Bruch's Membrane Opening Minimum Rim Width Measurement with SD-OCT: A Method to Correct for the Opening Size of Bruch's Membrane

A precise evaluation of the retinal nerve fiber layer thickness (rnflt) is key for diagnosing and monitoring glaucoma. the bruch's membrane opening minimum rim width (bmo-mrw) has been proposed as a reproducible assessment of the optic nerve. the bmo-mrw measures the minimum distance from the bmo to the internal limiting membrane. we propose an approach to correct the bmo-mrw using the bmo size for increased accuracy in interindividual comparisons in future studies. eighty-one healthy patients received spectralis spectral domain optical coherence tomography measurements for the peripapillary rnflt and bmo-mrw. we calculated a bmo size-corrected bmo-mrw using the mean bmo size of our cohort. bmo size was defined using the manufacturer-provided bmo area and manually measured bmo perimeter. we observed that the bmo-mrw correlated highly with the perimeter (r=-0.553,p<0.0001) and the area of the bmo (r=-0.546,p<0.0001). using these parameters,we provided a corrected bmo size-adjusted bmo-mrw which was better correlated with the rnflt compared to the noncorrected one (z=-3.3495,p=0.0004). we demonstrated the dependency of the bmo-mrw on onh size. furthermore,we showed the superiority of the corrected bmo-mrw using either the manually measured optic nerve head perimeter or the automatically provided onh for future studies. © 2017 robert kromer and martin stephan spitzer.