**Conflict of interest**

*Retinoblastoma - Past, Present and Future*

The common chemotherapeutic agents that are mostly used are carboplatin and topotecan. Experimental work showed that carboplatin peaks in the vitreous after 30 min of periocular injection and lasts for hours. Its concentration in the vitreous is approximately seven times more than that achieved by intravenous chemotherapy [76]. Several periocular drug administrative devices were explored and these include: plain liquid, Lincoff balloon, fibrin sealant, nanoparticles and iontophore-

This treatment modality fortunately has no systemic side effects. Ocular complications do occur, and these mostly affect the periorbital tissue possibly owing to local toxicity. The most common observed side effects are lid edema, lid erythema, periorbital pseudocellulitis, ptosis, orbital fat atrophy, optic nerve atrophy and muscle fibrosis causing ocular motility changes [7, 77, 78, 82, 83]. Concerns were raised regarding the toxic effect on the extraocular muscles; yet, a study examining the effect of sub-tenon topotecan on the extraocular muscles of 10 eyes concluded that it had no toxic effect on the muscles and it is a safe and

Although the number of studies on POC is limited overall, it had been shown that POC is principally effective when combined with other modalities of antineoplastic therapies. One long-term follow up study demonstrated that 39% (n = 33 eyes) of the enrolled eyes were saved when treated with POC in addition to other concurrent treatment modalities. The same report indicated that two eyes treated by POC as monotherapy were cured and remained disease free on

In the last two decades, significant new approaches have been employed in the treatment of retinoblastoma which is a curable disease when diagnosed early. Modalities to avoid enucleation and minimize the short and long term effects of exposure to systemic chemotherapy and radiation therapy continue to evolve and now set the platform in the treatment of retinoblastoma. Despite new techniques such as selective intra-arterial and intravitreal chemotherapy, it is paramount to individualize therapy according to multiple factors including patient age, tumor location, stage of disease, size, and extension, along with realistic visual expectations. Personalized medicine will be able to tailor therapy with the best response

We would like to thank the College of Medicine Research Center, Deanship of Scientific Research, and Ophthalmology Department at King AbdulAziz University Hospital under King Saud University, Riyadh, Saudi Arabia for funding and sup-

**5.2 Chemotherapeutic agents**

sis [76, 79–81].

**5.3 Complications**

effective alternative [84].

follow up [82].

**6. Conclusions**

**Acknowledgements**

porting this chapter.

**5.4 Outcomes and success rate**

and safety in children with retinoblastoma.

**80**

The authors have no conflict of interest to disclose.
