Capillary hemangioma or “strawberry nevus”, an abnormal growth of vascular tissue, is the most common vascular ocular tumor in children. It is more commonly seen in females with a ratio of 3:2, and its incidence is higher in premature babies. There is no apparent familial inheritance pattern.
This condition is congenital. A recent study suggested that capillary hemangioma could be a sequestered tissue of placental origin that grows rapidly due to post-natal escape from the intra-uterine factors, controlling placental growth.
Its natural course is unique. In one-third of cases, the vascular lesion is present at birth. It is usually small during the first few weeks of life. Then, it progressively increases in size over the next 3-6 months. This phase is followed by a period of stabilization and a period of spontaneous regression by the age of 4-7 years. Thirty percent regress by 3 years old, 60% by 4 years, and 70% by 7 years.
Most of the lesions are benign, but amblyopia may occur if the mass causes ptosis of the eyelid, blocking the visual axis. Even a small amount of ptosis can cause significant amblyopia. The prevalence of amblyopia ranges from 40-60% in orbital lesions. Bulky tumors often cause distortion of the eyeball causing corneal astigmatism. The astigmatism may resolve partially, particularly if the tumor regresses early. Prolonged occlusion of the visual axis may also lead to myopia, and the resultant inequality in the refractive error of the two eyes (anisometropia) may be another contributory factor in the development of amblyopia. Secondary strabismus may develop as a result of interruption of binocular vision.
Systemic complications of capillary hemangiomas are rare. An example is the Kassabach-Merrittt syndrome, a blood clotting problem due to consumption and entrapment of blood components within a large vascular hemangioma, often located in the viscera. It usually responds to platelet replacement and systemic corticosteroids. PHACE syndrome (posterior fossa malformations, hemangiomas, arterial anomalies, coarctation of the aorta and cardiac defects, and eye abnormalities) is not a complication of capillary hemangioma. It is a rare condition that proves an association between large facial capillary hemangiomas and cerebral and ocular malformations. “Morning glory disc” is an eye abnormality associated with capillary hemangiomas. This optic disc abnormality has visual implications.
It is very important that an accurate diagnosis is reached to plan treatment for this self-limiting condition. This will certainly help in reassuring anxious parents of children with cosmetically obvious lesions that no active treatment is necessary initially.
Clinical diagnosis is often enough in majority of cases. The lesion is commonly found in the upper lid or orbit, and its appearance depends on the depth of involvement. Superficial tumors have a red lobulated strawberry appearance, which gave rise to the name “strawberry nevus”. They may increase in size or become bluish with crying. Deeper tumors appear bluish or may show no significant skin color change. The diagnosis can be facilitated by everting the eyelid to visualize the vascularity of the hemangioma. Approximately one-third of lesions is located deep in the orbit, and may present with proptosis only, without any associated skin discoloration. A helpful diagnostic sign is an increase in proptosis with crying. Occasionally the proptosis may be severe enough to cause corneal exposure. In other cases, the enormous growth may obliterate facial structures.
Neuroimaging such as CT scan and MRI are recommended for cases that are difficult to diagnose based on clinical findings. These investigations will document the extent of the tumor. MRI will delineate the tumor better.
Treatment is conservative as much as possible, with treatment of significant refractive error and amblyopia, while awaiting spontaneous regression. Active treatment to reduce the size of the lesion is indicated only if there is occlusion of the visual axis or if a posterior lesion results in progressive proptosis with evidence of optic nerve compression, corneal exposure and significant and progressive amblyopia brought about by obscuration of vision or astigmatism. The list of choices for treatment is not long.
Corticosteroid injection is the most effective treatment for large hemangiomas that block the visual axis. There have been a few isolated reports of visual loss secondary to retrograde embolization of the central retinal artery during intralesional steroid injection but this can be avoided if the volume of injection is limited to a minimum. Steroid injections are most effective when done early in infants younger than 8 months of age. Repeat injections can be given every 6 weeks; however, long-term local steroid injections can cause hormonal imbalance and growth retardation.
Sight-threatening lesions which failed to respond to intralesional steroid may be amenable to treatment with interferon. However, it involves daily injections for several weeks and the response to this treatment is slow.
Some advocate systemic corticosteroids, however, they can cause significant side effects and do not deliver a large enough dose to significantly shrink most tumors. Lesions not limited to the orbital region are treated in conjunction with the dermatologist, who (after discussing side effects) gives oral steroids. Once again, early treatment appears to be more effective. Oral steroids should be tapered slowly because rebound phenomenon has been noted after abrupt discontinuation, with an increase in the size of capillary hemangioma.
Surgical excision is reserved for small localized lesions. It is usually avoided in larger lesions because of the risk of considerable bleeding, and because the infiltrative nature of the lesion requires removal of large amounts of skin. Surgery is indicated after failure with steroids.
Laser procedures are limited by the scarring that they produce.