A prospective randomized trial in which pre-term newborns were randomized to receiving oral propranolol with standard treatment or standard treatment alone found that oral propranolol showed a 48% relative risk reduction for progression to stage 3, 58% reduction for progression to stage 3 plus, and 100% reduction for progression to stage 4. Furthermore, there was a 52% relative risk reduction for the need for laser treatment or intravitreal bevacizumab. However 19% of the newborns experienced serious adverse effects including hypotension and bradycardia. A study in a mouse model of human ROP has shown that beta-blockade is protective against retinal angiogenesis and ameliorate blood-retinal barrier dysfunction. Follow up
Once diagnosed with ROP lifelong follow up (yearly) is performed in some centers. In others, only children treated for ROP are followed yearly. Follow up after laser or anti-VEGF treatment is individualized. Follow up of premature children (with or without ROP) is varying among centers and countries, mirroring the diverse states of health care system in different countries. Prognosis
Stages 1 and 2 do not lead to blindness. However, they can progress to the more severe stages. Threshold disease is defined as disease that has a 50% likelihood of progressing to retinal detachment. Threshold disease is considered to be present when stage 3 ROP is present in either zone I or zone II, with at least five continuous or eight total clock hours of disease, and the presence of plus disease.
The stage of ROP refers to the character of the leading edge of growing retinal blood vessels (at the vascular-avascular border). Monitoring
In order to allow timely intervention, a system of monitoring is undertaken for infants at risk of developing ROP. These monitoring protocols differ geographically because the definition of high-risk is not uniform or perfectly defined. In the USA the consensus statement of experts is informed by data derived by clinical trials and published in Pediatrics 2006. They included infants with birthweights under 1500 grams or under 30 weeks gestation in most cases. The first examination should take place within the first 4 weeks of birth, and regular, weekly examination is required until it is clear that the eyes are not going to develop disease needing treatment, or one or both eyes develop disease requiring treatment. Treatment should be administered within a 48 hours, as the condition can progress rapidly. Management
Treatment
Peripheral retinal ablation is the mainstay of ROP treatment. The destruction of the avascular retina is performed with a solid state laser photocoagulation device, as these are easily portable to the operating room or neonatal ICU. Cryotherapy, an earlier technique in which regional retinal destruction was done using a probe to freeze the desired areas, has also been evaluated in multi-center clinical trials as an effective modality for prevention and treatment of ROP. However, when laser treatment is available, cryotherapy is no longer preferred for routine avascular retinal ablation in premature babies, due to the side effects of inflammation and lid swelling.