Visual Function for Driving in Diabetic Macular Edema and Retinal Vein Occlusion Post-Stabilization with Anti-Vascular Endothelial Growth Factor

Structure-function associations between contrast sensitivity and widefield swept-source optical coherence tomography angiography in diabetic macular edema

PURPOSE

To evaluate the relationship between contrast sensitivity (CS) and widefield swept-source optical coherence tomography angiography (WF SS-OCTA) vascular metrics in diabetic macular edema (DME) was the purpose.

METHODS

This prospectively enrolled cross-sectional observational study included 61 eyes of 48 patients that were tested with the quantitative CS function (qCSF) test on the same day as imaging with WF SS-OCTA (PLEX® Elite 9000, Carl Zeiss Meditec) 3 × 3, 6 × 6, and 12 × 12 mm scans. Outcomes included visual acuity (VA) and multiple qCSF metrics. Vascular metrics included vessel density (VD) and vessel skeletonized density (VSD) in the superficial (SCP) and deep capillary plexus (DCP) and whole retina (WR) and foveal avascular zone (FAZ) parameters. Mixed effects multivariable linear regression models controlling for age, lens status, and diabetic retinopathy stage were performed. Standardized beta coefficients were calculated by refitting the standardized data.

RESULTS

SS-OCTA metrics had a significant association with CS and VA. The effect size of OCTA metrics was larger on CS compared to VA. For example, the standardized beta coefficients for VSD and CS at 3 cpd (βSCP = 0.76, βDCP = 0.71, βWR = 0.72, p < 0.001) were larger than those for VA (βSCP =  - 0.55, p < 0.001; βDCP =  - 0.43, p = 0.004; βWR =  - 0.50, p < 0.001). On 6 × 6 mm images, AULCSF, CS at 3 cpd, and CS at 6 cpd were significantly associated with VD and VSD in all three slab types (SCP, DCP, and WR), while VA was not.

CONCLUSION

Structure-function associations in patients with DME leveraging the qCSF device suggest microvascular changes on WF SS-OCTA are associated with larger changes in contrast sensitivity than VA.

Association Between Contrast Sensitivity and Central Subfield Thickness in Center-Involving Diabetic Macular Edema

Purpose: To evaluate the association between contrast sensitivity (CS) and central subfield thickness (CST) in diabetic macular edema (DME). Methods: This prospectively recruited, cross-sectional study included eyes with DME evaluated from November 2018 to March 2021. CST was measured using spectral-domain optical coherence tomography on the same day as CS testing. Only eyes with center-involving DME (CST >305 µm for women; >320 µm for men) were included. CS was evaluated using the quantitative CS function (qCSF) test. Outcomes included visual acuity (VA) and the following qCSF metrics: area under the log CS function, contrast acuity (CA), and CS thresholds at 1 to 18 cycles per degree (cpd). Pearson correlation and mixed-effects regression analyses were performed. Results: The cohort included 52 eyes of 43 patients. Pearson correlation analysis showed a stronger association between CST and CS thresholds at 6 cpd (r = -0.422, P = 0.002) than CST and VA (r = 0.293, P = 0.035). Mixed-effects univariate and multivariate regression analyses showed significant associations between CST and CA (β = -0.001, P = .030), CS at 6 cpd (β = -0.002, P = .008), and CS at 12 cpd (β = -0.001, P = .049) but no significant associations between CST and VA. Among the visual function metrics, the effect size of CST was largest on CS at 6 cpd (βStandardized = -0.37, P = .008). Conclusions: In patients with DME, CS may be more strongly associated with CST than VA. Including CS as an adjunct visual function outcome measure in eyes with DME may prove clinically valuable.

Contrast sensitivity and quality of life following intravitreal ranibizumab injection for central retinal vein occlusion

SYNOPSIS/PRECIS

We investigated the relationship between contrast sensitivity (CS) and vision-related quality of life (VR-QOL) in patients with central retinal vein occlusion following ranibizumab intravitreal injection; CS showed a stronger association with VR-QOL than visual acuity.

BACKGROUND/AIMS

To investigate the relationship between CS, VR-QOL and optical coherence tomography (OCT) findings in patients with cystoid macular oedema secondary to central retinal vein occlusion (CRVO-CMO) following intravitreal injection of ranibizumab.

METHODS

This was a multicentre, open-label, single-arm, prospective study. The study included 23 patients with CRVO-CMO who were followed up for 12 months after treatment. The best-corrected visual acuity (BCVA), letter contrast sensitivity (LCS) and OCT images were obtained every month. For VR-QOL assessment, the 25-item National Eye Institute Visual Function Questionnaire (VFQ-25) was administered to the patients before treatment and at 3, 6 and 12 months following treatment.

RESULTS

The LCS and VFQ-25 composite score improved significantly from baseline to 12 months following treatment. The multiple regression analysis revealed that the LCS of the affected eye and BCVA of the fellow eye were related to the VFQ-25 composite score following treatment. The LCS improvement showed a significant correlation with the improvement in the VFQ-25 composite score, whereas the BCVA improvement was not correlated with the improvement in the VFQ-25 composite score. Stepwise multiple regression analyses revealed that, at the time of macular oedema resolution, the distance between the external limiting membrane and retinal pigment epithelium (ELM-RPE) and average ganglion cell-inner plexiform layer (GCIPL) thickness were associated with LCS.

CONCLUSION

CS had a stronger association with VR-QOL than with BCVA in patients with CRVO-CMO. With the resolution of macular oedema, CS was associated with ELM-RPE thickness and average GCIPL thickness.

Baicalein—A Potent Pro-Homeostatic Regulator of Microglia in Retinal Ischemic Injury

Retinal ischemia is a common cause of many retinal diseases, leading to irreversible vision impairment and blindness. Excessive neuroinflammation, including microglial activation and T-cell responses, has been identified as a critical factor associated with neurodegeneration in retinal ischemia. Baicalein is a natural flavonoid reported to have broad anti-inflammatory and neuroprotective bioactivities. Herein, the effects of baicalein on microglia activation in vitro and in vivo were investigated. We found that baicalein exhibited robust anti-inflammatory effect on cultured human and mouse microglia, as demonstrated by decreased induction of pro-inflammatory cytokines and the phosphorylation of phosphoinositide 3-kinase (PI3K) and nuclear factor kappa B (NFκB). Proteomic analysis further unraveled baicalein’s effect on modulating IL-17 signaling pathways and its upstream regulator IL-1β. Intravitreal administration of baicalein in the mouse model of retinal ischemia/reperfusion (I/R) injury attenuated microglial activation and retinal T-cell infiltration, particularly the T helper 17 cells. Additionally, baicalein was shown to exert neuroprotective effects by significantly reducing the retinal ganglion cell (RGC) loss after I/R injury, leading to an improved retinal function and spatial vision. These results suggest that baicalein, a natural flavonoid, acts as a negative regulator of activated microglia and immune responses both in vitro and in vivo, effectively alleviating neurodegeneration in retinal I/R injury. This finding indicates that baicalein could be a potential therapeutic agent against currently incurable degenerative retinal diseases.

Contrast Sensitivity Changes in Center Involving Diabetic Macular Edema Treated with Aflibercept

Purpose

To characterize the changes in contrast sensitivity (CS) and retinal anatomy in patients with center involving diabetic macular edema (CDME) measured from baseline to post-loading doses of aflibercept.

Patients and Methods

This single center, prospective, open-label, non-controlled evaluation of five aflibercept intravitreal injections for treatment of CDME over a 16-week period. One eye in each of the forty patients will receive aflibercept every 4 weeks. Subject testing includes measurements of central retinal thickness (CRT), best corrected visual acuity (BCVA), Pelli–Robson (PR) CS, and CamBlobs (CB) CS at 20 weeks post baseline.

Results

A total of 40 eyes from 40 patients with CDME were analyzed. The mean age was 62.9 ±10.6 years and 55% were male. At baseline, CRT was 365 ±94.6µm with logMAR BCVA 0.25±0.20. CS PR at baseline was 1.46±0.13 logCS compared to the normal population 1.79±0.10 logCS (P=<0.01), and the CS CB was 1.55±0.16 logCS compared to 1.92±0.08 logCS in the normal population (P=<0.01). At the completion of the study, CRT was decreased to 289 ±43.7µm (P=<0.001), and the logMAR BCVA improved to 0.18±0.02 (P=<0.05). At the same point the CS PR was 1.52±0.16 and CS CB was 1.62±0.16 logCS. At the end of the study 85% of eyes obtained BCVA of 0.3 logMAR or better. There was a reduction from baseline of 82.5% to 57.5% in the number of patients that had a CS that was two standard deviations below the mean. The greatest improvement in CS was associated with those patients that had the greatest reduction in CRT.

Conclusion

CS impairment in patients with CDME is significant. Although treatment can be associated with improvement, there still remains a group with decreased CS that could impact activities of daily living. Earlier intervention using reduction in CS as a metric may be associated with reduced residual deficit associated with treatment.