The effect of size on paired 'C/D' estimations

Area of Science:

• Ophthalmology
• Optometry
• Medical Imaging Analysis

Background:

• Accurate estimation of optic nerve head cup-to-disc (C/D) ratios is crucial for glaucoma diagnosis and management.
• Clinical experience may influence the precision of these estimations, but this has not been definitively established.

Purpose of the Study:

• To compare the accuracy of cup-to-disc (C/D) ratio estimations among experienced optometrists, student clinicians, and beginning optometry students.
• To evaluate the impact of clinical experience on the accuracy of C/D ratio estimations using stylized targets.

Main Methods:

• A comparative study involving experienced optometrists, student clinicians, and beginning optometry students.
• Participants estimated C/D ratios on 16 stylized optic nerve head targets.
• Statistical analysis was performed to compare accuracy across different experience levels and target sizes.

Main Results:

• No significant difference in estimation accuracy was found based on clinical experience (alpha = 0.05).
• Overall, only 18.6% of paired estimations (horizontal and vertical) were exactly correct.
• Less than half (45.4%) of estimations were within +/- 0.05 of the true C/D ratios.
• Accuracy was higher for smaller targets and decreased for medium and larger targets.

Conclusions:

• Clinical experience does not significantly affect the accuracy of cup-to-disc ratio estimations.
• The accuracy of C/D ratio estimation is generally low, particularly for larger targets, posing potential challenges in glaucoma diagnosis and management.
• Standardized training and improved documentation methods may be necessary to enhance C/D ratio accuracy in clinical practice.