What is a significant indicator of retinoblastoma in children?

The absence of a light reflex, or the presence of a "white pupillary reflex," is a significant indicator of retinoblastoma in children. This condition is characterized by an abnormal growth of retinal cells and can lead to a critical loss of vision if not identified early. In a normal eye, when light is shone into it, a red reflex is observed due to the reflection of light from the retina. However, in cases of retinoblastoma, the tumor can block this reflex, leading to a noticeable absence of light reflex or a white appearance instead. This finding is often referred to as " leukocoria," which can be alarming and prompts further investigation for possible retinoblastoma.

In contrast to the correct answer, other symptoms such as cotton wool spots, severe itching, or painful lesions on the eyelids are not direct indicators of retinoblastoma. Cotton wool spots can occur in a variety of ocular conditions and do not specifically signify retinoblastoma. Severe itching of the eyelids might indicate allergic reactions or other benign conditions but is not associated with the presence of a retinal tumor. Painful lesions on the eyelids may suggest local infection or dermatological issues rather than a retinal pathology like retinoblastoma. Therefore