The following article is a part of conference coverage from the 2021 meeting of the North American Neuro-Ophthalmology Society, being held virtually from February 20 to 23, 2021. The team at Ophthalmology Advisor will be reporting on the latest news and research conducted by these leading experts in neuro-ophthalmology. Check back for more from the NANOS 2021 Meeting.
Isolated nasal involvement and optical coherence tomography (OCT) nasal quadrant retinal nerve fiber layer (RNFL) thickness can both be used to distinguish nasal optic disc hypoplasia (NODH) from ocular conditions such as glaucoma, according to a research study presented at the North American Neuro-Ophthalmology Society (NANOS) 2021 Annual Meeting. The conference was held virtually from February 20, 2021 to February 23, 2021.
Researchers shared the case of a 33-year-old man who presented with unresolved visual field defect in the right eye. In the previous 6 months, the patient had been followed for a cotton wool spot in the same eye, attributed to an Epstein-Barr virus infection.
The patient’s visual acuity was 20/15 in the right eye (SE, -2.00) and 20/20 in the left eye (SE, -1.75). Intraocular pressure was 15 mm Hg in both eyes and the patient had full-color vision and no relative afferent pupillary defect. On a dilated exam, the patient had a cup-to-disc ratio of 0.8 and 0.5 in the right and left eyes, respectively. Flash electroretinogram and visual evoked potential were normal.
The patient underwent OCT and visual field testing. The OCT results demonstrated a small superotemporal retinal nerve fiber layer defect and a superotemporal RNFL notch in the right eye.
Ultimately, the patient was diagnosed with NODH, a “congenital condition in which an inherent defect in the retinal ganglia causes nonprogressive temporal wedge-shaped scotoma extending horizontally from the optic nerve.” Per the researchers, isolated OCT nasal rim thinning separated the patient from potential infero/superotemporal glaucomatous optic nerve neuropathy and band atrophy of optic chasm pathology.
The researchers cited previous literature stating that OCT nasal quadrant retinal nerve fiber layer thickness can be used to distinguish NODH from glaucoma “with NODH-like temporal VFDs,” as well as an association between high myopia and smaller disc size compared with patients with glaucoma.2 They also cited a study emphasizing that isolated nasal involvement in RNFL thinning can help differentiate NODH from “the band atrophy of optic chiasm compression.”3
“Distinguishing NODH from other optic neuropathies is important for sparing patients from unnecessary testing and interventions,” the research says.
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- Commiskey P, Bowers L, Shazly T. Absolute scotoma in young man with recent Epstein-Barr virus. Presented at: North American Neuro-Ophthalmology Society Annual Meeting; February 20-23, 2021; Poster 18.
- Ohguro H, Ohguro I, Tsuruta M, Katai M, Tanaka S. Clinical distinction between nasal optic disc hypoplasia (NOH) and glaucoma with NOH-like temporal visual field defects. Clin Ophthalmol. 2010;4:547-555. doi:10.2147/OPTH.S9151.
- Haruta M, Kodama R, Yamakawa R. Optical coherence tomography detection of characteristic retinal nerve fiber layer thinning in nasal hypoplasia of the optic disc. Eye. 2017;31(7):1685-1668. doi:10.1038/eye.2017.134.