoms.
Fluorescein angiography involves injecting a yellow dye, fluorescein, into an arm vein. As the dye circulates, a special camera photographs the blood vessels in the retina and choroid. In a choroidal hemangioma, the dye shows a characteristic pattern of filling the tumor’s vessels early on, followed by leakage into the surrounding tissue in later phases. This helps differentiate it from other types of ocular tumors.
Treatment Approaches
The management of a choroidal hemangioma depends on the tumor’s size, location, and whether it is causing symptoms. Treatment is not always necessary, as asymptomatic hemangiomas that are not leaking fluid or threatening vision are monitored with regular check-ups and imaging tests to ensure the tumor remains stable.
When a hemangioma becomes symptomatic and leaks fluid that affects vision, treatment is initiated. The goal of any intervention is not to eliminate the tumor, but to reduce the fluid leakage, allow the retina to reattach, and thereby preserve or recover vision.
One of the most common treatments is photodynamic therapy (PDT). This procedure involves injecting a light-sensitive drug, verteporfin, into the bloodstream. The drug accumulates in the hemangioma’s abnormal blood vessels, and a low-energy laser is then aimed at the tumor to activate the drug, causing the vessels to close and stop the leakage.
In some cases, laser photocoagulation may be used. This technique employs a higher-energy laser to create small burns on the tumor’s surface to seal leaking blood vessels, but it is generally used for tumors located away from the central part of vision. For larger tumors or those that do not respond to other therapies, radiation therapy, such as plaque radiotherapy, may be considered. This involves placing a small, radioactive shield on the outside of the eye over the tumor to deliver targeted radiation.