C L I N I C A L A N D E X P E R I M E N T A L OPTOMETRY ORIGINAL PAPER. A market survey of contact lens practice in Hong Kong

Transcription

1 C L I N I C A L A N D E X P E R I M E N T A L Contact lens practice in Hong Kong Yung, Cho and Yap OPTOMETRY ORIGINAL PAPER A market survey of contact lens practice in Hong Kong Clin Exp Optom 5; 88: 3: Alice MS Yung BSc (Hons) Pauline Cho PhD FAAO Maurice Yap PhD Department of Optometry and Radiography, The Hong Kong Polytechnic University, HKSAR, China Submitted: 13 September 4 Revised: 5 January 5 Accepted for publication: 26 January 5 Purpose: The aim of this survey was to evaluate the use of contact lenses, current prescribing habits of practitioners and the development of the contact lens market in Hong Kong. Methods: Questionnaires were sent to all registered contact lens practitioners in Hong Kong. This questionnaire sought information about their choices on prescribing contact lenses and lens care products and their opinions on continuing education and future trends of contact lens development. Results: A total of 286 responses (22 per cent) were returned. On average, the respondents reported that 36 per cent of their patients were contact lens wearers and most were myopes. The ratio of new fittings to refittings was 1:3. Of the contact lens wearers, 66 per cent were fitted with planned replacement lenses, mostly daily disposable lenses. Multipurpose solution was the most popular lens care regimen prescribed. Only 48 per cent of astigmatic patients were fitted with toric lenses and the use of overnight orthokeratology and silicone hydrogel lenses was limited. Single vision contact lenses with over-spectacles and monovision contact lenses were the most popular management for presbyopes. Dryness was the major problem reported by contact lens wearers. Practitioners look forward to further development of custom-made toric, multifocal and silicone hydrogel lenses. The major source of new contact lens information was communication with contact lens suppliers. Conclusion: Compared to previous reports, there was no significant change in the prescribing habits of practitioners. The major complaint of contact lens wearers is still ocular dryness. The contact lens market is driven by younger contact lens wearers, and planned replacement soft contact lenses together with multipurpose solutions dominate. The use of bifocal/multifocal lenses remained low and practitioners want low cost bifocal/multifocal contact lenses with better visual performance and toric lenses with a wider range in parameters. The use of overnight wear lenses such as silicone hydrogel and ortho-k lenses is limited and days continuous wear silicone hydrogel lenses are prescribed mainly for daily wear. Key words: contact lenses, orthokeratology, silicone hydrogel lenses, survey, trends The first survey on contact lens usage in Hong Kong was conducted in 199, 1 followed by a second four years later. 2 The last was conducted in by Cheung and colleagues. 3 These surveys provided an indication of the prescribing behav- iour of optometrists, which could be useful to manufacturers and educators in the design of marketing and continuing education programs. With the introduction of new contact lens materials, the emergence of orthokeratology and increased continuing education, we were interested to know whether prescribing behaviour had changed. In addition, we were interested to find out the aspirations that optometrists had for the contact lens field. 165

2 METHOD A self-administered questionnaire (Appendix) was sent to all registered optometrists, who were permitted to prescribe contact lenses in Hong Kong (Table 1). We excluded registered optometrists residing or practising abroad and full-time academics. The questionnaires, which were in Chinese, were distributed in April 2 to 1,6 optometrists. To encourage the return of the questionnaire, a stamped addressed envelope was enclosed with each questionnaire, which was coded. The questionnaire was sent again one month after the first deadline to remind optometrists to return the questionnaire, if they had not done so. The code on the questionnaire helped to avoid double counting of respondents who had returned both copies of the questionnaire. Follow-up telephone interviews were conducted with optometrists from optical shops. Optical shops were contacted according to the order in which they were listed in the Yellow Pages telephone directory (as at 31 March 3) and asked whether their optometrists were willing to be interviewed. After calling 162 optical shops, optometrists ( from Part I, six from Part II and 14 from Part IV) agreed to be interviewed for comments on specific items and/or to clarify issues raised in the questionnaire. The results of these interviews were used only to support the discussion of the results and so are not presented in the Results section. Part of Qualification/eligibility Restriction on practice No. of register registrants # I Bachelor degree/professional Diploma May use diagnostic 456 in Optometry pharmaceutical agents II Higher Certificate in Optometry or other Not allowed to use 244 qualifications together with training, diagnostic pharmaceutical professional experience and skill agents except staining satisfying the Council* agents III The applicant has acquired substantial To practise refraction only 78 knowledge, experience and skill in the practice of his profession IV The applicant has acquired substantial Not allowed to use 665 knowledge, experience and skill in the diagnostic agents except practice of his profession or passed staining agents Optometrists Board examination on refraction and contact lens fitting IV The applicant has acquired substantial To practise refraction only 438 knowledge, experience and skill in the practice of his profession or passed Optometrists Board examination on refraction # as at 1 April 2 * the Council: the Supplementary Medical Professionals Ordinance Table 1. Classification and restriction on the practice of the Optometrist Register in Hong Kong Number of Number of of questionnaires sent responses responses Part I Part II Part IV Total Table 2. Numbers of responses from practitioners in each category of registration RESULTS As we were interested in annual changes in the contact lens market in Hong Kong, most of the questions required practitioners to give estimates rather than exact numbers. In the following paragraphs the results presented are the averages of the figures provided by the respondents (ranges are also presented to show the wide range of estimates among optometrists). Response rate A total of 286 questionnaires were returned, representing a return rate of 22 per cent. The distribution of the return rates from Parts I, II and IV optometrists is shown in Table 2. Fifty-one per cent of the respondents worked in private practices, 44 per cent worked in chain optical shops and the remaining worked in hospitals (Figure 1). The numbers of contact lens practitioners in each practice ranged from one to nine (average two). Refractive errors of contact lens wearers About 36 per cent of patients visiting the optometrists were contact lens wearers (Figure 2) and among these, 94 per cent were myopes. The ratio between new fittings and refitted contact lens wearers was about 1:3. The youngest contact lens patient of each surveyed optometrist was aged between and 14 years and the oldest patient was mostly between 5 and 59 years. Number of after-care visits The average number of after-care visits during the first year of contact lens wear was reported to be four for rigid lens wearers (both PMMA and rigid gas permeable) lens wearers) (range: 1 to 12), three for 166

3 Private practice Optical chain Clinic/hospital Overall (N = 286) Part I (N = 118) Part II (N = 42) Part IV (N = 126) Non-contact lens wearers Contact lens wearers Myopic Hyperopic Emmetropic Figure 1. Nature of practices in which respondents worked Figure 2. Distributions of contact lens and non-contact lens wearers consulting the respondents Planned replacement (soft) Conventional (soft) Cheung et al (2) Current study RGP PMMA Orthokeratology Daily disposable Biweekly disposable Monthly disposable Cheung et al (2) Current study #Silicone hydrogel DW #Silicone hydrogel EW # No usage of these lenses was reported by Cheung et al (2) DW: Daily wear EW: Extended wear Figure 3. Comparisons of the proportions of different types of contact lenses prescribed between current findings and those reported by Cheung, Cho and Edwards 3 Figure 4. Comparisons of the proportions of different planned replacement soft contact lenses prescribed in the current study and in the study of Cheung, Cho and Edwards 3 soft contact lens wearers (range: 1 to 12) and 12 for orthokeratology (ortho-k) lens wearers (range: 3 to 5). In the second year of contact lens wear, the average number of after-care visits required for both rigid and soft lens wearers was two (range: to 8) and for ortho-k wearers was six (range: 1 to ). Contact lens types Most of the prescribed contact lenses were soft lenses (93 per cent). Planned replacement lenses (66 per cent) were the most popular type of contact lens prescribed by practitioners (Figure 3). Surveyed practitioners reported that the major type of rigid lens fitted was the rigid gas permeable (RGP) lens (average 5 per cent); PMMA and ortho-k lenses were both fitted to less than one per cent of patients. Among planned replacement lenses, daily disposable lenses (25 per cent) were reported to be the most commonly prescribed, followed by biweekly (23 per cent) and monthly (15 per cent) replacement lenses (Figure 4). Silicone hydrogel lenses were prescribed to only three per cent of patients (Figure 4) and of these lenses, 77 per cent were prescribed for daily wear and 23 per cent for extended wear. Commonly recommended wearing schedule The most commonly recommended wearing schedule for RGP, conventional and most planned replacement soft lenses was 12 hours per day and six days per week (Tables 3 and 4), while that for daily wear of silicone hydrogel lenses was 14 hours per day and six days per week. For extended wear, most practitioners (81 per cent) usually prescribed silicone hydrogel 167

4 Hours per day Days per week PMMA (range: 5-14) 6 (range: 2-7) RGP 12 (range: 4-18) 6 (range: 5-7) Orthokeratology lenses 8 (range: 7-18) 7 (range: 4-7) Conventional DW 12 (range: 8-16) 6 (range: 5-7) Conventional EW 12 (range: 9-18) 6 (range: 5-7) DW: Daily wear EW: Extended wear Hours per day Days per week Daily 12 (range: 9-18) 6 (range: 1-7) Biweekly 12 (range: 9-18) 6 (range: 5-7) Monthly 12 (range: 9-18) 6 (range: 5-7) Silicone hydrogel DW 14 (range: -24) 6 (range: 5-7) DW: Daily wear Table 3. Most commonly recommended wearing schedules (average) for different types of contact lenses Table 4. Most commonly recommended wearing schedules (average) for different types of planned replacement contact lenses Contact lenses with overspectacles Monovision contact lenses Bifocal contact lenses Multifocal contact lenses Hydrogen peroxide systems AOSEPT Oxysept B12 Titmus Renu MultiPlus Opti- Free Multipurpose solutions Rubbing with cleaner Rubbing without cleaner Complete Solo Care Others Figure 5. Proportions of different management protocols for presbyopic contact lens wearers Figure 6. Proportions of recommended disinfecting regimens for contact lens wearers lenses for two to days extended wear and less than one-fifth (19 per cent) of the respondents prescribed these lenses for more than days extended wear. Use of toric contact lenses On average, respondents fitted around 48 per cent of their astigmatic patients (those with cylindrical correction greater than -.75 D) with toric contact lenses. The majority of respondents agreed that the disposable toric contact lenses currently available in the market, if appropriately fitted, can provide clear and stable vision (69 per cent), and that the ranges of spherical power (63 per cent) and axis (54 per cent) were adequate to cover the needs of their patients. Seventy-three per cent and 59 per cent of respondents disagreed that there were adequate choices of back optical zone radius (BOZR) and cylindrical power, respectively. Management of presbyopic contact lens wearers Single vision contact lenses used in conjunction with over-spectacles, and monovision contact lenses were the most common recommendations for presbyopic patients seeking contact lens wear (Figure 5). On average, bifocal contact lenses were prescribed to eight per cent (range: zero to 4 per cent) and multifocal contact lenses to eight per cent (range: zero to 5 per cent) of their contact lenswearing presbyopic patients. Recommended contact lens care regimen and use of daily cleaner The most commonly recommended care regimen was the multipurpose solution (62 per cent) followed by hydrogen peroxide systems (38 per cent) (Figure 6). For chemical care systems, all respondents recommended rubbing of lenses during lens cleaning; 64 per cent recommended patients using multipurpose solution to rub their lenses with separate daily cleaner and 36 per cent to rub with the multipurpose solution. For hydrogen peroxide users, 98 per cent of respondents recommended their patients to rub lenses with daily cleaner; the remaining two per cent did not recommend rubbing to their patients. The most commonly 168

5 Dryness Tearing Foreign body sensation recommended multipurpose care system was Bausch & Lomb ReNu MultiPlus and the most commonly recommended hydrogen peroxide system was Ciba Vision AOSEPT (Figure 6). Recommended enzymatic cleaning schedule For conventional soft lenses, most respondents (91 per cent) recommended weekly enzymatic cleaning. About 35 per cent and 44 per cent of the respondents recommended monthly disposable lens wearers to use enzymatic cleaning weekly and biweekly, respectively. For rigid lenses, most respondents recommended weekly (56 per cent) or biweekly (32 per cent) enzymatic cleaning. Common complaints of contact lens wearers Most respondents (82 per cent) ranked dryness during contact lens wear as the most common complaint made by contact lens wearers (Figure 7). The majority of respondents (64 per cent) recommended eye drops to over 9 per cent of their patients. Of these respondents, 69 per cent recommended multi-dose eye drops; the other 31 per cent recommended unit-dose artificial tears. Of the multi-dose eye drops the most commonly prescribed was Senju Contact Lens Lubricant (Senju Pharmaceutical Co Ltd) (48 per cent). Of the unitdose eye drops the most commonly prescribed (72 per cent) was Alcon Tears Naturale Free. Blur vision Pain Redness Figure 7. Common complaints made by contact lens wearers Availability and future development of speciality a contact lenses Most respondents (91 per cent) prescribed custom-made toric lenses. Silicone hydrogel lenses were fitted by 65 per cent of respondents, whereas multifocal and bifocal contact lenses were available only in 45 per cent and 51 per cent of practices, respectively. Only 15 per cent of the surveyed contact lens practitioners prescribed ortho-k lenses. According to the ranking by the respondents, prescription of silicone hydrogel lenses on a daily wear basis was expected to have the highest potential for development in the Hong Kong contact lens market (27 per cent); followed by custom-made toric, multifocal and silicone hydrogel lenses prescribed on an extended wear basis. Sources of contact lens information Direct communication with contact lens suppliers was the major channel through which most respondents (68 per cent) obtained updated contact lens information. Professional journals (13 per cent), colleagues (seven per cent), advertisements (six per cent) and continuing education courses (six per cent) were the secondary and tertiary sources of new product information. a. In this study speciality contact lenses included custom-made toric lenses, bifocal lenses, multifocal lenses, ortho-k lenses and silicone hydrogel lenses. Promoting contact lens usage Many of our respondents (4 per cent) found advertising to be the most effective way to help them to increase contact lens sales, followed by discount offers (25 per cent) and free trial fitting of lenses (22 per cent). DISCUSSION The response rate of this study compared favourably with our previous surveys. 2,3 As with these previous surveys, we investigated the trends of the usage of contact lenses in Hong Kong based on the observations and opinions collected from a group of contact lens practitioners through a questionnaire. To eliminate seasonal effects, we collected practitioners estimations of the usage of contact lenses over the year. This reduced the workload of participants and encouraged a higher response rate. A follow-up telephone interview of practitioners was conducted to clarify some issues arising from the questionnaire. Before the legislation to control optometry came into effect in 1996, anyone with or without an optometric education could prescribe contact lenses. After the legislation came into effect, only appropriately registered optometrists were allowed to carry out contact lens practice; however, it included optometrists with various levels of contact lens experience (Table 1). In this survey, questionnaires were sent to 1,6 practising optometrists who were registered to serve the 6.8 million residents of Hong Kong (according to the census results of 2 presented by the Census and Statistics Department of The Government of the Hong Kong Special Administrative Region). Most of our respondents were practising in optical chain stores or in private practices (Figure 1), which are the major primary optical service providers in Hong Kong. It has been estimated that in Hong Kong, there is a high incidence of myopia, ranging between 5 and 74 per cent for teenagers of age 17 years. 4,5 As expected, most contact lenses (94 per cent) were prescribed for the correction of myopia. Fifty-eight per cent of our respondents 169

6 reported that their youngest contact lens patients were between the ages of and 14 years. In addition, most interviewed practitioners (18/) reported that new contact lens patients were mainly secondary school students (aged between 11 and 18 years). It is expected that there will be a growing demand for contact lenses among teenagers and young adults. The numbers of after-care visits offered to soft and rigid contact lens wearers have not changed compared with previous studies, 1,2 remaining at approximately four for both soft and rigid lenses in the first year of wear. As expected, the number of aftercare visits for ortho-k was much more than for other lens types, on average 12 in the first year and six in the second year of lens wear. More after-care visits are necessary in ortho-k in view of the more demanding procedures required of this lens modality. In Hong Kong, over 75 per cent of these patients are children or teenagers younger than 16 years 6 and there is a wide range in the number of after-care visits (range: 3 to 5) among practitioners of ortho-k. This may be because of the differences in contact lens background (Table 1) of the optometrists registered in Hong Kong, as all licensed contact lens practitioners are permitted to prescribe ortho-k lenses without any additional training. The usage of soft contact lenses has increased from 78 per cent as reported in the 199 survey 1 to 93 per cent in the current study. Table 5 shows a summary of the reported lens types used in the surveys conducted in Hong Kong since 199. For soft contact lenses, planned replacement has become the major wearing modality prescribed in Hong Kong. The increased popularity of planned replacement lenses is likely to be part of a global trend and is the major wearing modality prescribed in the United States, the United Kingdom, Australia and Singapore. 7- Planned replacement soft lenses are favoured by practitioners, as they allow convenient contact lens wear and better availability, and have less deposit-induced problems and a lower prevalence of complications Among planned replacement lenses, the use of daily disposable lenses has become the most popularly prescribed modality Publication Respondents SCL RGP Others Soft Frequent (classification of Daily Bi-weekly Replacement optometrists) Conway and 76 optometrists* Cho 1 Cho, Conway 174 optometrists* and Ko 2 Cheung, Cho 273 optometrists 88 OK: and Edwards 3 (87 Part I, PMMA: 1 58 Part II, 1 Part IV) Current study 286 optometrists 93 5 OK: Monthly: 15 (118 Part I, PMMA: 1 SH: 3 42 Part II, 126 Part IV) *Before the legislation of optometrists in 1996 in Hong Kong, optometrists were not classified. SH = silicone htdrogel, OK = orthokeratology Table 5. The percentage use of different types of contact lenses as reported in previous studies (Figure 4). The increased popularity of daily disposable lenses may be because they help to eliminate contact lens solution problems 13 and allow more convenient contact lens wear. Large variations on the usage of daily disposable lenses have been reported in different countries and for three years these lenses have remained the most popular daily wear option in the United Kingdom. 8 In contrast, daily disposable lenses represent less than nine per cent of soft lenses prescribed in Australia 9 and two per cent of contact lenses prescribed in Singapore. The variations with the usage of daily disposable lenses may be due to differences in practitioners preferences and manufacturers marketing strategies. 14 Although the usage of conventional lenses has decreased in Hong Kong, we believe that conventional lenses are unlikely to be completely replaced by planned replacement lenses, as the latter usually have limited parameters. Conventional lenses are used when planned replacement lenses fail and for patients with special needs, for example, high hyperopes. The usage of RGP lenses appears to have decreased in Hong Kong (Table 5) from per cent in the previous report 3 to five per cent in the current study (Figure 3). However, this decrease may be overestimated and misleading because in the current study a large number of our respondents (53 per cent) worked in optical chain stores (Figure 1). In Hong Kong, only a few optical chain stores provide RGP lens fitting and consequently most RGP lenses are prescribed in private practices. At the follow-up interviews, one-third (/) of the interviewed practitioners did not prescribe RGP lenses, as they (7/) found the demand for these lenses was too small. For those who prescribed RGP lenses (/), nine agreed that there was a decreased usage of RGP lenses, nine found no change and the remaining two found an increased usage of these lenses. Initial discomfort, low availability and better soft contact lenses now available were the reasons proposed for the reduced usage of RGP lenses. Practitioners also commented that rigid lenses are prescribed mostly to current RGP lens wearers or to those who are not suitable for soft lens wear and they did not promote or encourage RGP lens wear in their practices. Silicone hydrogel lenses were intro- 17

7 tions for prescribing ortho-k lenses may be due to the lack of scientific evidence on the efficacy of myopic control using ortho-k at the time of this survey, inadequate training in fitting techniques, inadequately equipped ortho-k practices and the increased risk associated with overnight wear. 3 In contrast, recent publications have shown ortho-k to be a safe, rapid and effective method for myopic reduction and to be effective for myopic control in children. 18 Since these publications, an increase in the popularity of ortho-k practice is expected. Thus, in June 4, a comprehensive course in ortho-k was organised by The Hong Kong Polytechnic University, with the assistance of overseas experts and an input from local practitioners. It will be offered yearly to local practitioners who wish to take up ortho-k practice. There are few published reports on the usage of contact lenses in Asia (apart from Hong Kong). Comparing the results of this current study with that carried out in Singapore, a number of similarities regarding the usage of contact lenses can be observed. Soft contact lenses were the major choice of contact lenses used, with planned replacement lenses contributing the highest proportion. Unlike in Hong Kong, monthly disposable rather than daily disposable lenses were found to be the most popular frequent replacement lenses in Singapore. The Singapore report was conducted in 1998 and this may contribute to the differences in types of contact lenses used in the two countries. Only about 5 per cent of the astigmatic contact lens wearers (cylindrical correction greater than -.75 D) were fitted with toric lenses. This low usage of toric lenses may be due, in part, to the limited parameters of toric planned replacement lenses. More than half of the respondents reported that the current choices of BOZR and cylindrical power were inadequate to cover the needs of their astigmatic patients. As the demand for disposable or frequent replacement lenses increases, we envisage that there will be a need for manufactures to increase the range of parameters. From our interviews with the practition- duced into Hong Kong only after so there are no data on the usage of these lenses in Hong Kong and no comparison can be made. In this study, we found that silicone hydrogel lenses were prescribed to only three per cent of contact lens wearers. Interviews with practitioners revealed that concerns of serious ocular complications associated with overnight wear of contact lenses (9/), low market demands (7/) and high cost of these lenses (4/) were the major reasons for the low usage of silicone hydrogel lenses. This trend has also been observed elsewhere; it has been suggested that the passive approach of patients to lens selection together with the practitioner s negative attitude towards extended wear contact lenses led to the low usage of these lenses. 7 Without support from practitioners, the usage of extended wear is unlikely to increase significantly. Most silicone hydrogel lenses prescribed in Hong Kong were recommended for daily wear (77 per cent) rather than extended wear (23 per cent) and these daily wear silicone hydrogel lenses were prescribed for longer wearing hours than other soft lenses (Table 4). In agreement with the report of Cheung, Cho and Edwards, 3 these lenses were prescribed mainly for daily wear for problem patients, such as those with hypoxia after many hours of conventional lens wear. In view of the concerns about serious complications with extended wear, it was not surprising to find that those respondents mainly prescribed silicone hydrogel lenses for fewer than days of extended wear. This is much shorter than the days of extended wear recommended by the manufacturers. Inadequate after-hours emergency services for contact lens wearers by either practitioners or the accident and emergency departments in Hong Kong hospitals probably added to the hesitation of practitioners to prescribe extended wear contact lenses. From our results, ortho-k lens fitting services were available only in a limited number of practitioners workplaces (15 per cent) and not many surveyed practitioners (three per cent) thought that ortho-k lenses had a potential for further development in Hong Kong. The reservaers, the limited usage of bifocal/multifocal lenses was due to low market demand (17/ ), concerns with possible high rate of unsatisfactory visual performance (11/) and the high cost (4/) of these lenses. In the United States, the usage of bifocal lenses increased by three times after the introduction of planned replacement bifocal lenses, 7 however, no such effect was observed in Hong Kong. For interviewed practitioners, who prescribed bifocal/ multifocal lenses (19/), most (13/19) did not find that the introduction of planned replacement bifocal/multifocal lenses encouraged them to increase the usage of these lenses, as from experience they felt that these lenses could not provide better vision (distance or near) compared with conventional bifocal lenses. Until the mindset of practitioners is changed and their confidence in these lenses is increased, it is unlikely that the use of these lenses will change significantly. With the increased popularity of planned replacement lenses in Hong Kong, multipurpose solution has become the most popularly recommended disinfecting regimen, followed by hydrogen peroxide. Compared with Australia (up to 91 per cent), the use of multipurpose solution in Hong Kong (6 per cent) is still relatively low. 9 The majority of practitioners (19/) agreed that the increased popularity of planned replacement contact lenses has led to an increased usage of multipurpose solutions, as this combination facilitated convenient contact lens wear and multipurpose solutions were suitable for the care of frequent replacement lenses. The increased popularity of multipurpose solution in conjunction with disposable lenses shows the desire for convenience in contact lens wear. It is interesting to note that although no rubbing formulas are being promoted by some multipurpose solution manufacturers, all practitioners in this survey recommended their multipurpose solution patients rub their lenses with or without daily cleaners. At the interview, most practitioners (19/) commented from experience that multipurpose solution alone, without rubbing, was inadequate for removing deposits on contact lenses. 171

8 Over 8 per cent of respondents ranked dryness during contact lens wear as the most common complaint made by their patients. This explained why more than 6 per cent of our respondents prescribed artificial tears to nearly all (over 9 per cent) of their patients. The high incidence of dryness during contact lens wear is probably related to the short tear break-up time and lower tear volume of Hong Kong Chinese. 19 With the advances in technology, some older types are phased out, while new types of contact lenses are introduced regularly. Although continuing education courses are available to optometrists in Hong Kong, not many of our respondents reported that these courses were useful. This may be because only one or two courses were being offered every year and they found it difficult to attend because of their long working hours. In addition, these continuing education courses were not product specific but were more concerned with theory and patient management. This may explain why the contact lens suppliers, who provide direct access and free information of new products, were reported to be the major source of new contact lens information for practitioners in Hong Kong. These results suggest a need to design and organise continuing education courses to suit the practitioners, if the courses are to be considered useful. CONCLUSIONS The contact lens market in Hong Kong is driven by younger contact lens wearers. Compared to previous reports (not including silicone hydrogel and orthokeratology lenses), no significant change is found in the prescribing habits of practitioners. With the increasing demand for convenient contact lens wear, planned replacement lenses together with multipurpose solutions remain the most popular option. Contact lens practitioners want low cost bifocal/multifocal contact lenses with better visual performance and toric lenses with a wider range of parameters. The use of overnight wear lenses such as silicone hydrogel and ortho-k lenses is limited and silicone hydrogel lenses, though marketed as days continuous wear lenses, are mainly prescribed for daily wear. Ocular dryness during contact lens wear is reported to be the major complaint of contact lens wearers. The main source of contact lens information is from communication with suppliers, while time constraints and limited viability of continuing education courses have restricted the usefulness of this source of information to practitioners. ACKNOWLEDGEMENTS We would like to thank all the practitioners who responded to the survey and telephone interviews and extend special thanks to Eye smate Optical, The Optical Centre and The Optical Shop. GRANTS AND FINANCIAL SUPPORT This study was supported by The Hong Kong Polytechnic University and Johnson & Johnson Vision Care (HK) Ltd. REFERENCES 1. Conway R, Cho P. Contact lens practice in Hong Kong. Clin Exp Optom 199; 73: Cho P, Conway R, Ko KC. Current contact lens practice in Hong Kong. Clin Exp Optom 1994; 77: Cheung SW, Cho P, Edwards MH. Contact lens practice in Hong Kong in the new millennium. Clin Exp Optom 2; 85: Lam CSY, Goh WSH. The incidence of refractive errors among school children in Hong Kong and its relationship with the optical components. Clin Exp Optom 1991; 74: Goh WSH, Lam CSY. A visual survey of school children in Hong Kong. Clin Exp Optom 1993; 76: Cho P, Cheung, SW, Edwards MH. Practice of orthokeratology by a group of contact lens practitioners in Hong Kong Part 1. General overview. Clin Exp Optom 2; 85: Barr J. The Contact Lens Spectrum millennium report. Contact Lens Spectrum ; 15: Tanner J. Annual survey of prescribing habits and attitudes. Optician ; 219: Woods CA, Morgan PB. Contact lens prescribing in the Australian states and territories 1. Clin Exp Optom 2; 85: Lee YC, Lim CW, Saw SM, Koh D. The prevalence and pattern of contact lens use in a Singapore community. CLAO J 2; 26: Ilhan B, Irkec M, Orhan M, Celik H. Surface deposits on frequent replacement and conventional daily wear soft contact lenses: a scanning electron microscopic study. CLAO J 1998; 24: Poggio EC, Abelson MB. Complications and symptoms with disposable daily wear contact lenses and conventional soft daily wear contact lenses. CLAO J 1993; 19: Solomon OD, Freeman MI, Boshnick EL, Cannon WM, Dubow BW, Kame RT, Lanier JC Jr, Lopanik RW, Quinn TG, Rigel LE, Sherrill DD, Stiegmeier MJ, Teiche RS, Zigler LG, Mertz GW, Nason RJ. A 3-year prospective study of the clinical performance of daily disposable contact lenses compared with frequent replacement and conventional daily wear contact lenses. CLAO J 1996; 22: Woods CA, Morgan PB. Trends in Australian contact lens prescribing. Clin Exp Optom ; 83: Alharbi A, Swarbrick HA. The effects of overnight orthokeratology lens wear on corneal thickness. Invest Ophthalmol Vis Sci 3; 44: Tahhan N, Du Toit R, Papas E, Chung H, La Hood D, Holden B. Comparison of reverse-geometry lens designs for overnight orthokeratology. Optom Vis Sci 3; 8: Walline JJ, Rah MJ, Jones LA. The children s overnight orthokeratology investigation (COOKI) pilot study. Optom Vis Sci 4; 81: Cho P, Cheung SW, Edwards MH. The longitudinal orthokeratology research in children (LORIC) study in Hong Kong. A pilot study on refractive changes and myopic control. Curr Eye Res. In press. 19. Kwong YM Cho P. Evaluation of a selfprepared cotton thread test (SP-CTT) and the Phenol Red Thread (PRT) test. Contact Lens Ant Eye 1998; 21: Author s address: Alice MS Yung Department of Optometry and Radiography The Hong Kong Polytechnic University Hung Hom Kowloon HKSAR CHINA 172

9 Appendix 1. What is the nature of your practice? Chain store Private practice Hospital Others (please specify) 2. Under which part of registration are you registered? Part I Part II Part IV 3. How many people in your practice (include yourself) fit contact lenses? 4. Indicate the percentage of your clients who are in each of the following categories and the percentage of contact lens wearers in each category. Contact lens wearers Emmetropic % % Hyperopic % % Myopic % % Total % 5. Within the past 12 months, what percentage of your clients are new contact lens wearers and how many are refits? New % Refits % TOTAL % 6. On average, how many after-care visits do your clients require during their first year and second year of contact lens wear? 1st year 2nd year PMMA RGP Soft Orthokeratology 7. How old are your youngest and oldest contact lens clients? Youngest Oldest 8. What percentage of your clients is prescribed with each of the following types of lenses? PMMA % RGP % Orthokeratology % Soft Conventional Daily wear % Extended wear % Disposable Daily % Biweekly % Monthly % Silicone hydrogel Daily wear % (PureVision/Night & Day) Extended wear % TOTAL % 9. What is your recommended wearing schedule for the following types of lenses? Hours/Day Days/Week PMMA /24 /7 RGP /24 /7 Orthokeratology /24 /7 Soft Conventional Daily wear /24 /7 Extended wear /24 /7 Disposable Daily /24 /7 Biweekly /24 /7 Monthly /24 /7 Silicone hydrogel Daily wear /24 /7 (Pure Vision/Night & Day) Extended wear (Longest wearing schedule) Days 173

10 . On average, what percentage of your astigmatic clients (> -.75 D cyl) is prescribed with each of the following types of lenses? Spherical lenses % Toric lenses % TOTAL % 11. Considering the existing disposable toric lenses available in the market, do you agree with the following phrases? Agree Disagree Most of them provide stable and clear vision There are enough choices of back optical zone radius The range of spherical power is wide enough The range of cylindrical power is wide enough There are enough choices of axis 12. On average, what percentage of your presbyopic clients is prescribed with each of the following corrections? Monovision contact lenses % Bifocal contact lenses % Multifocal contact lenses % Single vision contact lenses with over-spectacles % TOTAL % 13. What percentage of your (asymptomatic) clients is prescribed with each of the following cleaning regimens? None % Hydrogen peroxide AOSEPT % Oxysept B12 % Titmus % Multipurpose solutions ReNu MultiPlus % OPTI-FREE Express % Complete % Solo Care % Others (please specify) % TOTAL % 14. How often do you advise your clients to carry out enzymatic cleaning? Weekly Biweekly Monthly Never Others (please specify) Conventional soft lens Biweekly disposable Monthly disposable Silicone hydrogel RGP/PMMA 15. What percentage of your clients is prescribed with each of the following artificial tears? No artificial tear % Multi-dose Tears Naturale II % Opti-Tear % Senju % Hyoptears % Renu Comfort Drop % Refresh contacts % Unit-dose Tears Naturale Free % Hypotear Plus SDU % Others (please specify) % TOTAL % 174

11 16. Do you routinely advise your clients who use each of the following care regimens to rub their lenses during cleaning? Rubbing with cleaner Rubbing without cleaner No rubbing AOSEPT Oxysept B12 Titmus ReNu MultiPlus OPTI-FREE Express Complete Solo Care 17. What are the most common complaints of your contact lens clients? (Please rank from 1 to 6, with 1 the most common complaint and 6 the least common complaint) Dryness Tearing Foreign body sensation Blur/unstable vision Burning/pain Redness Others (please specify) 18. Where do you usually get new contact lens information? (Please rank from 1 to 5, with 1 the most common source and 5 the least common source.) Advertisements Colleagues Professional journals Contact lens suppliers/manufacturers Continuous education courses Others (please specify) 19. In your opinion, which of the following lenses have the highest potential for development in the contact lens market in Hong Kong? Are they available in your shop? (Please rank from 1 to 6, with 1 the highest potential and 6 the least potential.) Market potential Available in your work place Custom-make toric lenses Multifocal lenses Bifocal lenses Orthokeratology Silicone hydrogel (Daily wear) Silicone hydrogel (Extended wear) Others (please specify). Which of the following is/are helpful in increasing your sale of contact lenses? (Please rank from 1 to 5, with 1 the most helpful and 5 the least helpful.) Advertising (eg: television, radio, road show) Free trial fitting Package deals (eg: buy 9 get 2 free) Extra gift (eg: Towels) Special discount Others (please specify) 21. If there is any other information that you think may be of use to this survey, please add your comments or suggestions below. You may also use this space for expanding on any of the areas of the questionnaire. 175