Intraobserver Variability in Evaluating Simultaneous–Stereo Optic Nerve Photographs: A Comparison of Film vs. Digital

Abstract

 

Abstract:

 

The optic disc must be accurately evaluated when diagnosing and managing patients with Glaucoma because changes in the optic nerve may precede glaucomatous damage measured by visual field testing. A prospective study of a cohort of 35 eyes from 35 patients with glaucoma or suspected of having glaucoma was designed with IRB approval in order to compare film and digital stereoscopic optic nerve photographs. The patients received pupillary dilation and their optic nerves were photographed with a stereoscopic camera (NIDEK 3DX) using digital and film techniques. Five observers, fellowship–trained Glaucoma specialists, each evaluated the photographs on two separate occasions to compare 1) vertical cup/disc ratio and 2) horizontal cup/disc ratio. Cup/disc ratios ranged from 0.0–1.0.

 

 

^{The data from the five expert observers was analyzed and R2 correlation coefficients determined for intraobserver and interobserver repeatability in addition to a comparison of the assessments of film versus digital images. The coefficients of variation (SD/mean) for the repeatability of the observers were calculated. Film versus digital data was evaluated using Bland–Altman analysis. There were no significant differences among observers or between digital and film photography of the optic disc. Digital photography is as reliable as film photography for evaluating cup/disc ratios and may be useful in future studies.}

 

 

Keywords: optic disc • imaging/image analysis: clinical