Retinal OCT biomarkers associated with reading performance in patients with persistent vs. resolved diabetic macular edema

BACKGROUND

Recent advancements in imaging technologies, particularly structural optical coherence tomography (OCT), have improved the understanding of diabetic macular edema (DME) pathophysiology and provided valuable biomarkers for disease progression and visual outcomes. This prospective study aimed to investigate the association between specific retinal biomarkers identified through OCT imaging and reading performance metrics in patients with previously treated persistent versus resolved DME and good visual acuity.

METHODS

Forty-nine eyes from 35 patients with a history of DME were enrolled. Reading performance was assessed using the Radner reading charts, which include standardized sentences with geometrically progressing print sizes. Structural alterations in the inner and outer retina, as well as the retinal pigment epithelium (RPE), were graded based on OCT images.

RESULTS

Reading performance, measured as maximum reading speed, was associated with specific retinal biomarkers. The disruption of the ellipsoid zone (EZ) in the parafoveal region and the presence of disorganization of the inner retinal layers (DRIL) in the parafovea were correlated with reduced reading speed. These associations were independent of the presence of intraretinal or subretinal fluid.

CONCLUSIONS

Understanding the relationship between retinal biomarkers and reading performance could contribute to a comprehensive evaluation of visual function and quality of life in patients with DME, leading to better management strategies and treatment outcomes.

Measurement properties of continuous text reading performance tests

PURPOSE

Measurement properties of tests to assess reading acuity or reading performance have not been extensively evaluated. This study aims to provide an overview of the literature on available continuous text reading tests and their measurement properties.

METHODS

A literature search was performed in PubMed, Embase and PsycInfo. Subsequently, information on design and content of reading tests, study design and measurement properties were extracted using consensus-based standards for selection of health measurement instruments. Quality of studies, reading tests and measurement properties were systematically assessed using pre-specified criteria.

RESULTS

From 2334 identified articles, 20 relevant articles were found on measurement properties of three reading tests in various languages: IReST, MNread Reading Test and Radner Reading Charts. All three reading tests scored high on content validity. Reproducibility studies (repeated measurements between different testing sessions) of the IReST and MNread of commercially available reading tests in different languages were missing. The IReST scored best on inter-language comparison, the MNread scored well in repeatability studies (repeated measurements under the same conditions) and the Radner showed good reproducibility in studies.

CONCLUSIONS

Although in daily practice there are other continuous text reading tests available meeting the criteria of this review, measurement properties were described in scientific studies for only three of them. Of the few available studies, the quality and content of study design and methodology used varied. For testing existing reading tests and the development of new ones, for example in other languages, we make several recommendations, including careful description of patient characteristics, use of objective and subjective lighting levels, good control of working distance, documentation of the number of raters and their training, careful documentation of scoring rules and the use of Bland-Altman analyses or similar for reproducibility and repeatability studies.