RETINOPATHY OF PREMATURITY
Retinopathy of prematurity (ROP) results from the aberrant growth of retinal blood vessels that may cause blindness in premature infants. ROP generally resolves without producing permanent retinal injury. However, severe ROP may force the retina to separate from the edge of the eye and potentially produce blindness. Infants who are born weighing 1,250 g or less and are less than 31 weeks of gestation are at greatest risk for developing ROP (American Association for Pediatric Ophthalmology and Strabismus, 2016). Nurses play a critical role in the monitoring, management, and screening of premature infants in the neonatal intensive care unit (NICU), thereby directly impacting the occurrence of ROP (Jefferies & Canadian Paediatric Society, Fetus and Newborn Committee, 2016).
It is estimated 15 million babies are born prematurely, before 37 completed weeks of gestation, throughout the world annually (World Health Organization, 2017). Approximately 3.9 million infants are born in the United States annually, with 28,000 of these infants weighing 1,250 g or less. Approximately 14,000 to 16,000 of these infants develop ROP (National Eye Institute, 2014). ROP contributes to visual damage in 1,300 children and significant visual loss in 500 children in the United States yearly. The rate of ROP for premature infants is almost 16% (Ozsurekci & Aykac, 2016). Minor cases of ROP resolve without residual damage and 90% of infants with ROP are in the milder category and do not need treatment. However, infants with more severe disease may develop impaired vision or even blindness. About 1,100 to 1,500 infants annually develop ROP that is severe enough to require medical treatment. Each year in the United States 400 to 600 infants are diagnosed as legally blind from ROP (National Eye Institute, 2014).
The incidence of ROP is higher in preterm infants with lower birth weights and decreased gestational age. Premature infants who are born before retinal vessels complete normal growth may develop ROP. Ischemia in the ocular region contributes to this disease. In the underdeveloped retina, hyperoxia leads to obliteration of the tiny blood vessels in the eye. Research has found that maintaining oxygen saturation at lower levels from birth decreases the occurrence of the severe form of this disease (American Academy of Ophthalmology, 2015).
Hyperoxia is a significant contributing factor to retinal changes and ROP. Extremely preterm infants generally require long-term mechanical ventilation and high levels of oxygen, which may lead to inflammation and oxidative stress that contributes to an increased risk of incurring lung, brain, and retinal injury 211(Poon et al., 2016). ROP occurs as blood vessels grow abnormally and proliferate throughout the retina. These blood vessels are delicate and may bleed, damaging and shifting the alignment of the retina, which results in retinal detachment, the chief cause of visual loss and blindness from ROP.
The eye begins to grow at approximately 16 weeks of gestation, and retinal blood vessels emerge from the optic nerve in the posterior ocular region. Oxygen and nutrients are delivered by the neovascularization that develops and stretches toward the periphery of the developing retina. The eye matures quickly in the last 12 weeks of gestation and is almost complete when a full-term infant is born. Retinal maturation is completed within the first month after delivery. However, if an infant is born prematurely before the blood vessels have extended to the retinal edge, abnormal blood vessel development may occur (National Eye Institute, 2014