Tim Stout

Retinoblastoma Presenting as Strabismus and Leukocoria

Figure 2. Close-up examination showing total retinal detachment in an eye filled with white tumor. A 22-month-old otherwise healthy girl presented for evaluation of an inturned left eye of 3 months duration. She had been followed approximately every 6 months via red-reflex evaluation by her pediatrician, who noted a dramatic change over a 4-month period. External examination revealed a left esotropia with leukocoria (Figure 1). Ophthalmologic examination revealed a normal right eye and total retinal detachment in a tumor-filled left eye (Figure 2). Magnetic resonance imaging showed a large heterogeneous mass filling the left globe with extension into the left optic nerve head, but no metastases or secondary lesions. Further questioning disclosed that the child’s mother had bilateral retinoblastoma requiring enucleation of both eyes 38 years earlier at 4 months of age. Retinoblastoma is the most common primary intraocular malignancy of childhood. It is caused by a mutation to the retinoblastoma tumor-suppressor gene on the long arm of chromosome 13. Affected children often present with strabismus, leukocoria, and amblyopia. Patients with bilateral disease are presumed to have germline mutations and have a 45% chance of having a child with retinoblastoma. Genetic counseling is an important part of the management of patients with retinoblastoma. Treatment varies depending on tumor size, number, and location. Current treatments include laser photocoagulation, thermotherapy, cryotherapy, local or systemic chemotherapy, external-beam radiotherapy, brachytherapy, and enucleation. Historically, treatment for survival involved enucleation, but current treatments have trended toward vision and globe-sparingmodalities. In de-