DEFINITION

Retinoblastoma is a cancer of the retina. It is a rare (1 in 20,000) tumor of the retina mostly affecting young children, under 5 years of age.

Retina is a thin membrane on the back portion of the eye that works like a camera, on which images are formed making things visible for us. Retina possess certain photoreceptors, cells which catch light in the retina. These cells due to mutation lead to some small round like structures, rosettes  which gather together forming a tumor. This tumor has areas of hemorrhage, thus breaking it in small portions which remains afloat in the viscous fluid in the eye.
These small tumors are called "vitreous seeds". This further goes on spreading firstly throughout the retina and further to other eye tissues, in the socket. then the optic nerves and further to brain and bones to bone marrow (thus, cancerous).

CAUSE

Hereditary Retinoblastoma: Caused by an inherited gene mutation; usually characterized by retinoblastoma in both eyes. If it occurs in only one eye, it soon affects the other eye.
Non Hereditary: Retinoblastoma affecting only one eye usually not inherited.
 

SYMPTOMS

• Appearance of strange light or whiteness in the pupil of the eye under certain lighting conditions (leukocoria or cat's eye reflex)
• Squint (crossed eye) - strabismus
• Poor vision
• Painful red eye
• Inflammation of the tissue surrounding eye
• Protrusion of the eye ball (proptosis) etc.

TYPES
Unilateral retinoblastoma: Tumors in one eye (60% cases)
Bilateral retinoblastoma:    Tumors in both the eyes (40% cases)
Familial retinoblastoma: Tumors occurred in relatives

DIAGNOSIS

• Physical exam and complete medical as well as family history
• Examination of eye with dilated pupil
• Ultrasound exam
• CT scan (CAT scan)
• MRI (Magnetic Resonance Imaging)
• Lumbar puncture
• Bone marrow aspirate

The above methods assist the ophthalmologist to detect the presence and the stage of the cancer so as to take appropriate actions.
 

TREATMENT

• Radiation therapy
• Photocoagulation
• Cryotherapy (for small tumors)
• Laser Surgery (for small tumors)
• Thermotherapy (for small tumors)
• Chemotherapy (chemo reduction)
• Enucleation (for large tumors)
• External Beam Radiation therapy
• Focal therapy (laser, cryotherapy, or radioactive plaques)
• Local Chemotherapy (subtennon’s carboplatin injections)
• Systemic Chemotherapy followed by Focal and Local therapy
• Surgery done, as a last option when vision cannot be saved