Characteristics, Behaviors, and Awareness of Contact Lens Wearers Purchasing Lenses Over the Internet.

OBJECTIVES: To describe the characteristics and hygiene habits of contact lens (CL) wearers who acquire CLs over the Internet, as well as their awareness of modifiable risk factors (RFs). METHODS: A web-based survey was conducted among clients of an online CL sales platform during 6 months. Demographic data, CL hygiene-related awareness, and compliance were collected and analyzed. RESULTS: The questionnaire was completed by 1,264 CL wearers: the average age was 40.8 years; most were women (71.1%), had myopia (76.4%), and wore monthly disposable CLs (63.6%). The frequency of eye examination was significantly lower among those buying the CL exclusively online (15.8% vs. 6.6%, P<0.001) and those who had begun CL use on their own (17.5% vs. 8.8%, P<0.001). Initiation to CL wear without the intervention of an eye care practitioner was more frequent in wearers with less experience. Common risk behaviors included water exposure (68.1% in swimming and 64.9% in the shower), use of the case (61.9%) and CL (65.1%) beyond the recommended replacement time, and reuse of the maintenance solution (31.9%). Ignorance of recommended hygiene increased the probability of risky behavior. CONCLUSION: There were no differences in compliance or awareness of risks between those purchasing exclusively online and other CL wearers. However, the growing frequency of self-taught initiation in CL wear among less-experienced online customers and online exclusive purchase was associated with a decrease in eye examination frequency and therefore worse compliance and increased risks. This finding underlines the importance of publicizing correct hygiene habits by all possible means so as to increase compliance.

Effects of a contact lens subscriber replacement program on patient lens care behavior in Japan.

PURPOSE: Compliance with practitioner recommended lens care guidelines was assessed and compared in two test groups: patients belonging to a subscription membership group and a nonaffiliated group of 2-week frequent replacement (2WFR) soft contact lens wearers. METHODS: Wearers (143 members and 149 nonmembers), whose clinical records were available for 18-24 months from September 2010 to August 2012, were queried by a written questionnaire: (1) source of lens purchase; (2) "rub" or "no-rub" care solution; (3) replacement interval of lens care products; (4) lens cleaning method; (5) noncompliant behaviors; and (6) replacement frequency of lens storage cases. RESULTS: The questionnaires were completed by 104 members and 100 nonmembers. Of member group wearers, 63.0% correctly recognized the types of lens care products used ("rub', "no-rub") vs. 77.4% of nonmembers. Of member wearers, 82.2% used "rub" and rubbed each time vs. 76.3% of nonmembers. The replacement interval for care products was 26.2% (members) and 27.6% (nonmembers) for 1 month or less, while replacement frequency of storage cases was 22.3% and 19.2% for 1 month or less in each group respectively. There were no significant differences observed between each of these group comparisons (p>0.05, Fisher exact test). CONCLUSIONS: Compliance with practitioner recommended lens care regimens was equally poor in both test groups. Subscription membership of CLs which does not provide lens care products is not accompanied by an increase in compliance with lens care practices.

Improvement of Subjective Symptoms and Eye Complications When Changing From 2-Week Frequent Replacement to Daily Disposable Contact Lenses in a Subscriber Membership System.

PURPOSE: Subjective symptoms and other eye complications were assessed and retrospectively compared in patients belonging to a proprietary membership system who switched from 2-week frequent replacement (2WFR) wear to daily disposable (DD) lens use. METHODS: Questionnaire responses were completed by all patients for a 5-year interval between October 2008 and September 2013 from 83 wearers in three Japanese clinics (59 female and 24 male; average age: 33.4±10.9 years). Complications were recorded for each patient at times of reexamination. RESULTS: Over the 5-year observation period, the 83 patients wore lenses for more than 26 months. The average duration of use of 2WFR lenses was 14.5±2.7 days/lens (n=83) and subsequently 1.03±0.12 days/lens (n=83) for DD lenses. Compliance with the duration of use was consistently good as monitored by requests for lens resupply in both wearing modalities. The subjective complaint of dryness tended to consistently show improvement by the change to DD wear: 18.1% vs. 30.1% (P=0.10, Fisher exact test). Among eye complications noted in each group, the occurrence of superficial punctate keratitis (SPK) was significantly decreased in DD wear: 9.6% vs. 26.5% (P=0.008, Fisher exact test). The main reasons given by patients for changing to DD wear were (1) "DD lens wear was more hygienic" (78.6%) and (2) "DD lens use is more convenient for travel/business trips" (64.3%). Comments after the switch in wear were (1) "easy and convenient" (95.7%) and (2) "I don't have to worry about expiration dates" on solutions (57.1%). Overall, 95.7% of wearers making the change answered as "satisfied" and "mostly satisfied." CONCLUSIONS: In the subscription membership program, which provided free lens replacement and/or reexamination, individual compliance with duration of wear in 2WFR wear cycles was good; however, these patients switching to DD wear tended to have improvement in their subjective complaints of dryness and objectively demonstrated a significant reduction of SPK at follow-up examinations.

The conformity of a soft contact lens on the eye.

An axisymmetric elastic shell deformation model has been created to predict the conformity of a soft contact lens when pressed against the eye. Regions of contact and gap may be predicted, and the nonuniform reaction pressure between the lens and eye may also be found. This is important for issues like abrasion and comfort. Bending, membrane and transverse shear loads within the lens are also computed. Commercial soft contact lenses and a representative eye shape are used for the examples. We find that the uniformity of loading against the eye is strongly affected by the degree to which the lens is shaped to fit the eye, and relatively unaffected by the thickness of the lens.

Part II. Clinical evaluation of toric hydrophilic contact lenses.

Five toric hydrogel contact lenses have been approved for marketing by the FDA and several more await final approval in the near future. Clinical use of these special design lenses for correction of astigmatism has increased during the past year, improvements in lens design and fabrication are taking place, but problems remain. Analysis of the reasons for fitting failures show that lens quality and axis mislocation are the primary causes of lens performance failures.