Repeatability of Heidelberg Retinal Tomography 3 and effect of alignment algorithm on glaucoma suspects

Area of Science:

• Ophthalmology
• Medical Imaging
• Glaucoma Diagnostics

Background:

• The Heidelberg Retina Tomograph (HRT) is a key tool for glaucoma diagnosis.
• Repeatability of HRT analysis tools (MRA, GPS) is crucial for glaucoma suspects.
• Intra-visit repeatability of HRT3 was assessed in glaucoma suspects.

Purpose of the Study:

• To investigate the intra-visit repeatability of the HRT3 instrument.
• To evaluate the impact of image registration on HRT3 measurement variability.
• To determine the significance of image registration for glaucoma diagnosis.

Main Methods:

• Two optic nerve head scans were performed on 164 eyes of 84 patients using HRT3.
• Variability of global and sectoral rim area, rim volume, and GPS was analyzed with and without image alignment.
• Repeatability was assessed by the absolute difference between two measurements.

Main Results:

• HRT3 demonstrated high repeatability for global rim area, rim volume, and GPS.
• Image registration significantly reduced variability for global measurements (p < 0.001 to p = 0.002).
• Sectoral analysis showed increased variability without registration, particularly for GPS (p < 0.001).

Conclusions:

• HRT3 exhibits high short-term repeatability, enhanced by image registration for global metrics.
• Image registration improves repeatability for sectoral analysis, especially for GPS.
• Image registration is vital for accurate interpretation of HRT3 results in glaucoma suspects.