No, I’m not going to channel my inner Robin Price, but I will say that a case that I saw in the office earlier this month reminded me of the iconic song Turn, Turn, Turn written by Pete Seeger with lyrics from Ecclesiastes, and this classic rendition of it by Bruce Springsteen and the Byrds’ Roger McGuinn.
Here is the case:
Mindy is a 7 year-old who was born with Persistent Fetal Vasculature Syndrome (PFVS) of the right eye. This is unilateral in 90% of the cases and typically results in posterior involvement through retinal detachment/folds and anterior involvement involving cataract as well as nystagmus due to early sensory deprivation. I don’t have a clinical photo, but here is a representative case from a published case series showing cataract surgery on a PFVS case.
As in the illustrative case above, Mindy underwent vitrectomy and lensectomy at 7 months of age. This left her with aphakia. Together with microphthalmia, repaired retinal detachment and subsequent folds, and secondary exotropia and nystagmus, that poor girl never really had a chance of useful vision through her right eye.
By the time I saw Mindy she had stopped wearing her high plus aphakic contact lens for well over a year. Each time she wore it, it would either tear or be uncomfortable resulting in frequent discharge. With the contact lens is place her visual acuity through that eye, with eccentric viewing, was 3/500.
Why was Mindy referred to me? Not because anyone expected me to miraculously “cure” that eye, but to determine if it had anything to do with her early academic struggles despite being a very bright child. Most eyecare practitioners have long presumed that no matter how much vision is compromised through an eye with so-called organic or refractive amblyopia (and Mindy’s right eye was a mixed product of disease induced and post-surgical refractive amblyopia), vision through the fellow eye is “normal” in the absence of disease or ametropia.
We now know that isn’t the case. There are frequently fellow eye deficits in amblyopia that can impair a child’s visuomotor and visuocogntive development. An article in the Journal of Binocular Vision and Ocular Motility in 2020 provides a nice overview. Mindy’s clinical measurement showed that her exotropic right eye could see only 3/500 through her contact lens. However, visual acuity through the left eye was only 20/40 unaided, and her BVA through that eye was only 20/30 through the +0.50 sphere that she scoped and accepted as distance. Nearpoint measures showed that her best accommodative response through the right eye was +1.75 sphere net. I therefore wrote her an Rx of +0.50/+1.25 for the left eye, with a balance lens for the right eye. Let’s scrap the contact lens for now, and perhaps re-visit it down the road if it impacts peripheral awareness for driving when she gets older.
While the focus to date had understandably been on trying to obtain some residual functionality of the right eye, it was now the season to turn our attention to the left eye, and to Mindy’s overall visual development as it impacted her day-to-day functioning in general, and academics in particular.
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