Review of Retinoblastoma and Report of Three Cases of Bilateral Retinoblastoma

Retinoblastoma is a retinal malignant tumor that occurs in early childhood. The annual incidence of retinoblastoma is approximately one per 14 000 live births. 250 to 300 new cases are reported in the United States each year. It develops due to inactivation of both alleles of the retinoblastoma susceptibility (RB1) gene. All hereditary cases (55%) are with bilateral and multifocal lesions, but in non hereditary cases (45%), retinoblastoma is always unilateral and unifocal. Leukocoria (white reflection of pupil) and strabismus are the most frequent clinical manifestations of retinoblastoma. In funduscopy under general anesthesia, the lesion appears as a white tumor with angiomatous dilatation of the vessels. Treatment approaches include chemotherapy, focal laser, enucleation and radiotherapy. The goals of treatment are eye preservation and improvement in patient survival rate reduction of local tumor relapse and recurrence and development of new tumors. Follow up is by general and complete eye examination in order to diagnose related malignancies, especially in cases of radiotherapy. We report three bilateral retinoblastoma cases (10 months, 5 and6 years old) with strabismus and visual loss. Imaging showed involvement of both globes without CNS involvement. The tumor was controlled by providing adequate treatment for the cases.