Abstract
Purpose :
Recently, the Minimum Rim Width(MRW) measurement was introduced as an objective parameter to assess the optic disc cupping(ODC) particularly in glaucoma. However, although pathologic ODC is often related to glaucoma, it can also occur other optic neuropathies. We evaluated the MRW and the peripapillary retinal nerve fiber layer(pRNFL) in eyes previously affected by optic neuritis(ON) due to neuromyelitis optica spectrum disorder(NMOSD) or MOG-associated disease(MOGAD) and in normal controls(CT).
Methods :
Twenty-seven ON eyes of 16 patients with MOGAD, 24 ON eyes of 15 patients with NMOSD, and 36 eyes of 19 CT were enrolled. All underwent ophthalmic examination, visual field (VF) and OCT(Heidelberg Spectralis) testing. Global and sectoral MRWand pRNFL measurements were obtained. MRW:pRNFL ratios were calculated. Groups were compared using Generalized Estimated Equations. Area under the receiver operating characteristic curve (AUC) was calculated. Relationship between VF mean deviation (MD) and global MRW or pRNFL was assessed.
Results :
MRW and pRNFL were significantly reduced in MOGAD and NMOS ON eyes compared to CT. For both diseases (alone or combined vs CT) AUC values indicated that pRNFL performed better than MRW parameters. No significant difference was found between MOGAD-ON and NMOSD-ON eyes in both parameters (Table 1). VF MD of MOGAD-ON eyes was higher than NMOSD-ON eyes (-5,82dB vs -11.71dB, p=0.023). Spearman correlation coefficients was greater between VF MD and global pRNFL (0.737) than with global MRW (0.453). MRW:pRNFL ratios were all higher in both disease groups than in CT but did not perform better than MRW or pRNFL isolated measurements and did not differentiate NMOSD-ON from MOGAD-ON eyes (Table 2).
Conclusions :
While ODC and MRW thinning develop in eyes affected by ON from NMOSD and MOGAD, it occurs at a smaller extent as compared to pRNFL loss. This finding was corroborated by the MRW:pRNFL ratios that were generally greater in both diseases than CT. There was a significant overlap in RNFL loss and MRW thinning in both ON groups, despite considerable difference VF MD, suggesting that ON in both diseases may lead to different rates of functional loss, despite similar OCT-measured structural abnormalities, although further studies are necessary to confirm it.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.