Should Glaucoma Patients Get Rid Of Their Cats? Not So Fast

Troubled by a recent study linking cats to glaucoma? Don’t panic, ophthalmologists say.

AsianScientist (Aug. 4, 2015) – A recent study published in American Journal of Ophthalmology described a link between sensitization to cat and cockroach antigens with an increased chance of glaucoma. Unfortunately, the study has been misrepresented in mainstream media with headlines such as “Why owning a cat could damage your SIGHT.”

Heightened media attention has caused some concerned, cat-owning glaucoma patients to ask Dr. Chelvin Sng, an ophthalmologist at National University Hospital in Singapore, if they should get rid of their cats at home.

“Fearing a surge in unnecessarily abandoned cats, we felt that some clarification was necessary, which led to this editorial in the British Journal of Ophthalmology (BMJ)],” Sng told Asian Scientist.

The original article conducted a retrospective cross-sectional study of 1,652 participants in the National Health and Nutrition Examination Survey (NHANES). They observed that there was an association between IgE levels to cat and cockroach allergens with glaucoma.

In an editorial response, the authors of the BMJ paper first noted that the proposal that cat and cockroach allergens could trigger an autoimmune response target against the optic nerve may be possible but weak. This is because it remains to be determined if the increase in autoimmune antibodies in immune-mediated glaucoma conditions is correlative or causative.

With regards to the study’s design, the authors noted that NHANES study was not designed to investigate glaucoma risk factors, as other established risk factors such as intraocular pressure and family history was not available in the study.

“The authors were cautious in the interpretation of their results, and recognized the limitations of their study,” Sng said.

In addition, what the original paper proposed was that cat allergy but not cat ownership was associated with glaucoma in their study. Cat allergens are present ubiquitously in the environment, and people may be exposed to cat allergens even without direct contact with cats.

Previous studies show that environmental cat allergens may be sufficient to trigger sensitization to cat allergens even in non-cat owners. Getting rid of the cats in the home therefore may not result in the alleviation of allergic reaction. In fact, Sng noted that early exposure to pets may be helpful in protecting allergies against animals.

“Cat owners can be reassured that keeping their kitties does not lead to an increased risk of glaucoma,” Sng said.

The article can be found at: Sng et al. (2015) Glaucoma and Allergies: ‘Should I Get Rid of My Cat?

Copyright: Asian Scientist Magazine: Photo: Mario Antonio Pena Zapatería/Flickr/CC.
Disclaimer: This article does not necessarily reflect the views of Asian Scientist or its staff.

Ying Ying completed her PhD in neurobiology at the University of Basel, where she studied the role of bone morphogenetic protein in structural plasticity of neurons.

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