Retinopathy of Prematurity: Stages, complications, causes & risk factors
By: Hassaan Javaid
A blinding eye anomaly occurring among premature infants weighing approximately 23/4 pound or less is known as retinopathy of prematurity. These babies are born more or less 31 weeks pre-gestation hence the term “prematurity”.
The smaller a baby at birth, greater are the chances of developing ROPwhich affect both the eyes. The disorder is one of the most common causes of vision loss in early childhood or lifelong blindness and visual impairment. Retinopathy of prematurity(ROP)was first diagnosed back in 1942.
Stages of development
ROP has been classified in five stages based on severity of the onset from mild (stage 1) to sever (stage 5). Let’s have a look at each in detail.
Stage 1 – An abnormal vessel growth but mild. Children with the onset at first stage usually improve without any treatment and develop normal vision overtime. ROP at this stage self-resolves without progression.
Stage 2 – Moderately abnormal vessel growth! Fortunately, children at second stage of ROP also develop normal vision in time without undergoing any treatment as the disease resolves on its own without advancing.
Stage 3 – The blood vessel growth is severely abnormal towards the eye’s centre rather than following the normal growth pattern that is along the retinal surface. While some may develop normal vision overtime without any treatment, a higher-degree of third stage also known as “plus disease”requires appropriate and timely management. Here, “plus disease”indicates enlargement and twisted retinal blood vessels which is a symptom of worsening of the ROP. Timely treatment can prevent retinal detachment at later stage.
Stage 4 – Retina is already partially detached! Retina is being pulled away from the eye wall due to bleeding and abnormal vessels following traction from the scar.
Stage 5 – The final stage of the onset and complete detachment of the retina! If eye is left untreated even at this stage, baby is more vulnerable to permanent blindness and severe visual impairment.
Infants with retinopathy or prematurity are at high risk of developing various eye anomalies at later stages of their life. These diseases can be strabismus (crossed eyes), myopia (near-sightedness), glaucoma, retinal detachment and amblyopia (lazy eye). In certain cases however, these eye anomalies can be controlled and even permanently treated.
Causes & risk factors
Growth and spreading of abnormal blood vessel throughout the retina is the primary cause of ROP. These vessels are susceptible to leaking and extremely fragile that can scar the retina and even pull it away from the normal position thereby causing retinal detachmentwhich is the primary cause of blindness and visual impairment.
The most common risk factor associated to the onset is baby birth at prematurity which hampers normal generation of the retinal blood vessels and stops essential oxygen and nutrient supply critical for normal growth. Other risk factors include difficulty in breathing, blood transfusion, anaemia and overall infant’s health.
Laser and cryo-therapy are performed only on the infants at advanced stage ofretinopathy of prematurity. That said, the course of treatment itself has improved with persistent research and technological boom in healthcare.