Improving outcomes

[caption id="attachment_7283" align="alignnone" width="325"] Norbert Pfeiffer MD[/caption]   Glaucoma treatment with preservative-free preparations has a positive impact on quality of life, medication adherence, overall costs, and long-term disease outcomes, Norbert Pfeiffer MD told a session of ESCRS Glaucoma Day 2016 in Copenhagen, Denmark. Dr Pfeiffer, Professor of Ophthalmology, Mainz University, Germany, reported that evidence from available clinical studies now favours this approach. He explained that understanding how study endpoints are affected by use of a preservative-free intraocular pressure (IOP)-lowering medication is important when one considers that the goal of glaucoma treatment, as stated in the European Glaucoma Society Guidelines, is “to maintain patients’ visual function and (vision related) quality of life… at sustainable cost”. He reminded attendees that benzalkonium chloride (BAK), which is commonly used as a preservative in ophthalmic medications, can cause allergic reactions and ocular surface disease. “Most likely, these side effects will have an effect on quality of life,” said Dr Pfeiffer, as he presented findings from an open-label study supporting his statement. MEDICATION ADHERENCE The investigation, conducted by Dr Pfeiffer and colleagues, included 158 patients who were experiencing adverse ocular signs and/or symptoms after being on preservative-containing prostaglandin analogue for at least six months. After enrolment, patients were switched to a preservative-free prostaglandin analogue product. Assessments performed after 12 weeks showed patients benefited, with significant reductions in the severity of their ocular signs and symptoms. In another study conducted by Dr Pfeiffer, 200 glaucoma patients were asked about their medication adherence. The results showed a higher self-reported adherence rate among patients using IOP-lowering medications without preservatives compared with patients using preservative-containing medications (87.5% vs. 68.0%). “In theory, long-term outcomes should be better if adherence is better, but proof of that concept would require a long-term comparative study,” Dr Pfeiffer said. As no such trial exists, Dr Pfeiffer and colleagues sought to investigate the issue by inputting published data into a model comparing 10-year outcomes when patients received first-line prostaglandin analogue monotherapy and second-line combination treatment with timolol using medications preserved with either BAK or a less cytotoxic alternative, polyquaternium-1 (Polyquad). The model analysed what proportions of patients would remain on first- or second-line medical treatment. Assuming different adherence rates, the results favoured treatment with IOP-lowering products containing Polyquad versus BAK. Norbert Pfeiffer: 
norbert.pfeiffer@unimedizin-mainz.de