Retinoblastoma is the most common primary ocular malignancy in children, and until recently was a major cause of childhood blindness, and, occasionally, death. In the last two decades, major advances in chemotherapy, delivered directly to the eye, have reduced the need for systemic chemotherapy, while maintaining good survival rates as well as eye / vision retention.
Retinoblastoma affects about 1 in every 30,000 children; at Ticho Eye Associates, we see 1-3 new cases/year. As there are only around three centers specializing in inter-arterial chemotherapy for retinoblastoma in the nation, these children are typically co-managed, with the chemotherapy performed in Philadelphia or New York, and local follow-up examinations as needed to reduce family travels.
When the retinoblastoma tumors respond to treatment, they generally regress in four different patterns. In Type 1 regression, the tumor has a calcified remnant; in Type 2 a non-calcified remnant; Type 3 regressed tumors have both calcified and non-calcified remnants; and Type 4 regression leaves an atrophic scar.
Monitoring these regressing tumors is an extended process over many years, requiring multiple dilated eye examinations. One newer method of detecting tumor regression – or reactivation – involves the use of optical coherence tomography (OCT), which can show tumor details which are invisible to regular eye examination.
An OCT technique variation which details the local blood supply (OCT angiography) was the subject of a recent retinoblastoma study from Duke University (Oph Surg Laser Imaging Ret 2020;51:43). This study present the first description of OCTA features in treated retinoblastoma.
While OCTA has previously demonstrated large superficial feeder vessels around untreated tumors, the Duke study demonstrated that even inactive lesions with type 1, 2 and 3 regression also have persistent intrinsic vascularity. In contrast, type 4 (atrophic scar) regression was characterized by absence of blood flow (“flow void”) on OCTA.
OCT angiography has a big advantage over standard fluorescein angiography, in that no injections are required, using laser light reflectance of the surface of moving red blood cells to accurately depict vessels. “I’m looking forward to applying this study results on our retinoblastoma patients,” said Benjamin Ticho, MD. “OCTA has been a big asset in monitoring diabetic and macular degeneration diseases, but now it may make monitoring just a little easier for these pediatric tumor patients.”