Make sure he is seeing a retinal specialist. Depending on how long the retinas have been detached and whether or not the macula was involved will determine what happens next. Surgery may do more damage and may be pointless especially if the retinas are completely detached.
It's such a shame that even w/ the treatment options available today for those w/ROP, there are some children who still go blind as a result. Even as an adult those w/ROP are at greater risks for other eye conditions. (Losing eyesight when you're an adult is a lot harder to adjust to than as a child, IMHO as an adult w/ROP).
If so his eye ophthalmologists will do so. He needs to be under the care of a retinal specialist ideally one that does a lot of pediatric ophthalmology.
JCH MD