Retinopathy of prematurity (ROP), is a disease that affects the retina of the eye. It affects the blood vessels on the retina in a preterm babies eyes, and is one of the leading causes of childhood blindness.
In most cases, the growth of the retinal blood vessels will slow down on its own, and vision will develop normally. Some premature babies may develop severe ROP. It is classified as according to different stages.In think in your case ,your 6 months old son come under stage 2/3.In this case treatment may be needed to stop the abnormal growth of blood vessels on the retina or to correct a retinal detachment. Treatments include cryotherapy, laser therapy, and retinal surgeries.
Most of the cases they opt for laser therapy which has better results than cryotherapy. A laser is used to make small burns on the parts of the retina affected by ROP. I think your doctor is right..do not wait give treatments as per the suggestion of your dr.