Illustration by Sai Merriam.
By Rebecca Salowe
Scheie Vision Summer 2017
On any given day, you may find
Dr. Gil Binenbaum treating babies in the neonatal intensive care unit at The Children’s Hospital of Philadelphia (CHOP), figuring out a clever way to examine a preschooler’s eyes in clinic, operating on the eyes of a grade-schooler, or performing eye muscle surgery on adults at the Scheie Eye Institute. You are equally likely to find him participating in a research conference call, working on a draft of a scientific publication, or helping a medical student or colleague design a study to answer an important ophthalmology research question. It’s hard to get him to pick the one thing he likes best—though, taking care of babies may win by a hair.
Dr. Binenbaum credits many mentors at the University of Pennsylvania who helped prepare him for such a multifaceted career. After attending the Perelman School of Medicine, he completed his residency in Ophthalmology at the Scheie Eye Institute and his fellowship in Pediatric Ophthalmology and Strabismus at CHOP. He then earned a Master’s degree in Clinical Epidemiology, also from Penn, while working as a new attending physician at CHOP and Scheie. A decade later, Dr. Binenbaum is now Director of Research in Pediatric Ophthalmology and has just received the Richard Shaffritz endowed Chair in Pediatric Ophthalmology research.
Much of his research centers on diseases affecting very young children. Dr. Binenbaum is an international expert on the ocular manifestations of child abuse. His team studies the patterns and causes of retinal hemorrhage in infants, so that abusive head trauma can be better distinguished from accidental and nontraumatic causes. “The specific pattern, not just the severity, matters when trying to identify the cause of retinal hemorrhage in young children,” he explains. He stresses, though, that child abuse is a “multidisciplinary diagnosis,” which requires collaboration of a team of experienced providers to make that decision.
Dr. Binenbaum also specializes in the care of the smallest and most fragile of patients: premature infants. He leads a large, multicenter research team that is developing a way to better predict which babies will develop retinopathy of prematurity (ROP), an eye disorder that can cause blindness in severe cases. Stevie Wonder, for example, was blinded by ROP as an infant. Tens of thousands of infants in the United States undergo repeated resource-intensive, sometimes physically stressful, retinal examinations in order to identify the less than 10% of infants who may require treatment to prevent progression to retinal detachment and blindness.
Dr. Binenbaum is the Principal Investigator for the Postnatal Growth and Retinopathy of Prematurity (G-ROP) Study Group. The goal of this NIH-funded study is to develop an algorithm to distinguish the highest risk infants, so that other infants can be spared examinations. He explains, “Our current screening model uses just birth weight and gestational age at birth to predict which infants need examinations. While these are the strongest risk factors, when we try to tighten these levels to examine fewer children, we begin to miss some infants who need treatment. We need to consider a third factor to capture those few bigger babies who develop severe ROP.”
That additional factor is slow growth, which is an indirect way of measuring a growth hormone in the body called IGF-1. Low blood levels of IGF-1 lead to poor growth of retinal blood vessels during the first weeks of life after premature birth. The retina becomes oxygen starved, and eventually, when IGF-1 levels finally begin to rise, new retinal blood vessels begin to grow out of control, which is the process that we call ROP. “So low IGF-1 early in life can be used to predict who will develop severe ROP later,” explains Dr. Binenbaum. “Slow postnatal weight gain, a surrogate sign of low IGF-1, is a less invasive measure for predicting which babies will have severe ROP.”
The first G-ROP Study enrolled over 7400 infants from 30 different hospitals in the U.S. and Canada. CHOP was the Study Headquarters, and Penn was the central Data Center. With data from these babies, the group has developed new screening criteria, which have tighter birth weight and gestational levels combined with postnatal weight gain thresholds for slow growth. This new model was able to identify all of the infants that needed to be treated, while cutting the number of infants that would have needed to be examined by almost a third.
The next stage for G-ROP is to validate the model in a new group of 4000 infants before it is used in practice. Ultimately, Dr. Binenbaum and colleagues hope to propose changes to the national screening guidelines for ROP, but only if the model does well when it is tested in this second study, which is already underway. “We need to have confidence that we won’t miss babies who need treatment, and we need a system that is simple enough that people will use it,” he said.
In addition to his research, Dr. Binenbaum is a passionate clinician. We asked him for some final words of advice about examining the eyes of children. He said the keys are “speed, which just takes practice, and distraction, which you have to think about a little. Never tell the child that you are examining his or her eyes. Just keep calm, quietly take out a small plastic Lego figurine, and with no instruction at all, a kid will look right at it and follow it as you move it around. In no time, you’ll have finished your examination. Videos on your cell phone work wonders too!”