Retinopathy of Prematurity
What is the Retina?
The retina is a layer of tissue that senses the light coming into the eye. It covers the inside of the back of the eye like a layer of wallpaper.
What is Retinopathy of Prematurity?
Retinopathy of Prematurity is a condition of the retina, which can occur in babies born prematurely. The retina of a baby born very prematurely doesn’t have a full blood supply and parts of the peripheral retina have no blood supply. The changes that occur after birth can lead to abnormal blood vessels growing and, without treatment; this process could lead to the retina detaching. This could result in the child having reduced vision or blindness.
All premature babies born before a certain number of weeks of gestation or below a certain weight have their eyes checked by an Ophthalmologist (Eye Doctor).
Your baby needs to be screened until they have developed a normal blood supply to the full retina. This takes a different amount of time for each premature child, but is usually complete within a few months of birth. Your ophthalmologist can see when the risk of retinopathy has gone and will tell you clearly when your child no longer needs further screening.
Before the retina has a full blood supply, the retina can develop ROP. Mild ROP usually does not require treatment as it often goes away with no treatment and the child goes on to develop a healthy retina and good vision. These children will be monitored closely until we know the ROP has gone. If the ROP starts to progress beyond a particular level then we should intervene and treat the child before it progresses to a severe stage.
The eye doctor bases this decision on many factors including the stage of ROP, the position of ROP and the characteristics of the retinal vessels as well as other factors. There are well-developed international guidelines, which help the eye doctor make this decision.
NB! it is very important that your baby does not miss any of their screening appointments after they are discharged from hospital
Standard treatment involves a procedure using a laser to treat the area of the retina, which has no blood supply. This area of retina with no blood supply is what is causing the ROP to develop and progress. Laser is very effective a stopping the ROP progressing before it causes Retinal Detachment and vision loss.
Laser for ROP is a very safe procedure but like all procedures there are some recognized possible risks from undergoing laser.
Laser treatment for ROP can be performed either under General Anaesthesisa or under intravenous Sedation (receiving a sedating medication through a drip). There are advantages and disadvantages to both of these methods. The medical doctors including the neonatologist and the eye doctor who will perform the treatment will discuss what the most appropriate method for each individual child is. Both sedation and general anaesthesia do carry some risk, however with proper monitoring in a specialist unit the risk of a serious adverse event associated with the treatment is very low. For this reason your child will be closely monitored during the procedure and following the procedure.
Local adverse events affecting the eye include but are not limited to:
Undertreatment. (Requiring further procedures)
Retinal burns, breaks , bleeding or detachment that is not desirable for treatment.
Corneal burns. (causing cloudy patches to the clear window at the front of the eye)
Iris injury (causing an irregular pupil size or rarely blood appearing in the front of the eye)
Cataract (Cloudy patches of the natural lens of the eye which if severe could have a negative impact on vision)
Myopia (Shortsightedness)- this may require glasses as a young child)
Most babies undergoing treatment with laser do not have any serious outcomes from laser and the benefit of treating this condition far outweigh the risks.
In some cases of ROP where there is a very large area of retina without a blood supply an injection of a drug is used instead of laser as the initial treatment. There are downsides to this drug also. Your ophthalmologist would discuss these with you before treatment. It is not usually recommended as standard treatment unless the blood supply is extremely bad and there is a very large area of retina without a blood supply. Babies treated with this drug will often require laser treatment at a later date also.
Thankfully ROP is now a very well defined condition, which is much better understood than it was in the past. The treatment we have available now leads to a good outcome in the vast majority of patients.