Diabetische Retinopathie

Therapeutic targeting of cellular senescence in diabetic macular edema: preclinical and phase 1 trial results

Compromised vascular endothelial barrier function is a salient feature of diabetic complications such as sight-threatening diabetic macular edema (DME). Current standards of care for DME manage aspects of the disease, but require frequent intravitreal administration and are poorly effective in large subsets of patients. Here we provide evidence that an elevated burden of senescent cells in the retina triggers cardinal features of DME pathology and conduct an initial test of senolytic therapy in patients with DME. In cell culture models, sustained hyperglycemia provoked cellular senescence in subsets of vascular endothelial cells displaying perturbed transendothelial junctions associated with poor barrier function and leading to micro-inflammation. Pharmacological elimination of senescent cells in a mouse model of DME reduces diabetes-induced retinal vascular leakage and preserves retinal function. We then conducted a phase 1 single ascending dose safety study of UBX1325 (foselutoclax), a senolytic small-molecule inhibitor of BCL-xL, in patients with advanced DME for whom anti-vascular endothelial growth factor therapy was no longer considered beneficial. The primary objective of assessment of safety and tolerability of UBX1325 was achieved. Collectively, our data suggest that therapeutic targeting of senescent cells in the diabetic retina with a BCL-xL inhibitor may provide a long-lasting, disease-modifying intervention for DME. This hypothesis will need to be verified in larger clinical trials. ClinicalTrials.gov identifier: NCT04537884 .

Diabetes mellitus and its influence on the incidence and process of diabetic retinopathy

OBJECTIVES

The main aim of the study was to show the effect of diabetes in relation to the gender of the patients, duration of the disease, and on the incidence of diabetic retinopathy. In this study, we investigated the prevalence of these two diseases, pathological ocular changes and progression of disease occurrence in relation to the duration of the disease with respect to their impact on the quality of vision of the patient.

METHODS

The prospective observational cross-sectional study included 3,951 patients (1,838 males, 2,113 females) with diabetes mellitus from 7 districts of eastern Slovakia. Patients with diabetes mellitus and diabetic retinopathy were identified by special screening in the number of 2,093 (1,094 females and 999 males). Subjects were divided by sex and by duration of diabetes into 5 groups: patients with diabetes under 5, 10, 15, 20, and over 20 years. We differentiated between proliferative and non-proliferative forms of diabetic retinopathy and monitored changes in visual quality. Manifestations of pathological changes were recorded using special examination methods in the eye clinic. We observed a decrease in vision by two lines, pathological changes on the retina and the occurrence of practical blindness.

RESULTS

Of the total number of diabetic patients examined, diabetic retinopathy was also present in more than half of the patients. The major form represented in the patients was the non-proliferative form of retinopathy. The obtained results confirmed that the representation of patients with diabetic retinopathy increases with increasing duration of diabetes. Similarly, pathological changes characteristic of this type of late complication of diabetes were also more frequent, such as deterioration of visual acuity, the appearance of aneurysms, hard exudates macular edema, and gradual loss of vision, which can result in practical blindness.

CONCLUSION

The percentage of people with diabetic retinopathy increases with the duration of diabetes, as well as the increased frequency of pathological late complication of diabetes, including deterioration of visual acuity, the development of aneurysms, hard exudates, macular oedema, and gradual loss of vision, which can result in practical blindness. Early diagnosis of the disease and introduction of appropriate treatment would alleviate the symptoms of the disease in more than half of the patients, so more frequent preventive check-ups with an ophthalmologist should be performed in diabetic patients to avoid detection of the disease in its late stages.

Prevalence of Impairment of Visual Acuity and Severity of Retinopathy in Patients with Diabetes Mellitus

AIMS

No information exists on the frequency of visual impairment in people with diabetes mellitus (DM) in Germany. In this study, the prevalence of vision impairment in those individuals was investigated.

METHODS

We retrospectively analyzed a cohort of 295 people (14221 consultations) at a university outpatient clinic with any type of DM and an available ETDRS-Score and visual acuity. The primary outcome was the prevalence of visual impairment, the secondary outcome was the correlation of the ETDRS-Score and limitations of visual acuity and the prevalence of higher ETDRS-Score with a visual impairment defined as a decimal-visus</=0.3.

RESULTS

The prevalence of visual impairment in participants with DM was 11.2%; among these individuals, 81.8% had no or non-proliferative retinopathy. In the DM2 subgroup, 81.5% (n=22) of the visually impaired participants had no DR, in contrast to only 16.7% (n=1) in the DM1 subgroup. Progression in ETDRS-Score led to worse visual acuity (r=-0.209; p<0.001). A significantly related covariates with impairment of the visual acuity for individuals with DM1 was the duration of diabetes (B=-0.007; p=0.001) and for individuals with DM2, the age (B=-0.008; p=0.009).

CONCLUSIONS

The prevalence of impaired vision in people with diabetes in our cohort was 11.2%,<20% of visual impairment in people with diabetes is caused by diabetic retinopathy, and 69.7% of participants with visual impairment had no DR. In our study patients without visual impairment showed a similar distribution of DR severity levels regardless of the type of diabetes.

Diabetic retinopathy - ocular complications of diabetes mellitus

In industrialized nations diabetic retinopathy is the most frequent microvascular complication of diabetes mellitus and the most common cause of blindness in the working-age population. In the next 15 years, the number of patients suffering from diabetes mellitus is expected to increase significantly. By the year 2030, about 440 million people in the age-group 20-79 years are estimated to be suffering from diabetes mellitus worldwide (prevalence 7.7%), while in 2010 there were 285 million people with diabetes mellitus (prevalence 6.4%). This accounts for an increase in patients with diabetes in industrialized nations by 20% and in developing countries by 69% until the year 2030. Due to the expected rise in diabetic patients, the need for ophthalmic care of patients (i.e., exams and treatments) will also increase and represents a challenge for eye-care providers. Development of optimized screening programs, which respect available resources of the ophthalmic infrastructure, will become even more important. Main reasons for loss of vision in patients with diabetes mellitus are diabetic macular edema and proliferative diabetic retinopathy. Incidence or progression of these potentially blinding complications can be greatly reduced by adequate control of blood glucose and blood pressure levels. Additionally, regular ophthalmic exams are mandatory for detecting ocular complications and initiating treatments such as laser photocoagulation in case of clinical significant diabetic macular edema or early proliferative diabetic retinopathy. In this way, the risk of blindness can considerably be reduced. In advanced stages of diabetic retinopathy, pars-plana vitrectomy is performed to treat vitreous hemorrhage and tractional retinal detachment. In recent years, the advent of intravitreal medication has improved therapeutic options for patients with advanced diabetic macular edema.