Título

MINIMUM RIM WIDTH AND PERIPAPILLARY RETINAL NERVE FIBER LAYER IN NEUROMYELITIS OPTICA SPECTRUM DISORDERS, GLAUCOMA AND HEALTHY CONTROLS

Objetivo

Pathologic optic disc cupping(ODC) is often related to glaucoma but can be caused by other optic neuropathies, leading to diagnostic difficulties. Previously, we found that a ratio between Minimum Rim Width(MRW) and peripapillary retinal nerve fiber layer(pRNFL) provided better discrimination ability between compressive optic neuropathy and glaucomatous optic neuropathy(GON), in comparison to isolated parameters. In this prospective observational clinical study we evaluated such parameters in eyes affected by optic neuritis(ON) due to neuromyelitis optica spectrum disorders(NMO), GON and controls(CT).

Método

Thirty-five eyes with ON-NMO, 27 eyes with perimetric GON and 41 CT eyes were enrolled. All underwent full ophthalmologic examination. Global and sectoral MRW and pRNFL measurements and MRW:pRNFL ratios were evaluated. Data were compared using Generalized Estimated Equations. Area under the receiver operating characteristic curve(AUROC) and positive and negative likelihood ratios(PLR and NLR) were calculated.

Resultado

MRW and pRNFL were significantly reduced in NMO and GON compared to CT. MRW was thinner in GON than in NMO (AUROC 0.74-0.94). For pRNFL, results varied according to sectors, with AUROC (0.51-0.75) demonstrating a significant overlap between NMO and GON(Table 1). MRW:pRNFL ratios slightly increased the ability to discriminate the diseases, as shown by higher AUROCs (0.77-0.97) and PLRs and lower NLRs, especially in the nasal sector and global and horizontal averages(Table 2).

Conclusão

ODC and MRW thinning are observed in eyes affected by both diseases, though more pronounced in GON. On the other hand, there is a significant overlap in RNFL loss in both groups. Better than these isolated parameters analysis, their combination through MRW:pRNFL ratios seems to increase the ability to distinguish both conditions. Although further studies are necessary to confirm it, we believe that MRW:pRNFL ratios may be helpful in the differential diagnosis of glaucoma-mimicking optic neuropathies.