Abstract
Purpose :
Vision degrading myodesopia (VDM) results from clinically significant vitreous opacities that reduce contrast sensitivity (CS) and visual quality of life (VQOL). In previous studies, quantitative ultrasonography (QUS) was applied to echo data collected using a single clinical scanner and was found to correlate with CS and VQOL, the latter measured by the N.E.I. Visual Function Questionnaire (VFQ). The present study evaluated a cohort of patients to investigate the machine independence of QUS to assess VDM by collecting data from patients using two different clinical scanners.
Methods :
28 eyes from 14 patients (age 56±14 years, 10 males, 4 females) experiencing VDM were enrolled in this study. All eyes were scanned with two different clinical ophthalmic ultrasound systems in succession: one with a 15-MHz single element transducer (23-mm focal length, 7-mm aperture) and one comprising a 20-MHz annular array (five elements, 22-mm focal length, 9-mm total aperture). Images were acquired as a horizontal plane through premacular vitreous in temporal gaze. Three QUS parameters were computed from the vitreous region within each set of log-compressed envelope data and averaged over artifact-free frames. All three QUS parameters were then used to calculate a composite score to summarize the presence of vitreous echodensities.
Results :
A linear regression comparing the three QUS parameters and composite score computed from echo data collected with each system showed statistically significant correlations (R≥0.86,p<0.001). The QUS composite score correlated with CS (R=0.70,p=0.004) and VFQ (R=0.54,p=0.04). Moreover, the total area of the vitreous evaluated with both systems – the region from which QUS parameters were computed – exhibited no statistically significant difference (p=0.43).
Conclusions :
QUS is effective at quantifying the presence of vitreous echodensities and predicting their effect on CS and VQOL. Importantly, results from this study suggest the QUS parameters and the composite score are machine independent and could be universally applied to assess VDM across clinical ophthalmic ultrasonic imaging systems.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.