vision loss

Optic Neuropathy
Short Summary

Child with progressive exotropia secondary to the profound vision loss that appears to be to an optic neuropathy. The expert recommends to obtain additional studies in order to exclude potential diagnosis such as glioma, pathological disc edema, optic nerve drusen or dominant optic atrophy OPA-1 gene related.

Patient's Questions

The expert's opinion is requested regarding additional studies, diagnosis and treatment recommendations.

Medical Background

There is progressive exotropia secondary to the profound vision loss of the left eye. The vision loss appears to be to an optic neuropathy. The report states that there is optic disc swelling in the right eye in the setting of normal visual acuity and color vision.

Expert's Opinion

Current medications include: no information given

Summary/Recommendations: There is progressive exotropia secondary to the profound vision loss of the left eye. The vision loss appears to be to an optic neuropathy. It is unclear if this is a unilateral or bilateral process. The report states that there is optic disc swelling in the right eye in the setting of normal visual acuity and color vision. However, it is unclear if this swelling is physiologic or pathologic. Additionally, I have some questions about the work-up that need to be addressed:

1. Was a high quality MRI with thin cuts through the orbits performed with gadolinium? This is absolutely essential to exclude a glioma. If gadolinium was not given, the MRI needs to be repeated with gadolinium. Does the child have any cutaneous stigmata of neuro-fibromatosis type I?

2. Is there primary or secondary optic atrophy of the left eye? Secondary atrophy would imply that the optic nerve was initially swollen and might be a clue to the diagnosis.

3. Is the right optic nerve pathologically swollen? The report says it is swollen but in children there is often nasal prominence that is normal and can be easily interpreted as abnormal. This is critical to differentiate because if it is pathologically swollen, this implies a process is affecting both optic nerves. A fluoresce in angiogram can be performed to look for pathological disc leakage on the right. Additionally, a B-scan ultrasound should be performed to exclude drusen of the optic nerve head. Optic nerve drusen causes “pseudopapilledema” and can cause an ischemic optic neuropathy that results in optic atrophy. It can be unilateral or bilateral

4. Was the opening pressure of the spinal tap accurate? Was the manometer held at the level of the spine in an otherwise cooperative child? If there is any question, this should be repeated. It is critically important to have an accurate measurement of the opening pressure.

5. NMO antibodies are pending and this could ultimately be the etiology although I think this is very unlikely.

6. You could consider sending OPA-1 gene to exclude dominant optic atrophy. This is not a great fit in this case but I think it should be excluded.

7. Is the child taking any medications that can be toxic?

8. I would check B12 levels, VDRL and FTA

9. Is there a history of trauma that could explain a traumatic optic neuropathy? A clue would be cupping and pallor of the neuro-retinal rim.

10. Are there any white matter lesions seen on the MRI that could be consistent with multiple sclerosis?

11. Did the vision loss follow a recent immunization? There are reports of immunizations resulting in optic neuritis and ultimately optic atrophy.

Additional studies to be obtained:
1. Fluorescein angiogram to confirm pathological disc edema

2. B-scan ultrasound to exclude optic nerve drusen

3. MRI orbit with gadolinium (if gadolinium was not used in prior study)

4. If LP was not performed under ideal circumstances, consider repeating it for opening pressure

5. Send OPA-1 gene testing

6. Check B-12, VDRL and FTA

Treatment Recommendations: none until the diagnosis is established.
 

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