Retinopathy of prematurity (ROP) is a disease that results from abnormal growth of blood vessels on the retina in a small percentage of premature babies.
In ROP, the retina is not fully vascularised and the retina is ischaemic (insufficient blood). The ischaemic retina produces angiogenic factors which causes uncontrolled growth of blood vessels (neovascularisation). This causes fibrovascular scar formation. When the scar matures, it will contract and result in tractional retinal detachment.
Not all premature babies will develop ROP. In some cases, the abnormal blood vessels may shrink and go away without treatment.
Who are at risk of ROP?
- Low birth weight
- Prematurity (e.g. a 12-week premature baby has higher risk of ROP than 8-week premature baby)
- Use of supplemental oxygen after birth
- Complicated postnatal course
- Respiratory complication
- Race (Caucasians are more at risk than African-Americans)
How is ROP detected?
An ophthalmologist (eye doctor) can examine baby’s eyes for ROP in hospital’s NICU (neonatal intensive care unit) or in the clinic. Eye drops to dilate the eyes (to enlarge the pupils) will be given prior to examination. A speculum (to hold open the eye) and an indenter (to help the doctor to examine the peripheral retina) are used during the examination. To minimize any discomfort, anaesthetic eye drop will be instilled.
Some ROP will only be apparent after 4-6 weeks following birth. If ROP is diagnosed, regular examinations will be performed until the abnormal vessels growth goes away on its own, failing which treatment will be offered.
Instruments and eyedrops used for examination of ROP
As premature babies are more likely to develop visual problems such as high refractive error, squint, amblyopia etc., they should be followed up regularly for vision test.