Statins Decrease Glaucoma Risk in Those With Hyperlipidemia
October 10, 2012 — In patients with hyperlipidemia, statin use for 1 year decreased the hazard of developing open-angle glaucoma (OAG) by 5%, and use for 2 years decreased it by 9%, according to a retrospective, longitudinal cohort analysis. Individuals who used statins also had a decreased risk of progressing from suspected glaucoma to OAG and needing intraocular pressure–lowering medications.
Joshua D. Stein, MD, an assistant professor in the Department of Ophthalmology and Visual Sciences at the University of Michigan in Ann Arbor and colleagues, published their findings in the October issue of Ophthalmology.
This study was prompted by findings from an earlier study in which they evaluated whether patients with components of metabolic syndrome had an increased risk for OAG, said Dr. Stein.
"We found that, unlike diabetes and high blood pressure (each of which was associated with an elevated risk for OAG), the presence of hyperlipidemia was associated with a reduced risk for glaucoma. That result led us to wonder whether it might in fact be the medications used to treat hyperlipidemia (primarily agents from the class of drugs called statins), rather than the condition of hyperlipidemia itself, that could protect against the onset of OAG," Dr. Stein explained.
To find out, they analyzed data for eye-related claims obtained from detailed records of all enrollees in a managed care network with members located across the United States.
Of the 524,109 enrollees with hyperlipidemia, 316,182 (60.3%) had 1 statin prescription, 20,776 (4%) were prescribed nonstatin cholesterol-lowering medications only, and 187,151 (35.7%) were prescribed no cholesterol-lowering drug during follow-up.
A total of 92,955 (29.4%) statin users also filled 1 prescription for a nonstatin cholesterol-lowering drug.
Of the 241,711 patients eligible for the incident OAG analysis 10,266 (4.3%) patients were given at least 1 incident diagnosis of OAG while in the medical plan.
With every additional month of statin use the hazard of developing OAG decreased 0.3% (adjusted hazard ratio [HR], 0.997; 95% confidence interval [CI], 0.994 - 0.999; P < .0056) after adjustments for sociodemographic factors, and medical and ocular comorbid conditions.
Individuals who took statins for 1 year during the 2 prior years had a 4% decreased hazard (adjusted HR, 0.960; 95% CI, 0.933 - 0.988) of OAG relative to those who took no statins in the 2 prior years, if all other characteristics were alike.
Similarly, those who used statins continuously for 2 years had an 8% decreased risk (adjusted HR, 0.922; 95% CI, 0.870 - 0.976) of OAG relative to patients who used no statins during the prior 2 years.
No association was found between use of nonstatin cholesterol-lowering drugs and OAG development (P = .12).
After individuals given a diagnosis of OAG during their first 2 years of enrollment were excluded, 6934 individuals (14.0%) developed OAG among the 49,628 patients in whom suspected glaucoma was diagnosed during the look-back period.
After adjustment for confounders, the risk of progressing from suspected glaucoma to OAG decreased 0.4% (adjusted HR, 0.996; 95% CI, 0.993 - 0.999; P = .0062) for every additional month of statin use.
Individuals who used statins for 1 year during the prior 2 years had a 5% decreased risk (adjusted HR, 0.952; 95% CI, 0.920 - 0.986) of progressing from suspected glaucoma to OAG relative to patients with suspected glaucoma who used no statins in the prior 2 years.
Individuals who used statins continuously for 2 years had a 9% decreased hazard (adjusted HR, 0.907; 95% CI, 0.846 - 0.973) of OAG relative to those who used no statins in the prior 2 years.
There was no difference in the hazard in patients who used nonstatin cholesterol-lowering drugs (P = .077).
The risk for receiving a glaucoma medication prescription decreased 0.4% (adjusted HR, 0.996; 95% CI, 0.993 - 0.998; P = .0002) for every additional month of statin use after adjustment for confounders.
Use of statins for 1 year during the prior 2 years resulted in a 5% decreased risk (adjusted HR, 0.950; 95% CI, 0.924 - 0.976) of needing an intraocular pressure–lowering drug relative to those who used no statins in the prior 2 years.
Individuals who used stains continuously for 2 years had a 10% decreased risk (adjusted HR, 0.902; 95% CI, 0.854 - 0.953) of needing a pressure-lowering drug relative to those who used no statins in the prior 2 years.
Individuals who used nonstatin cholesterol-lowering medications had a 0.6% (adjusted HR, 0.994; 95% CI, 0.990 - 0.998; P = .0017) hazard per month for being prescribed a glaucoma medication.
Use of a nonstatin cholesterol-lowering medication for 1 year during the prior 2 years resulted in a 7% decreased risk (adjusted HR, 0.928; 95% CI, 0.886 - 0.972) of being prescribed glaucoma medications. Use of a nonstatin cholesterol-lowering medication for 2 years was associated with a 14% (adjusted HR, 0.862; 95% CI, 0.785 - 0.946) decreased risk of receiving a prescription for a glaucoma medication.
A total of 8236 individuals with an incident OAG diagnosis had no glaucoma surgical intervention coded before that diagnosis. Of those patients, 1009 (12.3%) later required laser or incisional glaucoma surgery while enrolled in the plan.
The risk of an enrollee going on to require laser or incisional glaucoma surgery was not significantly different (adjusted HR, 1.002; 95% CI, 0.994 -1.010) with each additional month of statin use (P = .68) after adjustment for confounders. Findings were similar for nonstatin cholesterol-lowering medications (adjusted HR, 0.992; 95% CI, 0.978 - 1.006; P = .27).
New Treatment Pathway?
"This is a very exciting new report suggesting that there may be an entirely new pathway for treating or preventing glaucoma," said Joel Schuman, MD, a clinical correspondent for the American Academy of Ophthalmology. Dr. Schuman, who was not involved in the study, is a professor at the Eye & Ear Foundation, chairman of ophthalmology at the University of Pittsburgh School of Medicine, director of the UPMC Eye Center, and interim director of the Fox Center for Vision Restoration in Pittsburgh, Pennsylvania.
Encouraged by his team's findings, Dr. Stein told Medscape Medical News, "Although physicians already have various effective treatment options...the discovery of a lower-cost option with relatively few side effects could be enormously useful. Also, because strict adherence to prescribed treatment regimens involving topical glaucoma medications can be challenging for many patients, the prospect of a potential alternative taken orally could ultimately mean the difference between sight loss and preserved vision for countless adults."
He said the next step should be a "randomized controlled trial to test the potential efficacy of statin drugs to prevent glaucoma or halt disease progression."
However, Dr. Schuman cautioned that these findings may not apply to everyone. "It is important to remember that subjects studied were treated with statins for hyperlipidemia. While this retrospective study sets the stage for a larger-scale prospective trial to assess the benefit of statin treatment in people predisposed to or with glaucoma, it does not mean that all such people should be treated with statins to prevent or manage the disease."
This study was supported by the National Eye Institute K23 Mentored Clinician Scientist Award; American Glaucoma Society Clinician Scientist Grant, Blue Cross Blue Shield of Michigan Foundation, Research to Prevent Blindness, and a National Eye Institute Core Grant. The authors and Dr. Schuman have disclosed no relevant financial relationships.
Ophthalmology. 2012;119:2074-2081. Full text
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