Diabetic Retinopathy. Association with Metabolic Compensation, Duration of Diabetes and Other Micro and Macrovascular Complications in Patients with Type 1 Diabetes Mellitus
Authors: Ullase Lelde , Ducena Kristīne , Markevica Dace , Laganovska Guna 
Published: November 2020

Summary

Introduction
Diabetic retinopathy (DR) is a severe complication that can lead to complete vision loss and still is one of the main blindness-causing reasons among patients with type 1 diabetes mellitus (T1DM). DR as a complication can cause vision loss to people at their working age. More than 90% of patients with type 1 diabetes will develop DR by 20 years post diagnosis (Leslie R. Dye, 2018). DR is more likely to develop in patients with T1DM (Kanski's Clinical Ophthalmology, 2016). This complication can be very serious speaking of the ability to see. Sometimes vitrectomy plays a vital role in the management of severe complications of DR at its end-stage (Myron Yanoff et al., 2020).

Aim of the study
To prove the development severity of DR that depends on the duration of diabetes and metabolic compensation. Additionally, to determine retinopathy's association with other micro and macrovascular diabetes mellitus complications for a better understanding of what are the contributory factors for these complications to develop and which of those may coexist.

Materials and Methods
A retrospective study was held at the Pauls Stradins Clinical University Hospital (Riga, Latvia). From January 2016 to March 2018, 79 (158 eyes) patient histories were analyzed who have type 1 diabetes mellitus. To obtain more precise research results, almost all patients have done check-up visits to one certain ophthalmologist. The IBM SPSS Statistics version 25.0 was used to process data. Tables were made in SPSS and Microsoft Excel 2016 programs. Statistically significant value (p) was set at < 0,05.

Results
No statistically significant difference is seen in the mean duration of the disease: in the group of proliferative diabetic retinopathy (PDR): 25.23 (median = 22.0) years and non-proliferative group: 24.68 (median = 23.50) years. Results show that the duration of diabetes mellitus is considerably smaller in a group without DR 11.24 (median = 8.50) years. Metabolic compensation (%) in diabetes mellitus is not statistically different between patients with diverse forms of DR; no association found either. No statistically significant difference in best corrected visual acuity (BCVA) was detected among patients with various forms of DR. Three groups were compared: both types of DR and no DR. It was detected that BCVA in patients without DR was higher in both eyes: 0.83 ± 0.27 dioptres. No statistically significant difference (pχ > 0.05) was detected between the groups of DR and therefore no association was made between the form/existence of DR and arterial hypertension. There is a strong association between DR and microvascular complications (V = 0.40) with the existence of DR and there is an even stronger association (V = 0.61) with the forms of DR. There is no statistically reliable difference (pχ > 0.05) between the groups of DR; therefore, no association with the existence of microvascular complications and also risk factors.

Conclusions
More than two-thirds of patients included in the research have some signs of DR. Because of the strong association of DR and other microvascular complications, patients with diabetes should be screened regularly for retinopathy, nephropathy, and neuropathy. And likewise, if a patient has at least one microvascular complication, he or she should be tested for the rest possible complications as well. According to data, most of the patients in this study have poor metabolic compensation; consequently, the metabolic compensation screening should be done certainly every three months.