Evaluation of two‐dimensional Bruch's membrane opening minimum rim area for glaucoma diagnostics in a large patient cohort

Abstract

In a heterogenous clinical cohort of glaucoma patients, all analysed SD-OCT parameters excel DM-RA of CSLT. The two-dimensional parameter BMO-MRA shows comparable levels of diagnostic power to detect glaucoma compared to established parameters BMO-MRW and RNFL thickness. Given higher comparability between ONH sizes, BMO-MRA might become an additional standard tool in SD-OCT imaging for glaucoma.

Diagnostic capability of a linear discriminant function applied to a novel Spectralis OCT glaucoma-detection protocol

“…Our results showed that the OCT parameters obtained with the BMO-MRW and the Spectralis OCT GMPE (either BMO-MRW or pRNFL thickness in three concentric circles cantered on the ONH) have a similar diagnostic capability to the standard pRNFL application in differentiating mild In this study, we found differences between mild glaucoma eyes and control eyes (both BMO-MRW and pRNFL) in all global OCT parameters analysed, except in the case of BMO-MRW area. This contrasts with other authors, such as Enders et al [20], who found that BMO-MRW area offers good diagnostic capability in a large glaucoma cohort (including different levels of glaucoma and ocular hypertensive patients). This difference could be due to the early stage of glaucoma and the small sample size in our study.…”

“…Previous studies have shown the clinical utility of BMO-MRW parameters in diagnosing glaucoma, especially in cases of extreme optic-disc sample size, demonstrating better diagnostic capability than confocal scanning laser tomography and exhibiting a good structure function correlation [9,21]. In general, many studies have shown the SD-OCT BMO-MRW and pRNFL thickness parameters to surpass confocal scanning laser tomography as regards diagnostic capacity to detect glaucoma [3,5,18,20,22]. There is less agreement on whether preference should be given to one of the two morphometric SD-OCT parameters.…”

Optical coherence tomography evaluation of the optic nerve head neuro‐retinal rim in glaucoma

“…Although it should be noted that the MRW parameter (rim width) correlated equally well to the visual field and RNFL thickness in that study even without adjustment for disc size . It is likely that disc size has greater impact at the extremes, that is, for very small or very large discs or discs of highly myopic eyes . Other similar approaches based on minimum distance mapping have confirmed the advantages it provides for glaucoma diagnostics …”

“…The minimum distance approach constrains the thickness measurement to being made at the thinnest point along the rim and as close to being perpendicular to the axon bundles as possible . This theoretical strength proves to have meaningful clinical benefits such as avoiding the over‐estimates of rim thickness produced by other methods that are based on less sound geometry, resulting in improved diagnostic performance and stronger correlations to visual field sensitivity …”

“…When the thickness of the optic nerve head rim tissue is measured in an OCT scan as the distance from the BMO point to the nearest point along the optic disc surface, it is commonly termed the BMO‐minimum rim width (BMO‐MRW) or simply MRW . The MRW parameter enhances diagnostic performance as compared to methods of rim width measurement based on less appropriate geometry, such as implemented in CSLT or older OCT approaches, where the width is determined ‘horizontally’ (within the reference plane) and from an outer edge defined by the clinical disc margin instead of by specific anatomical features such as the BMO or anterior scleral surface …”