Table 1.

Tabular representation of the Reese Ellsworth’s Classification of Retinoblastoma

Groups	Likelihood of salvage	Features used to classify the tumour
I	Highly favourable	1a: Solid, solitary tumour that is less than 4-disc diameter in size and is present behind the equator or at the equator.
		1b: Multiple tumours with the largest of them not exceeding 4-disc diameters in size present behind or at the equator.
II	Favourable	2a: Solitary tumour behind or at the equator ranging between 4–10-disc diameters in size.
		2b: Multiple tumours ranging between 4–10-disc diameters in size behind the equator.
III	Doubtful	3a: Tumour is anterior to the equator of the eye.
		3b: Single tumour that is larger than 10-disc diameters behind the equator.
IV	Unfavourable	4a: Multiple tumours with some being larger than 4-disc-diameters in size.
		4b: Tumour extending past the ora serrata of the eye
V	Highly unfavourable	5a: Tumour large enough to involve more than half of the retina.
		5b: Vitreous seeding