Table 1 The Reese Ellworth classification
From: Retinoblastoma
Group I |
a) solitary tumor, < 4 disc diameters in size, at or behind the equator |
b) multiple tumor, none > 4 disc diameters in size, at or behind the equator |
Group II |
a) solitary tumor, 4–10 disc diameters in size, at or behind the equator |
b) multiple tumor, 4–10 disc diameters in size, behind the equator |
Group III |
a) any lesion anterior to the equator |
b) solitary tumor >10 disc diameters behind the equator |
Group IV |
a) multiple tumors, some >10 disk diameters |
b) any lesion extending anteriorly to the ora serrata |
Group V |
a) massive tumors involving more than half the retina |
b) vitreous seeding |