INTERNATIONAL PRESCRIBING

International Contact Lens Prescribing in 2009

We report on a prospective analysis of more than 25,000 contact lens fits from around the world during 2009.

By Philip B. Morgan, PhD, MCOptom, FAAO, FBCLA; Craig A. Woods, PhD, MCOptom, DipCLP, FAAO; Ioannis G. Tranoudis, DO, MSc, PhD; Magne Helland, BSc, MScOptom, FIACLE; Nathan Efron, PhD, DSc, FBCLA, FCCLSA, FIACLE, FAAO (DipCCLRT); Razmig Knajian, DO, FAAO; Christina N. Grupcheva, MD, PhD, FEBO; Deborah Jones, BSc, FCOptom, DipCLP, FAAO; Kah-Ooi Tan, BOptom (Hons), PhD, MBA; Alice Pesinova, BSc; Ole Ravn; Jacinto Santodomingo, OD(EC), MSc, PhD, MCOptom, FBCLA, FAAO; Edit Vodnyanszky; Nir Erdinest, BOptom, MSc; Hreinn Ingi Hreinsson; Giancarlo Montani, FIACLE; Motozumi Itoi, MD, PhD; Jolanta Bendoriene, MD, PhD; Eef van der Worp, BOptom, PhD, FAAO, FIACLE, FBCLA; John Hsiao, BA, OD, FIACLE; Geraint Phillips, BSc, OD, MCOptom, DipCLP; José Manuel González-Méijome, OD, PhD, FIACLE; Simona Radu, MD; Vadim Belousov; & Jason J. Nichols, OD, MPH, PhD, FAAO

This is the eighth consecutive year that we have presented data from a survey of international contact lens prescribing in Contact Lens Spectrum. In this article we report on an assessment of 25,801 fits across 28 contact lens markets located in North America, Europe, the Middle East, Asia, and Africa. As in previous years, we opted for a prospective approach to this work. Up to 1,000 survey forms were randomly disseminated in each market to contact lens practitioners (ophthalmologists, optometrists, and/or opticians depending on the market), and information about the first 10 patients prescribed with lenses after receipt of paper or electronic survey forms was anonymously recorded.

Wearer Demographics

Some of our findings have remained very stable over the course of this project. For example, the proportion of contact lenses fitted to female patients remains at two-thirds (Table 1) with a range from 55 percent in Italy and Qatar to 81 percent in Romania. The oldest patient at fitting was a 95-year-old male who was prescribed soft contact lenses to be replaced on a two-week basis. The youngest was a 6-month-old boy who was prescribed extended wear soft lenses. The mean age at fitting was close to 31 years, with a spread from 24.9 years in Jordan to 38.0 years in the United Kingdom (Figure 1). As in previous years, the markets that have been established for a longer period of time (the United Kingdom, the United States, Australia, Canada, New Zealand) tend to have older patients at fitting compared to the developing markets (Bulgaria, China, Jordan, Russia).

Table 1. Demographic information for the 28 countries surveyed in 2009.

Figure 1. The proportion of contact lens fits to females versus mean wearer age.

Overall, 9 percent of lenses are prescribed to patients for part-time wear (three days per week or less). There is significant variation across markets for this parameter, however. Lenses for part-time use are prescribed to more than 20 percent of patients in Australia, the United Kingdom, and Italy whereas this figure is 2 percent or less in the United Arab Emirates, Bulgaria, Hong Kong, Jordan, the Netherlands, and Qatar.

Rigid Lenses

Overall, rigid contact lenses accounted for 8 percent of fits (Table 2). Table 3 shows a detailed analysis for the 10 countries that provided information for 35 or more rigid lens patients. Fourteen percent or more patients received rigid contact lenses in New Zealand, the Netherlands, Japan, Italy, and Israel compared to 2 percent or fewer patients who were fitted with rigid lenses in 13 of the markets evaluated. Few rigid lenses (12 percent) had Dk values less than 40 units, with similar levels of mid-Dk (40 to 90 units) and high-Dk (greater than 90 units) lenses.

Table 2. Breakdown of lens fits into six key categories of lenses. See Table 1 for country abbreviations.

Table 3. Detailed information for prescribed rigid lenses only. See Table 1 for country abbreviations. Data presented for countries reporting >35 rigid lens fits. EW=extended wear.

Toric, multifocal/monovision, and orthokeratology lenses accounted for 10 percent, 14 percent, and 7 percent of prescribed rigid lenses, respectively. Orthokeratology lenses accounted for 26 percent of rigid lenses prescribed in Spain. A high majority of rigid lenses prescribed in the United States, the United Kingdom, Spain, and Italy were on a planned replacement basis, typically annually.

Soft Lenses

Soft lenses dominated most markets and accounted for more than 90 percent of new fits in 22 of the 28 markets assessed (Table 4). For the first time, silicone hydrogels were the most widely fitted soft lens materials of the four available categories in this work, accounting for 39 percent of new soft lens fits. In the United States and Kuwait, silicone hydrogel materials were prescribed for more than 70 percent of fits (Figure 2). In contrast, only 6 percent of fits in China were with silicone hydrogels.

Table 4. Detailed information for prescribed soft lenses. See Table 1 for country abbreviations. EW = extended wear.

Figure 2. Silicone hydrogel materials prescribed to daily wear soft contact lens patients.

Low-water content (<40 percent water) hydrogel lens materials account for less than 10 percent of fits with traditional hydrogels worldwide, with mid-water hydrogel lenses making up most of the traditional (non-silicone hydrogel) lenses prescribed.

The nature of lenses fitted to presbyopes can be misleading when looking at the overall market. If considering all patient ages, 6 percent of lenses are multifocal and 2 percent are monovision. However, when considering only patients 45 years old and greater, these values rise to 35 percent and 10 percent, respectively (the cumulative figure reached more than 90 percent in Portugal). While this infers that more than half of those in the presbyopic age range are prescribed ‘non-presbyopic’ contact lens options, a substantial proportion do receive a multifocal or monovision correction.

Toric lens prescribing once again varies significantly among markets. More than 30 percent of soft lenses prescribed are of toric design in 11 of the markets assessed, including the United States, Hungary, Portugal, Spain, and the Czech Republic. This lens type is prescribed for less than 10 percent of soft lenses in Bulgaria, Lithuania, Russia, and Taiwan.

The frequency of lens replacement continues to vary greatly among markets. Daily disposable lenses, for example, are prescribed for 4 percent of fits in Bulgaria and for 85 percent of fits in Qatar. North America remains below the global average for the proportion of daily disposables fitted, with these lens types accounting for 10 percent of fits in Canada and 17 percent in the United States. The Nordic markets surveyed (Norway, Denmark, and Iceland) all show a high use of daily disposable lenses. Worldwide, fewer than 10 percent of lenses are prescribed for replacement less frequently than monthly.

Extended wear contact lenses are fitted to less than 10 percent of patients worldwide, although there are notable exceptions with Hungary, Italy, Lithuania, and Norway prescribing this modality in more than 20 percent of contact lens fits. CLS

Data for materials and designs pertain to daily wear new fits only.

Figure 3. The proportion of monovision and multifocal lenses prescribed to patients in the presbyopic age range.

This survey was funded by the sponsors of Eurolens Research at the University of Manchester: Bausch & Lomb Incorporated, Alcon Laboratories (UK) Limited, Abbott Medical Optics (UK) Limited, Ciba Vision (UK) Limited, CooperVision Limited, Johnson & Johnson Vision Care, Menicon Co. Ltd., and Sauflon Pharmaceuticals Limited. Additional funding and/or assistance was provided for the following: United Arab Emirates, Bulgaria, Hungary, Israel, Jordan, Kuwait, Romania, South Africa - Johnson & Johnson Vision Care; Australia - Optometrists Association Australia; Norway – the Norwegian Association of Optometry; Netherlands – Bausch & Lomb Benelux; Spain – Spanish College of Optic-Optometrists. We thank Valentina Capuano for help with the Italian data.