Interobserver variability of optic disk variables measured by confocal scanning laser tomography

Area of Science:

• Ophthalmology
• Medical Imaging
• Glaucoma Research

Background:

• Confocal laser scanning tomography (CLST) is a key imaging technique for evaluating the optic nerve head in glaucoma.
• Accurate measurement of optic disc parameters is crucial for glaucoma diagnosis and monitoring.
• Interobserver variability in CLST measurements can impact diagnostic reliability.

Purpose of the Study:

• To evaluate interobserver variation in CLST measurements of the optic nerve head.
• To determine if adding clinical optic disc photographs reduces this observer-related variation.

Main Methods:

• Four glaucoma specialists independently assessed optic disc variables from 16 eyes using CLST (Heidelberg Retina Tomograph).
• Interobserver variability was calculated for initial CLST measurements.
• A second review incorporated stereoscopic color optic nerve head photographs to assist in defining the optic disc margin.

Main Results:

• Parameters like cup shape measure and maximum cup depth showed the least interobserver variation.
• Parameters such as volume above/below surface/reference exhibited the highest interobserver variation.
• Adding optic disc photographs significantly increased observer variation for certain volumetric parameters in two examiners.

Conclusions:

• Clinical optic disc photographs enhance CLST by improving optic disc margin definition.
• Interobserver variation in tomographic optic disc measurements can be substantial, even among experienced specialists.
• Centralizing CLST measurements in reading centers is recommended for multicenter glaucoma studies.