Contact Lens Spectrum
Issue link: https://clssupplements.epubxp.com/i/740958
c l s p e c t r u m . c o m C O N T A C T L E N S S P E C T R U M S P E C I A L E D I T I O N 2 0 1 6 21 the tear film with a contact lens results in a series of compositional changes that can lead to an unstable tear film on the front surface of the lens and changes to the post-lens tear film (Craig et al, 2013; Mann and Tighe, 2013). Interactions are dependent on the lens material and the tear chemistry and can be influenced by the environment of the wearer. The dynamics of these in- teractions affect the ocular surface. Over the course of a day, these interactions contribute to symptoms and the overall experience of the contact lens wearer. The culmination of these experiences result in the wearer's overall and continued satisfaction with lens wear. Key elements of the wearing experience may be shared with the eyecare professional during a follow-up examina- tion and must not be ignored or overlooked. THE PATIENT'S PERSPECTIVE To explore the dynamics of the contact lens wearing experience from the patient's point of view, investigators recruited current wearers of soft contact lenses to par- ticipate in an evaluation to assess the following: • frequency of various symptoms • conditions under which symptoms occur • steps taken by patients to combat the symptoms • the influence of the symptoms on their wearing experience (Kadence, 2012). The evaluation had two phases. In Phase 1, par- ticipants' feedback was based on spontaneous recall of symptoms. In Phase 2, a subset of participants from Phase 1 provided feedback based on tracking symptoms over a day of lens wear. For inclusion in this evaluation, participants must have visited an eyecare professional within the previous 2 years. Anyone diagnosed with astigmatism or presbyopia was excluded. Five hundred and sixty-eight contact lens wearers participated in Phase 1; 136 (24%) participants wore Viewing the tears as structural, with each compo- nent playing a key role, aids in understanding tear dys- function. The mucin-glycocalyx complex serves as a foundation for the tear structure, transforming the hy- drophobic surface into a hydrophilic one and anchor- ing the tear layer in place. The bulk of the tears, mostly a mix of aqueous and mucins, provides viscoelastic protection, just as walls would provide struc- ture. Finally, the outermost layer of the tear structure is comprised of a thin film of complex lipids, containing non-polar lipids for structure and as a moisture barri- er and polar lipids that allow this outer layer to adhere to the un- derlying primarily water-based structure. This lipid layer, when complete, stretches across the ocular surface like a tarpaulin providing structure as well. Contact lens wear alters the relationship of the tear film and the ocular surface. Partitioning VISUAL PERFORMANCE ALL PARTICIPANTS (n=568) Gender Male 34% Female 66% Age 18-24 years 14% 25-34 years 42% 35-44 years 31% 45-54 years 13% Overall Duration of CL Wear 1 year or less 2% More than 1 - 5 years 9% More than 5 - 10 years 20% More than 10 years 69% Unsure 1% DEMOGRAPHICS AND CONTACT LENS WEARING HABITS T A B L E 1 AVERAGE HOURS/DAYS DOING ACTIVITY WEARING CLs (MEAN) ALL PARTICIPANTS (n=568) Use computer at office 5.3 Use computer at home 2.0 Watch TV 2.3 Drive at night 1.0 Surf on smartphone/tablet 1.0 Read books/magazines/newspapers 1.0 Play electronic games 0.4 AVERAGE NUMBER OF HOURS SPENT PER ACTIVITY T A B L E 2