Optics 2.0


PCA Stroke

Ernie is a pleasant 67 year-old gentleman who experienced an acute stroke a year and a half ago while driving.  He was outside the window of tPA and therefore suffered right-sided hemiplegia, right facial droop, and right neglect.  Due to repeated atrial fibrillation episodes, he has experienced left PCA territory infarction.  Frontiers in Neurology has a nice primer on ischemic posterior circulation stroke.

Ernie’s BVA OU is reduced to a struggling 20/150 whole line, and 20/80 isolated letters.  Isolating the letters on a chart helps him scan better to search for what he’s looking toward.  As predicted by the slide above, Ernie has right homonymous hemianopia (RHH), visual deficits, and memory deficits.  He had significant difficulty recognizing alphabet letters when we first saw him, mirroring the path a number of PCA stroke patients with RHH (Ruth always comes to mind).  Here are Ernie’s visual fields:

Ernie Right Eye RHH

Ernie Left Eye RHH

Here’s where optics comes into play.  Ernie has the following Rx in Progressive Addition Lens (PAL) form:

OD: -3.00-0.75cx030/+3.00

OS: -3.00-1.00cx100/+3.00

PALs are hard enough for any patient with acquired brain injury to function with, distorting the periphery and compromising visual-vestibular interactions.  But they’re a double whammy for Ernie, because when he fixates he tends to elevate his chin and rotate his head toward the right to maximize viewing angle with his intact left field.  Ernie isn’t reading yet.  He’s still working in letters, so a PAL interferes with his distance vision because he elevates his chin and rotates his head to search for intact field and clarity.  Also note Ernie’s myopic Rx power.  When he is working on reading readiness skills, including individual letters, he can imply remove his Rx and be in focus at near.  Simply to give him the convenience of one Rx, we re-wrote it as a bifocal – but it is crucial in his case to set the bifocal line considerably lower than normal due to his chin elevation and head tilt.

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4 thoughts on “Optics 2.0

  1. Bernell has nice rummel hemianopsia buttons to let others know he has trouble on his right side periphery. I have a few of these and I have a person walk on the blind side of the patient walking down the sidewalk.
    Cortical blindness is defined by profound vision loss exclusively from bilateral lesions in the visual cortex and is a subset of cerebral blindness. Is the print in the slide about in red what Ernie has, but not cortical blindness?
    I have been using the blue tech lens on some of these patients for increase in contrast sensitivity.
    Just meself thinking. August
    As a side note, one of your blogs had a free download app similar to the ann arbor workbook where the patient finds the symbols. Which blog was that. Thanks.

  2. Good points on how optics are critical. These are often simple things that can be life changers for our patients, thanks!

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