Effect of Lens Care Systems on the Clinical Performance of a Contact Lens

Clinical characterisation of contact lens discomfort progression

PURPOSE

This study aimed to assess the subjective and objective differences among the steps of the contact lens discomfort (CLD) progression classification established by the Tear Film & Ocular Surface Society (TFOS) using questionnaires and clinical signs, and to propose a simplified classification.

METHODS

Contact lens (CL) wearers were evaluated in a single visit. The Contact Lens Dry Eye Questionnaire (CLDEQ)-8, the Contact Lens Discomfort Index, and Visual Analog Scales for discomfort and dryness were administered. The non-invasive break-up time, the tear film lipid layer thickness, conjunctival hyperaemia and papillae, lid-parallel conjunctival folds, the fluorescein tear film break-up time, corneal and conjunctival staining, lid wiper epitheliopathy, and the Schirmer test were assessed. Sign and symptom scores were compared among TFOS CLD progression steps using analysis of variance or the Kruskal-Wallis H test. Steps 1 and 2 (reduced comfort), and steps 3 and 4 (reduced wearing time) of the TFOS classification were combined to obtain a simplified classification, and the same comparison was performed. A p-value ≤ 0.05 was considered statistically significant.

RESULTS

One hundred-fifty CL wearers (97 women and 53 men) aged 34.4 ± 12.6 years were included. In the TFOS classification, there were significant differences between step 0 (no CLD) and the rest of the severity steps for the scores obtained in all questionnaires (p ≤ 0.015). All steps were differentiated (p ≤ 0.032) based on the simplified classification for all questionnaires, except steps 1 and 2 for the CLDEQ-8 and dryness VAS (p = 0.089 and p = 0.051, respectively). There were no differences (all p ≥ 0.06) between the sign scores among the steps of either classification.

CONCLUSION

CLD management is encouraged from its first appearance. Simplifying the phases of CLD severity may allow a more accurate classification and a better awareness of the problem by clinicians and CL wearers by using more straightforward simple messages.

Silicone hydrogel versus hydrogel soft contact lenses for differences in patient-reported eye comfort and safety

BACKGROUND

Ocular discomfort is the leading cause of permanent discontinuation of soft contact lens (SCL) wear. Silicone hydrogel and hydrogel materials are the two major categories of SCLs, with silicone hydrogel materials being newer and more breathable than hydrogel materials. Whether comfort is associated with SCL material is controversial despite numerous studies. Similarly, the difference between these materials in terms of safety outcomes (e.g. frequency of microbial keratitis) is unclear.

OBJECTIVES

To evaluate the comparative effectiveness and safety of silicone hydrogel compared with hydrogel SCLs on self-reported comfort, dry eye test results, and adverse events in SCL-wearing adults 18 years of age or older.

SEARCH METHODS

The Cochrane Eyes and Vision Information Specialist searched the electronic databases for randomized controlled trials (RCTs). There were no restrictions on language or date of publication. We searched the Cochrane Central Register of Controlled Trials (CENTRAL, including the Cochrane Eyes and Vision Trials Register; 2022, Issue 6), MEDLINE Ovid, Embase.com, PubMed, LILACS (Latin American and Caribbean Health Science Information database), ClinicalTrials.gov, and World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP). We also searched the reference lists of identified studies, review articles, and guidelines for information about relevant studies that may not have been identified by our search strategy. Furthermore, we contacted investigators regarding ongoing trials. The most recent database search was conducted on 24 June 2022.

SELECTION CRITERIA

Our search selection criteria included RCTs, quasi-RCTs, and cross-over RCTs.

DATA COLLECTION AND ANALYSIS

We applied standard Cochrane methodology.

MAIN RESULTS

We included seven parallel-group RCTs conducted in the USA, the UK, Australia, Germany, India, and Turkey. A total of 1371 participants were randomized. The duration of SCL wear ranged from one to 52 weeks. Study characteristics and risk of bias The median number of participants per trial was 120 (interquartile range: 51 to 314), and the average age ranged from 20.7 to 33.0 years. Women represented the majority of participants (range 55% to 74.9%; 5 RCTs). Collectively, the included trials compared eight different silicone hydrogel SCLs with three different hydrogel SCLs. Five trials compared daily disposable SCLs, and two compared extended wear SCLs (worn for seven days and six nights). New SCL wearers were enrolled in three trials. Two trials included both new and established SCL wearers, and two trials did not report participants' history of SCL use. Five trials were sponsored by industry. We judged the overall risk of bias to be 'high' or 'some concerns' for the safety and efficacy outcomes. Findings One trial reported Ocular Surface Disease Index (OSDI) results, with the evidence being very uncertain about the effects of SCL material on OSDI scores (mean difference -1.20, 95% confidence interval [CI] -10.49 to 8.09; 1 RCT, 47 participants; very low certainty evidence). Three trials reported visual analog scale comfort score results, with no clear difference in comfort between materials, but the evidence was of very low certainty; trial results could not be combined because the three trials reported results at different time points. The evidence is very uncertain about the effect of SCL material on discontinuation of contact lens wear (risk ratio [RR] 0.64, 95% CI 0.11 to 3.74; 1 RCT, 248 participants). None of the included trials reported Contact Lens Dry Eye Questionnaire (CLDEQ-8) or Standard Patient Evaluation of Eye Dryness (SPEED) scores. There was no evidence of a clinically meaningful difference (> 0.5 unit) between daily disposable silicone hydrogel and hydrogel SCLs in corneal staining, conjunctival staining, or conjunctival redness (very low certainty evidence). Adverse events Very low certainty evidence from two trials comparing daily disposable SCLs suggested no evidence of a difference between lens materials in the risk of vision-threatening adverse events at one to four weeks (RR 0.68, 95% CI 0.08 to 5.51; 2 RCTs, 368 participants). Two trials comparing extended wear SCLs indicated that hydrogel SCLs may have a 2.03 times lower risk of adverse events at 52 weeks compared with silicone hydrogel SCLs (RR 2.03, 95% CI 1.38 to 2.99; 815 participants), but the certainty of evidence was very low.

AUTHORS' CONCLUSIONS

The overall evidence for a difference between all included silicone hydrogel and hydrogel SCLs was of very low certainty, with most trials at high overall risk of bias. The majority of studies did not assess comfort using a validated instrument. There was insufficient evidence to support recommending one SCL material over the other. For extended wear, hydrogel SCL may have a lower risk of adverse events at 52 weeks compared to silicon hydrogel. Future well-designed trials are needed to generate high certainty evidence to further clarify differences in SCL material comfort and safety.

TFOS Lifestyle: Impact of contact lenses on the ocular surface

Several lifestyle choices made by contact lens wearers can have adverse consequences on ocular health. These include being non-adherent to contact lens care, sleeping in lenses, ill-advised purchasing options, not seeing an eyecare professional for regular aftercare visits, wearing lenses when feeling unwell, wearing lenses too soon after various forms of ophthalmic surgery, and wearing lenses when engaged in risky behaviors (e.g., when using tobacco, alcohol or recreational drugs). Those with a pre-existing compromised ocular surface may find that contact lens wear exacerbates ocular disease morbidity. Conversely, contact lenses may have various therapeutic benefits. The coronavirus disease-2019 (COVID-19) pandemic impinged upon the lifestyle of contact lens wearers, introducing challenges such as mask-associated dry eye, contact lens discomfort with increased use of digital devices, inadvertent exposure to hand sanitizers, and reduced use of lenses. Wearing contact lenses in challenging environments, such as in the presence of dust and noxious chemicals, or where there is the possibility of ocular trauma (e.g., sport or working with tools) can be problematic, although in some instances lenses can be protective. Contact lenses can be worn for sport, theatre, at high altitude, driving at night, in the military and in space, and special considerations are required when prescribing in such situations to ensure successful outcomes. A systematic review and meta-analysis, incorporated within the review, identified that the influence of lifestyle factors on soft contact lens dropout remains poorly understood, and is an area in need of further research. Overall, this report investigated lifestyle-related choices made by clinicians and contact lens wearers and discovered that when appropriate lifestyle choices are made, contact lens wear can enhance the quality of life of wearers.

Challenges to the new soft contact lens wearer and strategies for clinical management

Soft contact lens discontinuations have a dramatic impact on the overall success of this form of vision correction, and evidence suggests that the reasons for contact lens cessation are different for new wearers than for established lens users. In descending order, these relate to vision, discomfort, handling, inconvenience/loss of interest, ocular health and cost. This paper considers the background and underlying evidence for these causes of soft lens discontinuation in new wearers, and presents clinical management strategies to minimise this phenomenon. Such measures can reasonably be expected to significantly reduce the number of contact lens discontinuations leading to happier patients, increased satisfaction for eye care professionals (ECPs), and greater success for both individual practices and the contact lens industry more broadly.

Ocular signs and symptoms of orthokeratology patients associated with povidone iodine-based disinfecting solution

PURPOSE

To determine the frequency and severity of ocular symptoms and signs in new orthokeratology (ortho-k) subjects using a povidone iodine (PI) disinfecting system compared to those present before lens wear, and whether these were associated with cleaning regimes.

METHODS

This study recruited 80 subjects from two myopia control studies, who used a PI disinfecting solution for routine use. Ocular symptoms and signs at baseline, one- and six-month after lens wear were reported via questionnaires and ocular examination, respectively. To determine if rates of occurrence were attributable to differences in cleaning regime, subjects were randomly assigned into four groups with respect to routine care procedures, which involved various combinations of rubbing and use of a daily and/or enzymatic cleaner.

RESULTS

Sixty-eight subjects completed all aspects of the study. As there were no significant differences in incidence of signs and symptoms between the four groups before and after lens wear (Friedman tests, p > 0.07), data were combined for further analysis. Prior to lens wear, itchiness (69 %) and dryness (53 %) were the most commonly reported symptoms. The frequency and severity of all symptoms remained similar after lens wear (p > 0.10). Presence of follicles in the lower tarsal conjunctiva (22 %) and conjunctival injection (15 %) was frequently observed, but reduced significantly after lens wear (p < 0.01). Mild corneal staining, noted in 13 % of subjects at baseline, did not change significantly over time (p = 0.17). Ocular signs were not necessarily reflected in symptoms and vice versa.

CONCLUSION

Use of a PI-based solution did not increase the frequency or severity of ocular signs and symptoms observed before lens wear. Absence of a difference in occurrence of ocular discomfort with respect to cleaning regimes indicated that the use of the PI-based solution may adequately clean the lenses over a 6-month period.

Wearer Experience and Eye Care Professional Acceptance with a 1 Day Multifocal Contact Lens

Purpose

A large observational survey was undertaken to determine eye care professional (ECP) and patient experience of stenfilcon A multifocal soft contact lens (MyDay multifocal) when prescribed in a real-world setting.

Methods

A total of 196 ECPs from eleven countries fit up to ten presbyopes with stenfilcon A multifocal. Data were collected on fit success at the initial visit, patient satisfaction with comfort, vision at distance, intermediate, and near, overall vision, overall satisfaction, and handling at the initial and follow-up visits after 1-2 weeks of wear. ECPs completed questionnaires on multifocal fitting experience and expectations before and after the fitting period.

Results

A total of 196 pre-fitting and 141 post-fitting ECP surveys were collected. A total of 1505 initial fits (mean age 53.4, range 38 to 81 years, 73% female, 27% neophytes) and 1440 follow-up visits were completed. The mean distance vision contact lens prescription was -1.32DS (range -12.00DS to +8.00DS) with Add powers: Low 56%, Medium 24%, and High 21%. At the follow-up visit 77% (n=1108) of trials were successful. Mean patient satisfaction ratings (1-10 scale, where 1 is not at all satisfied, and 10 extremely satisfied) at the initial visit were higher than eight out of ten for comfort, vision, and overall satisfaction, and were not significantly different after 1-2 weeks of wear. Stenfilcon A multifocal was preferred by 66% of patients over their habitual correction. In most cases mean satisfaction scores and the proportion of patients highly satisfied were not significantly different between myopes and hyperopes, across Add range, between new and habitual wearers, and wearers of frequently replaced and 1 day contact lenses.

Conclusion

ECPs in real-world clinical settings found stenfilcon A multifocal contact lenses easy to fit to a wide range of patients, with a high fit success rate and high levels of patient satisfaction for overall comfort, vision, satisfaction, and handling.

Topical Review: Contact Lens Eye Health and Safety Considerations in Government Policy Development

SIGNIFICANCE

As new federal or state policies are introduced in the United States to shape the evolving contact lens market, it has never been more important to amplify the importance of patient health and safety during contact lens wear and promote the value of the eye care professional-patient relationship.Within the United States, contact lenses are regulated by the Food and Drug Administration as class II or III medical devices that require additional regulatory and professional oversight to keep consumers safe. The contact lens market and broader eye health landscape are rapidly changing. Recently, the U.S. Federal Trade Commission finalized its 10-year review of the Contact Lens Rule, implementing new policies that will shape the contact lens market in the United States for years to come. The purpose of this clinical perspective was to compile and review key data regarding contact lens-related adverse events, including their economic impact on the health care system, to inform government policy development. Although contact lenses provide many benefits to the wearer, a variety of complications can occur ranging from asymptomatic events or mild discomfort to severe sight-threatening adverse events such as microbial keratitis. Patients who do not routinely visit their eye care professional or do not receive the lenses prescribed to them are at a greater risk of contact lens-related adverse events. Nearly 1 million people in the United States experience ocular infections or inflammation annually, resulting in significant health care costs. The economic burden of contact lens-related microbial keratitis in the United States has been estimated to be approximately $175 million annually. The importance of eye care professional oversight of contact lens wear cannot be emphasized enough to key stakeholders, including lawmakers, government regulators, contact lens manufacturers and distributors, and the broader eye health community.

Polyhexamethylene biguanide hydrochloride (PHMB)-properties and application of an antiseptic agent. A narrative review

The prevention and management of ocular surface infections is still one of the great challenges for ophthalmologists. The spread of antimicrobial resistance makes it necessary to use antiseptic substances with a broad antimicrobial spectrum. Polyhexamethylene biguanide hydrochloride (Polyhexanide, PHMB) is a broad-spectrum antiseptic with excellent tolerance and a low-risk profile. Its physicochemical action on the phospholipid membrane and DNA replication or repair mechanism, prevents or impedes the development of resistant bacterial strains. PHMB revealed its effective against numerous organisms like viruses, Gram-negative and Gram-positive bacteria, and fungi. Polyhexanide is commonly used as preservative in commercially available disinfecting solutions for contact lens care and in ophthalmic formulations at different concentrations ranging from 1 µg/ml to 50 µg/ml. The administration of 0.02% (200 µg/ml) PHMB is often the first-line therapy of Acanthamoeba keratitis. However, to date, only one close-out randomized controlled study tested the efficacy of 0.02% PHMB in Acanthamoeba keratitis and a phase III study is still ongoing. This paper reviews the antiseptic agent PHMB, focusing on biochemical mechanisms, safety profile and applications in ophthalmology.

Dry eye syndrome: comprehensive etiologies and recent clinical trials

Dry eye syndrome (DES) is multifactorial and likely to be a cause of concern more so than ever given the rapid pace of modernization, which is directly associated with many of the extrinsic causative factors. Additionally, recent studies have also postulated novel etiologies that may provide the basis for alternative treatment methods clinically. Such insights are especially important given that current approaches to tackle DES remains suboptimal. This review will primarily cover a comprehensive list of causes that lead to DES, summarize all the upcoming and ongoing clinical trials that focuses on treating this disease as well as discuss future potential treatments that can improve inclusivity.

Addressing common myths and misconceptions in soft contact lens practice

Advances in contact lens technology over the past 50 years since the commercialisation of the first soft lenses in 1971 have been incredible, with significant changes in contact lens materials, frequency of replacement, care systems and lens designs occurring. However, despite the widespread availability of contact lenses, penetration rates for those who need vision correction remain in the low single digits and many practitioners seem to hold on to concepts around the potential value of contact lenses that appear based in the dim and distant past and are certainly no longer valid today. This review addresses 10 common 'myths and misconceptions' around soft contact lenses using an evidence-based approach that can hopefully dispel some of these incorrect assumptions.

All soft contact lenses are not created equal

Soft contact lenses that have been prescribed by eye care practitioners are sometimes substituted for alternative lenses by unqualified, unregulated and sometimes even fully regulated lens suppliers, in the mistaken belief that there is essentially no difference between different soft lens types. This review considers the implications of inappropriately substituting soft contact lens types in terms of (a) lens properties: surface treatment, internal wetting agents, material, total diameter, back optic zone radius, thickness, edge profile, back surface design, optical design, power, colour (tint) and ultraviolet protection; and (b) lens usage: wearing modality (daily versus overnight wear) and replacement frequency. Potential aspects of patient dissatisfaction and adverse events when prescribed soft lenses are substituted for lenses with different properties or intended usage are considered. Substitution of 15 of the 16 lens properties considered (i.e. except for back surface design) was found to be related to at least one - and as many as six - potential sources of patient dissatisfaction and adverse ocular events. Contact lens are medical devices which are prescribed and fitted; they should never be substituted for another lens type in the absence of a new prescription further to a full finalised fitting, for the simple reason that all soft contact lenses are not created equal. A substituted lens may have properties that results in undesirable consequences in respect of vision, ocular health, comfort and cosmetic appearance, and may be incompatible with the lifestyle of the patient.

Effect of material and care system combination on subclinical inflammation of the ocular surface in soft contact lens wear

PURPOSE

To investigate the ocular subclinical inflammatory response in two soft contact lens materials when used in combination with two different care systems ('solutions').

METHODS

Fifteen established soft contact lens wearers wore each of two lenses: Acuvue® 2 (CH) and Acuvue® Oasys® (SiH) or no lenses in random sequence for one week. Two care systems were used: a peroxide system: Oxysept 1 Step® (P) for the right lens and Opti-Free® Replenish® (MPS) for the left lens. After one week of lens/no lens wear, in vivo confocal microscopy (IVCM) of corneal and conjunctival regions was carried out. Density of presumed dendritic cells (DC) and 'white spots' (WS) were quantified. Impression cytology of the bulbar and upper eyelid margin conjunctivae was carried out and samples were analysed for CD45+, CD3+ and CD11c+ cells.

RESULTS

The SiH + MPS combination showed a greater inflammatory response compared to SiH + P in seven out of 12 parameters investigated (p < 0.05). The remaining five were not statistically different between the two solutions. The converse was found for the CH lens, with four of the 12 parameters showing a greater response with the P solution compared to the MPS (p < 0.05).

CONCLUSION

This study suggests that the SiH lens investigated demonstrated an upregulated response when used with a MPS compared to a P solution whereas the converse is true for the CH lens which showed a reduced response when used with a MPS compared to a P solution. This finding aids in the understanding of the biological underpinnings of manifest corneal inflammatory events during contact lens wear.

Fast versus gradual adaptation of soft monthly contact lenses in neophyte wearers

AIM

To determine if a gradual adaptation period is necessary for neophytes when fitted with modern hydrogel or silicone hydrogel reusable disposable contact lenses.

METHOD

Across four sites, 74 neophytes (18-28 years) were randomly assigned to a reusable lens cleaned nightly with Opti-Free® Puremoist® multi-purpose contact lens solution: Proclear® (hydrogel) or Biofinity® (silicone hydrogel) and an adaptation schedule: fast (10 h wear from the first day) or gradual (4 h on the first day, increasing their wear time by 2 h on each subsequent day until they had reached 10 h). Masked investigators graded ocular surface physiology and non-invasive tear breakup time (NIBUT) and a range of comfort, vision and lens handling subjective ratings (0-100 visual analogue scales) were recorded at the baseline visit and after 10 h of lens wear, 4-6 days and 12-14 days after lens fitting. Subjective scores were also repeated after 7 days.

RESULTS

There was no difference (p > 0.05) in ocular surface physiology or NIBUT between fast and gradual adaptation groups at any time point in either lens type with the exception of increased corneal staining (p = 0.019) in the silicone hydrogel fast adaptation group after 4-6 days, but was similar by 12-14 days. Subjective scores were also similar across the visits and lens types with the exception of 'lens awareness' (p = 0.019) which was less in the gradual versus the fast adaptation silicone hydrogel lens group at 12-14 days.

CONCLUSION

There seems to be no clinical benefit for recommending a gradual adaptation period in new wearers fitted with modern soft reusable disposable contact lenses. The findings of this work add to a growing body of evidence suggesting that such advice is unnecessary in regular soft contact lens wear, which has important ramifications for the initial clinical management of these patients.

Activity of Deposited Lysozyme on Contemporary Soft Contact Lenses Exposed to Differing Lens Care Systems

Purpose

The amount of protein deposition on soft contact lenses and to what extent the proteins are denatured may have an impact on comfortable wearing times of contact lenses. The purpose of this study was to evaluate the effects of two lens care systems on total protein and the quantity and activity of lysozyme deposited on worn senofilcon A, silicone hydrogel contact lenses.

Participants and Methods

Thirty symptomatic soft contact lens wearers were enrolled into a 4-week prospective, randomized, bilateral eye, daily-wear, crossover, double-masked study. Participants were fitted with biweekly senofilcon A lenses and were assigned either a polyquaternium-1 and myristamidopropyl dimethylamine-containing system (OPTI-FREE RepleniSH) or a peroxide-based system (CLEAR CARE). After each wear period, proteins were extracted from the lenses and analyzed for total protein, total lysozyme quantity and activity.

Results

The use of either the peroxide-based system or the polyquaternium-1 and myristamidopropyl dimethylamine-containing system resulted in no difference (P>0.05) to the amount of total protein deposited on the lenses (6.7 ± 2.8 micrograms/lens versus 7.3 ± 2.8 micrograms/lens, respectively) or to the amount of denatured lysozyme deposits (0.8 ± 0.7 versus 0.9 ± 0.7 micrograms/lens), respectively. The total amount of lysozyme deposited on the lenses was significantly lower when using the peroxide-based system (1.3 ± 0.9 micrograms/lens) compared to the polyquaternium-1 and myristamidopropyl dimethylamine-containing system (1.7 ± 1.0 micrograms/lens) (P=0.02).

Conclusion

The inactivation of lysozyme deposited on senofilcon A lenses when disinfected with the peroxide-based or the polyquaternium-1 and myristamidopropyl dimethylamine-containing systems were neither statistically nor clinically significant and the overall amounts of denatured lysozyme recovered from the lenses were low (<1 microgram/lens).

Frequency of Contact Lens Complications Between Contact Lens Wearers Using Multipurpose Solutions Versus Hydrogen Peroxide in the United States and Canada

OBJECTIVES

To retrospectively compare frequency of contact lens (CL) complications in soft CL users of hydrogen peroxide (H2O2) and multipurpose solutions (MPS).

METHODS

This was a multicenter, retrospective chart review of CL records from each patient's three most recent eye examinations at academic and private practices. Patients must have used the same solution type for at least 3 years. Univariate analyses were conducted using t tests, and chi-square or Fisher's exact test for categorical measures.

RESULTS

There were 1,137 patients included, with 670 (59%) using MPS and 467 (41%) H2O2. In total, 706 (62%) experienced at least one complication; 409 used MPS and 297 used H2O2. There was no difference in the proportion of patients experiencing at least one complication between MPS (61%) and H2O2 (64%) (P=0.38). Multipurpose solutions users were more likely to report discomfort compared with H2O2 users (P=0.04). Presumed microbial keratitis was experienced by 16 MPS and nine H2O2 users (P=0.60).

CONCLUSIONS

No significant differences were found in the frequency of CL complications between MPS and H2O2. H2O2 users were less likely to report discomfort and thus switching to a H2O2 system may be an alternative in CL users with discomfort.

CLEAR - Evidence-based contact lens practice

Evidence-based contact lens -->practice involves finding, appraising and applying research findings as the basis for patient management decisions. These decisions should be informed by the strength of the research study designs that address the question, as well as by the experience of the practitioner and the preferences and environment of the patient. This reports reviews and summarises the published research evidence that is available to inform soft and rigid contact lens history and symptoms taking, anterior eye health examination (including the optimised use of ophthalmic dyes, grading scales, imaging techniques and lid eversion), considerations for contact lens selection (including the ocular surface measurements required to select the most appropriate lens parameter, lens modality and material selection), evaluation of lens fit, prescribing (teaching self-application and removal, adaptation, care regimen and cleaning instructions, as well as -->minimising risks of lens wear through encouraging compliance) and an aftercare routine.

Interactions between contact lenses and lens care solutions: Influence in optical properties

PURPOSE

Investigate changes in optical properties of contact lenses materials (transmittance and reflectance) and lens care solutions (absorption and fluorescence) resulting from its interaction.

METHODS

From an experimental study, triplicate measurements of transmittance and reflectance of five contact lenses (Senofilcon A, Lotrafilcon B, Balafilcon A, Comfilcon A, and Omafilcon A), as well as UV-vis absorption and fluorescence of four lens care solutions (LCS) (ReNu MultiPlus, Biotrue, OPTI-FREE PureMoist, and AOSept Plus), were evaluated before and after 8 h, one day and one week in storage. The outcomes were provided by Shimadzu UV3101-PC UV-vis-NIR spectrophotometer equipped with an integrating sphere, between 200-700 nm, and SPEX-Fluorolog 2 FL3-22 spectrofluorometer.

RESULTS

All variables exhibited statistically significant differences over time. Comfilcon A showed the lowest ultraviolet radiation (UVR) A & B attenuation. Balafilcon A and Lotrafilcon B displayed a slight suppression of UVR. Senofilcon A was effective in UVR protection and showed less effect on the fluorescence of lens care solutions. Overall, the reflectance decreased after storage (p < 0.05). AOSept Plus absorbance and fluorescence demonstrated lower interactions than multipurpose solutions (MPS), and Lotrafilcon B induced more remarkable changes in optical properties of LCS than the other materials.

CONCLUSION

The findings suggest that optical variables of lens care solutions and contact lenses changed mutually after storage, probably associated with biochemical and biophysical interactions between components and the release of some polymer compounds. These findings can provide additional information about the interaction of CL materials and LCS in clinical behavior.

A 12-month Prospective Study of Tear Osmolarity in Contact Lens Wearers Refitted with Daily Disposable Soft Contact Lenses

SIGNIFICANCE

Tear osmolarity has been reported as one of the best diagnostic tests for dry eye disease and its management. Contact lens wear is thought to influence tear homeostasis. Understanding how regular wear of contact lenses and their type affect tear osmolarity is important.

PURPOSE

The purpose of this study was to assess changes in tear osmolarity and ocular symptoms over a period of 12 months following refitting contact lens wearers with daily disposable contact lenses.

METHODS

Fifty subjects aged (mean ± SD) 26 ± 4 years were refitted with either silicone-hydrogel (delefilcon A, SiHy, n = 34) or hydrogel (omafilcon A, Hy, n = 16) daily disposable soft contact lenses. Study included seven visits: baseline measurements without contact lenses; two visits for contact lens fit and selection; follow-up measurements after 3, 6, and 12 months of contact lens wear; and a post-study visit without contact lenses. Lens type selection was based on a set of objective measurements. Subjects were instructed to follow strict wearing rules. Impedance-based osmometer was used to collect samples from the lower tear meniscuses. The Ocular Surface Disease Index (OSDI) and the eight-item Contact Lens Dry Eye Questionnaire were used to assess subject-reported ocular symptoms and contact lens discomfort, respectively.

RESULTS

Downward trend of tear osmolarity was noted over the time course of study. Statistically significant differences were noted in tear osmolarity (Friedman test, χ = 21.91 [P < .001], and χ = 13.89 [P = .003]) for the right and left eyes, respectively. A statistically significant decrease in tear osmolarity was apparent only for initially symptomatic subjects (for OSDI ≥13: χ = 26.25, P < .001; for OSDI <13: χ = 5.65, P = .13). Statistically significant differences were not noted in OSDI and the eight-item Contact Lens Dry Eye Questionnaire between the baseline and 12-month visit (χ = 5.92 [P = .12] and R = 0.015 [P = .87], respectively). There was a difference between baseline and post-study visits (P = .002) in OSDI, showing lower score at the latter visit.

CONCLUSIONS

Refitting with daily disposable contact lenses was demonstrated to lower tear osmolarity.

Not All Dry Eye in Contact Lens Wear Is Contact Lens-Induced

OBJECTIVES

To compare subjective and clinical outcomes in three study groups: (1) asymptomatic contact lens (CL) wearers (ASYM); (2) symptomatic CL wearers who become asymptomatic on lens removal; and (3) symptomatic CL wearers who do not resolve on lens removal.

METHODS

Ninety-two subjects completed the Berkeley Dry Eye Flow Chart with and without lenses, ocular surface examinations, and a battery of questionnaires.

RESULTS

Thirty-seven subjects (40%) were ASYM, 30 (33%) had contact lens-induced dry eye (CLIDE), and 25 (27%) had underlying physiological DE. Visual Analog Scale ratings, OSDI score, and SPEED score were significantly better for the ASYM group (P<0.001) but did not distinguish CLIDE from DE. The DE group was significantly worse than CLIDE and ASYM, which were similar, in precorneal noninvasive tear breakup time (8.2 sec DE vs. 12.3 sec CLIDE and 14.3 sec ASYM; P=0.002), anterior displacement of the Line of Marx (P=0.017), and superior conjunctival staining (P=0.001).

CONCLUSIONS

Many CL wearers presenting with dryness symptoms have an underlying DE condition and will not respond to treatments aimed at changing lenses or solutions. Contradictory results from research studies of DE in CL wearers could be due in part to a failure to distinguish subjects with symptoms due specifically to CL wear from those whose symptoms have underlying causes unrelated to CL wear.

The use of preservatives in dry eye drops

Topical ocular preparations are widely recommended by health care professionals, or chosen by patients, to help manage dry eye disease (DED). The chronic and progressive nature of DED may result in the administration of topical products several times a day, over a period of many years. Given DED is a condition that by definition affects the ocular surface, it is important to understand how the repeated use of eye drops may impact the ocular surface, influence clinical signs, affect symptoms, and impact the overall disease process of dry eye. The component in topical preparations with the greatest potential to adversely affect the ocular surface is the preservative. This paper reviews the literature in relation to the use of preservatives in formulations for dry eye. The ocular effects of benzalkonium chloride (BAK) are summarised and compared to the performance of alternative preservatives and preservative-free formulations. Use of preserved and preservative-free drops in relation to the management of varying stages of DED is discussed.

Review of Contact Lens-Related Complications

The purpose of this article is to provide a review of existing literature describing complications with contemporary contact lenses and their management. It is envisioned that this will serve as a useful summary of noninfectious and infectious complications associated with contact lens wear.

Measuring Daily Disposable Contact Lenses against Nonwearer Benchmarks

SIGNIFICANCE

Since becoming a popular form of refractive error correction, contact lenses have aspired to replicate the nonwearer experience. This study assessed how well currently available daily disposable soft lenses have achieved that goal, using a graphical representation to show individual lens behavior relative to benchmarks.

PURPOSE

The purpose of this study was to assess comfort, vision, and adverse events during daily disposable contact lens wear, relative to emmetropes and spectacle wearers.

METHOD

Three-month clinical studies, where participants either wore one of five daily disposable contact lenses (n = 201), were full-time spectacle wearers with no history of contact lens wear (n = 34), or emmetropic non-contact lens wearers (n = 40). Vision quality and comfort were assessed at the beginning and end of the day (1 to 10). Corneal infiltrative events were recorded. Between-group comparisons were made using a linear mixed model and literature estimates of clinical significance.

RESULTS

Initial comfort among emmetropes (mean ± 95% confidence interval, 8.0 ± 0.5) was not significantly different from any of the lens types (range, 7.2 ± 0.4 to 8.0 ± 0.4, all P > .06) or spectacle wearers (7.3 ± 0.5, P = .45). Comfort deteriorated during the day in all groups (P < .05). End-of-day comfort for emmetropes (7.3 ± 0.6) was significantly better, only than lenses B (5.7 ± 0.6, P < .001) and D (6.2 ± 0.5, P = .01). Vision quality for emmetropes (8.6 ± 0.5) was better than spectacle wearers (7.8 ± 0.5, P = .04) and lenses A (7.6 ± 0.4, P = .003) and B (7.5 ± 0.4, P < .001). Corneal infiltrative events occurred in 0% of emmetropes and 2.9% of spectacle wearers and ranged from 2.4 to 7.5% in lens wearers.

CONCLUSIONS

Under the conditions of this study, comfort and vision with some contemporary daily disposable contact lenses were indistinguishable from nonwearing emmetropes. Although the contact lens-wearing groups had rates of corneal infiltrative events that were not statistically different from the nonwearers, the study had insufficient power to permit robust conclusions in this respect.

Comparison of Silicone Hydrogel and Hydrogel Daily Disposable Contact Lenses

OBJECTIVE

To compare subjective, objective and safety performance of silicone hydrogel (SiHy) daily disposable (DD) with hydrogel (Hy) DD contact lenses.

METHOD

Retrospective analysis on approximately 40 participants (Px) each in 5 trials. Lenses grouped into SiHy (delefilcon A, somofilcon A, narafilcon A) and Hy (omafilcon A, nelfilcon A). Participants attended follow-up visits at baseline, 2 weeks, 1 and 3 months. Subjective ratings (1-10 scale), adverse events (percentage of Px), physiological variables (0-4 scale), and wearing time were collected at each visit and compared between groups.

RESULT

Trials enrolled 201 Px totally. No differences in age, sex, and lens wear experience were found between SiHy and Hy groups (P≥0.09). There was greater increase in limbal redness from baseline in Hy group (0.18±0.38 vs. 0.02±0.47, P<0.001), whereas conjunctival staining and indentation were less in Hy group (P<0.001). No differences in comfortable wearing time were found between groups (P=0.41), and comfort at insertion, during day, and end of day was also no different (P≥0.71). Incidence of corneal infiltrative events (SiHy vs. Hy: 6.7% vs. 2.5%; P=0.32) and mechanical adverse events (SiHy vs. Hy: 0.0% vs. 0.0%; P=1.00) were no different.

CONCLUSION

Though some statistical significance was found between the groups, these differences were within measurement error. Neither material types showed superiority in comfort, and adverse event rates were low with both material types. These findings suggest that choice of material is a patient and practitioner preference; however, for patients at risk of hypoxia-related complications, SiHy materials should be considered.

Daily versus monthly disposable contact lens: Which is better for ocular surface physiology and comfort?

PURPOSE

To investigate the effect of soft contact lenses (SCL) wearing modality and lens materials on the changes in conjunctival bulbar and limbal redness and conjunctival and corneal staining after two months of SCL wear. Comfort level was also analyzed.

METHODS

In this longitudinal clinical trial, forty-seven neophyte myopic subjects were fitted with a monthly disposable lens (lotrafilcon-B or comfilcon-A or balafilcon-A) in one eye and a daily disposable lens (nelfilcon-A or stenofilcon-A or nesofilcon-A) in the other eye, randomly selected. Conjunctival bulbar and limbal redness and conjunctival and corneal staining were evaluated before and after lens wear. Effect of lens wearing modality and lens materials on these changes was also determined. Level of comfort was evaluated subjectively twice per day. Comfort level and reduction in end-of-day comfort were compared between different lens wearing modalities and materials.

RESULTS

Bulbar and limbal redness and conjunctival and corneal staining were increased (p<0.001) after lens wear, and changes were similar with daily and monthly disposable lens wear (p>0.05). Limbal redness was associated with lens materials, and lotrafilcon-B induced the least among the studied lenses (p<0.05). There was no significant association between the wearing modality and the average comfort level and reduction of end-of-day comfort (p>0.05).

CONCLUSION

Two months of SCL wear increased conjunctival redness, conjunctival and corneal staining, which were not associated with the lens wearing modality. There was a reduction in end-of-day comfort, similar to daily and monthly lenses. The change in limbal redness and reduction in end-of-day comfort were associated with the characteristics of the lens material.

Epidemiology of contact lens-induced infiltrates: an updated review

Corneal infiltrative events (CIEs) are well established as a risk associated with soft contact lens wear. The incidence of symptomatic CIEs during extended soft lens wear ranges from 2.5 to six per cent; when asymptomatic CIEs are included, the incidence can be as high as 20-25 per cent. In daily soft lens wear, the annual incidence of symptomatic CIEs is about three per cent. There are various accepted methods of categorising CIEs, and a scoring system based on clinical signs and symptoms is a good approach to grade severity. Lens-related risk factors include extended wear, silicone hydrogel material, the use of multipurpose solutions, bacterial bioburden and reusable lenses. Recent studies report that daily disposable lenses reduce the risk of CIEs.

TFOS DEWS II iatrogenic report

Dry eye can be caused by a variety of iatrogenic interventions. The increasing number of patients looking for eye care or cosmetic procedures involving the eyes, together with a better understanding of the pathophysiological mechanisms of dry eye disease (DED), have led to the need for a specific report about iatrogenic dry eye within the TFOS DEWS II. Topical medications can cause DED due to their allergic, toxic and immuno-inflammatory effects on the ocular surface. Preservatives, such as benzalkonium chloride, may further aggravate DED. A variety of systemic drugs can also induce DED secondary to multiple mechanisms. Moreover, the use of contact lens induces or is associated with DED. However, one of the most emblematic situations is DED caused by surgical procedures such as corneal refractive surgery as in laser-assisted in situ keratomileusis (LASIK) and keratoplasty due to mechanisms intrinsic to the procedure (i.e. corneal nerve cutting) or even by the use of postoperative topical drugs. Cataract surgery, lid surgeries, botulinum toxin application and cosmetic procedures are also considered risk factors to iatrogenic DED, which can cause patient dissatisfaction, visual disturbance and poor surgical outcomes. This report also presents future directions to address iatrogenic DED, including the need for more in-depth epidemiological studies about the risk factors, development of less toxic medications and preservatives, as well as new techniques for less invasive eye surgeries. Novel research into detection of early dry eye prior to surgeries, efforts to establish appropriate therapeutics and a greater attempt to regulate and oversee medications, preservatives and procedures should be considered.

Impact of Contact Lens Material, Design, and Fitting on Discomfort

OBJECTIVE

To review the effect of contact lens (CL) material, design, and fitting characteristics on CL discomfort.

METHODS

A PubMed search identified publications describing subjective comfort and CL material, fitting, and design parameters. The review included clinical signs associated with discomfort that may be a consequence of these parameters.

RESULTS

Reduced lens movement or more CL tightness were associated with improved comfort. Increased lens-induced paralimbal conjunctival staining and indentation, considered as quasi-indicators of CL fitting or edge design, were also associated with better comfort. No recent studies have evaluated varying CL design parameters and subjective comfort. Silicone hydrogel CLs are no different in comfort compared with hydrogel CLs. Lower equilibrium water content is associated with improved comfort in hydrogel CL wear. Coefficient of friction shows promise as a material factor potentially associated with comfort. Lid wiper epitheliopathy and lid-parallel conjunctival folds have been linked with comfort in established wearers.

CONCLUSIONS

Recent studies have confirmed the association between more mobile CLs and more discomfort, whereas closer conformity of the CL to the bulbar conjunctiva improved subjective comfort. There is no evidence to support the perceived comfort difference between silicone hydrogel and hydrogel CL. There has been limited progress in understanding the impact of varying specific CL design parameters. Although specific clinical signs may be predictive of discomfort, their role in the natural history of discomfort remains unclear. A better understanding of the relationship between coefficient of friction and comfort and strategies to improve lubricity may hold promise for limiting CL discomfort.

Pilot Study to Determine the Effect of Lens and Eye Rinsing on Solution-Induced Corneal Staining (SICS)

PURPOSE

The main purpose of this study was to determine whether two interventions (rinsing the lens before lens insertion and rinsing the ocular surface post-lens removal) had any impact on solution-induced corneal staining (SICS). In addition, the presence of hyper-reflective epithelial cells in the presence of SICS was investigated.

METHODS

Twenty subjects wore new balafilcon A lenses, which had been soaked overnight in a multipurpose care product containing polyhexamethylene biguanide for 2 hours. The study was conducted across three phases. In phase 1 (investigator and subject masked, randomized eye), one lens was rinsed with nonpreserved saline before lens insertion. In phase 2 (investigator masked, randomized eye), one eye was rinsed with nonpreserved saline after lens removal, before staining assessment. Corneal staining was recorded as the percentage area of the cornea exhibiting superficial punctate staining. In both phases, ocular comfort and presence of specific symptoms were captured. In phase 3, there was no randomized treatment; confocal images of the epithelium were obtained after 2 hours of wear.

RESULTS

In phase 1 (lens-rinse), there was no significant difference in staining between the treated and untreated eyes (84 vs. 92%, respectively; p = 0.06). In phase 2 (eye-rinse), there was also no significant difference between the treated and untreated eye (86 vs. 86%, p = 0.92). Most subjects were asymptomatic. In phase 3, images of hyper-reflective cells were captured in 97% of the eyes imaged.

CONCLUSIONS

The two rinsing procedures did not affect the level of the SICS response. Hyper-reflective epithelial cells were found to be present in a significant number of eyes exhibiting SICS, and their presence warrants further investigation.

Ocular discomfort responses after short periods of contact lens wear

PURPOSE

To investigate if contact lens-related discomfort is a function of the time of day at which lenses are worn.

METHODS

This was a randomized, crossover, open-label clinical trial where subjective responses, with and without contact lenses, were assessed every 2 hours during five stages (A to E). Each stage began at the time when subjects would normally have inserted their contact lenses (T0). During stage A, no lenses were worn, whereas in stage B, lenses were worn continuously for 12 hours. In stages C to E, lenses were worn for only 4 hours. Contact lenses were inserted at T0 for stage C, but for stages D and E, lenses were not inserted until T0 + 4 and T0 + 8 hours, respectively. Mixed linear models were used for statistical analysis.

RESULTS

In the absence of contact lenses, ocular comfort and dryness remained reasonably constant throughout the observation period. Ocular comfort and dryness decreased during 12 hours of continuous lens wear and became significantly worse from the 8-hour time onward compared with insertion (p < 0.023). There were no significant differences in terms of ocular comfort and dryness between any of the 4-hour lens wear stages (p < 0.82). During each 4-hour stage, both comfort and dryness behaved in a similar fashion (p > 0.05) to the first 4 hours of continuous contact lens wear. Comparing the scores of each of these stages with the no-lens response at the corresponding time showed no significant differences for comfort (p > 0.23) or dryness (p > 0.37).

CONCLUSIONS

Short periods of wear can be experienced at any time of day without significant change in ocular discomfort and dryness. This suggests that subjective responses at the end of the day are determined by the length of time lenses are in contact with the eye, rather than the time of day at which lenses are worn.

Performance of three multipurpose disinfecting solutions with a silicone hydrogel contact lens

Purpose. To evaluate the clinical performance of a silicone hydrogel (Si-Hy) soft contact lens (CL) in combination with three different multipurpose disinfecting solutions (MPDSs). Methods. This was a prospective, randomized, single-masked, crossover, and comparative study in which 31 habitual soft CL wearers were randomly assigned to one of the three MPDSs (Synergi, COMPLETE RevitaLens, and OPTI-FREE PureMoist) for 1 month with a 1-week wash-out period between each exposure. All subjects were successfully refitted with a Si-Hy CL (Biofinity). Subjects were then scheduled for follow-up visits after 1 month of lens wear, being evaluated at 2 and 8 hours after lens insertion. Visual Analogue Scales (VAS) were used to gauge comfort rating. Results. The tarsal conjunctiva showed a significantly different degree of lid redness between the MPDSs at the 2-hour visit (P < 0.05, Kruskal-Wallis test), being lower for COMPLETE RevitaLens compared to the other two MPDSs (Mann-Whitney U test). Furthermore, a significantly different degree of lid roughness at the 8-hour visit was seen (P < 0.05, Kruskal-Wallis test), being higher for Synergi (Mann-Whitney U test). The subjective comfort was similar with the three MPDSs. Conclusion. Tarsal conjunctival response should be also considered in the context of the clinical performance of MPDs at the ocular surface.

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

PURPOSE

Replacing 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.

METHODS

Prevalence 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.

RESULTS

Thirty-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.

CONCLUSIONS

A 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.

The TFOS International Workshop on Contact Lens Discomfort: report of the subcommittee on neurobiology

This report characterizes the neurobiology of the ocular surface and highlights relevant mechanisms that may underpin contact lens-related discomfort. While there is limited evidence for the mechanisms involved in contact lens-related discomfort, neurobiological mechanisms in dry eye disease, the inflammatory pathway, the effect of hyperosmolarity on ocular surface nociceptors, and subsequent sensory processing of ocular pain and discomfort have been at least partly elucidated and are presented herein to provide insight in this new arena. The stimulus to the ocular surface from a contact lens is likely to be complex and multifactorial, including components of osmolarity, solution effects, desiccation, thermal effects, inflammation, friction, and mechanical stimulation. Sensory input will arise from stimulation of the lid margin, palpebral and bulbar conjunctiva, and the cornea.