Iris neovascularization, increased intraocular pressure and vitreous hemorrhage as risk factors for invasion of the optic nerve and choroid in children with retinoblastoma

A review of 289 eyes enculeated for retinoblastoma to evaluate prognostic factors for involvement of the choroid or optic nerve revealed choroidal invasion in 67 eyes (22%) and optic nerve invasion in 84 eyes (27%) due to retinoblastoma. Intraocular pressure (IOP) > or = 22 mmHg was found in 85 eyes prior to enucleation. A total of 118 eyes (38% showed histopathologic evidence of the development of glaucoma: 90 of them with iris neovascularisation and 28 with angle closure configuration. Patients with elevated IOP, iris neovascularisation and angle closure configuration had a significantly higher risk of optic nerve (P < 0.005) and choroidal (P < 0.002) involvement. On the other hand, optic nerve invasion due to retinoblastoma was significantly more frequent in eyes with elevated IOP (P < 0.02) and iris neovascularisation or angle closure configuration (P < 0.01). Risk factors for choroidal invasion of retinoblastoma were raised IOP (P < 0.04) and iris neovascularisations or angle closure configuration (P < 0.01) (univariant analysis). Raised IOP, iris neovascularisations and vitreous haemorrhage remained significant in the multivariant analysis. This study emphases the importance of IOP, iris neovascularisation and angle closure configuration as risk factors for outspreading invasion due to retinoblastoma.