weeks, and 8 percent of children with gestational ages of less than 24 weeks (Marlow et al., 2005; Vohr et al., 2005).
Timely diagnosis and the prompt treatment of ROP are essential for improving visual outcomes. Screening ophthalmologic examinations require an experienced examiner and careful examination of the retina to the periphery with an indirect ophthalmoscope and lid speculum after dilation of the pupils. Revised guidelines for screening preterm infants for ROP have recently been published, with recommendations for which infants should be screened (infants with birth weights of less than 1,500 grams or gestational ages of less than 32 weeks or selected other preterm infants with an unstable clinical course), the timing and frequency of screening examinations, and the indications for treatment (Section on Ophthalmology, AAP, 2006)
Although visual outcomes have improved, ROP continues to be a major problem, especially in the most immature infants. The primary method of prevention is to prevent preterm births. Prevention of wild swings in blood pressure, blood oxygen and carbon dioxide levels, and acidosis has been recommended (Madan et al., 2005). There is much interest in the role of oxygen in ROP, but the optimal blood oxygen levels and oxygen saturation levels remain controversial (Saugstad, 2005; STOP-ROP, 2000; Tin 2002; Tin and Wariyar, 2002). Although the intravenous administration of high doses of vitamin E appears to reduce the incidence of severe ROP and blindness in infants with birth weights of less than 1,500 grams, it also appears to increase the incidence of sepsis and IVH (Brion et al., 2003).
Other ophthalmologic complications of prematurity include refractive disorders (especially myopia), strabismus (i.e., ocular misalignment), amblyopia (i.e., visual loss associated with reduced development of the visual cortex), optic nerve atrophy, cataracts, and cortical visual impairment (Repka, 2002) (see Chapter 11). Late ophthalmologic problems include angle closure glaucoma (i.e., increased pressure in the eye), retinal detachment, and phthisis (i.e., shrinkage and disorganization of the eye severely affected by ROP); but fortunately, these are rare. Severe threshold ROP is associated with other complications of prematurity, including BPD/CLD and IVH.
Neuromaturation is a dynamic process in which the central nervous system (CNS) is formed by a continuous interaction between the programmed genetic processes encoded within the genome and then the intrauterine environment, followed by the extrauterine environment. The successive turning on and then turning off of specific genes propel development forward, whereas surrounding cells, temperature, nutrients, and unknown environmental factors influence cell division, differentiation, function, con-