Market Utilization of Silicone Hydrogel Lenses

With this year marking the tenth anniversary of the introduction of silicone hydrogel lenses on the worldwide market, it is interesting to reflect on the differences we have seen in utilization patterns and growth in this material’s market share worldwide.  The most accessible place to find that information is the International Contact Lens Prescribing Survey, a yearly, multi-country, collaborative project headed by Dr Philip Morgan, Director of Eurolens Research (Manchester, UK) with help from researchers around the globe.  Most recently, this team reported on data from the 2008 survey (Morgan et al. 2009), which included 27 different countries.

Looking at the results of the survey, it is apparent that there is great diversity with respect to the utilization of silicone hydrogel materials. Overall, the growth of silicone hydrogel lens wear has increased four-fold from 2002 to 2008, increasing from just under 5% to just under 30% of the soft lens market.  This would appear to be quite dramatic growth in a short period of time.  It is interesting to note that when you review the initial growth (2000 to 2002) of silicone hydrogel lens wear in both the Australian and Canadian markets that growth was relatively small in the first three years, being under 20% of lens wear (Figures 1 and 2) (Woods et al. 2004 and Woods et al 2007). The data reported from Canada does extend past this initial period and shows a dramatic shift to 40% utilisation (Woods et al. 2007) (Figure 2).  This dramatic change  in Canadian prescribing corresponded with the launch of additional silicone hydrogel lenses specifically marketed for daily wear and when the first lenses also began to be marketed for daily wear (in addition to extended wear).  While other factors may have influenced this change in prescribing, we suspect this marketing shift contributed to the growing popularity of these lenses.

Figure 1: Proportion of soft lens fits in Australia (2000-02) by material groups, (Woods and Morgan 2004)

Figure 2: Proportion of soft lens fits in Canada (2000-06) by material groups, (Woods et al 2007)

In 2008 overall, 77% of all extended wear lenses prescribed were fabricated from silicone hydrogel materials, but that global figure doesn’t tell the whole story. In Egypt, silicone hydrogel lenses made up only 5% of the 8% market share of extended wear lenses.  In Taiwan, silicone hydrogels made up 0% of the 13% extended wear market.  In contrast, silicone hydrogel lenses made up 100% of the extended wear market in both New Zealand and Australia. Data reported by Woods et al. (2007) clearly shows the impact of the introduction of silicone hydrogel materials for extended wear on prescribing preference (Figure 3).  In 2008, practitioners in some countries continue to prescribe conventional hydrogel lenses for extended wear despite evidence that, with their high oxygen transmissibility, silicone hydrogel materials are more conducive to maintaining corneal health.

Figure 3: Proportion of extended wear contact lenses fits in Canada (2000-06) by material groups, (Woods et al 2007)

While silicone hydrogel lenses were initially marketed for extended wear, they were very quickly incorporated into the daily wear market by both manufacturers and practitioners.  By 2008, silicone hydrogel lenses represented 29% of all soft lens fits.  Once again, this number does not demonstrate the diverse use of this material in different countries:  Silicone hydrogels represented 1% of lens wear in China and 3% of lens wear in Taiwan, compared to 62% in New Zealand and 59% in Jordan.
The popularity of daily disposable lenses may be a factor influencing the utilization of silicone hydrogel materials.  Both lenses offer patients significant benefits:  a superior physiological response resulting from the oxygen transmissibility of silicone hydrogel lenses versus the minimalist care requirements of daily disposable lenses.  The results of the 2008 practitioner survey made it clear that in some countries, practitioners are clearly polarised between one modality and the other.  Silicone hydrogels made up 2% of lens wear in Taiwan compared to 50% daily disposable lenses.  Silicone hydrogels made up 63% of lens wear in Slovenia compared to just 10% daily disposable lenses.  In Denmark, silicone hydrogels made up 7% of the market share compared to 64% for daily disposables.  Daily disposables are more popular in the United Arab Emirates (33%), Hong Kong (36%), Kuwait (40%), Norway (36%), Taiwan (50%), and the United Kingdom (32%).  Conversely other countries have a preference for silicone hydrogel lenses, including:  Australia (36%), Belgium (38%), Canada (45%), the Czech Republic (56%), Hungary (52%), New Zealand (37%), Slovenia (63%), the United States (46%) and South Africa (44%). 

In summary, as we celebrate the tenth anniversary of the availability of silicone hydrogel lenses, it appears that their place has been established in the contact lens market, but that role is very different in different countries.  It would appear the alternative to the silicone hydrogel lens is daily disposable lens wear.  The use of silicone hydrogel lenses in the extended wear market appears to be polarized, indicating that some practitioners associated with those markets could use further education with respect to the importance of oxygen transmissibility, particularly with overnight wear. It would be interesting to see the results of further iterations of this survey when more markets can access silicone hydrogel daily disposables. 

References

1. Woods CA and Morgan PB. Use of silicone hydrogel contact lenses by Australian optometrists. Clin & Exp Optom 2004;87:19-23.
2. Woods CA, Jones DA, Jones LW and Morgan PB (2007) A seven year survey of the contact lens prescribing habits of Canadian optometrists. Optom Vis Sci 2007;84:505-510 .
3. Morgan PB, Woods CA, Tranoudis Y, Efron N, Knajian R, Grupcheva CN, Jones D, Tan KO, Pesinova A, Ravn O, Santodomingo J, Vodnyanszky E, Montani G, Itoi M, Bendoriene J, van der Worp E, Helland M, Phillips G, Gonzalez-Meijome JM, Radu S, Belousov V, Silih MS, Hsiao JC and Nichols J. International Contact Lens Prescribing in 2008. Contact Lens Spectrum 2009;23:28-32.