Optic Nerve Pit

Optic Nerve Pit
SYMPTOMS Visual field defects
May experience a decrease in vision and/or metamorphopsia if serous fluid is found at the macula
SIGNS Typically unilateral (can be bilateral 15% of the time)
Oval gray-white depression (presence of glial tissue in the depression) typically along the inferior temporal aspect of the optic nerve, Peripapillary chorioretinal atrophy, Possible macular involvement (Macular schisis, Sensory retinal detachment at the macula, Cystoid macula edema)
The disc margin and cup are typically unaffected
WORK-UP Pupils, Full eye exam with dilation, Visual field (presence of an arcuate scotoma or enlarged blind spot), OCT of the optic nerve, OCT of the macula (may present with a macular schisis, sensory retinal detachment at the macula, or cystoid macular edema), Fundus Autofluorescence, Fluorescein Angiography, Fundus photos, Watzke-Allen test, Macular photostress test, Amsler grid
TREATMENT Give take home Amsler grid in order to monitor for macula involvement
Optic nerve pit with no macular involvement: Monitor. No treatment is needed
Optic nerve pit with macular involvement (macular schisis, sensory retinal detachment at the macula, cystoid macula edema): Refer to a retinal specialist ASAP for further evaluation and treatment
FOLLOW-UP If monitoring, the patient should be seen back in 6-12 months
After patient is evaluated and treated by a retinal specialist and the retina/macula is stable, the patient should be seen back every 6 months
ETIOLOGY Developmental optic nerve dysplasia (defect in the cribiform plate where there is communication between the retina and subarachnoid space)
DIFFERENTIAL DX Optic disc coloboma, Tilted optic nerve, Optic nerve hypoplasia, Glaucoma, Central serous chorioretinopathy
NOTES 25-75% of patients with optic pits will experience macular involvement by their third or fourth decade of life
If maculopathy develops secondary to an optic pit, 80% of patients will see 20/200 or worse (there is, however, an 87% success rate with surgery)