A European study just published in the well-known journal Diabetes argues that theAdoption of a calorie-controlled regimen may influence the onset of diabetic retinopathy (DR). DR is a complication of diabetic disease that, if neglected, can significantly impair the visual function and quality of life of the affected person.
RD aetiopathogenesis and the microbiome: what does the latest research say?
The etiopathogenesis of DR is still the subject of much research as the causes, as well as the risk factors, behind its occurrence can be multiple. However, in recent years, much progress has been made in understanding its aetiology and one of the latest research studies highlights a possible correlation between the composition of the gut microbiome and DR. The authors of the study, in fact, demonstrated that a caloric diet with periods of intermittent fasting (alternating between days with significant calorie restriction and days with a normal calorie regime), in patients with type 2 diabetes mellitus, results in a improvement in insulin sensitivity and in the circulating glucose levels, parameters that are essential for the control and prevention of DR. Studies in mice have also shown that intermittent fasting causes an change in the composition of the gut microbiome with the predominant bacterial species being the Firmicutes spp., responsible for a well-functioning intestinal barrier. In addition to this, this intermittent diet is able to increase the production levels of tauroursodeoxycholate (TUDCA)-a bile acid-where it plays an neuroprotective function at the level of the retinal nerve cells.
Diagnosis
The diagnosis of DR includes a ocular fundus examination and a comprehensive eye examinationwhich, as recommended by the 2015 Guidelines drafted by the Study Group on the Ocular Complications of Diabetes of the Italian Society of Diabetology (http://www.iapb.it/IMG/pdf/retinopatia-diabetica-linee_guida_2015.pdf)is required to assess eye pressure, visual acuity, pupillary reflexes and the anterior and posterior segment of the eye.
Treatment
Therapeutic strategies for DR include both the laser therapy as well as drug therapy. The former was for many years the gold standard for the treatment of DR. Indeed, laser photocoagulation is able to reduce the incidence of blindness five years after the onset of proliferative DR (from 60% to 5%) and to reduce the decrease in visual acuity (doubling of the visual angle) in diabetic macular oedema by one third (ETDRS Report No. 9. Ophthalmology 98: 766-785, 1991). However, the thermal heat of the laser is often accompanied by certain functional impairments such as the appearance of more or less disabling scotomas, visual field reduction and loss of contrast, so that in recent years less aggressive procedures such as laser micropulsed subthreshold. The second, on the other hand, involves the use of fanti-VEGF armaceuticals and corticosteroids.
Prevention
Scientific evidence shows that early diagnosis and intervention, RD and EMD (diabetic macular oedema) can be prevented and/or delayed through regular eye check-ups (http://care.diabetesjournals.org/content/41/Supplement_1/S1) and following a few tricks (https://www.oculistaitaliano.it/articoli/prevenire-ledema-maculare-diabetico-si-puo/)
Sources
-Intermittent Fasting and Prevention of Diabetic Retinopathy: Where Do We Go From Here? Haluzík M. et al. 67(9): 1745-1747. 2018;
- Early photocoagulation for diabetic retinopathy. ETDRS report number 9. Early Treatment Diabetic Retinopathy Study Research Group. 98(5 Suppl):766-85, 1991.
Dr. Carmelo Chines
Direttore responsabile
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