Abstract: Comparing different artificial tears through rose tinted glasses

This study's bottom line is unsurprising but still significant and I appreciate seeing a study confirm what so many of us know in practice: Those OTC lubricants, well, there's a reason we're using them but there's not much to choose between most of them. The measure in this study however is rose bengal staining.

Efficacy of different dry eye treatments with artificial tears or ocular lubricants: a systematic review.
Ophthalmic Physiol Opt. 2009 Aug 14. [Epub ahead of print]
Doughty MJ, Glavin S.
Department of Vision Sciences, Glasgow-Caledonian University, Glasgow, G4 OBA Scotland, UK.

Purpose: To objectively review the outcome of clinical studies where rose bengal stain (RB) has been used as an outcome measure to assess the efficacy of artificial tears (AT) in patients with dry eye.

Methods: From peer-reviewed articles published between 1947 and 2008, information was sought on dry eye status, as reported using a grading scheme, after use of RB as a diagnostic test, before and after use of a specific regimen of artificial tears or ocular lubricants for approximately 30 days. Mean baseline scores and post-treatment scores were calculated, along with the net change and the percentage change in the RB scores.

Results: From a total of 33 suitable data sets, published between 1985 and 2006, the group mean pre-treatment RB score was 4.25 +/- 1.55 (+/-S.D.), which decreased to 2.84 +/- 1.24 after 30 days of treatment. This represented a net change of -1.43 (95% CI of -1.04 to -1.45). For use of traditional AT (saline, hypromellose, etc), the net change was -0.95, it was -1.33 for use of carbomer (polyacrylic acid) gels and -2.10 for hyaluronic acid (HA) products. These changes represented net improvements of 25.9 +/- 18.4%, 38.0 +/- 20.7% and 41.8 +/- 16.3% respectively. The greater change with HA was not associated with a lower final outcome score, but with higher pre-treatment scores.

Conclusions: Based on RB grading schemes used by numerous different clinicians over many years, treatment of dry eye with artificial tears or ocular lubricants can be expected to improve the condition of the exposed ocular surface. Assuming no improvement without treatment, a 30 days treatment period can be projected to produce an overall improvement of around 25%, but with no unambiguous statistical differences between product types.