Size and location decisive in treatment outcome
Retinal haemangioblastoma is a rare disease that is difficult to manage, involving a careful assessment of the balance between potential visual loss caused by the tumour vs. visual loss induced by therapeutic treatments.
When a disease is defined as 'rare
The European Union defines 'rare' as a disease that occurs in 0.05% of the population, i.e. a disease is defined as 'rare' when it affects no more than 5 people per 10,000 inhabitants (1 case per 2,000 inhabitants). This definition is also used in Italy.
Retinal vascularisation
The retina is the photosensitive tissue of the eye and is richly vascularised.
This multitude of blood vessels can grow and proliferate abnormally, either from birth or acquired, giving rise to various retinal vascular tumours.
Types
They stand out four types of retinal vascular tumours:
- Capillary hemangioblastoma (sometimes associated with Von Hippel-Lindau disease).
- Cavernous haemangioma.
- Peripheral vasoproliferative tumours.
- Racemose hemangioma (congenital retinal arteriovenous communications).
Symptoms
Symptoms depend on the type of tumour and its location. Retinal haemangioblastoma and vasoproliferative tumours may exudate, i.e. leak fluid, leading to an exudative retinal detachment, or they may generate proliferations that exert traction on the retina.
In these cases the patient undergoes a progressive decrease in vision. Cavernous and racemose haemangiomas are congenital and if located near the centre of the retina can lead to an insufficient visual development (amblyopia).
Treatment
There are multiple alternatives, depending on the type of tumour, its location and associated complications. The most commonly used treatments are intravitreal injections of drugs that reduce vascular permeability, laser, cryotherapy, vitreoretinal surgery to treat tractional complications or retinal detachment, episcleral brachytherapy, and external radiotherapy. In many cases, combined treatments are necessary. It is a complex pathology that must be treated in a referral centre.
Size and location decisive in treatment outcome
In the specific case of haemangioblastoma, the identification of the best treatment and its correlation with tumour size and location is much debated.
In current clinical practice, asymptomatic non-exudating tumours are generally kept under observation, particularly if they are peripapillary or perimacular, and therapy is undertaken if progressive subretinal fluid loss, exudation, or intra-retinal oedema occurs.
Tumours with peripheral localisation are usually treated early, at the time of diagnosis.
Retrospective clinical study
A retrospective study published in Retina The research team of Dr. Hyesun Kim (South Korea) proposes an aggressive therapeutic strategy with direct photocoagulation for small retinal haemangioblastomas, which generally respond well to treatment.
As the size of the tumour increases, staged therapy is advisable in order to reduce side complications.
For medium to large tumours, TTT (Transpupillary Thermo-Therapy) can be effective with regression rates of 70%.
Transpupillary thermotherapy (TTT) is a technique used today only for the treatment of intraocular neoplasms. It is based on a principle similar to that of classic photocoagulation, but generates a lower rise in choroidal temperature, albeit above 45°C.
Early diagnosis & early treatment of haemangioblastoma
The best treatment protocol therefore implies the earliest possible diagnosis (when the tumour mass is small) and timely therapeutic treatment, also because advanced tumours tend to present vitreoretinal exudation with tractional retinal detachment, peripheral ischaemia and in some cases neovascular glaucoma.
For more details see Retina. 2014;34(12):2479-2486.
On the subject of ocular tumours, see also:
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