The following article shares YO clinical knowledge and skills that hopefully will be useful for other YOs. In a two part series, Jelena Potic (Serbia), who is a Fellow in Surgical Retina and Ocular Oncology at the Hôpital Ophtalmique Jules-Gonin, Switzerland, discusses important diagnoses not to miss.
Most Common Childhood Ocular Tumour – Retinoblastoma
Retinoblastoma (RB) is the primary ocular malignancy in the paediatric population, and it was first described nearly 200 years ago as a distinct disease entity by James Wardrop, a Scottish ophthalmologist. In 1920, Verhoeff suggested that the origin of this tumour was in embryonic retinal cells, and he called this disease “retinoblastoma”, which became the accepted term since 1926.
Prior to 20th century, RB was considered as a fatal disease. Nowadays, survival rates in developed countries are over 95%. However, in developing countries, this disease is still difficult to treat and has a lower survival rate. This is often due to late presentation or delayed diagnosis. Unfortunately, in Asia and Africa, about 40% of children diagnosed with RB do not survive.
How to Recognize the Early Symptoms of RB?
To diagnose RB, it is vital to start with good and detailed history.
Age is an important factor, as RB is usually seen in children between 3 months to 3 years of age, and mostly before the 5th year of life. In some children, however, RB can be seen at birth.
Always listen to parents and symptoms they noticed, with special attention paid to the following:
- Leukocoria (white pupillary reflex),
the most common reported concern ( 1)
- Strabismus being the second most common
- Poor vision
- Red eye
- Other signs of extraocular extension,
g. mass lesions on sclera
Information about the gestation period, as well as the family history (including parents and other family members) of RB and other malignant diseases, are also very important.
Clinical Examination of a Child Suspected of RB
Examples of leukocoria, often the first sign of retinoblastoma
Slit lamp examination of the anterior segment will help to determine if there are any anterior chamber seeds or tumour invasion. Other signs of RB in the anterior segment include cataract, neovascularization of the iris, hyphaema, and pseudohypopyon. Intraocular pressure measurement is also needed to check for secondary glaucoma.
A detailed dilated fundus examination with indirect ophthalmoscopy is the most important for the diagnosis of RB. Small tumours are represented usually as round translucent lesions or thickening of sensory retina. With tumour growth, they become more opaque and white, or develop a yellowish appearance, followed with the development of intratumoral blood vessels. Large tumours are represented often with retinal detachment, vitreous and/or subretinal seeding (Figure 2).
Investigations include fundus photography, fluorescein angiography (FA, useful for intratumoural blood vessel detection), ultrasonography, and magnetic resonance imaging (MRI).
Classification and Staging of Retinoblastoma
||RB ≤ 3mm (refers to 3mm in basal dimension or thickness)
||RB > 3mm or
· Macular location (≤ 3mm to foveola)
· Juxta-papillary location (≤ 1.5mm to disc)
· Subretinal fluid ≤3mm from margin
· Subretinal seeds ≤3mm from tumour
· Vitreous seeds ≤3mm from tumour
· Both subretinal or vitreous seeds ≤3mm from tumour
· Subretinal seeds >3mm from tumour
· Vitreous seeds >3mm from tumour
· Both subretinal or vitreous seeds >3mm from tumour
||Extensive RB occupying 50% globe or
· Neovascular glaucoma
· Opaque media from haemorrhage in anterior chamber, vitreous or subretinal space
· Invasion of post-laminar optic nerve, choroid (>2mm), sclera, orbit, anterior chamber
RB can be classified in four different ways:
- Unilateral or bilateral
- Sporadic or familial
- Non-heritable or heritable
- Somatic or germline
There are also several staging systems. The most commonly used is the ICRB (International Classification of Retinoblastoma), which was developed in 2003 (Table 1).
Treatment Modalities for RB
Collaboration with pediatricians is very important at this stage and varies widely between different patients as well as health care systems.
There are several modalities to treat patients with RB. Traditionally, advanced cases of RB were treated surgically by enucleation, or with external beam radiotherapy. However, over the years, the aim of RB treatment has now shifted from simply saving life to conservation of the globe and, more recently, vision retention. This is thanks to new treatments such as intravenous chemotherapy, intra-arterial chemotherapy, focal adjuvant therapies, and intravitreal injection of cytostatic agents.
Figure 2. Example of RB patient with retinal detachment treated with intraarterial chemotherapy (IAC).
A) RB at presentation, B) RB after first IAC C) RB after three IAC
Even though the new and modern treatment modalities are not universally available, formations of dedicated large paediatric oncology centres and international collaboration have made it possible to successfully treat these children and to give the best chance of high quality of life and vision.
The key is to recognize this rare disease early in order to minimise the risk of fatality.