Abstract
Purpose :
To develop a single-scale, structural metascore (SMS) that combines measurements from four imaging devices to facilitate measurement of long-term structural glaucomatous damage and analyze its predictive performance
Methods :
The SMS combines measurements from four imaging devices (optic disc photography [ODP] rim area to disc area ratio [RADAR], 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) and expresses them as a single measurement from 0 (worst) to 100 (best). The SMS was plotted against time with previously reported methods (De Gainza 2022). SMS performance was evaluated by ability to predict future values (internal validation), and how well slope correlated with the average grades assigned by three expert graders (external validation).
Results :
SMS plots were created for 2914 eyes of 1556 patients. The average baseline age (± SD) was 60.5 (±11.2), mean follow-up 12.0 (±4.8) years, and mean number of images per eye 14.0 (±5.8). The mean numbers of images per device were 3.9 (±1.4), 3.9 (±2.4), 4.8 (±3.0), and 1.5 (±3.0) for ODP, HRT, Cirrus, and Spectralis, respectively. The SMS slopes’ median was −0.4 (interquartile range 1.1). The average absolute predictive ability was 7.74/100 (where 100 = entire normalized scale). Correlations between the average grades assigned by the three clinicians and the SMS slopes were −0.51, −0.66, and -0.56 for the first (graders had structural imaging device printouts alone), second (SMS plots alone), and third (printouts + SMS plots) gradings, respectively. Agreement was highest between graders when they had access to both the device printouts and SMS plots (grader A & B = 88%; grader A & C = 77%; grader B & C = 83%).
Conclusions :
This newly developed SMS included automated measurements from ODPs and showed similar predictive ability and higher agreement among graders compared to our previous SMS. With inclusion of ODPs, acceptable accuracy can be obtained in interpretation of long-term structural glaucoma progression on a single scale across different, previously incomparable platforms.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.