Topical glaucoma therapy falls short of goals, physician says

May 2, 2006

With glaucoma being the second leading cause of blindness in theworld, treatment consisting of eye drops has inherent problems andstops only about half of the damage. While the effect of treatmentwithin the confines of a clinical trial far exceeds those ofpatients being treated outside the framework of a clinical trial,the reality is that most patients are in the "real world,"according to Harry Quigley, MD, who spoke at the annual meeting ofthe Association for Research in Vision and Ophthalmology.

With glaucoma being the second leading cause of blindness in the world, treatment consisting of eye drops has inherent problems and stops only about half of the damage. While the effect of treatment within the confines of a clinical trial far exceeds those of patients being treated outside the framework of a clinical trial, the reality is that most patients are in the "real world," according to Harry Quigley, MD, who spoke at the annual meeting of the Association for Research in Vision and Ophthalmology.

There are numerous problems associated with glaucoma therapy in that the delivery system and the physician's ability to instruction patients on proper instillation of eye drops are wanting, with the result that patients waste about 50% of their medication by using many more drops than prescribed. Compliance is an issue, as shown in trials that indicated that by 36 months after the initial prescription was filled, many of the patients (70%) had discontinued their medication.

"Persistence is far from ideal," said Dr. Quigley, of the Glaucoma Service, Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore.

Even considering looser criteria, 49% of patients were found not to go for follow-up examinations 15 months after the initial examination, and almost a quarter of patients do not fill the second prescription.

However, when questioned during a phone survey, 95% of patients claimed to use every drop of medication, and doctors think the compliance rate is as high as 80%, when patients are actually using their medication about 60% of the time, Dr. Quigley pointed out. The reasons for this falling off of the use of medications include cost, patients "forget" to use the medication (i.e., travel, run out of drug), fear of side effects of the drops, 20% of patients don't believe the medication works, and depression.

Other consequences of anti-glaucoma eye drops are cataract, allergy, color changes in iris, and even more serious ones such as heart attack, sedation, falls, and death resulting from elevated cholesterol levels.

Dr. Quigley also pointed out that the total cost of treating patients, including testing, surgery, and drugs, was $3.9 billion in 2001 and the cost per eye saved from blindness is about $800,000.