ROP

What is ROP  Retinopathy of prematurity (ROP) is a potentially blinding eye disorder that primarily affects premature infants weighing about 2¾ pounds (1250 grams) or less that are born before 31 weeks of gestation.  In ROP, blood vessels swell and overgrow in the light-sensitive layer of nerves at the back of the eye (retina). When the condition is advanced, the abnormal retinal vessels extend into the jelly-like substance (vitreous) that fills the center of the eye. Bleeding from these vessels may scar the retina and stress its attachment to the back of the eye, causing partial or complete retinal detachment

Preterm infants risk of ROP  By the fourth month of pregnancy, the unborn child's retina has begun to develop vascularization. Such formation of blood vessels appears to be very sensitive to the amount of oxygen supplied, either naturally or artificially.  In most cases, ROP resolves without treatment, causing no damage. Advanced ROP, however, can cause permanent vision problems or blindness.  As such, all preterm babies are at risk for ROP, and very low birth weight is an additional risk factor. Both oxygen toxicity and relative hypoxia can contribute to the development of ROP.

ROP due to Oxygen  Premature babies in the NICU in which oxygen therapy is used on due to the premature development of their lungs. It is thought to be caused by disorganized growth of retinal blood vessels which may result in scarring and retinal detachment.  In infants, the administration of high levels of oxygen can induce overgrowth of the blood vessels in the eye and lead to blindness, because oxygen is known to be a vasoconstrictor.  For this reason a very low oxygen level is administered from 21%-40% FiO2 along with a blender when apnea or central cyanosis is present at birth.  Supplemental oxygen exposure, while a risk factor, is not the main risk factor for development of this disease. Restricting supplemental oxygen use reduces the rate of ROP, but may raise the risk of other hypoxia-related systemic complications, including death.

Controlling the amount of oxygen  Controlled amounts of supplemental oxygen might actually keep ROP from progressing from moderate to severe. If controlled amounts of supplemental oxygen could help prevent the progression of ROP, then infants could avoid this threat to their sight and consequently the invasive surgery for severe ROP, with its possible long- term side effects.

Treatment of ROP  The most effective proven treatments for severe ROP are cryotherapy and laser therapy, which usually will stop the growth of abnormal blood vessels and prevent retinal detachment, but laser surgery requires general anesthesia, which may be risky for preterm infants.  cryotherapy therapy involves a freezing treatment  Cryotherapy and laser therapy are considered invasive surgeries on the eye, and doctors don’t know their long-term side effects.  An anti-cancer drug, bevacizumab (Avastin), is shaping up to be an effective alternative to laser surgery in ROP.

Stages of ROP from mild -savere