Retinoblastoma, an embryonal retinal tumor, is the most common intraocular tumor in kids. More than 50% of children worldwide succumb to the metastatic spread of the illness and die, despite the very high survival rates for retinoblastoma in children in the USA and other industrialized nations. Additionally, there are significant problems that still need to be resolved, such as the associated vision loss and side effects of treatment.

Retinoblastoma has a cumulative lifetime incidence of about 1:20,000 live births, and it makes up 4% of all pediatric cancers. Over 90% of cases are diagnosed in children under the age of five, with the median age of diagnosis being around two years. Most children with retinoblastoma have unilateral tumors, with the others having bilateral tumors. About two thirds to three quarters of those youngsters have unilateral tumors.

Epidemiology:

Epidemiology: Two mutational events are necessary for the development of the retinoblastoma tumor, according to Knudson's "two-hit" model of oncogenesis (chapter 486). The initial mutation in the RB1 gene is passed down by germinal cells in the hereditary form of retinoblastoma, and a second mutation follows in somatic retinal cells. The loss of the normal allele and concurrent loss of heterozygosity are common outcomes of second mutations that cause retinoblastoma.

Hereditary Form of Retinoblastoma: In some cases of retinoblastoma, individuals inherit a single mutated copy of the RB1 gene from one of their parents. This inherited mutation is present in all cells of the body, including germinal cells (sperm or egg cells).

First Mutation: The first mutation (the "first hit") occurs in one of the two copies of the RB1 gene in the germinal cells. This is the initial genetic event that increases an individual's susceptibility to developing retinoblastoma. However, a single mutation is typically not enough to cause cancer.

• Somatic Mutation: For retinoblastoma to develop, a second mutation (the "second hit") must occur in the other, non-mutated copy of the RB1 gene. This second mutation typically occurs in somatic cells (cells of the body that are not germinal cells), specifically in the cells of the retina.
• Loss of Heterozygosity (LOH): The second mutation often results in the loss of heterozygosity, meaning that both copies of the RB1 gene are now mutated or inactivated in the same retinal cell. This loss of normal function of the RB1 gene disrupts the regulation of cell growth and division.
• Tumor Development: The loss of RB1 gene function in retinal cells leads to uncontrolled cell growth and division, ultimately resulting in the formation of retinoblastoma tumors.

Pathogenesis:

Retinoblastoma manifests histologically as a little, rounded blue cell tumor with Flexner-Wintersteiner rosettes. It may develop in any of the retina's nucleated layers and show varying levels of differentiation.

Because retinoblastoma tumors frequently exceed their blood supply, necrosis and calcification ensue. Endophytic tumors, sometimes referred to as vitreous seeding, develop from the inner surface of the retina and spread into the vitreous. Exophytic tumors, which develop from the outer retinal layer, can separate the retina. Both endophytic and exophytic tumors are possible

Clinical signs and symptoms

Leukocoria, a pupillary reflex, is the typical initial sign of retinoblastoma and is frequently discovered when a red reflex is absent during a standard newborn or well-child examination or in a flash shot of the child.

Treatment only 10% of retinoblastoma patients are routinely recognized.

screening for eye diseases in the presence of a favorable family history.

Diagnosis:

The diagnosis of retinoblastoma includes other causes of leukocoria, including persistent hyperplastic primary vitreous, goats disease, cataract, endophthalmitis from Toxocara canis,choroidal coloboma, and retinopathy of prematurity.

Treatment:

 The type of sickness the child has—hereditary or sporadic—as well as the size and location of the tumors—determine the course of treatment. Always, the main objective of treatment is to cure; additional objectives include maintaining vision and the eye itself.

Primary enucleation is being performed less frequently as new techniques for the local management of intraocular malignancies and more efficient systemic chemotherapy have emerged.

Most unilateral diseases manifest as a single, sizable tumor. If there is no chance for the recovery of usable eyesight, enucleation is done. The conventional method of enucleating the most seriously damaged eye and irradiating the other eye in cases of bilateral illness was replaced with chemoreduction in conjunction with Focal treatment.All first degree relatives of children with hereditary retinoblastoma, whether known or suspected, should have

FAQs:

Q:What is retinoblastoma?

Ans:Retinoblastoma is an eye cancer that begins in the retina — the sensitive lining on the inside of your eye.

Q:What is the most common cause of retinoblastoma?

Ans:A genetic mutation (a change in the child's genes) causes retinoblastoma. The gene that causes retinoblastoma is called RB1.

Q:How long is treatment for retinoblastoma?

Ans:If systemic chemotherapy (chemotherapy given by vein) is used, it is typically given for about 6 months 

     to shrink the tumor as much as possible.

Q:What is the main treatment for retinoblastoma?

Ans: Surgery (Enucleation) for retinoblastoma. Radiation therapy for retinoblastoma. Laser therapy (Photocoagulation or Thermotherapy) for retinoblastoma.

Q:What age does retinoblastoma occur?

Ans: The average age of children is 2 when it is diagnosed. It rarely occurs in children older than 6. 

Conclusion:

Approximately 95% of  children with retinoblastoma are cured with modern treatment in the USA. Current efforts using chemotherapy in combination with focal therapy are intended to preserve useful vision and avoid external - beam or enucleation. Routine ophthalmologic examinations should continue until children are over age 7y.