Health Awareness blog

Retinopathy of prematurity was previously known as ‘retrolental fibroplasia’ (RLF). Approximately 50,000 children worldwide are blind from ROP and the incidence is increasing at developing countries. It is caused by disorganized growth of retinal blood vessels and affects premature infants. It is found that prematurity was the main risk factor and also there is a significant association between gestational age, birth weight, oxygen therapy and blood transfusion. ROP consist of 5 stages (stage I to stage IV).

Stage I is the mild form of ROP, consist of mildly abnormal blood vessel growth. Majority of the child that develops stage I will eventually recovered and develop normal vision without any treatment. The disease usually resolves without further progression and the prognosis is good. Stage II consists of moderately abnormal blood vessels growth. This stage also has a good prognosis where usually no treatment is needed and the disease usually resolves on its own without become worsening in condition. The child will eventually develop normal vision.  Then, Stage III refers to severely abnormal blood vessel growth. The abnormal growth occurs toward the center of the eye instead of following the normal growth pattern along the surface of the retina. In terms of prognosis, some infants will improve without any treatment and eventually able to have normal vision like other kids. However, in some infants especially when he/she has a certain degree of stage III and ‘plus disease’, treatment is recommended to prevent retinal detachment. At this point, the treatment usually ensure good outcome. “Plus disease” means the blood vessels of the retina has become enlarged and twisted. These indicate the worsening of the ROP. For, Stage IV and stage V is already considered severe. Stage IV referred to partially detached retina. It occurs by the traction from the scar that produced by bleeding. In other words the abnormal vessels pull the retina away from the eye wall. Stage V is very severe defined by complete detached of retina. This is the end stage of the disease. The prognosis is poor, without treatment, the baby may have severe visual impairment. Blindness won’t be rare.

Risk factors for ROP are low birth weight, shortened gestation, exposure to prolong ventilation or oxygen and respiratory distress syndrome ROP affects over 20% of infants weighing less than 1500gram. Sepsis or infection at neonatal stage (in preemies) also may contribute to ROP. Furthermore, ROP is significantly associated with smaller, more immature and also sicker neonates.

There are some short term complications of ROP like retinal detachment,  blindness and low vision. The patient (when they grow up later) may also have myopia or hypermetropia. Myopia is short sightedness and far more common compared to hypermetropian or far sightedness.

Regardless the gestational age at birth, if ROP is going to occur, it will occur between 34 and 40 weeks after conception. That is why the newborn at risk should be sent for screening at this stage. The laser treatment is applied to the retina anterior to the vascular shunt that does not yet have a blood supply. The means of this treatment is to prevent retinal detachment. This is based on the idea abnormal vessels should be eliminated before they progress and lay down enough scar tissue that will cause traction of the wall of the eye. There are some other options of treatments include cryopexy, sclera buckle and vitrectomy.

References:

1.   Gilbert, C. Retinopathy of prematurity: A global perspective of the epidemics, population of babies at risk and implications for control. Early Human Development, 2008 February . 84 (2) : 77-8.

2.   Wheatley, CM., Dickson, JL., Mackey, DA., Craig JE. and Sale, MM. Retinopathy of prematurity: recent advances in our understanding. British Journal of Ophthalmology, 2002. 86:  696-700.

3.   Darlow,BA., Hutchinson, JL., Henderson-smart, DJ. Donoghue, DA,  Simpson, JM., Evans, NJ. Neonatal prenatal factors for severe retinopathy of prematurity of among very preterm infants of the Australian and New Zealand network. Pediatrics. 2005 April.  115 (4): 990-996.

4.      Karkhaneh, R,  Mousavi, SZ, Riazi-Esfahani, M, Ebrahimzadeh, SA., Roohipoor, R., Kadivar, M. Ghalichi, L, Mohammadi, SF. and Mansouri, MR. Incidence and risk factors of retinopathy prematurity in a tertiary eye hospital in Tehran. British Journal of Ophtalmology.  2008. 92: 1446-1449.

5.      Strobel, S,  Marks, S,  Smith,PK., El Habbal, MH. and Spitz, L. The great Ormond Street colour handbook of paediatrics and child health, London: Manson Publishing; 2007.

6.      Chye, JK.,  Lim, CT.,  Leong, HK. and Wong, PK. Retinopathy of prematurity in very low birth weight infants. Annals Academy  Medicine of  Singapore. 1999. 28: 193-198 .

There are a range of complications of prematurity, including respiratory, neurology, and gastroenterology. Respiratory problems mainly arise because the lung is immature. The lung usually matures at 36 weeks gestation and above. This is the main apprehension in dealing with premature baby. Some examples of respiratory complications are respiratory distress syndrome (RDS), transient tacypnoeic of newborn and bronchopulmonary dysplasia (BPD) or sometimes known as chronic lung disease.

RDS is due to lack of surfactant that important to prevent the lung from collapse. Treatment includes oxygen supplement and doses surfactant. In some severe cases, the baby may need endotracheal intubation and ventilator. Transient tacypnoeic is rapid shallow of breathing effort of the infants. Close observation is mandatory. Oxygen supplement is depending on the child condition. Recovery usually occurs within 3 days and no other treatment require. BPD occurs when a baby’s lung have shown evidence of deterioration. Although some preemies need ventilator, some cannot withstand the constant pressure of the ventilator and lead to other problems. Those need to be ventilated for more than 28 days are at risk. BPD will be explained later in the next part.

Sometimes, the preemies (premature infants) might “forget” to breathe and this lead to apnea and bradycardia. Apnea is the absence of breathing for up to 15 seconds, whereas, bradycardia is the reduction of heart rate. Most of the time, only stimulation of touch is require but in severe case, medication like neulin might be needed. Premature infants also could face risk of congenital pneumonia and infection because their immune system is immature. The child will be put in incubator to keep warm and reduce the potential of infection. In congenital pneumonia, antibiotics will be given as well as oxygen supplemental and intubation. If left untreated, it may evolve to deadly infection like sepsis and meningitis.

Intraventricular hemorrhage (IVH) in bleeding in the brain can affected baby born at less than 34 weeks. This is due to immature blood vessels that sometimes cannot tolerate the changes in circulation that take place during labour process. This may lead to future complications like cerebral palsy, mental retardation and learning difficulties. According to American Pregnancy Association, Intracranial hemorrhage affects about 33.3% of baby born between 24 – 26 weeks gestation. It is estimated that some degree of hemorrhage occurs in 40% of very small babies although it only cause damage in minority of cases.

Gastroenterology problem also commonly affected premature infants. Immature gastrointestinal and digestive system prevent them to absorb nutrients safely. Total parenteral nutrition (TPN) is indicated in severe case. In few cases, premature infants also need to be feed through ryles tube initially because they are still not strong enough to swallow or suck on their own. In unfortunate infants, they may develop necrotizing enterocollitis (NEC). This is the infection of the bowel wall. Very early feeding may also lead to NEC. In this case, intravenous feeding and antibiotics are necessary. Rarely, operation is indicated.

Other complication is inguinal hernia that often affects the premature babies’ particularly male gender. This is due to the nature of the growth itself where the testicles only descent into the scrotum after 32 completed week’s gestation follows by the contraction of the processus vaginalis at the inguinal canal. If the baby need ventilator, persistent increase abdominal pressure also may contribute to this problem. As a treatment, the patients need surgical intervention. Further discussion will be done later.

Patent ductus arteriosus (PDA) is a cardiac cause that causes breathing difficulties after delivery. It is most common in the preterm infant. This is due a failure of ductus arteriosus to close. Ductus arteriosus is a blood vessel that connects the aorta with vena cave to allow blood from the heart to bypass the lung when the baby in utero since the baby does not breathe till after delivery. A chemical compound called Prostaglandin E made in circulates in his or her blood to keep the vessel open and the level falls at full term birth to close that vessel. In premature infants, level of prostaglandin E remains high causing the ductus to open, this is one reason why the infants may have murmur after birth. In few cases the PDA will close spontaneously but in some cases indomethacin (inhibitor of prostaglandin synthesis) is indicated. Spontaneous closure occurs up to 3 months after birth. Today, the surgical intervention like open heart surgery or percutaneous interventional method is rarely done.

Retinopathy of prematurity (ROP) is eye disorder that commonly affect premature infants and has potential to cause blindness if no early intervention. It affects preemies between 24-26 gestations and rarely affects those after 33 weeks gestation. More detail discussion will be held later in this report.

Premature babies are also at risk of hypothermia so they usually were kept warm under warmer. Very low birth weight babies will need incubator nursing. They are also at risk for jaundice due to immature liver. The risk of hearing loss is increase with the degree of prematurity. The entire hearing system is still maturing till as late as 26 weeks and vulnerable to injury afterward. Infection and severe jaundice will increase the risk for hearing impairment. This is why early hearing assessment is mandatory because so that early the treatment and intervention can be start promptly. This to ensure family and the affected babies learn important communication skills.

            Anemia is  another complication of premature infants caused by abnormally low concentrations of red blood cells. One important substance is hemoglobin. This is vital as hemoglobin is necessary to carry oxygen in the circulation. Normal count is 15 grams per litre blood. Blood transfusion is indicated in severe case.

Now we know that there are wide ranges of the complications of premature birth, from head to toe. Prevention is always better than cure. As conclusion, do avoid any possible causes like smoking and infections that might lead to preterm birth.

References:

1.      American Pregnancy Association complications. Premature birth complications.  Available online http://www.americanpregnancy.org/labornbirth/complicationspremature.htm. 2007.

2.      Newell, S.J. and Darling, J.C.Lecture notes paediatrics. Eight edition. Singapore. Blackwell Publishin; 2008.

3.      Brooker, R.W. and Keenan, W.J. Inguinal hernia: relationship to respiratory disease in prematurity. Journal of Pediatric Surgery.2006, November.Vol. 41, issue 11. 1818-1821.