OSD and glaucoma

Ocular surface disease can degrade treatment outcomes

Howard Larkin

Posted: Friday, November 1, 2019

Christophe Baudouin, MD, PhD, FARVO

Preventing optic nerve degeneration by controlling intraocular pressure (IOP) is the top priority in glaucoma treatment. As a result, some ophthalmologists – and even patients – view topical drug side-effects such as red eyes, irritation and burning as tolerable and not worth treating, according to Christophe Baudouin, MD, PhD, FARVO.

However, over the multiple decades glaucoma must be treated, ocular surface disease (OSD) can significantly degrade outcomes, Dr Baudouin said. Beyond reducing medication compliance, OSD reduces the IOP-lowering effect of topical drugs, and increases failure rates of subsequent glaucoma surgery.

“OSD is not a minor side-effect, it is a major problem for glaucoma care that should be recognised and treated,” said Dr Baudouin, who is Professor and Chair, Quinze-Vingts National Eye Hospital, and Vision Institute, Paris, France.

About 20% of patients have dry eye signs and symptoms before topical glaucoma treatment begins. Preservatives in glaucoma eyedrops, notably benzalkonium chloride (BAK), can cause inflammation, and the risk increases with the number of preserved drops a patient takes. In addition, about 20% of patients have interactions with active medication compounds. In one survey Dr Baudouin conducted, 40% of 300 general glaucoma patients said they had changed or stopped a topical medication due to OSD signs or symptoms.

“It’s not 3 or 4%, it’s 40%. That’s huge.”

Dr Baudouin recommended checking for OSD in glaucoma patients who complain of foreign body sensations, burning, dry eye or irritation; display signs such as conjunctival redness or tearing; or who regularly use artificial tears – and it doesn’t take long.

“One drop of fluorescein, and in 30 seconds you get a lot of information on surface disease.”

Where surface damage is not severe, OSD often can be managed without referral to a corneal specialist, Dr Baudouin said. In patients taking multiple glaucoma drops, reducing the number often helps, and treating OSD can reduce the number of glaucoma drops needed (Dubrulle P et al. J Glaucoma. 2018 Dec;27(12):1105-1111).

“Try to identify if there was a drug added that caused the problem and try removing it first,” he advised.

Using combined drugs when available, switching from a more reactive compound to a less reactive alternate in the same category and using unpreserved drugs when possible also help. Combining strategies may be particularly powerful. One recent study found that moving from a bimatoprost-timolol combination, whether preserved or unpreserved, to an unpreserved tafluprost-timolol combination, significantly reduced OSD signs and symptoms (Bourne R et al. BMJOpen 2018; 9(4)). Procedures such as trabeculoplasty also can reduce the need for topical drugs, and choosing a surgical option earlier, especially with the new range of MIGS, can be more effective in the long-term, Dr Baudouin said.

Christophe Baudouin: