Non-arteritic anterior ischemic optic neuropathy (NAION) with segmental optic disc edema Jonathan A. Micieli, MD Valérie Biousse, MD
A 75 year old white woman lost vision in the inferior part of her visual field of the right eye for 1 week She has a history of hypertension and diabetes Visual acuity is 20/40 OD, 20/20 OS There is a right 0.6 log unit relative afferent pupillary defect Color vision is 10/14 OD, 14/14 OS correct Ishihara plates
Figure 1. Right eye Left eye
Figure 1. Right eye Left eye There is superior segmental disc edema in the right eye (red arrows)
Figure 2. 33s 49s 59s 2min 42s 5min 5s 6min 37s Intravenous fluorescein angiography of the right optic disc
Figure 2. 33s 49s 59s 2min 42s 5min 5s 6min 37s Intravenous fluorescein angiography shows leakage from the superior part of the optic disc only (there is hyperfluorescence that increases in intensity and size with time)
Figure 3. Left eye Right eye 24-2 SITA-Fast Humphrey visual fields are shown
Figure 3. Left eye Right eye Humphrey visual fields show a right inferior arcuate defect (red box)
A careful history did not reveal any systemic symptoms of giant cell arteritis Laboratory investigations were normal: ESR 12 mm/hr (normal is [age+10 divided by 2] for women) CRP 1.4 mg/l (normal less than 10) Platelets 293 (normal 150-400) The patient has a painless right anterior optic neuropathy of sudden onset, suggesting an ischemic etiology. Given the vascular risk factors (hypertension and diabetes), segmental disc edema in a small optic disc, and no clinical or laboratory evidence of giant cell arteritis, a non-arteritic anterior ischemic optic neuropathy (NAION) was diagnosed
The patient was seen in follow-up 6 weeks later. She had no further changes in her vision Visual acuity is 20/30 OD, 20/20 OS There is a right 0.6 log unit relative afferent pupillary defect Color vision is 11/14 OD, 14/14 OS correct Ishihara plates
Figure 4. Right eye Left eye There was resolution of the right optic disc edema
Figure 5. Left eye Right eye 24-2 SITA-Fast Humphrey visual fields show a right inferior arcuate defect
Figure 6. Retinal nerve fiber layer (RNFL) analysis Ganglion cell layer (GCL) analysis Optical coherence tomography (OCT) of the RNFL and GCL are shown The RNFL is thicker in the left eye because of persistent mild optic disc edema The ganglion cell complex analysis is abnormal in the affected right eye
Figure 7. OCT Deviation map of the RNFL (blue box), ganglion cell complex (GCC) (black box) and pattern deviation from the 24-2 SITA-Fast Humphrey visual field
Figure 7. The inferior arcuate visual field defect (grey box) corresponds to the superior macular ganglion cell complex thinning (black box) and superior retinal nerve fiber layer thinning (blue box). The ganglion cell layer is formed by cell bodies of the retinal ganglion cell and the RNFL is composed of axons of the retinal ganglion cells The inferior retina corresponds to the superior visual field.
Summary points: Segmental optic disc edema is a classic finding in NAION Optic disc edema should resolve in 6 to 11 weeks after symptom onset -persistent edema beyond this time requires further investigations All patients older than 50 yo with presumed NAION require a detailed history and laboratory workup (complete blood count, platelets, erythrocyte sedimentation rate and C-reactive protein) to exclude giant cell arteritis