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Quantitative Comparison of a Handheld and a Table-Top Fundus Camera for Retinal Microvascular Assessment
Lazaros K Yofoglu1, Georgios Zervas2, Christina Konstantaki2
1Cardiovascular Prevention and Research Unit, Clinic/Laboratory of Pathophysiology, School of Medicine, National and Kapodistrian University of Athens, 115 27 Athens, Greece.
A handheld fundus camera shows strong correlation with a table-top device for retinal microcirculation assessment. However, device-specific bias means absolute measurements aren't interchangeable, requiring calibration for cross-device comparisons.
Area of Science:
- Ophthalmology
- Medical Imaging
- Retinal Microcirculation Analysis
Background:
- Quantitative assessment of retinal microcirculation is crucial for diagnosing and monitoring various ocular diseases.
- Established biomarkers like CRAE, CRVE, and AVR are used to evaluate retinal vasculature.
- Digital non-mydriatic fundus cameras offer accessible retinal imaging, but device comparability is essential.
Purpose of the Study:
- To compare the quantitative assessment of retinal microcirculation using a table-top camera (Topcon TRC-NW-8) and a handheld camera (Optomed Aurora IQ).
- To evaluate the agreement and correlation of biomarkers central retinal arteriolar equivalent (CRAE), central retinal venular equivalent (CRVE), and arterio-venous ratio (AVR) between the two devices.
Main Methods:
- A cross-sectional study involving 26 participants (51 eyes) was conducted.
- Retinal imaging was performed on both eyes using the Topcon TRC-NW-8 and Optomed Aurora IQ devices.
- Static retinal vessel analysis was employed to quantify CRAE, CRVE, and AVR.
Main Results:
- Strong correlations were found between the two devices for CRAE (r=0.84), CRVE (r=0.75), and AVR (r=0.83), with high agreement (ICC values 0.91, 0.85, 0.90).
- A consistent device-dependent bias was observed, limiting direct interchangeability of absolute measurements.
- Regression-based equations were derived to facilitate approximate cross-device comparisons.
Conclusions:
- The handheld Optomed Aurora IQ camera demonstrates good relative agreement and strong correlation with the table-top Topcon TRC-NW-8 for retinal microcirculation biomarkers.
- Direct interchangeability of absolute measurements is limited due to consistent device-dependent bias.
- Derived transformation equations may aid approximate comparisons, but external validation is necessary; calibration strategies are highlighted for integrating measurements across platforms.
