We read with interest the article by Puustjärvi et al.1 We were impressed with the results of this trial and believe that it makes a significant contribution to promoting compliance in patients requiring two ophthalmic medications for the treatment of chronic open angle glaucoma. However, our major criticism is that it compares patients receiving more than one medication with patients previously only receiving monotherapy, ie, 0.5% timolol twice daily or 4% pilocarpine three times daily. The results reported recently in a similar study over a shorter period were similar.2 However, surely the important study is to discover whether a fixed-ratio combination of timolol and pilocarpine is as effective as timolol and pilocarpine used concomitantly but not in combination.
Obviously, one would expect a timolol and pilocarpine fixed-ratio combination to be more effective than treatment with monotherapy, even if the strength of pilocarpine in the combination formula is 2%
Moriarty AP, Dowd TC. Timolol-Pilocarpine Fixed-Ratio Combinations in the Treatment of Chronic Open Angle Glaucoma. Arch Ophthalmol. 1993;111(10):1313-1314. doi:10.1001/archopht.1993.01090100019005