Study looks at potential of suppressing ocular cancer in children

Researchers say they have been able to pin down the stage when the retina develops in humans—and when retinoblastoma, the most common ocular cancer in young children, gets its start.

The study was published Sept. 13 in PNAS (Proceedings of the National Academy of Sciences of the United States of America.) Researchers were associated with the Vision Center at Children's Hospital Los Angeles and the University of Southern California, Los Angeles.

Retinoblastoma (RB) affects 1 in every 20,000 children in this country, primarily around the age of 5.

Study researchers say that retinoblastoma forms from mutations in the RB1 gene and the loss of functional RB protein. In their study, they compared the development of these mutations in human and mouse models, concluding that they developed differently and called into question the accuracy of mouse retinoblastoma models used in research. The more accurate the model, they say, the more opportunity there is "to improve treatment and prevent tumorigenesis in genetically predisposed children.

"In conclusion, our data supports a model in which human RB-deficient maturing cone precursors initially form proliferative lesions that resemble differentiated retinoblastomas in which the majority of cells exits the cell cycle to form non-proliferating retinomas and a minority remains in the cell cycle, possibly in an indolent state, to form retinoblastoma tumors," they wrote in the study.

"Understanding the parameters that enable proliferating RB-deficient cone precursors to enter or bypass the retinoma state could provide opportunities to suppress retinoblastoma in genetically predisposed children," they say.

Earlier intervention

Kerry Beebe, O.D., began conducting infant eye assessments through the AOA's  InfantSEE^® program, which began in 2005. Managed by  Optometry Cares ^®—The AOA Foundation , InfantSEE and its volunteer doctors of optometry provide no-cost, comprehensive eye and vision assessments to infants within the first year of life, regardless of a family's income or access to insurance coverage.

Dr. Beebe, now retired, calls the study "interesting" for its potential in the long range. However, more research is needed, he says.

"What the study means right now is really nothing different in terms of how we're treating patients or diagnosing them," he says.

"But, as optometrists, we now understand a little more about the earliest changes in the retina and the development of retinoblastoma," he adds. "And maybe down the road, we can intervene to stop that process from happening. There may come a time when we can actually prevent the tumor cells from forming, which would be at the earliest stage possible. That's what is exciting about this research. Until then, the earlier a diagnosis is made, the higher the chance for a successful outcome.

In the meantime, Dr. Beebe says, the research serves another important purpose—reinforcing the essentialness of regular, in-person eye examinations. The AOA recommends infants get their first eye assessment between 6 months and one year.

"We're primary eye care providers for our patients—for their lifetimes," Dr. Beebe says.

Access AOA resources

See the AOA Evidence-Based Clinical Practice Guideline: Comprehensive Pediatric Eye and Vision Examination.