Table 1.

International intraocular Rb classification [1].

Group A: very low risk

Small discrete tumors not threatening vision

(i) All tumors are 3 mm or smaller, confined to the retina

(ii) Located at least 3 mm from the foveola and 1.5 mm from the optic nerve

(iii) No vitreous or subretinal seeding

Group B: low risk

No vitreous or subretinal seeding

(i) Tumors of any size or location not in group A

(ii) No vitreous or subretinal seeding

(iii) Subretinal fluid no more than 5 mm from tumor base

Group C: moderate risk

Focal vitreous or subretinal seeding and discrete retinal tumors of any size and location

(i) Local, fine, and limited seeding

(ii) Discrete intraretinal tumors of any size and location

(iii) Up to one quadrant of subretinal fluid

Group D: high risk

Diffuse vitreous or subretinal seeding

(i) Diffuse intraocular disseminated disease

(ii) Extensive or “greasy” vitreous seeding

(iii) Subretinal seeding may be plaque-like

(iv) More than one quadrant retinal detachment

Group E: very high risk

Very high risk with one or more of the following:

(i) Irreversible neovascular glaucoma

(ii) Massive intraocular hemorrhage

(iii) Aseptic orbital cellulitis

(iv) Tumor anterior to anterior vitreous face

(v) Tumor touching the lens

(vi) Diffuse infiltrating Rb

(vii) Phthisis or prephthisis