As we were getting ready to take Amina home from the hospital the day after she was born, the physician's assistant came by to give her one last assessment in order to give us the green light to take her home. Our little baby was eating, spitting up, burping, pooping, peeing, sleeping, and being generally adorable just as every good baby should. Jacob had gone to the hotel to pack everything up when the PA looked in Amina's eyes. Her eyes had been pretty swollen (newborns eyes usually are, if you can imagine) so she had not been able to get a good look the day before. Today when she looked she said, "Hmmm. She's got coloboma."
Coloboma? I had never heard that word before. The PA showed me Amina's "keyhole" shaped pupils, and went to call an expert at the Casey Eye Institute. The expert said that sometimes coloboma is associated with a syndrome that includes, among many other things, heart and kidney problems and esophageal atresia. To rule out the syndrome, they passed an orogastric tube down into Amina's tummy to check for atresia and they took an x-ray to check for extra kidneys etc. They found that everything was very normal. Happily, her coloboma is not the kind that is associated with a syndrome.
So what is coloboma? It is basically a gap in both her eyes where they did not form completely during development. Since this blog belongs to a nurse and, what's more, a nerdy nurse, I will get technical here. For those who snore when things get technical, feel free to skip to the cute videos at the end.
For you other nerds out there: I have learned a thing or two about coloboma over the past 6 months from the Coloboma Moms yahoo support group, two pediatric ophthalmologists, and a lot of internet searches. Colobomas happen about 1 in 10,000 births and each case affects the vision of the individual differently depending on how much of the eye is affected. During the fifth week of pregnancy, the eyes start to form in an arch-shaped tunnel. Nutrients flow through the tunnel to help form the eye. Later on, the bottom of the arch zips up to complete the round eye. Amina's eyes never zipped up completely. The name "coloboma" is a Greek word that means "unfinished".
Colobomas are often associated with having one or both eyes smaller than usual. Amina's right eye is smaller than her left eye. Depending on what part of the eye does not zip, there can be visual impairment ranging from mild light sensitivity to blind spots to total blindness. We were told this last bit when Amina's colobomas were first discovered, and we had to wait six weeks until her first visit to the ophthalmologist before we found out that her colobomas do in fact go all the way through, affecting the iris and the retina including the fovea, macula, and optic nerve in both eyes.
The fovea and macula are the parts of the retina responsible for sharp vision - the ability to see detail. A good fovea is essential for high visual acuity. Because Amina's colobomas go through this area, the ophthalmologist believes that the best visual acuity she will ever be able to have is somewhere between 20/80 and 20/400. She will fall somewhere in that range, her left eye likely seeing better than her smaller right eye. In fact, her right eye has recently started to turn inward which can be a sign that the vision in that eye is bad enough that the brain has decided to ignore the signals from that eye rather than try to reconcile the images from that eye with the other eye. To strengthen the eye-brain connection in the right eye, we have started patching the left eye for two hours a day. Amina can still obviously see lights and colors and movement with her right eye when the other eye is patched, but we won't know the details of what she can see until she is old enough to tell us.
There is nothing that can be done to "fix" the colobomas, no more than one could grow a missing finger. No amount of fabulous glasses will improve her visual acuity, either, because there is nothing wrong with her lenses. In a camera, you can have the best lens in the world, but if you have bad film, you're not going to get a good picture. Similarly, even with glasses, Amina will not be able to see sharp details because her retinas simply can't capture them. There are things that we can do, however, to maximize the vision that she does have and we will do all that we can to make that happen.
Unless you know about Amina's eyes, you would never guess that there is anything different about her vision. She behaves like a perfectly happy, perfectly normal baby and has met all of her milestones with ease. We have had vision teachers from Early Intervention programs come to our home nearly monthly since she was born and they are all amazed at how well she is doing and how well she seems to be able to see. Everyone assures us that brains are amazing things and that Amina's brain will do great things with the visual input that it receives. She will likely get around just fine.
Amina vs. The Orogastric Tube and the Squeaky Binky
A note about coloboma and light sensitivity.
Normal irises dilate and constrict to admit appropriate amounts of light onto our retinas. Amina's irises have gaps in them which let in a great deal more light than her retinas would like. This makes her very sensitive to sunlight and also gives her super night vision. We have gotten super cute baby sunglasses for her to wear outside. She usually uses them as a teething toy, but she occasionally leaves them be and I think she will soon learn that they make her eyes more comfortable in the light and will leave them on. The following is a video that I took when Amina was four weeks old which I watched many times to prove to myself that my little girl wasn't going to be completely blind. Anyone who reacts that much to sunlight couldn't be blind, I told myself. I was right.
Here is a picture of the Amina who helped guide your daddy through the dark that night. Who knew that one day we would have our very own little Amina who can see so well in the dark. Now it is your turn to take your daddy by the hand and guide him when he can not see.
