Glaucoma lecturer likens preserved drops to processed foods-neither is the healthiest ideal

June 28, 2013

San Diego

 

San Diego-“Trying to reduce BAK load is the right thing to do overall,” said Michael Chaglasian, OD, associate professor at Illinois College of Optometry and chief of staff at the Illinois Eye Institute. In his lecture yesterday morning, Preservative vs. Preservative Free Medication in Glaucoma, Dr. Chaglasian made a strong case that there are several deleterious effects of BAK, which should prompt practitioners to avoid them in many cases.

Dr. Chaglasian admitted he wasn’t always concerned about BAK. In fact, he said he didn’t used to pay much attention to ocular surface disease in his glaucoma patients. But, the Dry Eye Work Shop (DEWS) report in 2007 was a wake-up moment for him. The DEWS conclusion that the elimination of preservatives from OTC lubricants was a huge leap forward in ocular surface care made him think more seriously about the effects of preservatives in the glaucoma meds he prescribed. He wondered, “If preservatives play such a big role in ocular surface health, how might they be affecting my glaucoma patients, who use them long term?”

Since effects of preserved drops in glaucoma treatment tend to be subtle and build up over time, they are often overlooked. “But they can have a significant impact,” he said. BAK has several effects on the ocular surface, including:

  • Decreased epithelial cell integrity

  • Increased conjunctival inflammatory cells

  • Loss of goblet cells

  • Reduced tear function

  • Reduced TBUT

Beyond it’s relationship to ocular surface disease, BAK is associated with filtration bleb failure in trabeculectomy patients and inflammatory cell infiltration in the trabecular meshwork. Furthermore, new research also suggests that BAK affects the eyelid muscles, causing incomplete blink and lagophthalmus in animal models.

Dr. Chaglasian recommended that doctors consider the following factors when prescribing topical medications as these contribute to preservative toxicity:

  • Concentration

  • Frequency and duration of use

  • Tear production and clearance

  • Contact lens use

  • Number and type of concurrent meds

  • Type of preservative

Not every patient needs to be treated with BAK-free drops but, he said, clinicians need an evaluation and workup to avoid harming at-risk patients.ODT