We’ve been asked often why Ben’s eyesight is declining, so here is my very non-medical explanation.
First, legal blindness is defined as your STRONGER eye having an acuity of 20/200 with corrective lenses. You can have only one functional eye but if it sees better than 20/200 you are not legally blind. (Which means when people say they are “legally blind in one eye” that’s not accurate – that just means one of their eyes isn’t strong. You also cannot be legally blind without your glasses, which I hear- legally blind is defined based on corrected vision.)
The other definition of legal blindness is a visual field of 20 degrees or less. Basically you can only see right in front of you with blind fields on your sides.
Ben sees 20/30 (HOORAY!!) and 20/200 right now with glasses but that is anticipated to change over the years. We knew he was losing depth perception because of the discrepancies in acuity between his eyes and he was patched for years to try and get his weaker eye to respond. He told us last year that weaker eye “doesn’t work anymore” and he essentially relies on just his stronger eye.
Ben is also losing peripheral vision, which is why he qualifies as legally blind now. If his siblings are standing next to them he cannot see them – which was a painful lesson for them to discover, physically and emotionally.
There is also complete blindness when people can only see shapes, or literally nothing at all depending on their eye condition. There is a BIG difference between legal blindness and complete blindness.
Ben’s vision issues are caused by his prematurity and a condition called
ROP. In generations past ROP caused complete blindness for babies born too early and receiving high concentrations of oxygen. They have modified O2 levels and watch saturation closely to make sure babies are getting enough oxygen now for their lungs and brains but not so much that it damages their eyes. (The ROP link above explains how the O2 alters blood vessel growth in their eyes which can cause retinal scarring and detachment.) Ben was so tiny and his little lungs really struggled – he was on a special high frequency oscillating vent for six weeks, conventional vent for another six weeks, then CPAP then cannula oxygen when he came home (with a later re-intubation and vent time for a couple weeks with RSV.) They monitored him so closely but it was a balancing act of lungs and brain and eyes. (Just since Ben was born I also read about changes in saturation level parameters for preemies, but Ben’s case really was extraordinary with his extreme prematurity and lung condition.)
Ben’s eyes were also closely watched with eye exams every two weeks and when he developed ROP it was FAST, one exam was clear and we were so grateful and next exam he needed surgery ASAP. He had stage three ROP with Plus disease. The laser surgery prevented his retinas from detaching so he did not go completely blind, but there is scar tissue that cannot be removed.
The way it was explained to us, as his eyes grow and stretch the scar tissue cannot stretch and the eyesight declines. He loses peripheral vision, colors change, his light sensitivity gets more extreme, and his prescription has to get stronger. He’s higher risk for a retinal detachment, but we try to avoid high impact sports and balls to the face and he has sports goggles. We were warned that because of the scar tissue he could wake up one day with detached retinas BUT we consider that highly unlikely because it’s too awful to consider. (We have talked with preemies for whom that happened but we think it’s pretty rare.) There are treatment options if a retina begins to detach (they can “buckle it” back to the eye) but Ben’s retinas are examined at least yearly and are okay right now. (“Okay” meaning scarred but attached.)
Unless Ben experienced a complete retinal detachment he will maintain at least some vision – he won’t go completely dark. We are clinging to that hope that even as his eyesight declines he will have SOME functional eyesight, despite being legally blind. We were also told that until he is an adult his eyes will keep changing and we won’t know what degree of vision he will maintain.
At this time we are not aware of any future treatment options for damaged retinas. We’ve been asked about transplants – that is just for corneas and lenses, not retinas. Another laser surgery at this stage would not improve things BUT technology changes so fast that we are holding onto hope that new options will be developed. When he is a bit older we will try specialized contact lenses along with glasses to see if that helps improve his acuity and visual field. We are optimistic!
This situation was not a surprise to us – we were told before he was born that blindness was one of the many challenges micro-preemies may face. We feel incredibly grateful that losing his eyesight is Ben’s only remaining effect of his painfully early arrival. However, we know Ben – he doesn’t let anything slow him down! He’s going to continue to surprise and amaze us like always.
Still have a question? Feel free to ask!