Effect of Visual Impairment on Teleretinal Imaging for Diabetic Retinopathy Screening.

BACKGROUND AND OBJECTIVE

To evaluate the effect of decreased visual acuity on image quality obtained by non-mydriatic retinal photography in diabetic subjects. PATIENTS AND METHODS This case-control study comprised 422 eyes (211 cases with ungradable images after non-mydriatic retinal photography, and 211 controls). All subjects underwent complete ophthalmic examination. The association between ungradable image rate and several eye factors, such as corrected distance visual acuity (CDVA), spherical equivalent (SE), astigmatism, and cataracts, was evaluated using a generalized estimating equations model.

RESULTS

Visual impairment (Snellen CDVA worse than 20/40) was significantly associated with an increased likelihood of ungradable images. The odds ratio (OR) for this association was 7.79 (95% CI, 4.19-14.50; P < .0001). This relationship remained significant in the multivariable model (OR: 5.23; 95% CI, 2.82-9.71; P < .0001). Similarly, refractive error worse than -6.0 diopters (D) SE or +5.0 D SE was associated with increased risk of ungradable scans, with an OR of 13.21 (95% CI, 2.61-66.77; P = .002).

CONCLUSION

Decreased visual acuity may be a predictor of inaccurate image analysis in subjects screened for diabetic retinopathy by non-mydriatic retinal photography.