Metformin use associated with protective effects for ocular complications in patients with type 2 diabetes – observational study

Abstract

<div class="WordSection1"><p><strong>Objective. </strong>The aim was to study the association of the use of an oral antihyperglycemic agent metformin with the presence of ocular complications in patients with type 2 diabetes (T2D). <strong>Methods. </strong>Medical records were reviewed for 234 patients with diagnosed T2D. 81.2% (n=190) patients were using metformin and 18.8% (n=44) using other oral antihyperglycemic agents. Plasma glucose concentration, glycated haemoglobin, and the presence of ocular complications in patients treated with metformin were compared to those in patients treated with other oral antihyperglycemic agents. <strong>Results. </strong>Ocular complications occurred in 65 patients (27.8%). Patients treated with metformin had fewer ocular complications compared to patients treated with other oral antihyperglycemic agents (χ2=19.985; p<0.0001). After adjustment for gender, age, duration of T2D, serum concentration of cholesterol, smoking, body mass index and presence of other diseases, treatment with metformin decreased <strong>the</strong> odds of both glaucoma (OR=0.14, 95% CI: 0.03-0.57, p=0.006) and diabetic retinopathy (OR=0.33, 95% CI: 0.14-0.82, p=0.017) compared with other oral antihyperglycemic agents. <strong>Conclusion. </strong>Our results suggest that metformin may have a protective effect on ocular complications, especially glaucoma, in patients with T2D. The effects of metformin either regarding prevention of ocular complications or ocular complications already developed in patients with T2D, should be further investigated.</p></div>

Metformin and Glaucoma—Review of Anti-Fibrotic Processes and Bioenergetics

“…As age-related tissue effects changes significantly contribute to glaucoma development [4], the antiaging effect of metformin as a calorie restriction (CR) mimetic could delay the progression of disease [120]. Similar results were found in an observational study by Maleskic et al of 234 patients with T2DM, which showed that metformin was associated with decreased odds of POAG (OR = 0.33) compared to other anti-hyperglycaemic agents (p = 0.017) [15]. Interestingly a separate study, in which metformin use was significantly associated with elevated IOP in participants using a high dose (>2 g/day/year), systemic use of metformin was associated with a reduced risk of POAG, in a duration-dependent manner [121].…”

“…Metformin, a biguanide derivate commonly used in patients with type 2 diabetes, has come to be a front-runner recently in addressing this need, following a line of publications linking its use in a diabetic population with reduced incidence of POAG [14,15]. The cellular mechanism through which metformin is acting to combat glaucoma is not yet understood but likely involves effects on the pathogenesis of fibrosis and mitochondrial bioenergetic dysfunction in glaucoma.…”

Association of metformin use among diabetics and the incidence of primary open-angle glaucoma – The Chennai Eye Disease Incidence Study

“…The literature suggests that the increased risk of glaucoma in patients with diabetes is due to increased corneal stiffness, corneal hysteresis, and enlargement of the optic cup. [ 9 ] In our study, IOP was found to be increased in diabetics than the nondiabetics whereas there was no difference in VCDR among diabetics and non-diabetics.…”

Commentary - Association of metformin use among diabetics and the incidence of primary open-angle glaucoma – The Chennai Eye Disease Incidence Study

“…[ 3 4 5 ] AMPK upregulation alters the tone of cells in the trabecular meshwork, thus lowering the IOP and preventing the progression of glaucoma. [ 6 7 ] Preliminary results from animal studies have also shown that metformin exerts neuroprotective effect by upregulation of AMPK. Metformin regulates the methylation at cellular levels and promotes ganglion cell survival.…”

“…Maleškić et al . [ 6 ] postulated that the gero-protective effect of metformin could delay tissue damage, which can be a major factor in delaying the progression of glaucoma. Lin et al .…”