Requirement: enucleation for retinoblastoma
Histologic parameters:
(1) choroidal involvement
(2) scleral involvement
(3) optic nerve involvement
(4) anterior segment involvement (ciliary body or iris)
Low risk group – all of the following:
(1) no or minimal choroidal involvement
(2) no optic nerve involvement or prelaminar involvement
(3) no involvement of the anterior segment
High risk group – any of the following:
(1) optic nerve involvement at the surgical margin
(2) extrascleral extension
All other patients were intermediate risk – any of the following:
(1) massive (extensive deep) choroidal involvement
(2) intralaminar and/or retrolaminar involvement of the otpic nerve
(3) involvement of the anterior segment
where:
• Lamina refers to the lamina cribrosa
• High risk corresponds to Stage II of the International Retinblastoma Staging System.
