Optic nerve evaluation among optometrists.
OBJECTIVE
To determine agreement among optometrists regarding assessment of optic nerve C/D ratios and perceived glaucomatous damage and to separately analyze these results on the basis of residency training, practice setting, and glaucoma patient experience.


METHODS
Fifty-six optometrists from various modes of professional practice evaluated 33 stereoscopic optic nerve photographs. Observers were asked to estimate the vertical cup-to-disk (C/D) ratio and determine the glaucomatous status of the optic nerve. The mean vertical C/D ratio, percentage perceived as glaucomatous, and levels of interobserver and intraobserver agreement (kappa) are reported.


RESULTS
Estimated C/D ratios differ significantly on the basis of training (p = 0.02) practice setting (p = 0.001), glaucoma patient experience (p = 0.001). Glaucomatous damage interpretation was significantly different (p = 0.006) based upon an optometrist's practice setting. Interobserver agreement regarding C/D ratios is significantly higher among optometrists who have completed a residency (kappaw = 0.59) and practice in clinical settings (optometry school/medical center/hospital) (kappaw = 0.59) compared with non-residency-trained optometrists (kappaw = 0.52) and those practicing in commercial settings (kappaw = 0.54). Interobserver agreement of glaucomatous damage is significantly higher among optometrists who have completed a residency (kappa = 0.50) compared with non-residency-trained optometrists (kappa = 0.42).


CONCLUSIONS
Intraobserver agreement is higher than interobserver agreement among optometrists when C/D ratios are estimated and the glaucomatous status of the optic nerve is assessed. Optic nerve evaluation among optometrists is significantly influenced by residency training, practice setting, and glaucoma patient encounters.
Spalding
J M
JM
Orlando VA Healthcare Center, Florida 32803, USA.
Litwak
A B
AB
Shufelt
C L
CL
D002983:Clinical Competence; D005260:Female; D005901:Glaucoma / Q000175:diagnosis*; D006801:Humans; D007396:Internship and Residency; D008297:Male; D015588:Observer Variation; D009900:Optic Nerve / Q000473:pathology*; D009901:Optic Nerve Diseases / Q000175:diagnosis*; D009907:Optometry / Q000193:education / Q000592:standards*; D010781:Photography; D011364:Professional Practice / Q000706:statistics & numerical data; D015203:Reproducibility of Results; D014787:Vision Tests / Q000592:standards