Retinopathy of prematurity (ROP) is a proliferative vascular eye disorder that affect infants with a young gestation period and are born underweight. The condition was initially referred to as retrolental fibroplasias. In the 1940s and 1950s, it was a primary cause of blindness in infants.
ROP is an eye medical condition that primarily affects immature vasculature in premature infants (Bashour, 2013). It is potentially blinding. The majority of the infants affected weigh about 2.75 pounds or less. The babies affected are born before they are thirty-one weeks of conception considering that a fully gestation period is 38-42 weeks (National Eye Institute, 2009). The tinier the infant is during birth, the more potentially the infant is going to develop ROP. The condition typically affects both eyes. It is among the most common means by which infants lose visual ability.
ROP develops when irregular blood vessels develop and extend through the retina, the layers that cover the back of the eyes. These vessels are delicate and can burst or leak. The leakage blemishes the retina and pushes it out of position. Subsequently, the retina detach from the back of the eye. The detachment is the primary cause of eye impairment leading to blindness in ROP.
In premature infants, the development of the blood vessels slows or stops completely after the delivery of a premature baby. This marks the initial stage of ROP. Additionally, the degree of non-perfusion area of the retina during the early stages of ROP plays a role in determining the successive level of neo-vascularization (Gharehbaghi et al, 2012).
Retinopathy of premature stages
The condition is categorized into five stages. The stages are from mild to severe.
- Stage I – This stage is marked by irregular development of the blood vessels. Majority of the infants affected at this recover without any treatment. Gradually, they develop normal visual ability. The disorder disappears on its own and does not progress further.
- Stage II – This stage is marked by moderate irregular blood vessel development. Majority of the infants who progress to this stage gradually improve without any treatment. Eventually, they develop ordinary vision. The condition disappears on its own and does not progress further.
- Stage III – This stage is marked by extreme irregular development of blood vessels. The irregular blood vessels develop towards the center of the eyes. This is in direct opposite to the normal development pattern where the vessels are supposed to develop along the retinal surface. Few infants who progress to this stage recover without any treatment. Gradually, they develop normal eyesight. On the other hand, children with a certain level of stage III ROP and an “additional disease” develops, it is recommended that they be treated. “Additional disease” in this context implies that the retinal blood vessels are expanded and warped. This is an indication that the condition is getting worse. Prompt treatment of the condition at this stage helps in the prevention of the detachment of the retina.
- Stage IV – This stage is marked by partial detachment of the retina. The bleeding that occurs due to blood vessel leakages lead to the irregular vessels pushing the retina away from the lining of the eye.
- Stage V – This is the final stage of ROP. It is stage is marked by complete detachment of the retina from the back of the eye. Failure to treat the condition at this stage may lead to visual destruction and subsequent blindness.
The parts affected
The disorder affects the eyes of the infants and can lead to complete blindness of not diagnosed early. It is a leading cause of blindness that can be prevented through treatment when detected early. Globally, thousands of children develop the condition that can be from mild to severe threatening the sight of infants. The condition requires treatment. In most cases, the condition affects both eyes with few cases affecting one eye. Early detection and timely treatment of severe ROP considerably diminish the incidence of extreme visual loss and the subsequent outcome. The disorder causes unusual blood vessels to develop in the retina. The coating of nerve tissue in the eyes gives one the capacity to see. The odd development usually causes the retina to separate from the rear of the eye causing blindness (Sonja, 2010). Of all the infants with ROP, 30 percent of those with extreme complications have 20/200 or lower in the eye that is not severely affected.
The effects of ROP on the visual system
Research indicates that ROP has a variety of complex factors that are accountable for the occurrence of ROP. The primary factors are premature birth and the use of oxygen. Normally, the eyes begin to develop after sixteen weeks of conception. It is at this stage that the retinal blood vessels start to develop at the optic nerve. Gradually, the blood vessels develop towards the ends of the growing retina. They supply oxygen and other essential nutrients. There is rapid development of the eyes within the final twelve weeks of the gestation. When a child is born at full-term, the blood vessels of the retina are almost fully developed. Normally, the retina stops developing several weeks to a month after delivery. In situations where the infant is delivered prematurely before the complete development of the blood vessels to reach the retinal ends, ordinary development of the blood vessels may be terminated. The retinal ends, the periphery, may not receive sufficient oxygen and other essential nutrients.
It is believed that the retinal periphery eventually send out signals to the remaining areas of the retina for nutrients. Consequently, new irregular blood vessels start to develop. The irregular blood vessels are typically delicate and frail. They easily leak blood causing the scarring of the retina. Once the scars contract, they drag the retina. As the pulling is repeated, the retina is detached from the back of the eye. Oxygen also plays a role in the detachment of the retina. Excess level of oxygen is typically related to the development of ROP. On the other hand, extremely low amounts of oxygen results in advanced respiratory complications. The complications may lead to death of premature children.
Strabismus is a condition that arises due to ROP. It is the crossing in of the eye. The loss of sight in one eye may lead to the complication. It is also associated with the great refractive disparity between the eyes. The disparity is referred to as antimetropia. One eye may be 2 units of myopia while the other may be 7 units of myopia. ROP may lead to the development of cataract and corneal problems. Severe damage of the retina may result in Phthisis bulbi. This is the shrinking of the extremely damaged eyes. It is possible for glaucoma to develop with the occurrence of ROP either early or later if ROP leads to complication without treatment. Children affected by ROP may experience high levels of nearsightedness referred to as myopia. ROP patients who have significant visual loss may encounter rapid fluttering of the eyes. This condition is known as nystagmus. It is common in infants with ROP and who loose visual ability at an early age.
ROP is contemporary a preventable and treatable disorder. In the developing countries, the treatment of chidren with ROP is a common occurrence. Prior to the multicenter trial of Cryotherapy for ROP, standard guidelines did not exist in treating the disorder. The most effectual and verified treatment of the ROP condition include laser treatment and cryotherapy. The cryotherapy burns away the edges of the retina. Typically, the edges contain irregular blood vessels. The method involves the use of a device that creates freezing temperatures. The freezing temperature is made to temporarily touch certain points on the outside of the eye that cover the edges of the retina. The two types of treatment obliterate the outer edges of the retina. This slows down the irregular development of the blood vessels. Unluckily, the treatment affects a considerable quantity of side vision. The treatment is undertaken to ensure the saving of the primary part of the vision – the sharp, essential sight necessary for ‘directly ahead’ actions including reading, driving among many others.
The two treatments are undertaken in children with ROP starting from stage III ROP with the presence of an additional disease. The treatments are regarded as invasive operation on the eye. The physicians conducting the surgery do not always know the long-term implications of each treatment. During the last stages of the disorder, there are other management options including sclera buckle and vitrectomy.
This entails the placement of a silicone band all round the eye. The band is then tightened. This facilitates the maintenance of vitreous coagulate in place preventing it from pulling on the scar tissues. This lets the retina to level back down against the back of the eye. Children with the buckle require to have the buckle taken out after a considerable duration which may even be years later. This is because the eye continues to develop. If the band is not remove, the patient become shortsighted. The procedure is performed on children with ROP stage IV or stage V.
The procedure entails the removal of the vitreous gel. It is then replaced with a salty solution. Upon the removal of the vitreous, the scarred tissue of the retina can either be sliced away or strip back. This allows the retina to loosen up laying back down on the back of the eye. The procedure is performed on patients with stage V ROP.
The treatment of the disorder diminishes the chances for losing sight. However, it does not prevent it forever. The response of the ROP patients is not always positive for some. In some instances, the disorder increases in severity. When the treatment of the condition does not work, there are high chances that the retina will detach. Typically, only some fraction of the retina is detached particularly in stage IV. Under such circumstances, further treatment is not recommended. This is because fractional detachment may persist or may recover on its own without medical management. In some situations, doctors may opt to treat the condition even with partial detachment to avert further detachment of the retina. When the central part of the retina or the whole retina is detached, the central sight is jeopardized. This requires surgical procedures to reattach the retina.
Congenital, adventitious, progressive or stable
ROP is a congenital condition. Essentially, it is not a precondition that all children born prematurely will be affected by ROP. Children born with too little weight or falls sick at an early age are most likely to acquire the disorder. Children born weighing more than 2.75 pounds rarely acquire the condition. Typically, ROP is often mild. As the child grows, the condition is likely to disappear on its own several weeks later. More than 95 percent of children diagnosed with ROP usually require no treatment to stabilize the condition. The disorder in its mild condition normally disappears without any outside intervention. In situations where the condition is severe requiring treatment, 90 percent of the infants recover with the disappearance of the disorder. They recover completely and regain the visual ability.
Anticipated functional implication
Severe ROP usually results in complete blindness. The loss of sight has significant implications of the lives of those affected as well as those living with them. Naturally, the blind lack the capacity to perform most of the activities performed by those with normal eyesight. It is imperative to recognize this so that one may be able to assist the blind in terms of activities to be performed. In order to assist the patients of ROP, one may utilize multisensory learning approach. This may include the combination of the use of vision with audio, tactual and kinesthetic approach. Parents and teachers should use actual objects and involve the affected in every day actions that take place in life. It is also imperative to describe depictions, events, body language signs and sounds as elaborately as possible. Since the children cannot see, it is important to help them in developing excellent listening skills.
As the child with ROP grows, they will advance to school. The school environment is usually challenging for children with vision impairment. It is hence important to support them perform basic activities in school and improve other senses such as touch. One may consider assisting the patient to learn how to scan their environment. The use of Braille is essential as completely blind children cannot read without the equipment. The progress of recovery should be regularly evaluated to determine any changes in ROP
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