Impaired vascular endothelial function in patients with diabetic macular edema

The Association of Systemic Endothelial Dysfunction With Diffuse Diabetic Macular Edema

Our aim was to assess whether systemic endothelial dysfunction, evaluated non-invasively by flow mediated dilation (FMD), is associated with diabetic macular edema (DME) and to determine if it is further impaired in patients with diffuse-DME. Consecutive patients (n = 84) with type-2 diabetes mellitus (T2DM) and diabetic retinopathy were enrolled. DME was not present in 38 (non-DME) and present in 46 patients; 25 with focal and 21 with diffuse-DME. No differences were detected between DME and non-DME groups regarding the clinical and demographic characteristics, except for the age of T2DM initiation (lower in non-DME). FMD values were significantly impaired in DME compared with non-DME patients, even after adjustment for multiple covariates (3.56 ± 1.03 vs 4.57 ± 1.25%, P = .003). Among DME patients, no differences were found concerning the clinical and demographic data, while FMD levels were significantly lower in diffuse-DME patients, compared with the focal-DME ones, regardless of the impact several confounders (2.88 ± 0.65 vs 4.08 ± 0.95%, P = .002). It is noteworthy that FMD values of non-DME and focal-DME patients did not differ significantly (4.52 ± 1.24 vs 4.21 ± 1.06%, P = .307). Moreover, among DME patients, impaired FMD was an independent predictor of diffuse-DME (odds ratio: 0.06, 95% CI 0.01-0.47, P = .007).

Association of periodontitis and diabetic macular edema in various stages of diabetic retinopathy

OBJECTIVES

Periodontitis and diabetes are known to have a bidirectional relationship. Diabetic macular edema is a complication of diabetes that is strongly influenced by inflammatory pathways. However, it remains to be established whether inflammation at other locations, such as periodontitis, affects diabetic macular edema. Here, we investigated the prevalence of periodontitis in patients treated for diabetic macular edema.

MATERIALS AND METHODS

Patients with diabetic macular edema were recruited for this cross-sectional study at the Medical University of Graz. Macular edema was documented by optical coherence tomography. Periodontal status was assessed by computerized periodontal probing and panoramic X-ray imaging. Bleeding on probing, clinical attachment level, probing pocket depth, and plaque index were compared between different stages of diabetic retinopathy.

RESULTS

Eighty-three eyes of 45 patients with diabetic macular edema were enrolled. Forty-four eyes (53.0%) had early stages of diabetic retinopathy (mild and moderate), and 39 eyes (47.0%) had late stages (severe and proliferative). Patients with mild or moderate DR were more likely to have more severe periodontal conditions than patients with severe or proliferative DR. Fourteen patients with mild DR (82.4%), 7 patients with moderate DR (87.5%), 4 patients with severe DR (100.0%), and 15 patients with proliferative DR (93.8%) had some degree of PD. The periodontal inflamed surface areas and the percentages of tooth sites that bled on probing were significantly higher in patients with early stages of diabetic retinopathy than in those with late stages of the disease (p < 0.05). Patients with periodontal inflamed surface areas of more than 500 mm² required significantly more intravitreal injections in the last year than those with milder forms of periodontitis (n = 6.9 ± 3.1 versus n = 5.0 ± 3.5, p = 0.03).

CONCLUSION

In patients with diabetic macular edema, periodontitis is more prevalent in early stages of diabetic retinopathy. We suggest regular dental check-ups for diabetic patients, especially when diabetic macular edema is already present.

CLINICAL RELEVANCE

Patients with diabetic macular edema should be screened for periodontitis and vice versa, particularly early in the course of diabetes.

[Impact of antiangiogenic therapy on ocular blood flow and microcirculation in diabetic macular edema]

Today, diabetic macular edema (DME) is still one of the main causes of vision loss in patients with diabetes.

PURPOSE

To identify changes in the ocular blood flow and microvascular network of the macular zone in patients with DME after antiangiogenic therapy.

MATERIAL AND METHODS

In the course of the study, 25 patients (50 eyes) with monolateral clinically significant DME aged 67.5±3.85 years were examined. Control group consisted of 75 healthy subjects (150 eyes). All patients underwent ultrasound examination of the eyes and orbits (in Color Doppler Imaging (CDI) and Pulse-Doppler modes) and OCT-angiography (OCT-A) before the intravitreal injection of ranibizumab, as well as 3 days, 2 weeks, and 1 month after the treatment.

RESULTS

According to OCT-A, the initial values of microvascular network parameters were significantly below the norm (p<0.05). After intravitreal ranibizumab injection (IRI), no significant changes in the density of microcapillaries or in the parameters of foveal avascular zone (FAZ) were recorded. However, a transient increase of the FAZ area was revealed 2 weeks after the injection, as well as an increase of microcapillaries density in the central quadrant together with a decrease of density in the peripheral quadrants 1 month after IRI. By the end of the follow-up period, a decrease in the initially raised maximum systolic velocity (Vsyst) and resistance index (RI) in the ophthalmic artery (OA) of the affected eye were documented. Additionally, an increase in Vsyst and 2-fold increase in end-diastolic velocity (Vdiast), as well as a decrease in RI in the central retinal artery (CRA) on the affected and paired eyes were detected.

CONCLUSION

The study revealed no negative effects of the angiogenesis inhibitor ranibizumab on retinal microcirculation or ocular blood flow. The registered changes in blood flow may indicate improvement of hemodynamic parameters after resorption of macular edema.