Purpose. There is evidence from several large-scale clinical trials that reduced intake of lutein, a major component of the macular pigment, is a risk factor for the development of AMD. In the present study (LISA; Lutein Intervention Study Austria) it was hypothesized that lutein supplementation increases macular pigment optical density (MPOD). In addition, an investigation was conducted into whether lutein supplementation improves visual acuity (VA) and macular function (mean differential light threshold; MDLT), as assessed with microperimetry. Methods. One hundred twenty-six patients with AMD (AREDS [Age-related Eye Disease Study] stages 2, 3, and 4) were included in this randomized (2:1), placebo-controlled, double-masked parallel group study. Lutein or placebo was administered for 6 months. MPOD was measured with a custom-built reflectometer. VA was assessed with ETDRS (Early Treatment Diabetic Retinopathy Study) charts, and MDLT was assessed with a microperimeter. Results. Lutein significantly increased MPOD by 27.9% ± 2.9% (P < 0.001 versus placebo). No significant effect of lutein supplementation on MDLT or VA was seen, although a tendency toward an increase was seen for both parameters (MDLT, P = 0.096 versus placebo; VA, P = 0.070 versus placebo). A significant correlation was found, however, between the increase in MPOD after 6 months and the increase in MDLT after 6 months (r = 0.25, P = 0.027), as well as between the increase in MPOD after 6 months and the increase in VA after 6 months (r = 0.27, P = 0.013). Conclusions. The present study demonstrates that lutein supplementation increases MPOD, as assessed with an objective method. The correlation between the change in MPOD and the change in VA and MDLT indicates that patients who show a pronounced increase in MPOD also benefit in terms of visual function. (ClinicalTrials.gov number, NCT00879671.)

Purpose. A variety of studies have shown that flicker-induced vasodilatation is reduced in patients with diabetes. It is, however, unclear whether reduced neural activity or abnormal neurovascular coupling is the reason for this phenomenon. In the present study, we hypothesized that retinal neurovascular dysfunction precedes neural dysfunction in patients with early type 1 diabetes. Methods. In the present study, 50 patients with type 1 diabetes without retinopathy and 50 healthy age- and sex-matched control subjects were included. The retinal vascular response to flicker stimulation was measured using the dynamic Retinal Vessel Analyzer. In addition, the response in retinal blood velocity to flicker stimulation as assessed with laser Doppler velocimetry was studied in a subgroup of patients. Pattern electroretinography (ERG) was used to measure neural retinal function. Results. The flicker responses of both retinal arteries and veins were significantly reduced in patients with diabetes (veins in the diabetic group: 3.5 ± 2.3% versus healthy control group: 4.6 ± 2.0%; P = 0.022 between groups, whereas arteries in the diabetic group: 2.0 ± 2.7% versus healthy control group: 3.8 ± 1.7%; P < 0.001 between groups). Likewise, the response of retinal blood velocity was reduced in patients with diabetes, although adequate readings could only be obtained in a subgroup of subjects (diabetic group [n = 22]: 19 ± 7%; healthy control group [n = 24]: 43 ± 19% P < 0.001 between groups). The parameters of pattern ERG were not different between the two groups. Conclusions. The study confirms that flicker responses are reduced early in patients with type 1 diabetes. This is seen before alterations in pattern ERG indicating abnormal neurovascular coupling. (ClinicalTrials.gov number, NCT00712842.)

Purpose. To investigate whether intravitreal ranibizumab (0.05 mL) treatment affects retinal vessel diameters and retrobulbar blood velocities in patients with acute branch retinal vein occlusion (BRVO). Methods. Thirty patients with clinically significant macular edema secondary to BRVO were included. The duration of the study was three months. Patients were studied before and one week, one month, two months, and three months after the first ranibizumab injection. Depending on the clinical requirements, up to three ranibizumab injections were administered. Retinal vessel diameters were measured using a retinal vessel analyzer. Flow velocities in the retrobulbar central retinal artery were measured using color doppler imaging. Best-corrected visual acuity was assessed using ETDRS charts. Measurements were done in the affected as well as in the contralateral eye. Results. Three patients were lost for follow up. In the remaining 27 patients, significant vasoconstriction was observed in retinal veins (P < 0.001 versus baseline) and in retinal arteries (P = 0.001 versus baseline) of the affected eyes. In addition, a significant reduction in flow velocities was observed in the BRVO eyes over time (peak systolic velocity: P = 0.003, end diastolic velocity: P = 0.003). The reduction in retinal vessel diameters and flow velocities did not correlate with changes in visual acuity or number of re-treatments. In the contralateral eyes no change in retinal blood flow parameters was seen. Conclusions. BRVO is an ischemic retinal disease. Given that ranibizumab treatment reduces retinal perfusion in these eyes the potential long-term effects of this vasoconstriction need to be considered. (ClinicalTrials.gov number, NCT01027481.)

OBJECTIVE: Flicker-induced vasodilatation is reduced in patients with vascular-related diseases, which has at least partially been attributed to endothelial dysfunction of retinal vessels. Currently, the standard method to assess endothelial function in vivo is flow-mediated vasodilatation (FMD). Thus, the present study was performed to investigate whether a correlation exists between flicker-induced vasodilatation and FMD in patients with known endothelial dysfunction and healthy subjects. RESEARCH DESIGN AND METHODS: In the present study, 20 patients with type 1 diabetes, 40 patients with systemic hypertension (systolic blood pressure 140–159 mmHg; diastolic blood pressure 90–99 mmHg) and/or serum cholesterol levels ≥0.65 mmol/l, and 20 healthy control subjects were included. The flicker response was measured using the Dynamic Retinal Vessel Analyzer. FMD was determined using a high-resolution ultrasound system, measuring brachial artery diameter reactivity during reperfusion after arterial occlusion. RESULTS: The flicker response of both retinal arteries and veins was significantly reduced in the two patients groups. Likewise, FMD was significantly reduced in patients compared with healthy control subjects. However, only a weak correlation between flicker-induced vasodilatation and FMD was observed. CONCLUSIONS: The study confirms that flicker responses and FMD are reduced in the selected patient groups. Whether the weak correlation between FMD and flicker is due to the different stimulation type, the different vascular beds measured, or other mechanisms has yet to be investigated.

Purpose. Various studies have shown that retinal vessels in patients with diabetes mellitus have a reduced capacity to adapt to changes in perfusion pressure and to stimulation with flickering light. Structural and functional changes in retinal vessels in diabetes could lead to a general reduction of vasodilator and/or vasoconstrictor capacity. To gain more insight into this topic, we compared the response of retinal vessel diameters to systemic glyceryl trinitrate (GTN) and stimulation with diffuse luminance flicker in patients with diabetes and healthy control subjects. methods. Twenty patients with type 1 diabetes mellitus featuring no or mild nonproliferative diabetic retinopathy and 20 healthy, age-matched subjects were included in this study. A vessel analyzer was used for measurement of diameters of retinal arteries and veins. The response of diameters was measured continuously during stimulation with flickering light, as well as immediately after sublingual application of 0.8 mg GTN. results. The response of retinal vessels to flickering light was significantly reduced in the patients with diabetes (arteries: 2.9% in diabetes versus 7.0% in control subjects, P < 0.002; veins: 4.6% in diabetes versus 6.8% in control subjects, P = 0.020). GTN-induced vasodilatation was not different between the patients with diabetes and the healthy control subjects (P ≥ 0.70). conclusions. The present study confirmed reduced response of retinal vessels to stimulation with flickering light in diabetes. The response of retinal vessels to a direct NO-donor, however, was maintained. This result indicates that abnormal flicker-induced vasodilatation in diabetes is not a consequence of generally reduced retinal vascular reactivity (ClinicalTrials.gov number, NCT00432029).

Background: The optic nerve has been recommended as an additional region for demonstrating dissemination in space (DIS) in diagnostic criteria for multiple sclerosis (MS). Objective: To investigate whether adding the optic nerve region as determined by optical coherence tomography (OCT) as part of the DIS criteria improves the 2017 diagnostic criteria. Methods: From a prospective observational study, we included patients with a first demyelinating event who had complete information to assess DIS and a spectral-domain OCT scan obtained within 180 days. Modified DIS criteria (DIS+OCT) were constructed by adding the optic nerve to the current DIS regions based on validated thresholds for OCT inter-eye differences. Time to second clinical attack was the primary endpoint. Results: We analyzed 267 MS patients (mean age 31.3 years [SD 8.1], 69% female) during a median observation period of 59 months (range: 13 - 98). Adding the optic nerve as a fifth region improved the diagnostic performance by increasing accuracy (DIS+OCT 81.2% vs. DIS 65.6%,) and sensitivity (DIS+OCT 84.2% vs. DIS 77.9%) without lowering specificity (DIS+OCT 52.2% vs. DIS 52.2%). Fulfilling DIS+OCT criteria (≥2 of 5 DIS+OCT regions involved) indicated a similar risk of a second clinical attack (HR 3.6, CI 1.4 – 14.5) compared to a 2.5-fold increased risk when fulfilling DIS criteria (HR 2.5, CI 1.2 – 11.8). When the analysis was conducted according to topography of the first demyelinating event, DIS+OCT criteria performed similarly in both optic neuritis and non–optic neuritis. Conclusions: Addition of the optic nerve, assessed by OCT, as a fifth region in the current DIS criteria improves diagnostic performance by increasing sensitivity without lowering specificity. Classification of Evidence: This study provides Class II evidence that adding the optic nerve as determined by optical coherence tomography (OCT) as a fifth dissemination in space (DIS) criterion to the 2017 McDonald criteria improves diagnostic accuracy.