Kajal Seema S.1, Binu S.S.2, Bhaskar M.K.3,
BACKGROUND
Dyslipidaemia has been proposed as a possible risk factor for diabetic retinopathy
(DR) but results from previous studies are inconsistent. We designed this study to
find the association of abnormal serum lipid levels with diabetic retinopathy and
diabetic macular oedema (DME).
METHODS
This was a single centre observational study conducted at a tertiary care hospital,
where patients with type 2 diabetes of more than five years duration were
enrolled. A comprehensive ophthalmic evaluation was performed on all study
subjects. Detailed fundoscopy was done after obtaining the best possible mydriasis
with 1 % tropicamide and 5 % phenylephrine eye drops using direct
ophthalmoscopy, indirect ophthalmoscopy with + 20 D lens and stereoscopic slit
lamp biomicroscopy of the disc and macula using + 78 D Volk lens. Fundus
photographs were taken in patients with any grade of diabetic retinopathy by
Topcon fundus camera. DR and DME were diagnosed and classified according to
the Early Treatment Diabetic Retinopathy Study (ETDRS) grading system. Fasting
blood sugar (FBS), fasting lipid profile and glycated haemoglobin (HbA1c) was
assessed for each patient.
RESULTS
A total of two hundred and twelve participants was enrolled. Mean age of the study
group was 63.93 ± 9.52 and the mean duration of diabetes was 13.54 ± 6.07. DR
was present in 164 (78.1 %) of whom 71 (43.3 %) had mild non proliferative
diabetic retinopathy (NPDR), 42 (25.6 %) had moderate NPDR, 31 (18.9 %) had
severe NPDR, and 20 (12.2 %) had proliferative diabetic retinopathy (PDR). Of
those with DR, 59 (36 %) had DME. Duration of diabetes (14.62 ± 6.18 vs 9.72 ±
3.68 years, P < 0.001), higher fasting blood glucose (176.79 ± 59.13 vs 138.46 ±
49.44 mg / dL, P < 0.001), higher HbA1c (8.21 ± 1.38 vs. 7.48 ± 1.25 %, P =
0.002), higher total cholesterol (215.04 ± 49.78 vs 184.37 ± 30.84 mg / dL, P <
0.001), higher triglyceride levels (155.23 ± 59.06 vs 125.13 ± 37.3 mg / dL, P =
0.001) and higher low density lipoprotein (LDL) cholesterol levels (139.28 ± 37.38
vs 120.85 ± 22.75 mg / dL, P = 0.002) were significantly associated with the
severity of DR. Higher total cholesterol, higher triglyceride levels and higher LDL
cholesterol levels were also associated with DME.
CONCLUSIONS
There is a significant association of abnormal serum lipid levels and
hyperglycaemia with the presence and severity of DR and presence of DME. Early
identification and intervention to control these modifiable risk factors,
hyperglycaemia and dyslipidaemia may delay the development and progression of
DR in diabetic patients. These observations also support the current management
strategies for diabetes, which include control of dyslipidaemia in addition to
hyperglycaemia.
