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Contact lens prescribing trends 2016

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Nathan Efron AC PhD DSc
Emeritus Professor, Institute of Health and Biomedical Innovation, and School of Optometry, QUT

Philip B Morgan PhD
Professor and Director, Eurolens Research, The University of Manchester, Manchester UK

Craig A Woods PhD
Professor, School of Medicine (Optometry), Deakin University, Geelong

The 17th annual survey of Australian contact lens prescribing was conducted from January to April 2016. The same format as in previous years was employed. An email was sent to all members of Optometry Australia with a link to a downloadable questionnaire, and a request that this be accessed, printed and completed to provide details of the first 10 patients fitted with contact lenses after receipt of the questionnaire.

The survey was specifically designed to be straightforward to complete while capturing key information about their patients. Practitioners were asked general questions about themselves. For each contact lens fitting, they were requested to complete the following details: date of fitting, new fitting or refitting, age and sex of patient, lens material, lens design, frequency of replacement, times per week of wear, modality (daily- or extended-wear) and care system. Practitioners were asked to return the questionnaire by fax, post or email.

Completed questionnaires relating to 320 contact lens fittings were returned, which provides a sound basis for a meaningful analysis. Each fitting was given a weighting based on the number of lenses fitted per year by the practitioner, based on the date information on the form. This means that data generated by practitioners who have a higher frequency of fitting contact lenses were afforded a higher weighting than those taking longer to fit the 10 patients with lenses.

The discussion concentrates primarily on data relating to new lens fittings as opposed to refittings. We believe that new fittings are a more sensitive barometer of current patterns and future trends, whereas refittings are more indicative of previous fitting behaviours.

In keeping with other markets around the world,1 a majority of lenses (61 per cent) was fitted to females. The average age of contact lens wearers at the time of fitting was 36.3 ± 16.5 years. The age at fitting ranged from eight to 75 years.

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Figure 1. Detailed results for soft contact lens prescribing in the 2016 Australian survey. Si-H: silicone hydrogel, WC: water content

Soft lens materials and designs

Soft lenses are still the main type of contact lens fitted and as was the case last year,2 accounted for 95 per cent of new fittings. Figure 1 is a composite of pie charts detailing the key findings of the 2016 survey in relation to soft lenses. Silicone hydrogels are still the dominant material, representing 75 and 76 per cent of materials prescribed as new fittings and refittings, respectively. This is identical to 2015 data.2 The balance is more or less evenly split between low-water, mid-water and high-water content hydrogel materials. The reason for the apparent increase in the use of low-water content hydrogels over the past two years (nine per cent of new fittings), compared to zero per cent of new fittings in 2014,3 is unclear.

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Figure 2. Percentage of all soft lenses prescribed as toric lenses in Australia between 2000 and 2016. The dotted line represents the expected prescribing rate if all lens wearers with greater than or equal to 0.75 D of astigmatism were fitted with toric lenses.4

The key categories of lens designs are spherical, toric, multifocal, monovision, coloured (tinted) and anti-myopia. Spherical designs represent a small majority of new fittings (54 per cent). About one-quarter of soft lenses prescribed are in toric form (21 per cent of new fittings and 23 per cent of refittings). Figure 2 shows trends in toric lens prescribing between 2000 and 2016.

The level of prescribing in Australia has consistently fallen short of that which would be expected if all lens wearers with greater than or equal to 0.75 D of astigmatism were fitted with toric lenses.4,5 The slight decline in toric lens prescribing over the past three years is possibly attributed to accelerated prescribing of silicone hydrogel daily disposable lenses (see below), with the availability of toric designs lagging behind spherical designs for this lens type.

Continuing improvements in soft multifocal lens designs over the past decade have resulted in strong prescribing figures for these lenses. This year, multifocal lenses represent 15 per cent and 18 per cent of new fittings and refittings, respectively, which is a level of prescribing similar to 2015 data.2 It is evident that for new fittings, multifocals (15 per cent) are preferred over monovision lens wear (nine per cent) for correcting presbyopia. Coloured (tinted) lenses represented one per cent of new fittings and three per cent of refittings, which is broadly similar to last year’s result.2

Anti-myopia lenses incorporate special designs for arresting the rate of progression of myopia.6 No anti-myopia lens fittings were recorded, which may not be surprising because these lenses are still in the experimental and development phase. It indicates minimal off-label fitting as the single product now available in some markets (MiSight, CooperVision) is not yet commercially available in Australia.

 

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Figure 3. Percentage soft lenses categorised as reusable, single use extended-wear and single-use daily disposable, prescribed in Australia between 2000 and 2016.  EW: extended wear, DD: daily disposable

 

Soft lens replacement and wearing modality

Of the 34 nations we surveyed in 2015, Australia was the leading nation for daily disposable lens prescribing, which accounted for 62 per cent of new fittings. This level of prescribing has remained the same for 2016. Figure 3 demonstrates how the proportion of all soft lenses (new fittings and refittings combined) prescribed for daily replacement has risen relentlessly in the Australian market since 2000. It is evident that the increased prescribing of daily disposable lenses has largely been at the expense of reusable lenses and to a lesser extent, extended-wear lenses.

The balance of new fittings comprises largely monthly replacement lenses (35 per cent), with the fitting of one to two weeks replacement lenses having declined in recent years, from 21 per cent in 20127 to only two per cent over the past two years. Only one per cent of lenses were being replaced less frequently than monthly.

Multi-purpose solutions remain the lens care option of choice for those wearing reusable lenses, representing 91 per cent of prescribed care regimens. The balance comprises almost exclusively peroxide systems.

Extended-wear lenses represented three per cent of new soft lens fittings in 2016, so single-use lenses, that is, extended-wear and daily-disposable lenses combined, represented 64 per cent of new soft lens fittings this year. The prescribing of single-use lenses is likely to continue to rise.

Rigid lenses

Conventional and orthokeratology rigid contact lenses represented four per cent and two per cent of all contact lens fittings, respectively. Because of the low level of rigid lens fitting in Australia, a valid statistical analysis of subcategories of materials, designs and replacement frequencies cannot be undertaken. The limited extent of orthokeratology fitting in Australia is probably due to the specialist nature and complexities of this fitting activity.

Australia versus France

We have conducted annual contact lens fitting surveys in about 40 countries over the past few years.1 This provides an opportunity to benchmark against international colleagues and this year we compare contact lens prescribing in Australian with that in France. The comparison is interesting because contact lenses are almost exclusively fitted by optometrists in Australia and by ophthalmologists in France. The differences in patterns of prescribing between Australia and France can be largely attributed to type of practitioner.

 

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Figure 4. Percentage of all contact lenses prescribed in Australia (outer ring) compared with France (inner ring).  DD: daily disposable, DW: daily wear, EW: extended wear, OK: orthokeratology, Si-H: silicone hydrogel

 

The current pattern of contact lens fitting in Australia compared with that in France is displayed in Figure 4. Seven key categories of lens type are represented. The outer and inner rings display the Australian and French data,1 respectively.

Overall, Figure 4 reveals striking differences in contact lens prescribing patterns between Australia and France. Perhaps the starkest difference is seen in the prescribing of daily disposable lenses, which are represented by the combined grey (daily disposable hydrogel) and pale blue (daily disposable silicone hydrogel) arcs. The overall prescribing of daily disposable lenses in Australia is about three times greater than in France, which may reflect a highly conservative approach to contact lens prescribing by ophthalmologists compared with that of optometrists.

The higher rate in France of rigid lens prescribing, of both orthokeratology and non-orthokeratology designs, also reflects a traditional approach to contact lens prescribing.

Extended-wear lenses represent four per cent of all contact lens fittings in Australia, whereas extended-wear lenses are not fitted in France.1 The lack of extended-wear prescribing in France may reflect a cautious approach of French ophthalmologists relating to the known greater risk of developing microbial keratitis during overnight lens wear.

Conclusions

The results of our 2016 survey confirm the high rate of prescribing daily disposable lenses in Australia. The soft lens market overall is dominated by two lens replacement modalities: daily and monthly. Silicone hydrogels are firmly entrenched as the material of choice, representing three-quarters of all soft lens fittings.

We note continuing strong use of multifocals which now outnumber monovision fittings 2:1. The contact lens industry is continuing efforts to develop improved designs to cater for the vision needs of this growing demographic cohort. Toric contact lens fitting continues at high levels, despite falling a little short of the ‘optimal’ level of prescribing.

 

1.  Morgan PB, Woods CA, Tranoudis IG, et al. International contact lens prescribing in 2015. Contact Lens Spectrum 2016; 31: 1: 28-33.

2.  Efron N, Morgan PB, Woods CA. Contact lens prescribing trends 2015. Australian Optometry (Pharma Supplement) 2015; 36: 12: 2-4.

3.  Efron N, Morgan PB, Woods CA. Contact lens prescribing trends 2014. Australian Optometry (Pharma Supplement) 2014; 35: 12: 2-5.

4.  Holden BA. The principles and practice of correcting astigmatism with soft contact lenses. Aust J Optom 1975; 58: 279-299.

5.  Young G, Sulley A, Hunt C. Prevalence of astigmatism in relation to soft contact lens fitting. Eye Contact Lens 2011; 37: 20-25.

6.  Kollbaum PS1, Jansen ME, Tan J, et al. Vision performance with a contact lens designed to slow myopia progression. Optom Vis Sci 2013; 90: 205-214.

7.  Efron N, Morgan PB, Woods CA. Trends in contact lens prescribing 2012. Australian Optometry (Contact Lenses Supplement) 2012; 33: 11: 3-5.



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