Dopamine Treatment May Delay Onset of Diabetic Retinopathy

Rachael Allen, PhD

A cohort of veterans with diabetes undergoing dopamine treatment, including L-DOPA and dopamine agonists, had delayed onset of vascular pathology associated with diabetic retinopathy (DR), according to new research.

“This research demonstrates the value of long-term dopamine treatment for DR,” wrote study author Rachael Allen, PhD, Atlanta VA Medical Center.

These findings were presented at the Association of Research in Vision and Ophthalmology (ARVO) 2022 Meeting in Denver, Colorado.

The global prevalence of DR is expected to increase in the coming years. Although dopamine treatment protects against early neuronal dysfunction in DR, whether dopamine can function as an anti-angiogenic to reduce clinically-recognized vascular pathology in DR remains unknown.

The current retrospective study of veterans with diabetes aimed to determine whether taking L-DOPA or dopamine agonist delayed the onset of DR. An analysis of medical records was used to identify patients diagnosed with diabetes, with or without a history of treatment with L-DOPA or dopamine agonists.

For the primary outcome, investigators identified the time interval between initial diabetes diagnosis and diagnosis of DR. Patients with less than 100 days of dopamine prescriptions during the time between diagnoses (dopamine group, n = 463) were compared against patients with no history of dopamine prescriptions (untreated group, n = 9783).

Investigators compared factors across groups including age at diabetes diagnosis, gender, race, comorbidities, and insulin/hypoglycemic usage with unpaired t-tests for continuous variables and Chi-square tests for categorical variables.

Further, a multivariate linear model assessed the relative impact of dopamine treatment and other factors on the time to develop DR in this patient population.

Data show dopamine treatment delayed onset of DR in veterans with diabetes by 1.5 years (6.802 vs 8.381 years; P <.001). Investigators found on average, those in the dopamine group were older (55.01 years vs 57.24 years; P <.001) with a higher proportion of female patients (female: 6.4% vs 3.8%; P <.001).

Data additionally show a higher Elixhauser comorbidity score with van Walraven weighting (5.552 vs 3.338; P <.001). They observed no difference in the average HbA1c level between groups.

Investigators noted the primary dopamine drugs taken included D2-like agonists (77.4%), dopamine precursors (20.7%), and dopamine degradation enzyme inhibitors (1.9%).

"Future research will include a prospective study to examine the protective effects of L-DOPA on vascular pathology in DR," Allen concluded.

The study, “Dopamine treatment delays diabetic retinopathy onset in a retrospective study,” was presented at ARVO 2022.