Visual Field Defects

[tigerlilly]

You have a patient, female, early forties, moderate myope, successfully wearing a PAL for 1.5 years. What would you think if this pt suddenly experienced vertical diplopia and it took 3 diopters of prism to correct it? It has to be all three OD and can't be split or it doesn't help. A few weeks later pt complains of blurriness and loss of some visual acuity OD, verified by exam. Visual field testing shows a significant inferior bilateral defect, each area of loss almost a mirror image of the other on the chart. Pressure is fine, so it's not glaucoma. Everything in the eyes looks healthy, clear, quiet, etc.

Multiple doctors from various specialties are now involved, and an MRI is pending. That said, what would you think was happening with this patient? Has anyone ever seen something similar?

[drk]

Could be MS.

[Paul Smith LDO]

+1

Graves disease exhibits some of these as well.

[Michael I. Davis]

You have a patient, female, early forties, moderate myope, successfully wearing a PAL for 1.5 years. What would you think if this pt suddenly experienced vertical diplopia and it took 3 diopters of prism to correct it? It has to be all three OD and can't be split or it doesn't help. A few weeks later pt complains of blurriness and loss of some visual acuity OD, verified by exam. Visual field testing shows a significant inferior bilateral defect, each area of loss almost a mirror image of the other on the chart. Pressure is fine, so it's not glaucoma. Everything in the eyes looks healthy, clear, quiet, etc.

Multiple doctors from various specialties are now involved, and an MRI is pending. That said, what would you think was happening with this patient? Has anyone ever seen something similar?

I do not understand how the prism has to be in just one eye. 3BD OD is the same as 1.5BD OD and 1.5BU OS.

Just because the pressure is fie does not mean she can not have glaucoma. But it would not explain the diplopia.

The field defect suggest a problem at the chaism . Please let us know the results.

[Jubilee]

I have seen this presentation before with people who had a stroke, but did not recognize it at the time.

[tigerlilly]

I do not understand how the prism has to be in just one eye. 3BD OD is the same as 1.5BD OD and 1.5BU OS.
<snip>.

I know, it doesn't make sense. The doc was surprised at the presentation and checked the prism several times, and then tried splitting it. The patient didn't regain normal vision unless all three diopters were given OD.

[tigerlilly]

Here's an update for the curious: MRI showed a partially empty scilla, but no tumor or MS lesions. A lumbar puncture for confirmation is pending, but the diagnosis is intercranial hypertension, aka pseudotumor cerebri. It's basically all the symptoms of a brain tumor without the presence of an actual tumor. The vision loss has continued to progress, unfortunately. Hopefully medication will help lower the pressure and prevent the loss from being permanent, but surgery for optic nerve sheath fenestration is on the table. Google it - it's some wild and scary stuff.

Thanks to all who offered ideas!