Weight loss methods such as bariatric surgery or drugs may temporarily worsen diabetic retinopathy—a condition that affects the retina due to diabetes—due to rapid correction in blood sugar levels. However, the overall risk associated with weight loss tends to be small, and the benefits usually outweigh these temporary complications, according to a review.
The studies on this issue are inconsistent and the evidence is insubstantial, as pointed out by Basil K. Williams Jr., MD, of the University of Miami, and colleagues. They cited a study conducted in 1998 which showed that among patients undergoing intensive insulin therapy, around 3.5% (25 out of 711) experienced a worsening in diabetic retinopathy at the six-month mark. However, after four years, the condition hadn’t worsened compared to the baseline for either patient group.
Contrastingly, a multicenter case-control study conducted in 2020 drawing from 3,145 patients with Type 2 diabetes found no relationship between the use of GLP-1 agonists—a type of medication used for weight loss—and worsening diabetic retinopathy.
Williams suggests that for effective management of diabetic retinopathy, the focus should be on controlling blood sugars, blood pressure, and weight. There might be a temporary worsening of retinopathy, but in the long run, it will benefit the patients, he assured.
According to the review, nearly 9.6 million people in the U.S. suffer from retinopathy, making up one-quarter of the diabetic population. Rapid improvement in blood sugar levels has often been suspected to cause deterioration in eye health.
The new review aimed at understanding the effects of rapid weight loss by using GLP-1 agonists. Certain research pointed out a transient worsening in retinopathy upon rapid control of diabetes, generally improving over time. This is primarily attributed to changes in osmotic pressure in the vessels and alterations in the pressure gradient, leading to an initial increase in leakage, stabilizing over time.
The review further suggested that a sudden drop in HbA1c of 2% or more might influence the progression of diabetic retinopathy for six to twelve months. However, an improvement would follow this temporary deterioration.
Looking to the future, Williams expects that the new generation of weight-loss drugs will play a significant role in reducing the long-term effects of diabetic retinopathy. Still, they should be prepared for potential temporary worsening in a small percentage of patient cases.
The authors of the review recommended that before undergoing intensive glycemic control leading to rapid weight loss, patients should take a baseline retinal examination, followed by continuous monitoring.
The review analyzed studies on tight insulin control, bariatric surgery, and GLP-1 agonists. A 2022 review highlighted that four major randomized controlled trials associated GLP-1 agonists with rapidly worsening diabetic retinopathy but also reported cardiovascular benefits. Conversely, a study from 2016 connected the drug semaglutide to a higher risk of retinopathy complications, although the affected patient numbers were relatively small.
The review, however, did not include a study which suggested that the usage of GLP-1 agonists almost doubled the likelihood of progression from nonproliferative to proliferative retinopathy after three years and to higher rates of progression to diabetic macular edema.
Despite the seemingly conflicting reports, one fact remains consistent: proper management of diabetes is critical in trying to prevent or control diabetic retinopathy. Regardless of the method utilized to achieve this, the emphasis should always be on conscientious monitoring and patient education about the potential risks and benefits.
