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Case 49

Patient Presentation: A 9-year-old previously healthy girl presented with progressive, painless vision loss in her left eye over 2 weeks. Her past ocular history was unremarkable. A complete physical examination including a neurological assessment was within normal limits. Her BCVA was 20/20 OD and HM OS, and anterior segment examination was unremarkable. A dilated fundus exam was performed and the fundus image for the left eye is shown below:


Question: Describe the main findings.

On further questioning, her parents reported a large raccoon population in their neighborhood and the presence of raccoon stool on their porch.

Question: What condition are these findings consistent with?

OCT HD5 Line Raster was performed overlying the worm.


Question: What layer of the retina is the worm located?

OCT macula was performed in the left eye over the fovea and shown below: 


Question: What is the main abnormality on this OCT?

Question: Which of the following is an appropriate treatment option for this patient?

With photocoagulation, the worm was found to be immobilized on fundus examination.


For more information, see case report:

Learning Objectives:

  1. Recognize features of DUSN that help distinguish it from other conditions causing unilateral vision loss.

  2. Recognize key features of early and late stage DUSN.

  3. Recognize the treatment options for DUSN.

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