Study Examines Anticholinergic Drug Use and Age-Related Macular Degeneration

Understanding Age-Related Macular Degeneration

Age-related macular degeneration (AMD) is a condition where the light-sensitive cells in the central part of the eye gradually deteriorate. This can lead to the accumulation of fatty deposits and the growth of abnormal blood vessels, potentially resulting in vision loss. Researchers have suggested that anticholinergic drugs, frequently prescribed for conditions such as depression, allergies, uncontrolled urination, and Parkinson’s Disease, may play a role in the development of AMD due to their association with fatty deposit buildup and dementia.

Research Overview

A recent study conducted in France and published in JAMA Ophthalmology investigated the connection between anticholinergic drug use and AMD. The research involved patients diagnosed with late-stage AMD by an ophthalmologist, while a control group comprised patients over 60 who had been assessed for late-stage AMD but had not received a diagnosis. Patients with early-stage AMD were excluded from the study.

Defining Late-Stage AMD

Late-stage AMD was characterized by either geographic atrophy or neovascular AMD (nAMD). Geographic atrophy involves the deterioration of light-sensitive cells in the eye, while nAMD refers to the abnormal growth of blood vessels beneath the retina in one or both eyes.

Study Methodology

The researchers utilized medical records and patient interviews to gather data on age, diagnosis dates, and the onset of abnormal blood vessel growth. They also examined anticholinergic drug use and other medications taken three months prior to the trial and throughout the patients’ medical histories. Anticholinergic drug use was categorized as “never use,” “ever use,” “previous use” (ending before diagnosis), or “current use” (ongoing at the time of diagnosis). The duration of use was classified as non-use, less than 5 years, 5 to 15 years, or over 15 years. Various factors, including age, sex, weight, ethnicity, dietary habits, smoking, alcohol consumption, education, eye color, cardiovascular disease history, previous eye surgery, and family history of AMD, were also considered.

Study Findings

In total, 200 AMD patients and 200 control participants were involved in the study. The results indicated that AMD patients were more than twice as likely to smoke, nearly 60% less likely to consume alcohol moderately, and almost three times more likely to have a family history of AMD. Among the participants, 26 AMD patients (13%) were identified as ever-users of anticholinergic drugs, compared to 10 controls (5%).

The findings revealed that individuals who had ever used anticholinergic drugs were nearly three times more likely to have late-stage AMD compared to those who had never used these medications. Specifically, those with over 15 years of use were nearly six times more likely to develop late-stage AMD, and those using more potent anticholinergic drugs were over six times more likely than non-users to be diagnosed with late-stage AMD.

Additionally, ever-use of anticholinergic drugs was associated with over three times the likelihood of developing geographic atrophy, more than twice the likelihood of neovascular AMD, and nearly three times the likelihood of having AMD in one or both eyes when compared to never-users. Conversely, the study noted that blood thinners and steroidal anti-inflammatory medications were linked to a significant reduction in AMD risk.

Conclusion and Future Research Directions

The findings from this study suggest a potential association between anticholinergic drug use and late-stage AMD, with prolonged use and higher potency correlating to a more significant risk. However, as the study primarily focused on AMD risk, further research is necessary to determine whether anticholinergic drugs directly cause or contribute to the progression of AMD, or if AMD creates conditions that necessitate the prescription of anticholinergic medications.

Written by Raishard Haynes, MBS
Reference: Aldebert, G. et al. (2018). Association of Anticholinergic Drug Use With Risk for Late Age-Related Macular Degeneration. JAMA Ophthalmol. doi:10.1001/jamaophthalmol.2018.1719