Demographics of UK contact lens prescribing.

To assess the demographics of UK contact lens prescribing, data gathered from annual contact lens fitting surveys conducted over the past 12 years were mined for clinically useful information. Significant gender differences in age, lens design, wearing modality and wearing frequency are putatively explained in terms of cosmetic and lifestyle factors.     

The evolution of rigid contact lens prescribing

Rigid contact lenses have long been known to be a versatile form of optical correction. However, as documented in this report of the results of annual prescribing surveys conducted over the past 12 years, there has been a steady decline in rigid lens fitting over this period. This is attributed to factors such as the initial discomfort of rigid lenses and the increased sophistication of soft lens materials and designs. There is an apparent trend for rigid lenses to be used more for 'specialist' fits, such as sophisticated toric designs, multifocals and orthokeratology.     

Prescribing daily disposable contact lenses in the UK.

Patterns of prescribing daily disposable contact lenses in the UK were determined by mining through data gathered from annual contact lens fitting surveys conducted over the past 12 years. Spherical, toric and multifocal design daily disposable lenses represent a substantial proportion of all contact lenses prescribed, reflecting the significant ocular health and lifestyle advantages offered by this lens category.     

Factors influencing the prescribing of hydrogel contact lenses

Despite the current market popularity of silicone hydrogel contact lenses, conventional hydrogel lenses still represent a significant proportion of the overall contact lens market. Data gathered from annual UK contact lens fitting surveys over the past 13 years indicate that 64% of hydrogel lenses prescribed during this period were of low/medium water content (≤60% water). Whereas, in the past, practitioners would choose the water content of a hydrogel lens to meet specific clinical needs, this choice appears today to be largely governed by product availability.     

Patterns of prescribing extended wear contact lenses

Patterns of prescribing extended wear contact lenses in the UK were determined by mining through data gathered from annual contact lens fitting surveys conducted over the past 12 years. The increased rate of extended wear prescribing this century - which in 2007 had reached 7% and 19% of all soft lens new fits and refits, respectively - probably reflects the superior clinical performance of silicone hydrogel lenses for this purpose.     

Contact lens prescribing trends in the UK hospital eye service

PurposeThe aim of this study was to evaluate the types of contact lenses fitted by hospital optometrists within the Midlands region of the United Kingdom (UK).MethodA questionnaire was sent to all the lead optometrists of the Midlands Hospital Optometry Group (MHOG). This group includes optometry hospital eye departments within the Midlands region of the UK. The questionnaire requested information of their last ten contact lens fitting appointments. Details of the patient’s age, gender, lens type, wearing times, and presenting condition were retrospectively taken from the patients’ records using the appointment diary to identify the last ten patients fitted with contact lenses.ResultsDetails from a total of 109 contact lens fits were collected. This included 45 females and 64 males with a mean age of 39.4 ± 17.4 years. The mean wearing time was 6.3 ± 1.0 days per week and 10.7 ± 5.1 h per day. Sixty-one percent of the contact lenses fitted were for patients with keratoconus and over half of all the contact lenses fitted were corneal rigid gas permeable lenses.ConclusionThis study highlighted that the main reason for fitting contact lenses in hospital contact lens practice is primary corneal ectasia, and mainly keratoconus. Whilst most patients with keratoconus were fitted with corneal rigid gas permeable contact lenses, around 1 in 6 were fitted with soft contact lenses. This study addresses a gap in the literature about contact lenses fitted in UK hospitals and how they differ from community contact lens practice.     

Trends in the use of silicone hydrogel contact lenses for daily wear

Although the first silicone hydrogel contact lenses introduced onto the world contact lens market in 1999 held approval for both daily wear and extended wear use, the latter modality was promoted much more heavily by the manufacturers. The first silicone hydrogel lenses specifically promoted for daily wear were introduced in 2003. Data that we have gathered from annual contact lens fitting surveys demonstrate an immediate increase in market share whereby this lens type now represents more than one-third of soft lens fits in the United Kingdom. The success of this lens category is attributed to the health and safety benefits of silicone hydrogel materials and the positive impact of lens manufacturers by way of the effective marketing and distribution of these products.     

Prescribing soft contact lenses for astigmatism

There have been continued improvements in toric soft lens design over the past three decades. Data that we have gathered from annual contact lens fitting surveys demonstrate a commensurate increase in toric lens fitting as a proportion of all soft lenses fitted. The current toric lens prescribing rate (34% of all lenses when cosmetic tints, monovision and multifocal lenses are ignored) is roughly equivalent to the rate that would be achieved if all cases of astigmatism 1.00 D or more were fitted with toric lenses. Toric lenses tend to be fitted more to males and prescribed for monthly rather than daily replacement.     

International survey of contact lens fitting for myopia control in children

PurposeTo determine the extent of contact lens fitting for myopia control (MC) in children (defined as ≤ 17 years of age) worldwide and to characterize the associated demographics and fitting patterns.MethodsSurvey forms were sent to contact lens fitters in 66 countries between January and March every year for eight consecutive years (2011–2018, inclusive). Practitioners were asked to record data relating to the first 10 contact lens fits performed after receiving the survey form. Data were analysed for those countries reporting ≥ 100 contact lens fits to children.ResultsData were analysed for 535 MC fits and 23,295 other (non-MC) lens fits undertaken in 31 countries reporting ≥ 100 contact lens fits to children, with 52.1% of MC fits and 12.0% of non-MC fits being with rigid lenses (p < 0.0001). Overall, MC lenses represented 2.3% of all contact lens fits to children, with significant differences between nations (p < 0.0001), ranging from no MC fits recorded in the Czech Republic, Greece, Japan, South Korea and Puerto Rico, to 24.9% in Austria. There has been an increase in contact lens fitting for MC over the survey period (p < 0.0001). MC contact lenses were fitted to younger children compared to non-MC lenses (MC, median 13 years vs. non-MC, median 15 years) (p < 0.0001). There was no sex bias in the fitting of MC lenses (p = 0.89).ConclusionsMC lenses are currently being prescribed for younger children in equal measure in terms of soft vs. rigid lenses and males vs. females. The extent of MC fitting is low and varies between nations. The gradual increase in MC fitting throughout the survey period perhaps reflects growing concerns among practitioners over the myopia epidemic.     

How often are contact lenses worn?

There are important clinical, academic and commercial reasons for seeking to develop a comprehensive understanding of the frequency of wear of different forms of contact lenses. Data that we have gathered from annual contact lens fitting surveys over the past 12 years demonstrate that contact lenses are worn, on average, 5.4 ± 1.9 days per week. Rigid lenses tended to be worn on a full-time basis, typically seven days per week. The distribution of daily disposable lens wear is bimodal, with peaks at two days and seven days per week of wear. Over the survey period there appears to have been a small trend toward the use of contact lenses on a part-time basis.     

Trend of soft contact lens prescribing in an optometry centre in India: A 6-year analysis

This six-year retrospective longitudinal study was conducted to examine the changes in the pattern of prescribing soft contact lenses in an optometry centre located in a University in South India. Details regarding the type of lenses, lens material, wearing pattern and the clinical diagnoses were analyzed from January 2006 to December 2011. A total of 1273 soft contact lens fits (n = 1273) were analyzed. Two-third of the total lenses dispensed was for females and their mean age (24.0 ± 8.3 yrs) was less than that of male (27.0 ± 11.2 yrs) lens users. Nearly 70% of them had myopia and 48% wore conventional soft contact lenses. During the studied six years, the percentage of conventional lenses declined by 60%. This study demonstrated a gradual and significant increase in popularity of disposable contact lenses and silicone hydrogel lens material which is comparable to the global trend.     

Factors influencing the 8-item contact lens dry eye questionnaire score and comparison of translations in Japanese soft contact lens wearers

PurposeTo determine (1) the factors associated with a high degree of self-reported symptoms with Japanese translations of the 8-Item Contact Lens Dry Eye Questionnaire (J-CLDEQ-8) in a cross-section of soft contact lens (SCL) wearers in Japan and (2) whether the difference in translation of the CLDEQ-8 affects the scores between validated and non-validated versions of the Japanese translation.MethodsHabitual SCL wearers completed the validated J-CLDEQ-8 and a previous non-validated version. Demographics and SCL history questions were queried when they presented for routine eye care in nine geographically distinct clinics across Japan. The following risk factors for high J-CLDEQ-8 scores (≥11) were tested: sex, age, SCL replacement (daily disposable vs. bi-weekly and monthly reusable), years of SCL wear, and self-reported use of rewetting drops. The scores of the validated and non-validated questionnaires were compared.ResultsSignificant patient-related risk factors for high J-CLDEQ-8 scores were female sex, use of reusable SCLs, longer years of SCL wear, and use of rewetting drops. Scores for six out of eight questions in the validated J-CLDEQ-8 were significantly higher than those of the non-validated version, resulting in a significant difference in the average total score between the two questionnaires (validated J-CLDEQ-8: 10.5 ± 5.9 vs non-validated J-CLDEQ-8: 9.5 ± 5.8, P < 0.001).ConclusionsFemale sex, use of reusable SCLs, longer years of SCL wear, and use of rewetting drops were significant risk factors for high J-CLDEQ-8 scores in a cross-sectional clinical population of Japanese SCL wearers. Symptoms with SCL are not predicted by age and must therefore be queried at follow-up visits for all SCL wearers. Differences in the two translations affected the ability of the questionnaire to identify individuals with high symptoms associated with SCL wear.     

The influence of lens care systems on eyelid tissue changes during silicone hydrogel contact lens wear

Purpose

To compare the effects of a hydrogen peroxide (H₂O₂)-based lens care solution and a polyhexamethylene biguanide (PHMB) multi-purpose solution on the eyelids when used with silicone hydrogel (SiHy) contact lenses.

Corneal erosions in contact lens wear

Contact lens wear continues to be the highest single risk factor for microbial keratitis, particularly when worn in the extended wear modality. For microbial keratitis to occur, the presence of at least a bacterial load as well as a break in the corneal surface is required. One such break occurs in the case of a corneal erosion. These well-circumscribed areas of full thickness epithelial loss can occur both with and without contact lens wear, however the risk of infection is greater in the presence of a lens due to its capacity to provide a vector for the entry of bacterial pathogens. While erosions in non-contact lens wearers are thought to result from defective epithelial basement membrane anchoring, the underlying causes during contact lens wear are yet unknown. This article sets out to review corneal erosions associated with contact lens wear, their associated risk factors such as extended wear, the mechanisms that may be responsible for their formation and the factors that differentiate them from other contact lens related adverse events. Appropriate diagnosis and understanding of the relevant pathophysiology is important to the effective treatment and an understanding of the aetiological factors responsible for erosions is critical to the development of preventative strategies and effective clinical care.     

Efficacy of spherical aberration correction based on contact lens power

PurposeTo investigate the efficacy of spherical aberration (SA) correction with aspheric contact lenses (aspheric lenses) based on lens power, and compare the results with those of spherical contact lenses (spherical lenses).MethodsOcular higher-order aberrations were measured with a wavefront sensor, in 11 myopic subjects wearing an aspheric lens (Medalist Fresh fit (PUREVISION 2 HD); Bausch + Lomb) or a spherical lens (ACUVUE Oasys; Johnson & Johnson). Six different lens powers (−7.00 diopters (D), −5.00 D, −3.00 D, −1.00 D, +1.00 D, +3.00 D) were used for all subjects. The amount of SA correction from the contact lens at each power was calculated as the difference between SA with the contact lens on-eye and SA of the eye alone.ResultsFor the spherical lenses, SA correction was close to 0.00 μm for the +1.00 D lens, became more positive as the labeled lens power increased and became more negative as the labeled lens power decreased. For the aspheric lenses, SA correction was consistent, from −0.15 to −0.05 μm, for all lens powers except for the −1.00 D lens. SA correction for the spherical and aspheric lenses was significantly different at −7.00 D (p = 0.040), −3.00 D (p = 0.015), −1.00 D (p < 0.001), +1.00 D (p = 0.006), and +3.00 D (p < 0.001) powers.ConclusionAn aspheric lens is capable of correcting SA at different lens powers, and has SA correction in the range of −0.15 to −0.05 μm over a 6 mm aperture.     

Patterns of fitting cosmetically tinted contact lenses

Cosmetically tinted soft contact lenses are an attractive option for contact lens wearers. Data that we have gathered from annual contact lens fitting surveys demonstrate that those wearing tinted lenses are more likely to be female (4.6% of all soft lenses fitted vs. 1.6% for males; p < 0.0001) and younger (27 ± 11 years vs. 33 ± 13 years for those wearing non-tinted lenses; p < 0.0001). Tinted lenses tend to be worn more on a part-time basis and are replaced less frequently than non-tinted lenses. The decline in fitting tinted lenses over the past 12 years may be due to (a) the current limited availability of tinted lenses in silicone hydrogel materials and daily disposable replacement frequencies, which together represent a significant majority (78%) of new soft lenses fits today, (b) growing concerns among lens wearers and practitioners relating to the risks of complications associated with the wearing of tinted lenses, and (c) reduced promotion of such lenses by the contact lens industry.     

The use of fluorescein in contact lens aftercare

This short communication reports on the responses of a cohort of more than 2000 contact lens practitioners across five European countries, who were surveyed on the routine use of flourescein in soft contact lens aftercare. Although corneal staining has received extensive interest amongst the academic community, most practitioners do not routinely use fluorescein at aftercare visits. The arguments for not using the agent seem to be somewhat flawed in modern contact lens practice and it is hoped by education and wider communications of the value of staining that more practitioners use it more often.     

Influence of air quality on the selection tendency of contact lens wearers

ObjectiveThis study aimed to investigate whether air quality influences ocular comfort when wearing contact lenses and the selection tendency of myopic populations who wears contact lenses.MethodsQuestionnaires were distributed to one hundred and twenty corneal contact lens wearers to understand whether the respondents would reduce or stop the use of contact lenses according to air quality and to evaluate and compare their ocular status under different air quality conditions.ResultsForty-three point eight percent of the respondents were concerned about reduced oxygen permeability of contact lenses and increased contact lens-associated complications caused by the adsorption and accumulation of haze particles on the contact lens. Thirteen point four percent of the respondents stated that they would stop using contact lenses during moderate to severe air pollution and switch to glasses. Twenty-eight point six percent of respondents remarked that they would reduce the use of contact lenses depending on the situation during moderate to severe air pollution. However, this study did not find statistically significant differences in the ocular comfort while wearing contact lenses and in the eye scores of contact lens wearers under different air quality conditions.ConclusionAir quality has an impact on the selection tendency of some contact lens wearers. However, whether moderate or more severe air pollution causes ocular discomfort or contact lens-associated complications in contact lens wearers awaits further investigation.     

Quarter of a century of contact lens prescribing trends in the United Kingdom (1996 – 2020)

PurposeTo document contact lens prescribing trends in the United Kingdom over the past quarter of a century.MethodsAn annual survey of contact lens prescribing was conducted each year from 1996 to 2020, inclusive, by asking a random selection of optometrists and contact lens opticians to provide information relating to 10 consecutive contact lens fits between January and March.ResultsOver the 25 year survey period, 2,671 practitioners returned survey forms, reporting a total of 25,575 contact lens fits. The mean (± standard deviation) age of lens wearers was 35 ± 15 years, of which 64 % were female. Over the survey period, rigid lens new fits decreased from 22 % to 2%. The prescribing of silicone hydrogel lenses has increased steadily since their introduction towards the end of the 1990s, and now represent 80 % of soft lens fits. Soft toric lens prescribing has gradually increased to 47 % – a value at which astigmatism ≥ 0.75DC is theoretically corrected in all contact lens wearers. Daily disposable prescribing increased steadily over the survey period and now represents 63 % of lenses prescribed. Extended wear fits remain at very low levels, except for some prescribing for overnight orthokeratology. Multi-purpose lens care solutions are ubiquitous; peroxide and other systems are now seldom prescribed. Rigid lenses and monthly replacement soft lenses are predominantly worn on a full time basis, whereas daily disposable soft lenses are mainly worn part time.ConclusionsThis report documents the evolution of contact lens fitting in the United Kingdom over the past 25 years. The most likely lens fit is a spherical design silicone hydrogel daily disposable contact lens prescribed for a 35 year old female and worn on a part-time basis.     

Histochemical analysis of bandage contact lens precipitates.

Contact lens deposits have been reported previously with extended wear of soft contact lenses, with proteins, lipids, mucous, and various salts such as chloride, potassium and calcium being deposited on the lens surface [1]. We report an unusual case of precipitates on the surface of a bandage contact lens (BCL) following intensive treatment with topical preservative free artificial tears. Evaluation included microscopic and histochemical analysis of the BCL. We have also reviewed the literature for previous reports of contact lens precipitates.