Sydney ophthalmologist Dr. Caroline Catt has welcomed findings from a study into the treatment of retinopathy of prematurity presented at the American Association for Pediatric Ophthalmology and Strabismus meeting.
Dr. Terry S. Kang reported that a retrospective analysis of 49 eyes conducted at Texas Children’s Hospital, Houston found that a single low-dose injection of bevacizumab as primary intervention yielded a “good success rate” in treating type 1 retinopathy of prematurity. However, the study found that a second bevacizumab injection had not been successful.
Dr. Kang reported that even with a lower dose of 0.25 mg of bevacizumab an 88 per cent success was achieved with a single injection and only 4 per cent of eyes ultimately required surgery. He said babies who required more than one injection tended to be those who had lower birth weights, lower gestational age and tended to have more comorbidities.
He reported that 43 eyes (87.8 per cent) had no recurrence requiring re-treatment after one injection. Four eyes (8.2 per cent) required subsequent retinal laser and of these, three had undergone a second injection with bevacizumab. Two eyes (4.1 per cent) required subsequent pars plana vitrectomy; of these, one had undergone a second injection with bevacizumab.
It is amazing to see how quickly the disease disappears after an injection
Dr. Caroline Catt has treated six babies with retinopathy of prematurity over the past two years; one of whom she treated with intravitreal bevacizumab. She said injection treatment had an “amazing effect”.
Dr. Catt said that in 2011, the ‘Bevacizumab Eliminates the Angiogenic Threat of Retinopathy of Prematurity study’ (BEAT-ROP) reported the benefit of intravitreal bevacizumab over laser for stage 3 with plus disease in Zone 1. Since then, intravitreal anti-vascular endothelial growth factors have been used increasingly commonly in the management of retinopathy of prematurity (ROP).
“I’m the visiting ophthalmologist to Liverpool Hospital Neonatal Intensive Care Unit, one of the largest units in the state,” said Dr. Catt. “In the last two years I’ve treated six babies for ROP. Five babies required conventional laser therapy, but just last month, I treated a baby boy with intravitreal bevacizumab because of the location and sub-type of his ROP. He had a rare form of ROP called Aggressive Posterior ROP in Zone 1. I also treated several babies with intravitreal bevacizumab during my Fellowship training at The Hospital for Sick Children in Toronto, Canada. It is amazing to see how quickly the disease disappears after an injection. The effect is usually evident the next day, as it was with the baby I treated last month – the plus disease completely regressed within 72 hours.
“Because it is the largest trial with the most comprehensive data available to date, I use the BEAT-ROP protocol of 0.625 mg / 0.025 mL bevacizumab injected into the vitreous cavity, 1mm posterior to the limbus. With this protocol, neither I, nor my colleagues at The Hospital for Sick Children in Canada have had any need to repeat treatment, to date.”
Dr. Catt said using intravitreal bevacizumab over laser for treatment of ROP offered obvious benefits.
“These babies are tiny and fragile, with complex medical problems. An injection can be given at the bedside with just topical anaesthesia and sedation, whereas laser requires several hours under general anaesthesia. Also, the disease regresses very quickly after an injection, more quickly than after laser in my experience. As always, these benefits need to be balanced by the potential risks of intravitreal bevacizumab. Revascularisation after an injection is very slow, meaning treated children need to be followed closely for a very long time for potential late complications. Also, the systemic effects of anti-vascular endothelial growth factors are not fully understood at present. As Dr Kang points out, further studies are needed to establish the lowest effective dose that will treat ROP and minimise side effects and his study is important in getting the ball rolling in this regard,” she said.
However, Dr. Catt cautioned there are always risks and benefits that need to be considered for each baby, and the scientific evidence needs to be applied with intelligence and care. “This is particularly so when dealing with babies because they have a long life ahead of them and are relying on us to help their parents make decisions that have their best interests at heart.”
Reference
Kang TS. Treatment of type 1 retinopathy of prematurity with 0.25 mg intravitreal bevacizumab. Paper 12 presented at: American Association for Pediatric Ophthalmology and Strabismus 42nd annual meeting; April 6–10, 2016; Vancouver, British Columbia.
