Influence of the COVID-19 pandemic on contact lens wear in Spain

PurposeTo investigate the behaviour of contact lens (CL) wearers in Spain during the COVID-19 pandemic.MethodsAn anonymized web-based questionnaire was used to assess demographics, CL history, and activity, CL wear habits and perceived risk of infection due to CL wear during the COVID-19 pandemic.ResultsA total of 737 participants with an average age of 27.4 (±9.3) years completed the online questionnaire. The vast majority of respondents were soft CL wearers and reported at least two years of CL wear. Patients concerns about the increased risk of SARS-CoV-2 infection due to CL wear (40.6 % of participants) were significantly related (χ²(1) = 11.195, p < 0.05) to CL discontinuation (46 % of participants) during the COVID-19 pandemic. This fact joins the significant changes in the frequency of CL wear during the COVID-19 pandemic (χ²(4) = 31.982, p < 0.05), with a tendency to increase occasional CL wear from 29.1 % to 61.8 %. Interestingly, the majority of respondent (87.9 %) indicated that no professional had offered them information related to CL wear and COVID-19, and that they had not sought it on their own (82.2 %).ConclusionThere is a relationship between the perceived risk of infection and CL dropout during the COVID-19 pandemic, and a tendency to change the CL frequency of wear, with an increase in occasional CL wear. During the ongoing pandemic, eye care practitioners should reinforce CL patient education to minimize the risk of SARS-CoV-2 infection and CL-related complications requiring clinical care.     

Assessment of contact lens wearers’ attitude toward contact lens wear and care during Coronavirus Disease 2019 (COVID-19) pandemic: A cross-sectional online survey

AimCOVID-19 is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Several reports have provided conflicting recommendations regarding contact lenses (CL) use during COVID-19, causing confusion among CL wearers. The aim of this study is to assess CL wearers’ attitudes toward CL wear and care during COVID-19 pandemic.MethodsA web-based cross-sectional online survey was used to assess the participants’ attitude toward CL wear and care during the COVID-19 pandemic. The survey layout was based on Google form® specifically developed for CL wearers. Demographic characteristics and CL history and profile were also collected for each participant.ResultsA total of 196 CL wearers completed the online survey with an average age was 26 (± 4.1) and 90.8 % of participants were females. As reported by the participants, social media was the main source of information about COVID-19. 38.8 % of the study population reported stopping CL wear during the pandemic. The main stated reason for lens discontinuation was decreased social activities during the pandemic. 61.2 % of participants continued lens wear, with the majority reported considerable changes in their behaviors toward CL wear and care during the pandemic. This includes reinforced hands cleaning before and after lens wear, disinfecting of CLs and CL case and less frequent CL aftercare visits.ConclusionThe majority of the study population have continued CL wear during the pandemic. Contact lens wearers reported profound changes in attitudes toward CL wear including improved care and maintenance. Additionally, changes in CL purchase habit have been reported with more tendency for online purchase. CL cessation has been associated with several perceived reasons mainly attributed to reduced outdoor activity and fear of ocular infection. Levels of compliance among CL wearers should be assessed and reinforced during the current pandemic and similar lockdown situation to reduce possible CL-related complications and dropout.     

An investigation into disposal and recycling options for daily disposable and monthly replacement soft contact lens modalities

PurposeTo examine the annualised waste and end-of-life disposal options with two representative soft contact lens (CL) modalities.MethodsThe component parts of two representative soft CL modalities were catalogued, separated, weighed and inspected for material identification: somofilcon A soft CLs (clariti elite, CooperVision Inc.) used with multi-purpose solution (MPS) (All in one Light, CooperVision Inc.) and somofilcon A CLs (clariti 1 day, CooperVision Inc). Using a model that assumed compliant wear and care of CLs, the mass of material solid waste generated by CL use over a year was calculated. Disposal options were explored using household and specialist recycling streams in order to develop recommendations for responsible disposal of CL waste.ResultsFull-time daily disposable (DD) CL wear generates 1.06 kg of waste annually compared to 0.83 kg generated by reusable-monthly replacement daily wear (‘reusable’) CLs. Plastic was the dominant material in both modalities. With full-time use of DD CLs, 64% of waste by mass was plastic blister trays. For full-time use of reusable CLs, where figures from lens and MPS packaging are combined, plastics accounted for 67% of waste by mass. MPS bottles alone made up almost half the waste (45%) associated with full-time reusable CL wear.ConclusionFull-time DD wear generates 27% more waste annually than full-time reusable lens wear. Reusable CL wearers can recycle 78% of waste at home. DD lens wearers have access to recycling options that allow them to recycle 100% of CL related waste. Full-time CL lens wear represents just 0.20–0.26% of the 412 kg of household waste generated per person, per year in the United Kingdom. Worn CLs should never be disposed of down the sink or lavatory. CL wearers should be aware of responsible end-of-life recycling and disposal options for all CL waste.     

Assessment of compliance with contact lens wear and care among university-based population in Jordan

Purposethis survey aimed to assess levels of compliance with contact lens wear and care among university student’s population in Jordan.MethodsAn interviewer-administered questionnaire was used to assess the extent of compliance among contact lens wearers toward contact lens care in a university population. The questionnaire included 12 questions regarding compliance with contact lens care, lens case/solution replacement, general hygiene procedures related to contact lens and adherence to aftercare visits.Results210 contact lens wearers were interviewed. Of the study population 187 (89 %) were females and 23 (11 %) were males. The average age of the study group was 22.35 (± 3.77) years and all the study population were students (undergraduate or postgraduate).The average compliance rate of the study population was 75 %. High level of compliance was noticeable in the following aspects; not sharing lenses with others, not sleeping while wearing lenses, hand washing before lens use and not using water to clean lenses. Moderate level of compliance was reported in the following aspects; showering/swimming with lenses, using lenses longer than recommended replacement schedule and all behaviours related to contact lens care solution. However, low levels of compliance were reported in relation to cleaning and rinsing lens case and adherence to aftercare visits.ConclusionHigh to moderate levels of compliance were reported generally by participants. However, better strategies are recommended to further increase levels of compliance among contact lens wearers in Jordan related to adherence to aftercare visits. While this study is targeted contact lens wearers from a university student’s population, a future study is recommended to include larger sample of contact lens wearers from the general lay population.     

The relationship between tear film MMP-9 and meibomian gland changes during soft contact lens wear

PurposeTo investigate the association between levels of MMP-9, a common marker of inflammation in tears, and changes to the meibomian glands accompanying soft contact lens (CL) wear.MethodsFlush tears were collected from: (1) three groups of CL wearers who had worn CLs on a daily basis for different durations (Short: 2 ± 1 years, Moderate: 5 ± 1 years and Long experience: 10 ± 2 years); (2) a group of previous CL wearers (PWs) who had ceased wear for at least 6 months; and (3) healthy non-wearers (NW) as a control group. Total MMP-9 and its inhibitor, tissue inhibitor of MMPs-1 (TIMP-1) concentration were established using sandwich enzyme-linked immunosorbent assay. The MMP-9: TIMP-1 ratio was calculated for every individual, and then the average of all ratios for each group were compared. The non-parametric statistical Kruskal Wallis one-way analysis of variance was used for comparison, with Dunn’s testing post-hoc.ResultsTear samples from 100 participants (51 females; mean age ± SD: 25.4 ± 4.1 years) were analysed. MMP-9 concentrations and MMP-9:TIMP-1 ratio were significantly different between groups (Kruskal Wallis p = 0.001 and p < 0.001 respectively), while the concentration of TIMP-1 did not vary statistically between study groups (Kruskal Wallis, p = 0.32). Post hoc analysis indicated that only CL wearers with short experience had MMP-9 concentrations that were significantly high compared to NWs (23.1 ± 17.9 ng/mL and 4.1 ± 4.1 ng/mL, respectively, Dunn p < 0.001). Additionally, the ratio of MMP-9 to TIMP-1 concentration was only significantly greater in CL wearers with short experience (mean ratio ± SD = 1.15 ± 0.76) when compared to NWs (0.19 ± 0.29, Dunn P < 0.001), CL wearers with moderate experience (0.37 ± 0.41; P = 0.01) and PWs (0.38 ± 0.36; P = 0.02).ConclusionsThe early years of CL wear appear to be associated with increased expression of MMP-9 relative to its inhibitor TIMP-1. This may be indicative of low-level inflammation during this phase of wear. The role this plays in propagating dry eye disease and MGD in CL wear requires further exploration.     

The morphology of corneal endothelial cells in long term soft contact lens wearers in Kuala Lumpur

PurposeTo analyse and compare the alterations in corneal endothelium morphology induced by different materials and durations of wearing soft contact lenses (CL) among young adults living in Kuala Lumpur.MethodsHealthy soft CL wearers were invited to participate in this study. Visual acuity (VA) was measured using the Snellen chart, and subjective refraction was performed using cross-cylinder technique. Standard ocular assessments were conducted using a slit lamp biomicroscope and morphology of corneal endothelial cells (endothelial cell density, ECD, coefficient variation, COV, hexagonality, HEX and central corneal thickness, CCT) were evaluated using a non-contact specular microscope. Statistical analysis was conducted using ANOVA and data from the right eye only is included.ResultsA total of 72 subjects (32 SiHy and 40 HCL wearers) and 24 non-CL wearers (control) participated in this study. The gender distribution for study subjects was 13 males and 59 females, with a mean age 22.15 ± 1.84 years old. The mean refraction was −1.86 ± 1.25DS. The duration of wearing CL ranged from 1 to 9 years. Subjects were later divided into 2 groups following duration of CL wear: Group 1 (<5 years) and Group 2 (≥5 years) for analysis purposes. Statistical analysis showed significant alterations in ECD, COV and HEX of CL wearers (p < 0.05), with more changes found in HCL and Group 2 wearers. No significant change was found in CCT.ConclusionThis study concludes that soft CL wear induced alterations in the morphology of corneal endothelial cells. Contact lens material and duration of CL wear (in years) are factors that affect the alterations. Optometrists are recommended to regularly evaluate the morphology of corneal endothelial cells in CL wearers and provide necessary intervention when required.     

Improving your spectacle patients’ in-practice experience with contact lenses during frame selection

PurposeA market research survey was conducted to assess the impact of offering complimentary contact lenses (CLs) to spectacle-only wearing patients during frame selection with regards to their in-office experience, the transaction amount for their eyewear purchase and the likelihood of proceeding with a comprehensive contact lens fitting.MethodsFive optometry offices in the US participated. An initial interviewing phase served as a control during which optometrists treated spectacle-only wearing patients in the usual manner for frame selection. After this, the offices transitioned into a test phase where patients were offered the opportunity to wear CLs while selecting new spectacle frames. Only patients 18 or older who had not expressed an interest in CLs were invited to participate. A brief survey was completed on an iPad following the visit by all patients in both control and test phases.Results410 patients (205 test, 205 control) participated. 63% of the test group elected to wear CLs (40% spherical, 20% toric, 35% multifocal, 5% monovision). Patients wearing CLs spent more on their eyewear purchase ($708 vs $593, p = 0.04), were greater than 2.5X more likely to have received or scheduled a CL fit (p = 0.01), and were greater than 3X more likely to consider scheduling a CL fitting in the future (p = 0.0003). Additionally, 93% reported that they were highly satisfied with the experience and 86% said they would wear CLs to select frames again (86%).ConclusionsOffering CLs to spectacle-only patients positively impacts eyewear selection and purchase and can grow the overall CL business.     

Italian translation and validation of the Contact Lens Dry Eye Questionnaire-8 (CLDEQ-8)

PurposeTo translate and validate an Italian version of the CLDEQ-8 (CLDEQ-8_IT).MethodsThe study was carried out in two phases. In the first phase, a cross-cultural adaptation of CLDEQ-8 to Italian was performed by forward and backward translation in sequence. In the second phase, a multi-centre study was conducted for the validation of the questionnaire. Validity CLDEQ-8_IT was evaluated against three gestalt questions: overall opinion of soft contact lenses (CLs), global self-assessments of eye sensitivity and eye dryness. Reliability was evaluated by test–retest assessment in a subgroup of subjects. Finally, the psychometric properties of CLDEQ-8_IT were explored by Rasch analysis.ResultsTwo hundred and forty soft CL wearers, fluent Italian speakers (73 males and 167 females), between 18 and 70 years of age were enrolled. A significant correlation was found between CLDEQ-8_IT and each of the three Gestalt questions. The cutoff score of 12 points demonstrated the best balance between sensitivity and specificity in differentiating wearers grading their CLs as “Excellent/Very good” from those reporting their overall opinion as “Good/Fair/Poor”. The Intraclass Correlation Coefficient between test and retest was 0.88 (95% CI: 0.81–0.92). Finally, infit and outfit statistics using Rasch analysis for the 8 items were in a good range, however Principal Components Analysis revealed a certain degree of multi-dimensionality of the instrument. Also, item 8 analysis could be computed after merging the last two response categories.ConclusionThe CLDEQ-8_IT showed very good validity and reliability in measuring symptoms of CL wearers, comparable to the original English language version. A cut-off of 12 was confirmed as yielding the best balance between sensitivity and specificity in detecting CL wearers who could benefit from clinical management of their CL-related symptoms. Collapsing of the response options 5 and 6 in the last item of questionnaire could optimise its functioning.     

Impact of meibomian gland width on successful contact lens use

PurposeTo evaluate meibomian gland (MG) width and determine its impact on successful contact lens (CL) use and ocular health.MethodsA five-site study was conducted by recruiting 18- to 45-year-old subjects who had dropped out of CLs because of discomfort. CL dropouts were compared to age- and sex-matched successful CL wearers. Right eyes were evaluated for tear break-up time, tear meniscus height, MG expressibility, meibum quality, and meibography. Central MG widths were evaluated with a custom MATLAB program.ResultsCL dropouts (n = 56) and successful CL (n = 56) wearers had similar grades for upper (p = 1.0) and lower (p = 0.22) MG atrophy, upper (p = 0.07) and lower (p = 0.89) MG tortuosity, and upper (p = 0.92) and lower (p = 0.97) MG widths. Upper eyelid MG widths were narrower than lower eyelid MG widths (p = 0.03). Upper and lower MG tortuosity (p < 0.001) and widths (p = 0.03) were associated, but not atrophy (p = 0.42). Lower eyelid MG widths were associated with MG expressibility (p = 0.01), but MG widths were not with any other factors.ConclusionsSuccessful CL wear does not appear to be clinically influenced by MG width or other measures of MG structural integrity. Lower eyelid MGs were wider than upper eyelid MGs and narrower lower eyelid MGs were associated with worse MG expressibility, suggesting that narrower MGs may produce abnormal meibum. Data also suggests that MG factors of both eyelids should be evaluated in practice.     

Usefulness of a global rating change scale for contact lens discomfort evaluation

ObjectivesTo evaluate the usefulness of a global rate of change scale (GRCS) to detect variations in contact lens discomfort (CLD).MethodsSymptomatic contact lens (CL) wearers were recruited according to the ‘Contact Lens Dry Eye Questionnaire-8’ (CLDEQ-8). At the baseline visit, subjects scored their comfort following insertion of their habitual CL using a 0–100 visual analogue scale (VAS). After 4–10 h of CL wear, comfort was again self-evaluated with the VAS and with a GRCS (range, −50 to +50). Then, a daily disposable CL (DDCL) was fitted. After one month of DDCL wear, a follow-up visit was conducted where the same evaluations as the baseline visit were performed. Changes in comfort were estimated using a Student's t-test for normal variables and the Friedman test for multiple comparisons of non-parametric variables. Internal responsiveness was measured by calculating the standardised response mean. Agreement between scales was estimated by the intraclass correlation coefficient (ICC).ResultsTwenty-nine (22 females and 7 males) CL wearers with a mean age of 23.4 ± 5.4 years participated in the study. There was a significant decrease in comfort at both visits detected by the GRCS (baseline = −13.58 ± 17.48, p < 0.001; follow up = −6.86 ± 12.69, p = 0.007). However, the VAS did not detect that change, either at baseline (insertion = 64.28 ± 18.72 vs removal = 52.89 ± 17.64, p = 1.000) or follow-up visit (insertion = 81.97 ± 12.91 vs removal = 76.48 ± 16.02, p = 1.000). Comfort at insertion and removal times was significantly higher with the DDCL (p = 0.008 at insertion and p = 0.004 at removal). The standardised response mean was greater with the GRCS than the VAS at baseline (0.78 vs 0.63) and follow-up (0.54 vs 0.37) visits. Agreement between both scales was moderate and significant (p < 0.001) for both visits, ICC: 0.674 (95 % confidence interval (CI):0.411–0.833) (baseline) and 0.652 (95 % CI:0.377–0.821) (follow-up visit).ConclusionsThe GRCS can detect slight changes in CL wear comfort and shows higher responsiveness than the VAS. This subjective scale can allow detection of changes in comfort in a simple and quick way.     

The impact of patient behaviour and care system compliance on reusable soft contact lens complications

Reusable soft daily wear contact lenses (CLs) remain popular and were fit to just over half of all wearers in the most recent international CL prescribing survey. Unlike daily disposable CLs, reusables require cleaning and disinfecting after every use, along with storage in a CL case. These additional requirements add a number of steps to the daily wear and care routine, increasing the opportunities for CL wearers to exhibit non-compliant behaviour. The impact of non-compliance ranges from poor lens comfort through to potentially sight-threatening infective keratitis. The coronavirus pandemic has refocused the profession on the importance of hand hygiene in particular, and the need for promoting safe CL wear in general. This review summarises typical non-compliant behaviour related to reusable CLs, and examines strategies and opportunities to better support wearers. Patient education has a central role in encouraging compliant behaviour, although patient recall of information is low, and personal belief systems may result in continuation of non-compliant behaviour despite awareness of the risks. CL care solutions are required for the daily disinfection of lenses, however misuse of multipurpose solutions (MPS) and hydrogen peroxide (H₂O₂)-based care systems can challenge their ability to be fully efficacious. Standard efficacy testing is reviewed, with consideration of how well current protocols model real-world use of CL solutions. Although some recommendations are in place for the inclusion of additional variables such as lens cases, CL materials, organic soil and efficacy against Acanthamoeba, opportunity still exists to reevaluate global standards to ensure consistency of testing in all markets. Finally, potential future innovations are discussed which may further support increased safety in reusable lens wear through novel antimicrobial additions to both CL materials and cases.     

Clinical factors associated with contact lens dropout

PurposeContact lens (CL) dropout is estimated to be approximately equal to the number of new wearers per year, resulting in virtually no growth in the global CL market. The purpose of this study was to determine ocular and CL factors associated with CL dropout.MethodsThis five-site study recruited subjects 18–45 years of age who had ceased CL wear within the past 6–12 months due to discomfort. Dropout subjects were compared to age- and sex-matched currently successful CL wearers. Each subject was administered a symptoms survey and a study-specific survey that queried general CL history and compliance. Clinical testing included non-invasive tear break-up time, tear meniscus height, blepharitis assessment, meibum quality and expression, and meibography.ResultsA total of 56 matched-pairs were recruited. Dry eye was found to significantly increase a subject’s odds of dropping out of CLs. The odds of dropping out of CLs was also significantly increased with each worsening grade of upper or lower eyelid meibomian gland (MG) plugging, upper eyelid meibum quality, and upper eyelid MG tortuosity. No other factors analyzed increased a subject’s odds of dropping out of CLs.ConclusionsCL dropout may be precipitated by underlying dry eye symptoms, though most dry eye signs, with the exception of MG structure and function, had minimal predictive value for CL dropout. Nevertheless, evidence suggests that practitioners should screen for and educate CL patients about the importance of maintaining healthy MGs, which may potentially allow them to maintain comfortable CL use and increase their CL longevity.     

Contact lens complications among wearers in Ghana

PurposeContact lens (CL) practice is relatively new in Ghana; a country where the geographical location (warm climate) lends itself to harsh environmental conditions (high humidity) known to influence CL wear. Recent studies suggest an increase in CL wear (corrective and cosmetic), yet, there are no studies about CL-related complications. This study sought to determine the complications associated with CL wear in Ghana.MethodsThis was a retrospective cohort study. The medical records of contact lens wearers from five CL clinics in the two largest metropolises in Ghana, Accra and Kumasi, were reviewed. Included in the study were records of individuals who visited the clinics within the period of 2013–2016. Data on patients with contact lens-related complications were analyzed.ResultsThe prevalence of CL complications was 29.06 %. The mean ± SD age of patients with CL complications was 35 ± 15 years. Contact lens complications were more common in females (52.90 %). The majority of complications were in soft contact lens wearers (82.35 %). Refractive error correction was the most common indication for CL wear (61.76 %) among those with complications, followed by keratoconus (14.71 %), scarred blind eye (14.71 %), corneal ulcer (5.88 %) and anterior staphyloma (2.94 %). Contact lens complications reported were giant papillary conjunctivitis (41.18 %), corneal infiltrates (23.53 %), bacterial keratitis (14.71 %), corneal abrasion (11.76 %), dry eye (5.88 %) and corneal oedema (2.94 %). The causes of CL complication were inappropriate lens cleaning (29.41 %), poor hygiene (23.53 %), overnight contact lens wear (17.64 %), poor lens fit (14.71 %) and reaction to contact lens solution (14.71 %).ConclusionContact lens complications were more common in soft contact lens wearers in Ghana. Giant papillary conjunctivitis was the most common contact lens complication reported. Adherence to CL wear care regimen and good personal hygiene may prevent the majority of CL complications observed in Ghana.     

The use of daily disposable lenses in problematic reusable contact lens wearers

PurposeReplacing soft contact lenses (CLs) on a daily basis brings a number of advantages, most notably, reduced exposure to deposits, disinfectants, allergens, and other contaminants. This retrospective study estimated the prevalence of problems in current wearers of reusable soft CLs and tested the effect of refitting “problem” patients with daily disposable (DD) hydrogel lenses.MethodsPrevalence was estimated from 398 current reusable CL wearers for: frequent/constant discomfort or dryness, ≥2 h of uncomfortable wear, ≥grade 2 conjunctival hyperaemia (0–4), or ≥grade 3 corneal staining (0–15). In the second part of the study, 217 reusable CL wearers classified as problem patients were randomly refitted with DD lenses manufactured from one of two materials: etafilcon A (n = 96) or nelfilcon A (n = 121) and reassessed 1 week later.ResultsThirty-nine percent (154/398) had some qualifying criterion: reduced comfortable wearing time (CWT), 20%; dryness, 20%; irritation, 5%; corneal staining, 8%; and hyperaemia, 7%. After refitting with DDs, the prevalence of reduced CWT was decreased from 65% to 51% (P = 0.0039), dryness from 60% to 41% (P < 0.0001) and corneal staining from 28% to 21% (P = 0.04). There was no significant change in the prevalence of irritation, or hyperaemia. Some differences were noted between the two lens materials.ConclusionsA high proportion of reusable soft lens wearers encounter clinically relevant signs or symptoms with their current CLs. This study provides evidence that refitting with DD lenses is a useful strategy for alleviating some of the common problems of CL wear.     

Zeta potential of tear samples: A tool to explore the effects of wear of contact lenses

PurposeThe aim was to develop a method to assess the electrostatic properties of human tear samples, and to evaluate their modifications induced by the wear of contact lenses (CLs).MethodThe barrier method was developed for the measurement of the isoelectric point (IEP) on relatively small quantities. The method was applied to compare three groups: tears (T_NW) of non-wearers, tears (T_{W_etaf}) of regular wearers of etafilcon A CLs, and tears (T_{W_omaf}) of regular wearers of omafilcon A CLs. Zeta potential (ζ) as a function of pH was measured by a Zetasizer Nano ZS90 (Malvern Instruments) on 40%-diluted samples, obtained by mixing 57 μL of tears of different subjects of the same group with 85 μL of HCl aqueous solution. IEP was deduced as the pH at which ζ is zero, i.e. the net electric charge on tear constituents being neutralized.ResultsWithin an error of about 0.05, IEPs were found to be 2.90 (T_NW), 2.80 (T_{W_omaf}), and 3.16 (T_{W_etaf}). On average, a lower H⁺ concentration is needed to neutralize the surface charge of the tear components of etafilcon A wearers, compared to both T_NW and T_{W_omaf}.ConclusionIEP measurements on tear samples of wearers of different types of CLs are proposed in order to enhance the knowledge on the modifications of the profile of charged species in tears. The T_{W_etaf} results, compared to those of the other groups, are compatible with an increase, due to the wear of etafilcon A CLs, of the relative concentration of high-IEP proteins.     

Exploring non-adherence to contact lens wear schedule: Subjective assessments and patient related factors in children wearing single vision and myopia control contact lenses

PurposeTo determine factors associated with non-adherence to contact lens wear schedule involving single vision and myopia control contact lenses in children.MethodsData from 379 children enrolled in a prospective, double masked, randomized clinical trial, aged 8–13 years, cycloplegic spherical equivalent of -0.75 to -3.50D and wearing either: single vision silicone hydrogel (SiH) CL (control lens); two anti-myopia SiH CL that incorporated relative plus in the central and periphery in a stepped manner (test lens I and II); and two extended depth of focus hydrogel CL (test lens III and IV) was considered. A questionnaire was administered to the participants at every scheduled visit and gathered information on days of wear/week and subjective assessments of ocular comfort and visual quality on an analog scale of 1–10.Participants were categorized as “Adherent” when lens wear was ≥ 6 days/week or “Non-adherent” when lens wear ≤ 5 days/week. Categorized adherence data was summarized as a percentage across visits for each CL type. Differences between the two groups were analyzed using linear mixed model.ResultsFor the control lens, 79.6 % participants were adherent as compared to 63.7%–74.6% with test lenses (p=0.026). Non-adherence was greater in those that discontinued (p<0.001). Subjective ratings of visual quality for static and dynamic tasks were lower with non-adherent wearers and more variable between visits. Ocular comfort was also poorer in non-adherent wearers irrespective of lens material or lens design. Male gender, lower baseline myopia, lower high contrast visual acuity and esophoria were associated with a higher risk of non-adherence.ConclusionsThe study identified a wide range of factors associated with non-adherence to lens wear schedule. Paying specific attention to these factors when evaluating patients for CL wear and taking steps to ensure satisfaction in lens wear may promote longer term continuation of wear.     

In-vitro dewetting properties of planned replacement and daily disposable silicone hydrogel contact lenses

AimTo compare the in-vitro videokeratoscopic surface dewetting properties of new-generation silicone hydrogel (SiH) planned replacement contact lenses (CL) with those of daily disposable CLs.MethodA chrome coated cornea model was used for the in-vitro evaluation of surface dewetting. Pre-lens and post-lens film layers were formed by instilling a normal preservative-free normal saline solution (PFNs) (0.9 %) before and after the placement of the CL on the model cornea. The tests were carried out on fanfilcon A, lotrafilcon B, samfilcon A, and senofilcon A lenses, as well as such daily disposable lenses as delefilcon, nesofilcon A and senofilcon one day. Using videokeratoscopic methods, images were obtained at 30-second intervals up to 180 s in the lens and control groups and were analyzed by the ImajeJ® program.ResultsThe mean measured area of the keratoscopic rings was largest in the fanfilcon group (67.56 mm²), followed by 61.53 mm² in the lotrafilcon A group and 64.60 mm² in the samfilcon group, while the smallest area was measured in the senofilcon A group, at 56.90 mm². The area was measured as 64.33, 63.09 and 68.39 mm² for the delefilcon, nesofilcon and Senofilcon one day CLs, respectively. The dewetting patterns and properties differed in the CL groups (p < 0.05), while no significant differences were found between the measured areas of the planned replacement and daily disposable CL groups (p > 0.05).DiscussionVideokeratoscopy using in-vitro cornea models has been identified as a reproducible and reliable method for the analysis of the surface dewetting of CLs. The dewetting characteristics of CL groups have been found to differ from each other, despite all being produced from SiH materials. The surface wetting coating has been shown to affect CL dewetting performance.     

Ethnic differences in dry eye symptoms: Effects of corneal staining and length of contact lens wear

PurposeTo explore the relationships among length of contact lens (CL) wear, degree of corneal staining and severity of dryness symptoms, and to determine whether these relationships differ between Asians and non-Asians.MethodsAdapted soft CL wearers (n = 395; 180 Asian, 215 non-Asian) were required to discontinue CL wear for at least 24 h and report to the University of California, Berkeley Clinical Research Center (UCB-CRC). Fluorescein corneal staining was graded according to Brien Holden Vision Institute scales. Length of CL wear was reported by subjects and subjective dryness ratings were collected using the UCB-CRC Dry Eye Flow Chart (DEFC).ResultsMore Asian CL wearers exhibited corneal staining compared to non-Asians, and Asian CL wearers had a higher mean grade of corneal staining (p < 0.001), as well as a higher mean DEFC classification (p < 0.001). The difference between Asians and non-Asians in grades of corneal staining extent and depth were significant (p < 0.001). Among non-Asian CL wearers, dryness symptoms decreased with more years of CL wear and increased in the presence of corneal staining, which was not the case for Asian CL wearers.ConclusionsAsian soft CL wearers reported more severe dryness symptoms and demonstrated more severe corneal staining overall compared to non-Asians. Among non-Asians, dryness symptoms were less severe on average with increased years of CL wear and more severe in the presence of corneal staining. Dryness severity does not appear to be related to years of CL wear or corneal staining among Asians.