Reese - Ellsworth classification for intraocular tumours

Last reviewed 01/2018

Developed in the 1960s this classification isused when surgery and external-beam radiation therapy (EBRT) were the primary treatment options (1).

  • is used to predict the outcome in patients who were treated with EBRT (2)
  • this system is based on number, size and location of tumours and the presence of vitreous seeding (1)

The classification system has five groups:

  • Group I: very favourable prognosis
    • A: Solitary tumour, smaller than 4 disc diameters in size, at or behind the equator
    • B: Multiple tumours, none greater than 4 disc diameters in size, all at or behind the equator

  • Group II: favourable prognosis
    • A: Solitary tumour, 4–10 disc diameters in size, at or behind the equator
    • B: Multiple tumours, 4–10 disc diameters in size, all at or behind the equator

  • Group III: doubtful prognosis
    • A: Any lesion anterior to the equator
    • B: Solitary tumour, larger than 10 disc diameter, behind the equator

  • Group IV: unfavourable prognosis
    • A: Multiple tumours, some greater than 10 disc diameters
    • B: Any lesion extending anteriorly to the ora serrata

  • Group V: very unfavourable prognosis
    • A: Massive tumours involving more than half of the retina
    • B: Vitreous seeding (3)

With the introduction of newer treatment modalities (e.g. - chemotherapy) which have replaced EBRT, the usefulness of this classification system is less apparent (2). 

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