Purpose
To explore demographics, disease characteristics, and wear habits in cosmetic contact lens (CL)-related corneal infections in Asia.
Design
Prospective multicenter cross-sectional study.
Methods
Cases of CL-related corneal infection presenting over a 12-month period were prospectively identified from 11 centers in 8 countries in Asia. Case demographics, clinical features, microbiology, and compliance characteristics were compared between wearers using CLs for cosmetic purposes and those using CLs for the correction of refractive errors.
Results
Six hundred and ninety-four CL wearers with corneal infection presented: 204 cosmetic CL (29.4%) and 490 (70.6%) refractive CL wearers. Cosmetic CL infections comprised 7%-54% of cases across the region. Compared with noncosmetic CL wearers, cosmetic CLs wearers were significantly more likely to be female (90% vs 59%), young (aged <25, 68% vs 44%), and to have a shorter period of wear experience. Lenses worn by cosmetic CL wearers were more likely to be hydrogel materials and manufactured with the pigment located on the back surface of the CL. Presenting disease characteristics and visual outcomes were similar in both groups. Causative organisms were similar between the 2 groups; however, there was a higher rate of Acanthamoeba disease (9%) in cosmetic wearers, compared with refractive wearers (1%; P < .005).
Conclusions
Cosmetic CL infections represent a significant proportion of CL-related infections in Asia. Cosmetic CL users with corneal infections are generally young, female, and wearing hydrogel CLs. Internet supply, quality control, and regulation of the sale of these products provide significant challenges in managing this population of vulnerable wearers.
Corneal infection (microbial keratitis) is considered rare in the developed world but as a substantial but neglected tropical disease in low-income countries. Microbial keratitis is the fifth leading cause of overall blindness worldwide. In developed countries, the risk factors for corneal infection include contact lens wear, ocular trauma, prior ocular surgery, and previous ocular surface disease. Contact lens wear comprises 35%-65% of cases of corneal infection in major hospital centers, , , , where generally more severe cases would be managed. Contact lens use and ocular trauma comprise the majority of preventable keratitis cases and vision loss in a working age population.
The epidemiology of the microbial keratitis is well characterized in contact lens users wearing contact lenses for the correction of low refractive errors. However, cosmetic, colored, limbal circle or decorative contact lenses, often worn by young emmetropic females to modify or enhance the appearance of the eye, are becoming more prevalent, particularly in South East Asia. In the USA, colored lenses represent less than 1% of new lens fits by practitioners; however, 24% of wearers surveyed in Taiwan wore decorative or colored lenses.
There are several published case reports and case series of corneal infections with colored, cosmetic, limbal circle or decorative contact lenses, here referred to as “cosmetic” contact lenses. Cosmetic contact lens infections comprised 12.5% of all contact lens infections in a multicenter study in France, but 41% of infections in a recent multicenter study in South Korea.
The incidence of cosmetic contact lens–related infection has not been estimated, and there are limited studies where risk factors have been identified, partly because of the difficulty in identifying an appropriate unaffected cosmetic contact lens wearing control group. In a case control study carried out in France, where cases and controls were identified from university and hospital clinics, wearing a lens for cosmetic purposes was an independent risk factor that increased the relative risk of microbial keratitis by 1.37 times (95% confidence interval: 1.14-1.65).
There are limited studies of contact lens–related corneal infection in Asia, and given the increasing use of cosmetic contact lenses in the region and the restricted data on potential risk factors, this study sought to explore the frequency, demographics, disease characteristics, and wear habits in contact lens wearers with corneal infections across Asia and to compare infections with cosmetic contact lenses with corneal infections in wearers using lenses for refractive purposes. Therefore, the purpose of this article was to explore demographics, disease characteristics, and wear habits in cosmetic contact lens–related corneal infections in Asia.
METHODS
This study was part of the Asia Cornea Society Infectious Keratitis Study and reports a multisite prospective nonrandomized 12-month surveillance study of infectious keratitis from 11 hospital or university centers in 8 countries (India, China, Japan, South Korea, Taiwan, Thailand, the Philippines, and Singapore), carried out between 2012 and 2014. Methods have been previously reported in detail. The study adhered to the tenets of the Declaration of Helsinki. All study centers obtained local institutional review board approval, and the study was conducted in accordance with all local regulatory requirements, including gaining informed consent from all study patients. This trial was registered with ClinicalTrials.gov ( NCT01560208 ).
All cases of infectious keratitis presenting at each center within the study period, defined as any inflammatory corneal lesion likely to have an infectious etiology, were identified, and cases underwent standardized clinical and microbiological testing. A standardized case report form was used to document clinical features, demographic profile, treatment before presentation, and treatment after diagnosis.
Cases identified as contact lens wearers were asked to complete a compliance and risk factor questionnaire based on a previously published approach. Indication for lens wear (myopia, hyperopia, presbyopia, cosmetic to change the appearance of the eyes, astigmatism, and keratoconus), lens type, lens brand, mode of wear (extended wear defined as overnight use of lenses for 1 or more nights per week; occasional overnight use defined as overnight use of lenses for 1 night per fortnight or less often; daily wear defined as no overnight lens use), supply route, wear history, and hygiene compliance before the event were determined using a questionnaire based on previously published instruments. Based on the lens type and brand data reported, lens material information (hydrogel/silicone hydrogel) and, for those wearers identified as cosmetic contact lens users, location of pigment (front or back surface or laminate) were obtained from the manufacturers’ Web sites, where available.
Cases were managed per the local institution protocols or practice patterns and were followed up for a period of 6 months. Corneal scrapes or biopsies were collected from all cases, and the microbiology protocol involved inoculating corneal scrapes onto blood and chocolate agar for culture; staining a smear with Gram or Giemsa stain for bacteria; preparing a potassium hydroxide (KOH) mount for fungi, and using Sabouraud or potato dextrose agar for fungal recovery. Other tests were performed on indication, including using Brain Heart Infusion broth culture; Acanthamoeba recovery using non-nutrient agar with an Escherichia coli or Proteus sp. overlay; Lowenstein-Jensen agar culture; smear for acid fast bacilli; and smear with modified trichrome stain. A positive corneal culture for bacteria or fungi was defined as 3 or more colony-forming units on solid media with a similar morphology to the smear or that similar organisms were recovered from liquid and solid media (bacteria only). For Acanthamoeba, growth on non-nutrient agar with an E. coli or Proteus sp. overlay, with characteristic morphology, was considered a positive culture.
Statistical Analysis
The proportion of contact lens–related infections of the total infectious cases and the characteristics and demographics of wearers by country were evaluated using 1-way analysis of variance. Similarly, the proportion of cosmetic contact lens infections by country was compared using 1-way analysis of variance. Demographics, disease characteristics, wear habits, and culture results were compared between users of cosmetic contact lenses and users of refractive contact lenses using proportions testing and the χ 2 test, as appropriate.
RESULTS
Of the total 6,563 infectious keratitis cases identified during the 12 months of the study, 704 cases were contact lens–related infections (11%). Data for 10 wearers were excluded where no indication for contact lens wear data was available; the remaining 694 wearers were classified into colored, decorative or circle (“cosmetic”; n = 204; 29.4%) and other (refractive) contact lens wearers (n = 490; 70.6%). Table 1 shows the demographics of all contact lens–related infections by country and the wear patterns in cosmetic contact lens wearers.
| Country | CL-Related Infections (% of Total) | Age (y) | Female (%) | Cosmetic CL Infections (%) | Daily Disposable (%) | EW | Wear Modality Occasional O/N | DW |
|---|---|---|---|---|---|---|---|---|
| China | 4 (0.4) | 20 ± 7 | 50 | 2 (50) | 0 | 1 (50) | 1 (50) | 0 |
| India | 28 (0.8) | 23 ± 7 | 54 | 3 (11) | 1 (33) | 1 (33) | 1 (33) | 1 (33) |
| Japan | 77 (25.2) | 30 ± 12 | 68 | 13 (17) | 3 (23) | 0 | 3 (23) | 10 (77) |
| Korea | 35 (14.0) | 26 ± 10 | 77 | 14 (41) | 5 (36) | 1 (7) | 6 (43) | 7 (50) |
| Philippines | 44 (12.6) | 29 ± 11 | 63 | 20 (45) | 2 (10) | 0 | 2 (10) | 18 (90) |
| Taiwan | 101 (43.3) | 28 ± 10 | 66 | 28 (28) | 13 (46) | 4 (14) | 13(46) | 11 (39) |
| Thailand | 53 (18.9) | 27 ± 11 | 86 | 28 (53) | 0 | 0 | 5 (18) | 23 (82) |
| Singapore | 362 (68.2) | 27 ± 10 | 70 | 96 (27) | 6 (6) | 4 (4) | 15 (16) | 77 (80) |
| Total | 704 (10.7) | 28 ± 10 | 68 | 204 (29) | 39 (15) | 11 (5) | 46 (23) | 147 (72) |
The proportion of contact lens–related infections varied by country with significantly higher rates in Taiwan (43% of all infectious keratitis cases) and Singapore (68% of all infectious keratitis cases) ( P < .001). Corneal infections in cosmetic contact lens wearers comprised 29% of all contact lens–related infections, but the rates varied between countries, ranging between 11% and 56% ( P < .001). Countries with rates above 40% included Thailand (56%), the Philippines (49%), and Korea (41%). The most common lens wear modality was daily wear, with 72% of cosmetic contact lens infections in this group and extended wear comprising 5% of the cases. Fifteen percent of cosmetic contact lens–related infections occurred in daily disposable contact lens wearers and the proportion varied significantly between countries ( P < .001).
Compared with refractive contact lens wearers with corneal infections, wearers of cosmetic contact lenses were more likely to be female (90% vs 59%; P < .05), younger (aged below 25 68% vs 44%; P < .001), to have a shorter period of lens wear experience (40% vs 21%; P < .001), and to wear lenses for fewer hours per day (45% vs 34%, <10 hours per day; P < .001) and for fewer days each week (28% vs 18%, lens use for 1-4 days per week; P < .001) ( Table 2 ). Cosmetic lens wearers with infections were less likely to shower in their lenses and to air dry their cases compared with refractive contact lens wearers. Cosmetic wearers were slightly but not statistically significantly less likely to have had a check with an eye care practitioner in the last 12 months (34% vs 41%; P = .06) and more likely to share contact lenses with others (7% vs 3.5%; P <0.05). Eleven percent of cosmetic wearers had purchased their lenses via the Internet compared with 1% of refractive wearers ( P < .001). Other hygiene and compliance factors were similar between cosmetic and refractive contact lens wearers, including the frequency of occasional overnight lens use (27% vs 31%), frequency of contact lens disinfection (61% vs 73%), and never handwashing before lens handling (4% vs 3%)
