Retinopathy of prematurity: pathophysiology and clinical management

Retinopathy of Prematurity (ROP) is a disease that causes a disease of the retina of the eye. Primarily, it affects babies that are born very prematurely and is involves vessels in the retina that grow in an abnormal fashion. There are five different stages that this disease is classified in, and stages one & two do not usually require any kind of treatment. Stage three sometimes requires treatment, and stages four and five definitely require treatment. Stages four and five also often cause retinal detachment, which can be much more serious. In stage four, a retinal detachment is usually only partial, but a total detachment can occur if it is left untreated. Stage four can also have a rapid progression and can end up as stage five if something is not done quickly. Stage five involves a total detachment of the retina and is considered to be the disease's 'end stage.' There is often a white and dense membrane behind the eye's lens in this stage, and the retina is often seen to be adhered to this bit of scar tissue. If stage five retinopathy of prematurity is not treated, the premature baby will become completely blind in both eyes and can also develop other complications such as clouding of the cornea and a high intraocular pressure, which can lead to glaucoma in some cases. There are three different zones in the retina that can be affected by retinopathy of prematurity. Zone one is the most centrally located zone, and disease that develops in this area is often seen to be more serious than disease that develops in zones two and three (www.schepens.com, n.d.).

Regression of the disease or spontaneous healing is often seen, but if this does not happen blindness and severe visual impairment can occur. These problems can usually not be reversed and are obviously damaging to the overall welfare of the child as it grows and matures. Even though there have been many advances in recent years in neonatology, ROP remains a very serious concern. Primarily, ROP is seen most often in babies that have an extremely low birth weight. Having that low birth weight, a very young gestational age, and the amount of days that the baby has to receive supplemental oxygen all contribute to the disease and how significant it is. There have been other factors that have been associated with the problem more recently, but the severity of illness and the amount of time spent on oxygen seem to be the largest predicting factors. In other words, the infants that are the sickest and the smallest when they are born are the ones that have the highest risk of ROP, and also the ones that have the highest risk for the most serious stages of the disease. Interestingly enough, babies that are African-American appear to be less likely to experience ROP on a level that is considered severe (www.emedicine.com,2002).

During gestation, retinal vasculature usually begins developing around the 16th week. This vasculature grows in a circumferential pattern and does not become fully mature until the baby has reached full term. When a baby is born too early, the vasculature stops maturing. Many of the blood vessels then constrict and some of them are also obliterated. Naturally, this also slows down or stops the progression of normal development of the blood vessels. When the retina continues to grow it often does not get enough blood supply and retinal hypoxia can occur from this, as well as the overgrowth of blood vessels in an effort to increase the vascular supply to the retina (www.emedicine.com,2002).