Scientists assessed multispectral imaging as a novel diagnostic approach for diabetic retinopathy in clinical settings.

A total of 50 type 2 diabetic patients (99 eyes) were enrolled in this cross-sectional study. All subjects underwent digital fundus photography, MSI and fundus fluorescein angiography. Scientists calculated total exact agreement, sensitivity, specificity, positive predictive value and negative predictive value of no DR/mild nonproliferative DR and severe NPDR/proliferative DR grading based on DFP and MSI, and compared the findings with fundus fluorescein angiography.

Compared with fundus fluorescein angiography:
• the exact agreement for MSI was 0.835; for DFP it was 0.614;
• the sensitivity for no DR/mild NPDR in MSI and DFP was 100 percent, and for severe NPDR/PDR it was 97.4 percent and 88.3 percent.
• The specificity for no DR/mild NPDR in MSI and DFP was 96.3 percent and 95 percent, and for severe NPDR/PDR it was 100 percent in both.
• The positive predictive value for no DR/mild NPDR in MSI and DFP was 86.4 percent and 82.6 percent, and for severe NPDR/PDR it was 100 percent in both.
• The negative predictive value for no DR/mild NPDR in MSI and DFP was 100 percent, and for severe NPDR/PDR it was 91.7 percent and 71 percent in both.

Scientists found that multispectral imaging displayed excellent agreement with fundus fluorescein angiography in DR grading, suggesting it might serve as a new diagnostic technique for evaluating DR.

Researchers investigated the relationship between macular and peripapillary vessel density and progressive retinal nerve fiber layer loss in individuals with mild to moderate primary open-angle glaucoma, as part of a prospective, observational study. They included 132 eyes of 83 individuals with glaucoma followed for at least two years (average: 27.3 ±3.36 months).

Researchers acquired measurements of macular whole-image vessel density (m-wiVD) and optic nerve head whole-image vessel density (onh-wiVD) at baseline using optical coherence tomography angiography. RNFL, minimum rim width and ganglion cell plus inner plexiform layer thickness were obtained semiannually using spectral-domain OCT. Researchers used random effects models to evaluate the relationship between baseline vessel density parameters and rates of RNFL loss after adjusting for the following confounding factors:
• baseline visual field mean deviation;
• MRW;
• GCIPL thickness;
• central corneal thickness; and
• mean intraocular pressure during follow-up and disc hemorrhage, with or without including baseline RNFL.
The main outcome measures included effects of m-wiVD and onh-wiVD on rates of RNFL loss over time.

The average baseline RNFL thickness was 79.5 ±14.8 μm, which declined with a mean slope of -1.07 μm/year (CI, -1.28 to -0.85). In the univariate model— including only a predictive factor and time, and interactions—each 1 percent lower m-wiVD was associated with a 0.11 μm/year (p<0.001) faster rate of RNFL decline, and each 1 percent lower onh-wiVD was associated with a 0.06 μm/year (p=0.031) faster rate of RNFL decline. A similar relationship between low m-wiVD and onh-wiVD, and faster rates of RNFL loss was found using different multivariate models. The association between vessel density measurements and rate of RNFL loss was weak (r²=0.125 for m-wiVD and and r²=0.033 for onh-wiVD). Average CCT also was a predictor for faster RNFL decline in univariate (0.11 μm/year; p<0.001) and multivariate models.

Researchers concluded that lower baseline macular and optic nerve head vessel densities were associated with a faster rate of RNFL progression in mild to moderate glaucoma. They suggested that assessment of ONH and macular vessel density might add significant information to the evaluation of glaucoma risk and prediction of worsening disease.