A Metascore of Multiple Imaging Methods to Measure Long-Term Glaucoma Structural Progression

Area of Science:

• Ophthalmology
• Medical Imaging
• Data Science

Background:

• Glaucoma diagnosis and monitoring often involve structural measurements from various imaging devices.
• Longitudinal analysis of glaucoma progression is challenging due to device heterogeneity.

Purpose of the Study:

• To develop a unified structural metascore (SMS) for combining and comparing structural measurements from different ophthalmic imaging devices.
• To facilitate long-term structural analysis and patient follow-up in glaucoma care.

Main Methods:

• Three structural measurements (Heidelberg Retina Tomograph II [HRT] rim area, HD-Cirrus optical coherence tomography [OCT] average retinal nerve fiber layer [RNFL] thickness, Spectralis OCT RNFL global thickness) were normalized.
• A linear regression fit with variance approach was used to create the metascore, converting measurements to a Spectralis equivalent.
• SMS performance was validated internally for predicting future values and externally by comparing SMS slopes with clinician grades.

Main Results:

• The developed metascore approach facilitated the plotting of structural measurements over time for 3416 eyes.
• The median metascore slope was -0.3, indicating average structural change over the follow-up period.
• External validation showed strong correlations between SMS slopes and clinician grades, with the combined printout and metascore plots yielding the highest correlation (-0.69).

Conclusions:

• A method was developed to convert Cirrus global RNFL and HRT global rim area measurements to Spectralis global RNFL equivalents.
• This metascore approach simplifies and enhances long-term structural follow-up for glaucoma patients by unifying data from disparate devices.