This is rare benign hamartoma of the choroid. Hamartomas are normal tissues in the wrong place – they are not malignant.
Choroidal haemangiomas occur in 2 forms:
i) an isolated circumscribed lesion
ii) a diffuse form associated with Sturge-Weber syndrome.
The isolated variant is usuallly a smooth round, orange-red mass found posterior to the equator with somewhat indistinct edges. Vision may be affected particularly when associated with exudation (cystoid macular oedema and/or serous retinal detachment), hyperopic shift, degeneration of the overyling retina and very rarely, the presence of a choroidal neovascular membrane. Over the long-term, about 50% of patients have vision less than 6/60, 75% less than 6/15.
Treatment is only indicated for loss of vision and classically takes the form of proton beam radiotherapy or brachytherapy (radioactive discs sewn onto to the sclera behind the tumour for 3 to 4 days). These treatments themselves may induce vision loss. More recently, standard AMD photodynamic therapy has been tried with encouraging results. A report by Boixadera et al in Ophthalmology Jan 2009 demonstrated elimination of the serous retinal detachment in almost all cases, elimination of cystoid macular oedema and a reduction in tumour height. One to 4 treatments were given at 3 monthly intervals over a year. After conventional treatments, recurrences are common and we await long-term follow-up of these patients with interest.