Researchers in a recent study collected records of retinal findings in a Norwegian diabetic population to determine the effect of dietary polyunsaturated fatty acids (PUFAs) ingestion on the development of diabetic retinopathy.
The team, led by Knud Erik Alsbirk, MD Sotra Eye Clinic, observed that none of the patients in the study had a best-corrected visual acuity (BCVA) of less than 0.3 (log MAR 0.48) as a result of diabetic retinopathy .
From November 2009 to March 2011 a total of 514 patients with diabetes were recruited, of which 4 dropped out of the study after being rejected. Of the total remaining patient population, 50 type 1 diabetes patients (40% women) and 460 type II patients (47.4% women) were included, with all patients having a diabetes duration of ≥ 1 year.
All patients were scheduled for routine follow-up care at an ophthalmologist’s office in the study area, which serves a population of 40,000 in the local Norwegian communities.
Data were collected during the follow-up visit, including demographics, BCVA in the right and left eyes, and severity of retinopathy after dilation. In addition, the researchers collected data on the presence of vision-threatening diabetic retinopathy (VTDR) with a DME grade ≥2 or PDR.
Patients also reported medical parameters, including HbA1c levels, use of antihypertensive drugs and statins, and a self-reported nutritional history of estimated weekly fish feed intake and weekly PUFA supplement intake.
Researchers analyzed the association between fish oil intake and visual acuity by linear regression for BCVA and logistic regression for DME (DME> 1) and DR (DR> 0).
Analysis of the data shows the median age of the type 1 diabetes group and the median duration of diagnosis was 11.5 years. The data also shows that HbA1c levels were found in 92% of patients, with 39% of patients taking antihypertensive drugs and 34% taking statins.
In addition, the type 2 group had a median duration of diagnosis of 8 years and a mean age of 66 years. A total of 84% knew their HbA1c levels, with 66% of patients taking antihypertensive drugs and 64% taking statins.
The type 1 group (n = 50) showed photographic evidence of diabetic retinopathy in 48% of patients, with 8 patients (16%) having proliferative retinopathy (PDR) and 6 patients (12%) diabetic macular edema (DME) , Grade., Had 1 or 2. All patients had a BCVA of 0.5 (log MAR 0.3) in the better or best eye.
In addition, in the type 2 group (n = 460) 23.6% had a DR, 3% a PDR and 5% a DME. In addition, 19 patients had a VTDR.
The data also show that 7 patients (1.5%) had a VA of the best eye of worse than 0.3 (log MAR 0.48) and 98% of the patients had a VA of or better than 0.5 (log MAR 0 , 3) had the best eye.
In addition, the researchers found that the average number of fish meals per week was 3.2 in the type 1 group and 4.4 in the type 2 group. The data collection shows that 44% of type 1 patients and 55% of type 2 patients have regularly taken omega-3 supplements.
The researchers concluded that 0.4% of severe extraocular microangiopathy and the best preserved eye VA indicated low levels of severe microvasculopathy.
They found that timely ophthalmic care for diabetic patients would benefit the prevention of visual and systemic impairment in one of the world’s leading causes of blindness and morbidity.
“The conclusion seems certain that normal daily intake of fatty fish and / or fish oil may prove to be an important low-risk, low-risk prophylaxis against diabetic microangiopathy,” the researchers wrote. “More carefully designed multicenter studies, including monitoring of serum PUFA levels, are needed to resolve this important problem.”
The study “Diabetic retinopathy and visual impairment in a Norwegian coastal diabetic population with a high dietary intake of fish oils. An observational study, ”was published online in Acta Ophthalmologica.