Microcystic Macular Edema in Neuromyelitis Optica Is Associated with Visual Disability and Retinal Axonal and Neuronal Loss (IN4-1.009)

OBJECTIVE: The primary objective of this study was to assess neuromyelitis optica (NMO) eyes for morphologic retinal abnormalities utilizing high-definition optical coherence tomography (OCT) imaging and to examine associations with quantitative OCT measures and visual dysfunction. BACKGROUND: NMO-associated optic neuritis (ON) is characterized by poor visual outcomes, often resulting in blindness. Studies utilizing OCT have demonstrated severe retinal axonal and neuronal loss following NMO-associated ON, primarily thought to represent sequelae of optic nerve injury. However, abnormalities of the retinal vasculature have also been identified in NMO-ON eyes, suggesting that direct retinal injury may also be operative in NMO. Interestingly, aquaporin-4 (the target of NMO-IgG) is highly expressed in the retina. DESIGN/METHODS: In this cross-sectional study, 39 patients with NMO-spectrum disorders and 39 age and sex-matched healthy-controls underwent spectral-domain OCT and visual function testing. RESULTS: Microcystic macular edema (MME) of the inner nuclear layer (INL) was identified in 10 of 39 patients (26%) and was exclusively found in eyes with a history of ON. MME eyes had significantly lower high and low-contrast letter-acuity scores (100%:p=0.002; 2.5%:p=0.002; 1.25%:p=0.004), lower peri-papillary retinal nerve fiber layer (RNFL) thickness (p=0.04), lower macular-RNFL thickness (p=0.004), lower ganglion cell layer+inner plexiform layer (GCIP) thickness (p=0.007), higher INL thickness (p CONCLUSIONS: MME of the INL in NMO is associated with severe retinal axonal and neuronal loss and corresponding visual disability, and may contribute to poor visual outcomes following NMO-associated ON. Additionally, involvement of the anterior visual pathway may occur in NMO-spectrum disorders in the absence of symptomatic ON. Supported by: National Multiple Sclerosis Society (TR 3760-A-3 to P.A.C and RG 4212-A-4 to L.J.B. subcontracted to P.A.C), National Eye Institute (R01 EY 014993 and R01 EY 019473 to L.J.B. subcontracted to P.A.C), and Braxton Debbie Angela Dillon and Skip (DADS) Donor Advisor Fund (to P.A.C, E.M.F). Disclosure: Dr. Sotirchos has nothing to disclose. Dr. Saidha has received personal compensation for activities with MedicalLogix and Teva Neurosciences. Dr. Byraiah has nothing to disclose. Dr. Mealy has nothing to disclose. Dr. Ibrahim has nothing to disclose. Dr. Sepah has nothing to disclose. Dr. Newsome has received personal compensation for activities with Biogen Idec, Novartis, and Teva Neuroscience. Dr. Ratchford has received personal compensation for activities with Teva Neuroscience as a speaker. Dr. Ratchford has received research support from Biogen-Idec and Novartis. Dr. Frohman has received personal compensation for activities with Biogen Idec, Teva Neurosciences, Acorda, Astellas, Abbott, and Novartis. Dr. Balcer has received personal compensation for activities with Biogen Idec, Questcor, Novartis, and Vaccinex. Dr. Nguyen has received personal compensation for activities with Heidelberg Engineering, Inc. Dr. Nguyen has received research support from Heidelberg Engineering, Inc. Dr. Levy has received personal compensation for activities with ApoPharma Inc. Dr. Levy has received research support from ApoPharma Inc. Dr. Calabresi has received personal compensation for activities with Biogen Idec, Teva Neuroscience, Genzyme Corporation, Vaccinex, Vertex, and Novartis. Dr. Calabresi has received research support from the National Institutes of Health, the National Multiple Sclerosis Society, Nancy Davis Foundation, Biogen Idec, Vertex, Genentech, Inc., Abbott, and Bayer.