Assessing the Role of Statins as an Adjunctive Anti-VEGF Therapy for Clinically Significant Macular Edema (CSME) in Type 2 Diabetes Mellitus

Abstract

Aim: This study aimed to evaluate the effectiveness of statin therapy as an adjunctive treatment to anti-VEGF therapy in type 2 diabetic patients with non-proliferative diabetic retinopathy (NPDR) and clinically significant macular edema (CSME).

Materials and methods: In this prospective, randomized interventional study, patients were randomized into two groups: Group A received low-dose atorvastatin (10-20 mg), and Group B received high-dose atorvastatin (30-40 mg). All participants also received three loading doses of intravitreal ranibizumab (0.5 mg) at monthly intervals, followed by pro re nata treatment over a six-month period. Primary outcomes included the number of anti-VEGF injections required, best-corrected visual acuity (BCVA), and central macular thickness (CMT). Serum VEGF levels were measured at baseline and six months.

Results: The mean number of injections over six months was 3.4, with no significant difference between Group A (3.55) and Group B (3.33) (p = 0.24). Group A demonstrated substantial improvement in BCVA at both 3 and 6 months, accompanied by a notable reduction in CMT. In contrast, Group B's BCVA improvement was only significant at 3 months, with less consistent CMT reduction at 6 months. Serum VEGF levels decreased in Group A but increased in Group B, though these changes were not statistically significant.

Discussion: The findings suggest that low-dose atorvastatin, when used in conjunction with anti-VEGF therapy, may provide superior functional and anatomical outcomes in patients with CSME compared to high-dose statin therapy. The observed reduction in central macular thickness and improvement in visual acuity indicate a potential adjunctive benefit of statins, likely due to their pleiotropic effects, including anti-inflammatory and anti-angiogenic properties. Although the number of injections required was similar between the groups, the better response in the low-dose group highlights the need for further investigation into the dose-dependent effects of statins in managing diabetic macular edema.

Conclusions: Low-dose atorvastatin (10-20 mg) as an adjunct to anti-VEGF therapy resulted in better functional and anatomical outcomes in diabetic patients with CSME compared to high-dose atorvastatin. These findings suggest potential additional benefits of low-dose statins in managing patients with chronic subdural hematoma (CSME).

Keywords: BCVA = Best Corrected Visual Acuity; CAD = Coronary Artery Disease; CKD = Chronic Kidney Disease; CMT = Central Macular Thickness; COVID = Coronavirus Disease; CSME; CSME = Clinically Significant Macular Edema; DM = Diabetes Mellitus; DME = Diabetic Macular Edema; ETDRS = Early Treatment Diabetic Retinopathy Study; FBS = Fating Blood Sugar; FFA = Fundus Fluorescein Angiography; HDL = High Density Lipoprotein; HTN = Hypertension; IOP = Intraocular Pressure; KFT = Kidney Function Tests; LDL = Low Density Lipoprotein; LFT = Liver Function Tests; NPDR = Non-Proliferative Diabetic Retinopathy; OCT = Optical Coherence Tomography; PRN = Pro Re Nata; PTH = Para Thyroid Hormone; SGOT = Serum Glutamic Oxaloacetic Transaminase; SGPT = Serum Glutamic Pyruvic Transaminase; SPSS = Statistical Package for Social Sciences; TG = Triglycerides; VEGF - Vascular Endothelial Growth Factor; adjunct therapy; anti-VEGF; diabetic retinopathy; statin therapy; type 2 diabetes.