Progression to stage 4 (partial retinal detachment), or to stage 5 (total retinal detachment), will result in substantial or total loss of vision for the infant. Refractive errors including myopia (most common)
Squint
Amblyopia
Retinal detachment, traction of the retina and blindness
Glaucoma
Impairments in visual acuity, contrast sensitivity, visual field, convergence, and accommodation

Epidemiology
ROP prevalence varies, from 5 to 8% in developed countries with adequate neonatological facilities, to up to 30% in middle-income developing countries.There is increasing evidence that ROP and blindness due to ROP are now public health problems in the middle income countries of Latin America, Eastern Europe and the more advanced economies in South East Asia and the Middle east region. In these countries ROP is often the most common cause of blindness in children. ROP is highly likely to become an increasing problem in India, China and other countries in Asia as these countries expand the provision of services for premature infants. There is also evidence that the population of premature infants at risk of severe ROP varies depending on the level of neonatal intensive care being provided. In countries with high development indices and very low neonatal mortality rates (e.g. North America, Western Europe), severe ROP is generally limited to extremely preterm infants i.e. those weighing less than 1 kg (2.2 lbs) at birth. At the other end of the development spectrum, countries with very low development indices and very high neonatal mortality rates (e.g.
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.