Semiquantitative Optic Nerve Grading Scheme for Determining Axonal Loss in Experimental Optic Neuropathy

Abstract

The grading scheme had good inter- and intraobserver agreement, and high correlation with the TEM methods. It is a practical and time-saving method, requiring less than 1 minute per nerve and is an alternative to sampling methods that can yield significant errors.

Assessment of retinal ganglion cell damage in glaucomatous optic neuropathy: Axon transport, injury and soma loss

“…These values were combined to arrive at a damage grade from 0 (no damage) to 10 (100% damage). This method exhibited good correlation with quantification of the entire ON section (Chauhan et al, 2006).…”

“…However, despite the varying attempts to introduce objectivity it remains a qualitative estimate, with the potential of inter-and intra-observer variability. Chauhan et al (2006) proposed a semi-quantitative technique to assess axonal damage to attempt to diminish observer variability. In this method, sub-areas within each ON cross-section exhibiting similar degrees of axonal damage were spatially delineated and each assigned a percent-damage score as well as the percent-area that they represented within the ON cross-sectional area.…”

“…To further combine the relative strengths of both counting and grading techniques for efficiency and relative accuracy, Marina et al (2010) proposed a modification of the technique of Chauhan et al (2006). In an approach termed 'targeted sampling', ON cross sections were first subjectively separated into areas exhibiting similar degrees of damage.…”

Rodent Models for Glaucoma Retinopathy and Optic Neuropathy

“…1 and Table 1). Despite its semiquantitative nature, the damage score correlates well with RGC density assessed in flat-mounts, 91,92 axon density in the optic nerve, 92 severity of chronic ocular hypertension, 90 and age-dependent development of glaucoma in the DBA/2J mice. 87 The foremost advantage of this technique is that it provides a very convenient means to appraise quickly the overall injury in the optic nerve.…”

“…85,[88][89][90][91][92] This method uses dyes such as p-phenylenediamine to stain degenerated axons. On the basis of the extent of the staining, masked observers assign a numerical optic nerve damage score to each optic nerve ( Fig.…”