Retinoblastoma treatment — eye-sparing options explained

Retinoblastoma is a cancer that begins in the retina — the light-sensitive layer at the back of the eye that sends visual information to the brain. It is almost exclusively a cancer of young children; most diagnoses occur in children under five years of age, and a significant proportion are detected in infants under two. It can affect one eye (unilateral retinoblastoma) or both eyes simultaneously (bilateral retinoblastoma). The cancer arises when retinal cells that are still developing carry a specific genetic change — an alteration in a gene called RB1. In the hereditary form, children inherit a faulty copy of RB1 from a parent and are at risk of developing retinoblastoma in both eyes and, later in life, other cancers. In the non-hereditary form, the genetic change occurs spontaneously in a single retinal cell, and only one eye is typically affected. Retinoblastoma is not caused by anything the parents did during pregnancy.

Leukocoria — the white pupillary reflex, sometimes called “cat’s eye reflex” or “white glow” — is the most common first sign of retinoblastoma that a parent notices. In a photograph taken with a flash, a normal eye reflects the flash as a red dot (the familiar “red-eye” effect). In an eye affected by retinoblastoma, the flash reflects off the white tumour surface instead of the normal red retinal blood vessels, producing a pale or white glow in the pupil. Parents often first notice this in family photographs or when light catches the child’s eye at a certain angle. Other warning signs include a new and persistent squint (strabismus) in a child with no previous squint history, a visibly red or painful eye, a change in the colour or appearance of the iris, or a child who appears not to be tracking objects normally with one eye. Leukocoria is not always cancer — several other conditions can cause a white pupil reflex — but any white pupillary reflex in a child warrants urgent assessment by an ophthalmologist.

Eye-sparing treatment means treating retinoblastoma in a way that preserves the eye and as much vision as possible, rather than removing the eye surgically. Modern retinoblastoma treatment has shifted strongly toward eye-sparing approaches over the past two decades, and a significant proportion of children — especially those with smaller or less-advanced tumours — can now keep their eye with preserved or functional vision. Eye-sparing options include intravenous chemotherapy to shrink tumours, intra-arterial chemotherapy delivered directly into the eye’s blood supply, laser therapy (photocoagulation) and cryotherapy (freezing) applied to small tumours on the retinal surface, and intravitreal chemotherapy injected directly into the vitreous cavity of the eye for certain intraocular disease. Whether eye-sparing treatment is possible depends on how advanced the tumour is at the time of diagnosis, how many tumour sites there are in the eye, whether the tumour has reached the optic nerve or extended beyond the eye, and the overall health of the child. The International Classification of Retinoblastoma (ICRB) groups tumours into groups A through E, from smallest and most treatable to most advanced. Eyes with very advanced disease (group E) often require removal to ensure the cancer does not spread. The decision is always made by a multidisciplinary team, weighing the chance of saving the eye against the safety of the child.

Intra-arterial chemotherapy (IAC) — sometimes called ophthalmic artery chemosurgery — is a technique that delivers chemotherapy medicine directly into the ophthalmic artery, the main blood vessel that supplies the eye. A thin, flexible tube (catheter) is guided through a large artery in the groin all the way up to the ophthalmic artery under imaging guidance, and the medicine is then infused precisely at the site where it is needed. Because the medicine goes directly to the eye rather than travelling through the whole bloodstream, higher concentrations can be delivered to the tumour with far less effect on the rest of the body than standard intravenous chemotherapy. IAC has significantly improved the ability to preserve eyes that previously would have required removal, and it is now a standard part of retinoblastoma care at specialist centres. Not every child is a candidate for IAC — suitability depends on tumour group, the size and anatomy of the blood vessels, and whether the tumour has extended outside the eye. The procedure requires general anaesthesia in children and is performed by an experienced interventional team.

Enucleation — the surgical removal of the affected eye — is recommended when the tumour is so advanced that eye-sparing treatment cannot be safely offered, or when the risk of the cancer spreading outside the eye outweighs the benefit of attempting to save it. This most often applies to eyes classified as group E under the International Classification of Retinoblastoma, or to eyes where the tumour has reached or crossed the optic nerve. While losing an eye is a profound experience for any family, it is important to understand that enucleation is curative for most children with disease that has not spread beyond the eye, and it completely removes the source of cancer. Children adapt remarkably well to monocular vision; the remaining eye compensates, and children attend school, play sport, and lead full lives. A prosthetic eye (ocular prosthesis) is fitted after the socket has healed — typically within four to six weeks of surgery. Modern prostheses are carefully matched in colour and move naturally with the socket muscles, making them visually indistinguishable in most situations. Regular follow-up with the oncology team continues after surgery, and the child will also need monitoring for the hereditary form of retinoblastoma if relevant.

Yes. Hereditary retinoblastoma is caused by a change (mutation) in the RB1 gene that can be passed from parent to child. Children with the hereditary form have this change in every cell in their body, not only in the retinal cells. This has two important implications. First, siblings and other first-degree relatives of a child with bilateral retinoblastoma, or a child with unilateral retinoblastoma that is found to be hereditary on genetic testing, have a meaningful chance of also carrying the mutation and should be offered genetic testing and ophthalmic screening. Second, children who carry the RB1 mutation have a higher-than-average lifetime risk of developing other cancers, particularly certain sarcomas, later in life — which means long-term oncological follow-up is recommended even after retinoblastoma is successfully treated. Genetic testing (usually a blood test) can identify whether the RB1 mutation is present, and the results have significant implications for the whole family. A paediatric oncology team with genetic counselling support will guide the family through this process.