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Purpose Both emmetropic and myopic eyes elongate throughout childhood. The goals of this study were to compare axial elongation among untreated progressing myopes, progressing myopes treated with a myopia control contact lens and emmetropes, in order to place axial elongation in the context of normal eye growth in emmetropic children, and to consider whether normal physiological eye growth places limits on what might be achieved with myopia control. Methods Axial elongation data were taken from the 3‐year randomised clinical trial of a myopia control dual‐focus (MiSight® 1 day) contact lens. These were compared with data for myopic and emmetropic children in two large cohort studies: the Orinda Longitudinal Study of Myopia (OLSM) and the Singapore Cohort Study of the Risk Factors for Myopia (SCORM). Each study's published equations were used to calculate annual axial elongation. Four virtual cohorts—myopic and emmetropic for each model—were created, each with the same age distribution as the MiSight clinical trial subjects and the predicted cumulative elongation calculated at years 1, 2 and 3 for myopes and emmetropes using both the OLSM and SCORM models. Results The untreated control myopes in the MiSight clinical trial showed mean axial elongation over 3 years (0.62 mm) similar to the virtual cohorts based on the OLSM (0.70 mm) and SCORM (0.65 mm) models. The predicted 3‐year axial elongation for the virtual cohorts of emmetropes was 0.24 mm for both the OLSM and SCORM models—similar to the mean 3‐year elongation in MiSight‐treated myopes (0.30 mm). Conclusions The 3‐year elongation in MiSight‐treated myopes approached that of virtual cohorts of emmetropes with the same age distribution. It is hypothesised that myopic axial elongation is superimposed on an underlying physiological axial elongation observed in emmetropic eyes, which reflects increases in body stature. We speculate that optically based myopia control treatments may minimise the myopic axial elongation but retain the underlying physiological elongation observed in emmetropic eyes.

PURPOSE To investigate the effect of soft contact lens (CL) wear on the morphology of the epithelial-lamina propria junction as well as the possible association with symptoms of discomfort. METHODS Ninety-two subjects were recruited, including 60 soft CL wearers, 16 previous wearers, and 16 non-wearers. Additionally, subjects were classified as symptomatic or asymptomatic using the Contact Lens Dry Eye Questionnaire 8 for the CL wearers (a score ≥ 12 was considered symptomatic) and the Dry Eye Questionnaire 5 for the previous wearers and non-wearers (a score ≥ 5 was considered symptomatic). In vivo confocal microscopy of the tarsal conjunctiva was performed on a single occasion. Papillae density, shortest diameter, longest diameter, area, circularity, lumen/wall brightness ratio, irregularity, reflectivity, inhomogeneous appearance of wall and inhomogeneous appearance of rete ridges were evaluated. Effects of CL wear, symptoms and their interaction were analysed using two-way analysis of variance. Correlations were investigated using Spearman's coefficient. Data are presented as mean (standard deviation) or median [interquartile range]. RESULTS Contact lens wearers, compared to previous wearers and non-wearers, showed higher circularity [0.65 (0.08) vs 0.59 (0.10) vs 0.57 (0.11), p = 0.003]. Subjects with symptoms, compared to asymptomatic participants, showed higher circularity [0.64 (0.08) vs 0.61 (0.10), p

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.

To describe a ranked symptoms scale (RSS) discriminating subjective responses in contact lens (CL) wear in various situations.Forty experienced clinical trial participants were interviewed for their perceptions of ocular comfort scales, resulting in a numerical RSS. For further evaluation, 20 CL wearers enrolled into a prospective, randomised, crossover trial. Two silicone-hydrogel CLs and a lens care solution (LCS) [Combinations AB] were selected based on prior performance identifying best/worst combinations for end-of-day comfort. The RSS and a numerical rating scale (NRS) were administered at two time-points (insertion/removal) on alternating days for 6 days.Both NRS and RSS showed acceptable internal consistency for comfort, vision and handling (Cronbach alpha=0.71 for both scales) and similar repeatability for comfort and handling (coefficients-of-repeatability within 0.1 and 0.2 units, respectively, for each scale). The NRS and RSS discriminated differences between combinations for comfort (p≤0.031) and vision (p≤0.026) at both time-points. Additionally, the RSS showed lens/edge awareness influenced discomfort the most, ranking higher at insertion (p=0.038) and higher for Combination-B at both time-points (p≤0.002). Symptoms of dryness and tired eyes increased for both combinations at removal (p0.02). The RSS also showed haziness and blurred distance vision influenced vision dissatisfaction with Combination-B at lens removal (p≤0.038) while eye strain/headache increased for both combinations by time of removal (p≤0.013).The RSS is able to discriminate subjective responses between combinations and time-of-day. The RSS's ability to rank symptoms may be a useful tool in understanding perceptions of discomfort or dissatisfaction with CL wear.

Purpose Our aim was to quantitate day-to-day changes in the tear and meibum lipid profile of individual subjects in a pilot study of healthy humans. Methods Matched tear and meibum samples were obtained from four subjects on three consecutive days. Quantitative lipid profiles of human basal tears and meibum were compared using multivariate analysis by principal components. Results Substantial differences in the lipid profile between subjects were observed, while lipid profiles were steady across the three consecutive days of sampling. Multivariate principal component analysis demonstrated that lysophosphatidylcholine was the largest variant lipid class between subjects in tears, while wax esters comprised the most variation between subjects in meibum secretions. Conclusion Interday variability is shown to be much smaller than interpatient variability, suggesting that tears and meibum subjects both have unique profiles in humans.

AIM A series of proof-of-principle extended wear (EW) contact lens studies were conducted to assess what effect different interventions had on adverse events (AEs). Comparative analysis of AEs across studies was conducted to determine whether some interventions were more effective at reducing inflammatory AEs. METHOD Multiple logistic regression analysis of AEs from 30-day EW studies each with a different intervention including (1) nightly replacement (NR) of lenses, (2) morning replacement (MR) of lenses, (3) instillation of prophylactic antibiotic drops (AB) each morning/evening, (4) daily lens cleaning (LC) each morning. All studies conducted at the same site using same lens type (lotrafilcon A) and EW schedule. RESULTS Comparison of the different interventions to the individual control groups showed no difference in significant corneal infiltrative event (CIE) or mechanical events. Replacing lenses nightly, during an EW schedule, had the highest incidence of significant CIEs (4.9% [NR] vs. 2.5% [MR] vs. 1.8% [AB] vs. 0% [LC]); however, adjusted logistic regression analysis of the combined control data compared with the individual interventions showed no difference in significant CIEs (P=0.086) or mechanical AEs (P=0.140). CONCLUSIONS Replacing lenses each night seemed to be inferior compared with the other interventions of replacing lenses each morning, daily lens cleaning, and daily antibiotic drop instillation during EW. The results of the collective studies and additional analysis suggest that overnight wear of contact lenses seems to create an adverse environment that remains, despite the various interventions intended to improve this adverse environment.

Purpose: To develop a contact lens system that will control the release of an osmoprotectant and a moisturizing agent with the aim to reduce symptoms of ocular dryness.Materials and methods: Profiles of the release of osmoprotectant betaine and moisturizing agent dexpanthenol from senofilcon A and narafilcon B contact lenses were determined in vitro under sink conditions. Both types of lenses were also infused with vitamin E to increase the duration of drug release due to the formation of the vitamin E diffusion barriers in the lenses. The release profiles from vitamin E-infused lenses were compared with those from the control lenses.Results: Both dexpanthenol and betaine are released from commercial silicone hydrogel lenses for only about 10 min. Vitamin E loadings into contact lenses at about 20–23% can increase the release times to about 10 h, which is about 60 times larger compared to the control unmodified lenses.Conclusions: Vitamin E-loaded silicone hydrogel contact lenses released betaine ...

PURPOSE To determine the efficacy of written instructions on contact lens case hygiene and to quantify the effect of noncompliance on contact lens case contamination. METHODS Data were retrospectively analyzed from 16 prospective, 3-month daily-wear studies during which six commercially available silicone hydrogel contact lenses and seven lens care solutions (LCS) were tested following a similar protocol. Verbal instructions regarding case hygiene (rinse case with LCS, not tap water) were given in nine studies, while the same instructions were given verbally and in written format in seven studies. A survey on contact lens, LCS, and lens case hygiene was completed at 1- and 3-month visits and compliance with case hygiene instructions was determined. Regular contact lens cases were used for 1 month and collected for microbial analysis at the 1- and 3-month visits. The rate of case contamination and the types of microbes contaminating cases were evaluated. RESULTS Participants given verbal and written instructions were more likely to be compliant with case hygiene instructions than those just given verbal instructions (odds ratio [OR]: 2.19, p < 0.001, 95% confidence interval [CI]: 1.40-3.44). The overall case contamination rate was 79%. Use of tap water to rinse contact lens cases was associated with significantly more cases contaminated with Gram-negative bacteria (GNB) (30% vs. 10%, p < 0.001), a greater risk of GNB case contamination (OR: 2.91, p < 0.001. 95% CI: 1.72-4.92), and a higher quantity of GNB in cases (mean colony-forming unit/case ± SD: 28,286 ± 131,935 vs. 6477 ± 60,447, p < 0.001). CONCLUSIONS Lens case hygiene can be improved by effective communication of instructions. Contact lens wearers should be actively discouraged from rinsing contact lens cases with tap water because of the increased risk of GNB contamination.

PURPOSE Overnight lens wear is associated with increased lens contamination and risk of developing a corneal infiltrate or infectious event. Antibacterial lenses have been proposed as a potential strategy for reducing lens contamination. A proof-of-principle study was conducted to investigate what effect control of potential pathogens, through the use of antibiotic eye drops, would have on the incidence of corneal infiltrative events (CIEs) and on the ocular microbiota and lens contamination. METHODS This is a prospective, open-label, controlled, parallel-group, 1-month clinical study in which 241 subjects were dispensed with lotrafilcon A silicone hydrogel lenses for 30 days of continuous wear. Subjects were randomized into either test (moxifloxacin 0.5%) or control (rewetting solution) group. One drop was instilled into each eye on waking and before sleeping, while lenses were on-eye. Follow-ups were conducted after one night and 1 month. Lid margin swabs were taken at baseline and at 1 month and worn lenses were aseptically collected at 1 month. RESULTS The incidence of CIEs was not significantly different between the test (2.6%) and control (3.9%) groups (p = 0.72). Microorganism levels from the test group swabs were significantly lower than those from the control group (p = 0.001). Gram-positive bacteria were less frequently recovered from lower lid swabs from the test group (39.6% vs. 66.0% [p < 0.001], test vs. control, respectively) or from contact lens samples (1.9% vs. 10.5% [p = 0.015], test vs. control, respectively), but there was no difference in gram-negative bacteria (GNB). Corneal infiltrative events were associated with higher levels of lens contamination (p = 0.014) and contamination of lenses with GNB (CIE: 7.3% vs. 0.6% [p = 0.029], GNB contamination vs. no GNB contamination, respectively). DISCUSSION Twice-daily antibiotic instillation during continuous wear of lenses did not significantly influence the rate of inflammatory events. Corneal infiltrative events were associated with higher levels of lens contamination in general and with contamination by GNB specifically.

OBJECTIVE To compare the short-term clinical performance of two dual-disinfectant multipurpose disinfecting solutions (MPDS) when used in conjunction with two silicone hydrogel contact lenses. METHODS Participants wore galyfilcon A and balafilcon A lenses, randomly allocated one type to each eye. Multipurpose disinfecting solutions were double-masked and allocated using a randomized crossover design. Lenses were presoaked overnight in the allocated MPDS, containing either polyquaternium-1/alexidine dihydrochloride (PQ-alexidine) or polyquaternium-1/myristamidopropyl dimethylamine (PQ-MAPDA). Lenses were worn daily for 4 days and disinfected with the same MPDS in which they had been soaked. Clinical assessments occurred immediately after insertion, 2 hours after insertion, and after 2 hours of wear on day 4. Subjective ratings were collected at each assessment and after 6 hours of wear on days 1 to 3. Linear mixed models were used for statistical analysis. RESULTS Solution-induced corneal staining (SICS) incidence was significantly different between MPDS lens combinations (P=0.01) with PQ-MAPDA-balafilcon A showing the highest incidence (27.8%). The incidence of SICS was significantly higher when balafilcon A lenses were worn compared with galyfilcon A (19.4% vs. 2.8%; P=0.04). There was no significant difference in SICS incidence between MPDS (PQ-alexidine=5.6%, PQ-MAPDA=16.7%; P=0.08). Polyquaternium-1/alexidine dihydrochloride was associated with significantly fewer symptoms of burning/stinging (9.7±0.6 vs. 9.1±2.2; P=0.03) and self-assessed redness (9.8±0.5 vs. 9.2±1.9; P=0.03) on initial lens insertion. There were no significant differences between MPDS for comfort ratings (P>0.05). CONCLUSION These short-term clinical results provide an initial indication that PQ-alexidine is associated with fewer symptoms on insertion but no significant difference in ocular comfort compared with PQ-MAPDA. Longer studies are required to provide further evidence.

Purpose To evaluate subjective responses, rates of solution-induced corneal staining (SICS), and corneal infiltrative events (CIEs) associated with a silicone hydrogel when worn under a daily disposable (DD) or daily wear (DW) modality. Methods Data were obtained from seven prospective clinical trials, involving 283 subjects wearing Senofilcon A contact lenses (Johnson and Johnson Vision Care, Jacksonville, FL). Four groups wore the contact lens on a DW basis using multipurpose solutions (DW-MPS, n = 160), two groups using hydrogen peroxide (DW-H2O2, n = 83), and one group as a DD (n = 40). Participants were followed for 3 months using the same protocol. Subjective ratings were compared between DD and DW groups using a linear mixed model. Rates of SICS and CIE were calculated as the percent frequency of first events within the 3-month study. Association of SICS and CIE with subjective responses was analyzed using a linear mixed model. Results End-of-day comfort and dryness ratings were significantly better for DD (8.5 ± 1.7 and 8.6 ± 1.7, respectively) compared with DW-H2O2 (7.7 ± 1.8, p = 0.01; 7.6 ± 1.9, p = 0.006, respectively) and DW-MPS (7.7 ± 1.7, p = 0.004; 7.6 ± 2.0, p = 0.003, respectively). Compared with DD, a higher incidence of CIE and SICS was found for DW-MPS (0.0 vs. 3.9%, p = 0.021; 0.9 vs. 8.6%, p = 0.002, respectively). Comfort at insertion and end of day and end-of-day dryness scores were significantly lower for participants who experienced SICS (8.2 ± 1.6, 7.0 ± 1.9, and 7.0 ± 2.2) than those who did not (8.8 ± 1.2, p = 0.004; 7.9 ± 1.7, p = 0.002; and 7.9 ± 1.8, p = 0.003, respectively). Comfort at insertion scores were significantly lower for participants who experienced CIEs than those who did not (8.2 ± 1.5 vs. 8.8 ± 1.4, p = 0.032). Conclusions Senofilcon A clinical response is modulated by the lens care products. All lens care products tested reduced subjective responses relative to DD modality, whereas MPS increased the incidence of CIEs and SICS. Senofilcon A performs best when used on a DD basis.

Significant advances during the past decade in silicone hydrogel lenses have made them the primary mode for new contact lens wear. Their dominance in the market place is driven largely by the elimination of structural and physiological changes induced by contact lens-induced hypoxia, as exemplified especially by the reduction in limbal redness. However, end-of-day dryness and discomfort still drives many to discontinue lens wear. Evidence also indicates that the rate of serious adverse events, such as microbial keratitis, have not been impacted with the use of silicone hydrogel lenses. Moreover, there are additional challenges relating to 'corneal staining' and corneal infiltrates associated with the incompatibility of lens care product with contact lens polymers. On the other hand, technological advances enabled by the high oxygen platform present opportunities for expanding the use of contact lenses in areas that have exhibited limited uptake in the past such as astigmatism, presbyopia, and importantly myopia control. The challenges and opportunities facing the field will be discussed.

To determine if rating of ocular comfort during soft contact lens wear is affected by demographic factors.Retrospective analysis of ocular comfort ratings during soft contact lens wear extracted from 44 nonrandomized similar clinical trials (n = 986). Subjects wore one of seven daily wear silicone hydrogels (SiHy) in combination with one of nine lens care products (LCP), and two daily disposables lenses. The effects on comfort rating of demographic factors were examined after adjusting for lens and LCP effects using general linear model.Males reported lower comfort on insertion than females (7.9 ± 1.6 vs. 8.1 ± 1.6, p = 0.001). Over 45 years old had higher comfort ratings than those between 26 and 45 or26 years old at insertion (8.7 ± 1.3 vs. 8.1 ± 1.6 vs. 7.8 ± 1.6, p0.001), during the day (8.6 ± 1.2 vs. 8.0 ± 1.6 vs. 8.2 ± 1.2, p0.001), and end of day (7.7 ± 1.6 vs. 6.8 ± 2.0 vs. 7.0 ± 1.6, p0.001). Neophytes reported lower comfort on insertion (7.3 ± 1.6 vs. 8.2 ± 1.5, p0.001) and during day (8.0 ± 1.3 vs. 8.3 ± 1.3, p = 0.020) than experienced wearers. Participants with Rx ≥-3.50D had higher comfort ratings than those with ≤-3.50D on insertion (8.3 ± 1.4 vs. 7.8 ± 1.6, p0.001), during the day (8.4 ± 1.3 vs. 8.1 ± 1.3, p = 0.010), and end of day (7.2 ± 1.7 vs. 6.9 ± 1.8, p = 0.046). Comfort during the day was different between participants of different ethnic origin (p = 0.024) with Asians reporting the lowest (8.1 ± 1.3).Demographic factors such as age, gender, lens wear experience, ethnicity, and refractive status can influence the rating of ocular comfort in clinical studies. The confounding effects of such demographic factors can be controlled by implementing randomization and appropriate multivariable statistical analysis.

The aim of this study was to investigate the relationship between solution-induced corneal staining (SICS) and silicone hydrogel contact lens comfort and vision.A retrospective analysis of a series of open-label studies were conducted with 24 groups of approximately 40 participants, each wearing 1 of 6 silicone hydrogel contact lenses with 1 of 4 lens care products bilaterally for 3 months of daily wear. The presence of SICS and subjective ocular ratings were collected at 2 weeks and at 1 and 3 months.A total of 1,051 participants were enrolled. The participants with SICS rated significantly less favorably than did the participants without SICS for comfort during the day (7.9±1.7 vs. 8.5±1.4, P=0.03), comfort at the end of the day (6.6±2.1 vs. 7.4±1.9, P=0.03), overall dryness (7.4±1.9 vs. 8.0±1.7, P=0.04), dryness at the end of the day (6.7±2.2 vs. 7.5±2.1, P=0.01), feelings of burning and stinging (8.5±2.0 vs. 8.9±1.8, P=0.02), and overall vision (8.2±1.6 vs. 8.7±1.3, P0.001).The participants with SICS had lower subjective comfort and vision compared with those who did not experience SICS.

PURPOSE Contamination of contact lens cases has been associated with the production of adverse responses in the eye during contact lens wear. This study aimed to evaluate the contamination rate and types of microbes contaminating cases during use of contact lens disinfecting solutions and silicone hydrogel lenses. METHODS Two hundred thirty-two participants were allocated to one or more groups. The participants wore one or more of three silicone hydrogel lenses and used one or more of four contact lens disinfecting solutions. Cases were collected after use for 1 month and sent for routine microbial testing. The rate of contamination of cases and the types of microbes contaminating cases were evaluated. RESULTS Between 76 and 92% of all cases were contaminated. Use of different contact lenses did not affect contamination rate or the types of microbes isolated from cases. Use of AQuify (PHMB as disinfectant) was associated with the highest contamination rate (92%; p = 0.015) of cases for any microbe. Level and type of contamination with use of ClearCare (H2O2) was similar to use of PHMB (polyhexamethylene biguanide)- or Polyquat/Aldox-containing solutions. There was no difference in contamination rate of cases by fungi or Gram-positive bacteria, but for Gram-negative bacteria, use of Opti-Free Express (Polyquat and Aldox as disinfectants) resulted in a lower contamination rate (7% vs. 29 to 45%; p < 0.001). The average number of microbes contaminating a case was significantly less for Opti-Free Express (223 +/- 1357 cfu/case) compared with Opti-Free RepleniSH (Polyquat and Aldox as disinfectants; 63,244 +/- 140,630 cfu/case; p < 0.001), driven mostly by differences in numbers of Gram-negative bacteria, particularly contamination by Delftia acidovorans in cases exposed to Opti-Free RepleniSH. CONCLUSIONS Different disinfecting solutions used during storage in cases result in different levels of contamination and contamination by different types of microbes. These differences are not simply because of the types of disinfectants used, suggesting that other excipients in, or formulation of, the solution affect contact lens storage case contamination.

To compare the lipid composition of human meibum across three different meibum expression techniques.Meibum was collected from five healthy non-contact lens wearers (aged 20-35 years) after cleaning the eyelid margin using three meibum expression methods: cotton buds (CB), meibomian gland evaluator (MGE) and meibomian gland forceps (MGF). Meibum was also collected using cotton buds without cleaning the eyelid margin (CBn). Lipids were analyzed by chip-based, nano-electrospray mass spectrometry (ESI-MS). Comparisons were made using linear mixed models.Tandem MS enabled identification and quantification of over 200 lipid species across ten lipid classes. There were significant differences between collection techniques in the relative quantities of polar lipids obtained (P.05). The MGE method returned smaller polar lipid quantities than the CB approaches. No significant differences were found between techniques for nonpolar lipids. No significant differences were found between cleaned and non-cleaned eyelids for polar or nonpolar lipids.Meibum expression technique influences the relative amount of phospholipids in the resulting sample. The highest amounts of phospholipids were detected with the CB approaches and the lowest with the MGE technique. Cleaning the eyelid margin prior to expression was not found to affect the lipid composition of the sample. This may be a consequence of the more forceful expression resulting in cell membrane contamination or higher risk of tear lipid contamination as a result of reflex tearing.

To investigate if contact lens-related discomfort is a function of the time of day at which lenses are worn.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.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 (p0.023). There were no significant differences in terms of ocular comfort and dryness between any of the 4-hour lens wear stages (p0.82). During each 4-hour stage, both comfort and dryness behaved in a similar fashion (p0.05) 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 (p0.23) or dryness (p0.37).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.

To measure the power profile across the optic zone (OZ) of four commercially available soft contact lenses and establish the impact on the peripheral refractive error of the eye.The power profiles of a spherical conventional hydrogel contact lens (etafilcon A, JJ Vistakon, Jacksonville, FL USA) and three spherical silicone hydrogel contact lenses (lotrafilcon A and B, CIBA Vision, Duluth, GA USA; enfilcon A, CooperVision, Pleasanton, CA USA) with a labeled power of -3.00 and -6.00 diopters were measured using a Shack-Hartmann wavefront sensor power mapping device. Central and peripheral refraction across the horizontal meridian (nasal and temporal visual field at 20, 30, and 40 degrees) was measured with an open-field autorefractor (Shin Nippon NVision K5001, Osaka Japan) with and without contact lenses in 26 myopic subjects. The relative peripheral refractive error on the eye was estimated and compared with and without contact lenses and between contact lenses.Differences in the distribution of the power profile across the OZ were apparent between contact lens types and powers. No significant differences (p0.05) were found between contact lens types for their effect on on-axis refraction. Significant differences (p0.05) were found at all peripheral retinal eccentricities between contact lens types.For a given central power, the four contact lenses exhibited variations in optical power across the OZ of the lens. The distribution of optical power across the OZ has an influence on the peripheral refractive error of the eye.

Purpose To quantify the molecular lipid composition of patient-matched tear and meibum samples and compare tear and meibum lipid molecular profiles. Methods Lipids were extracted from tears and meibum by bi-phasic methods using 10:3 tert-butyl methyl ether:methanol, washed with aqueous ammonium acetate, and analyzed by chip-based nanoelectrospray ionization tandem mass spectrometry. Targeted precursor ion and neutral loss scans identified individual molecular lipids and quantification was obtained by comparison to internal standards in each lipid class. Results Two hundred and thirty-six lipid species were identified and quantified from nine lipid classes comprised of cholesterol esters, wax esters, (O-acyl)-ω-hydroxy fatty acids, triacylglycerols, phosphatidylcholine, lysophosphatidylcholine, phosphatidylethanolamine, sphingomyelin, and phosphatidylserine. With the exception of phospholipids, lipid molecular profiles were strikingly similar between tears and meibum. Conclusions Comparisons between tears and meibum indicate that meibum is likely to supply the majority of lipids in the tear film lipid layer. However, the observed higher mole ratio of phospholipid in tears shows that analysis of meibum alone does not provide a complete understanding of the tear film lipid composition.

A range of childhood disorders of the eye such as keratoconus, amblyopia, pediatric aphakia, and common refractive errors such as myopia can be effectively managed with contact lenses.1–9 Also, importantly, evidence suggests that contact lenses may play a significant role in controlling the progression of myopia.10–13 Despite the utility of contact lenses in children, there exists a general perception that contact lenses are not suitable for use in children. This concern stems from two areas (1) handling and care of contact lenses by children and (2) safety of contact lens wear, that is, the risk of developing contact lens–related complications. With regard to handling and managing contact lens wear, there now exists evidence that children aged 8 years and older can independently manage lens insertion and removal and also successfully wear contact lenses.7,9 There have been reports of microbial keratitis with contact lens wear in children and were mainly case reports or case series attending emergency departments and involving overnight lens wear or other predisposing risk factors.14–16 Although this information is useful in identifying the issues, there is little evidence from large well-designed clinical trials on the rate of complications with long-term use of contact lens wear in children. Since their introduction in 1999, the use of silicone hydrogel contact lenses has increased significantly.17 Originally introduced for overnight and continuous use, it was anticipated that the increased oxygen transmissibility would result in a healthier cornea that was capable of withstanding infections. Although the lenses eliminated hypoxia-related complications, it was not clear if silicone hydrogels used on an overnight wear basis impacted on the rate of microbial keratitis or inflammatory events.18 This led to a shift, with silicone hydrogels increasingly prescribed for use on a daily wear basis rather than continuous wear.19,20 A single study reported that the risk of developing adverse events was reported to be lower with daily wear of silicone hydrogels compared with that with continuous wear.21 Another study found the incidence of adverse events to be low with daily wear and to vary with the lens care system used.22 However, the latter study was short-term, and the lenses were used by an adult population. There have been no studies that have evaluated the incidence of adverse events with daily wear of silicone hydrogels in children. We initiated a prospective clinical trial in November 2008 involving the use of both standard and novel design silicone hydrogel lenses in Chinese children with myopia. Two hundred forty children were enrolled in the trial, and the aim was to determine the rate of progression of myopia with both standard and novel contact lenses. In the present article, we report the incidence and type of adverse events that occurred during the first 2 years of lens wear. The rate of discontinuations from lens wear and the reasons are also reported.

To report the performance of various contact lenses and lens care solution combinations based on the combined response of subjective comfort and adverse events (AEs).A retrospective analysis of 28 lens/solution combinations each tested on approximately 40 participants who wore their assigned combination on a daily wear basis and were followed for a 3-month period, with visits at baseline, 2 weeks, and 1 and 3 months. Lenses included frequent replacement and daily disposables. Solutions included hydrogen peroxide and multipurpose types. Subjective comfort (scale of 1 to 10) and AEs were collected and reported as a group mean and percentage, respectively. The data were converted into a ratio between 0 and 1 to represent the relative performance within the combination series, with a higher ratio indicating better performance in both AE rates and comfort.The overall AE rate was 3.6 events per 100 participant-months (95% confidence interval [95% CI], 2.7 to 4.7%). The rate was found to be lower in daily disposables compared with that in daily wear lenses (3.1 vs. 10.9%, p0.001). The overall comfort on insertion rating was 8.3 (95% CI, 8.1 to 8.4), and comfort at end of day was 7.2 (95% CI, 7.0 to 7.4). Based on the 28 lens/solution combinations, there was no significant correlation between overall AE rates and comfort on insertion or at end of day (Pearson correlation, -0.34, p = 0.08; and Pearson correlation, -0.23, p = 0.25, respectively). Less than 18% of the combinations tested combined good comfort with low AE rates.Both subjective comfort responses and AE rates varied according to the combination of lens type and care system in use. The combinations with the best comfort ratings did not necessarily have a favorable AE rate. Practitioners can maximize behavior with respect to both these factors by choosing an appropriate care system for the lenses they prescribe.

PURPOSE To determine if the ocular comfort of symptomatic contact lens (CL) wearers can be substantially influenced by choosing a better or worse performing CL-lens care product (LCP) combination. METHODS Twenty-four symptomatic and 13 nonsymptomatic CL wearers were enrolled into a prospective, crossover, randomized clinical trial. Two CL-LCP combinations were chosen from studies previously conducted at the Brien Holden Vision Institute that were found to provide the best (galyfilcon A/polyhexanide, combination 1) and worst performance (balafilcon A/polyquaternium-1 and myristamidopropyl dimethylamine + TearGlyde, combination 2) in terms of end-of-day comfort. Subjects were not informed whether they were categorized as symptomatic or nonsymptomatic nor were they aware of the rankings of each CL-LCP combination. Subjects were randomly allocated to one of the CL-LCP combinations for 8 days on a daily wear basis. Contact lens fitting was assessed after insertion from the packaging solution. Take-home questionnaires assessing ocular comfort and dryness (1 to 10 numeric rating scale) were completed on insertion and after 2 and 8 hours of wear on days 2, 4, and 6. Ocular symptoms were assessed on days 2, 4, and 6 after 8 hours of wear. A 48-hour washout period during which CLs were not worn was applied, with the procedure repeated using the second combination. RESULTS In symptomatic subjects, combination 1 was rated significantly better than combination 2 after 8 hours of wear for ocular comfort (7.7 ± 1.3 vs. 7.1 ± 1.5, p = 0.01) and ocular dryness (7.5 ± 1.6 vs. 7.0 ± 1.6, p = 0.045), with less frequent symptoms of ocular dryness (p < 0.01) and lens awareness (p < 0.01) reported. No significant differences were found in nonsymptomatic subjects. CONCLUSIONS Ocular comfort and symptoms in symptomatic CL wearers can be perceptibly improved by switching to an alternative CL-LCP combination. This finding provides justification for the efforts of both eye care practitioners and researchers to improve the comfort of CL wearers.

PURPOSE Compared with daily disposable wear schedule, continuous wear (CW) or extended wear of contact lenses has been associated with an increased risk of developing an ocular infection. Proof-of-principle studies were conducted to investigate the impact of daily replacement of lenses on the rate of contact lens-related ocular adverse events (AEs) during 30-night CW. METHODS A total of 215 subjects were dispensed with silicone hydrogel lenses on a 30-night CW schedule but replaced lenses daily either each night before sleeping (n = 178 eyes) or each morning after waking (n = 252 eyes). Scheduled clinic visits were conducted at 1 week and 1 month. Neophytes were required to complete 1 week of daily wear before commencing CW. A historical control (n = 191 eyes) using the same site, subject demographics, and visit schedule but monthly lens replacement was used for AE rates. RESULTS Logistic regression analysis showed a significant reduction in mechanical AEs (0.8 vs 5.2%, p = 0.01) and overall AEs (inflammatory and mechanical events) (4.0 vs 8.9%, p = 0.04) when lenses were replaced each morning compared with being replaced monthly. Estimation of handling-related lens contamination of unworn lenses in a subgroup of subjects showed isolation of Staphylococcus aureus from the lenses of 35% of subjects, and 65% of subjects had more than 1000 colony-forming units per lens of gram-positive bacterial contamination. CONCLUSIONS Morning lens replacement during CW reduced mechanical and overall ocular AEs. Replacing lenses at night had no beneficial effects perhaps because the benefit of a fresh lens at night might be partially negated by contamination of the contact lens caused by lens handling before overnight eye closure. Contact lens wearers on an extended wear or CW schedule should be advised to minimize lens handling before sleep to reduce the risk of complications.

To evaluate clinical performance of three lens types disposed of on a daily disposable (DD) basis.A total of 120 participants were randomized into one of three lens types (etafilcon A, narafilcon A, and senofilcon A), all worn bilaterally on a DD regime. Participants were observed at baseline, 2-week, and 1- and 3-month visits where ocular physiology and lens performance variables were collected on a 0 to 4 grading scale in 0.1 increments. Subjective comfort and vision ratings were collected on a 1 to 100 rating scale and in the form of symptom severity.Forty participants wore each lens type with no differences in age or gender between groups (P0.05). Etafilcon A exhibited more limbal redness compared with either of the other lens types (P0.01). More superior corneal staining was noted with narafilcon A lenses compared with senofilcon A (P0.01), and more superior conjunctival indentation was noted for narafilcon A compared with etafilcon A (P=0.001). No differences were found between lenses in the 1 to 100 rating scale (P0.05). Narafilcon A showed more moderate to severe dryness symptoms and symptoms of blurred vision at lens wearing visits (P0.05). One bilateral contact lens papillary conjunctivitis, one unilateral superior epithelial arcuate lesion, and one infiltrative keratitis were associated with narafilcon A only. Of the seven discontinuations, six were from the narafilcon A group.Different contact lens materials and designs, worn on the same DD modality, elicit different ocular and patient responses. Narafilcon A did not perform clinically as well as etafilcon A and senofilcon A worn on a DD modality.

PURPOSE. We provide a new procedure to quantify in situ corneal oxygen uptake using the micropolarographic Clark electrode. METHODS. Traditionally, upon placing a membrane-covered Clark microelectrode onto a human cornea, the resulting polarographic signal is interpreted as the oxygen partial pressure at the anterior corneal surface. However, the Clark electrode operates at a limiting current. Hence, oxygen flux is directly detected rather than partial pressure. We corrected this misunderstanding and devised a new analysis to quantify oxygen uptake into the cornea. The proposed analysis is applied to new polarographic data for 10 human subjects during open-eye oxygen uptake. RESULTS. Average open-eye corneal oxygen uptake over 10 subjects is approximately 11 lL/(cm 2 h), approximately five times larger than the average reported by researchers who invoke the original mathematical analysis. Application of the classical interpretation scheme to our experimental data also garners uptake values that are approximately a factor of three to five times smaller than those obtained with our new procedure. CONCLUSIONS. The classical procedure originally developed by Fatt and colleagues misinterprets the behavior of the Clark microelectrode. We corrected the analysis of the in situ polarographic technique to provide a simple yet rigorous procedure for analyzing both previous data in the literature and those newly obtained. Our proposed interpretation scheme thus provides a reliable tool for in vivo assessment of corneal oxygen uptake. (Invest Ophthalmol Vis Sci. 2012;53:6331‐ 6337) DOI:10.1167/iovs.12-10059

Purpose To quantify changes in contact lens parameters induced by lens wear and determine whether these changes are associated with contact lens-induced conjunctival staining (CLICS). Methods In vitro: Lens diameter, sag, edge shape, base curve of six contact lens brands (balafilcon, comfilcon, etafilcon, lotrafilcon B, omafilcon and senofilcon) measured at 21 °C and 35 °C (eye temperature). Ex vivo: Diameter of lenses collected from a prospective, randomised, contra-lateral, cross-over clinical trial from 36 subjects wearing all lens types for 1 week daily wear, measured in 35 °C PBS after removal. Ocular surface was examined for lens-induced conjunctival staining by masked examiner. Results In vitro: Changes in diameter and base curve outside ISO tolerance were found with etafilcon A and omafilcon A. Ex vivo: Comfilcon A and etafilcon A had greatest shrinkage in diameter (0.18 mm) and base curve (0.11 mm steeper) with temperature increase from 21 °C to 35 °C. Senofilcon A, lotrafilcon B and balafilcon A maintained most stable parameters between 21 °C and 35 °C. Changes in diameter and base curve from lens wear were not correlated with CLICS (p > 0.49). Multivariate analysis showed significantly greater levels of lens induced staining were associated with lens modulus (p Conclusions Parameter changes induced by lens wear were associated with increasing temperature, but these changes in lens diameter and base curve did not induce CLICS. Modulus and edge shape were associated with increased CLICS. The susceptibility of etafilcon A and omafilcon A lenses to parameter changes might be related to their high water content.

PURPOSE. To determine whether a novel optical treatment using contact lenses to reduce relative peripheral hyperopia can slow the rate of progress of myopia. METHODS. Chinese children, aged 7 to 14 years, with baseline myopia from sphere 0.75 to 3.50 D and cylinder 1.00 D, were fitted with novel contact lenses (n 45) and followed up for 12 months, and their progress was compared with that of a group (n 40) matched for age, sex, refractive error, axial length, and parental myopia wearing normal, single-vision, spherocylindrical spectacles. RESULTS. On adjusting for parental myopia, sex, age, baseline spherical equivalent (SphE) values, and compliance, the estimated progression in SphE at 12 months was 34% less, at 0.57 D, with the novel contact lenses (95% confidence interval [CI], 0.45 0.69 D) than at 0.86 D, with spectacle lenses (95% CI, 0.74 to 0.99 D). For an average baseline age of 11.2 years, baseline SphE of 2.10 D, a baseline axial length of 24.6 mm, and 320 days of compliant lens wear, the estimated increase in axial length (AL) was 33% less at 0.27 mm (95% CI, 0.22‐0.32 mm) than at 0.40 mm (95% CI, 0.35‐0.45 mm) for the contact lens and spectacle lens groups, respectively. CONCLUSIONS. The 12-month data support the hypothesis that reducing peripheral hyperopia can alter central refractive development and reduce the rate of progress of myopia. (chictr.org number, chiCTR-TRC-00000029 or chiCTRTRC-00000032.) (Invest Ophthalmol Vis Sci. 2011;52: 9362‐9367) DOI:10.1167/iovs.11-7260 I n addition to the cost, inconvenience, and complications associated with traditional optical and surgical correction strategies, myopia is associated with ocular complications that can lead to permanent vision loss. Excessive axial elongation in high myopia increases the risk for cataract, glaucoma, chorioretinal degeneration, and idiopathic retinal detachment 1‐3

INTRODUCTION This study aims to understand off-axis refraction during accommodation and to identify whether the relative hyperopia generally observed in myopic eyes changes with accommodation. METHOD Twenty bilateral myopes (18 to 33 years) between -0.50 D and -4.25 D (spherical equivalent) and astigmatism less than 1.25 D participated in this study. A soft contact lens was used to correct refractive error for all measurements. Non-cycloplegic autorefraction was measured at the fovea and 20 degrees, 30 degrees, and 40 degrees eccentricities in the nasal and temporal retina at distances of 2 m, 40 cm, and 30 cm. RESULTS Peripheral refractive error, relative to central refraction, became less hyperopic with increasing eccentricity and with increasing accommodation. Lag of accommodation increased with accommodation (p < 0.001) shifting the image-shell backward relative to the retina. In the farther periphery, there was either no change in refractive error or increased myopic shifts with accommodation. Astigmatism increased with eccentricity and significantly increased in the farther eccentricities with accommodation (p < 0.001). CONCLUSION Myopes display hyperopic shifts in the center and near peripheral field during near-viewing, while the farther periphery either remains unshifted or demonstrates a myopic shift. These results are due to the combined effect of lag of accommodation and an increased curvature of field during accommodation.

Purpose. To determine the types of microorganisms and their frequency of isolation on the external ocular surface in children wearing soft contact lenses on a daily wear schedule. Methods. Children aged 8 to 14 years were fitted with commercially available, soft contact lenses which were worn on a daily wear basis. The upper bulbar conjunctiva and the lower lid margins of each eye were swabbed at baseline and then at 6-monthly intervals for 2 years during lens wear. Swabs were processed, cultured and microorganisms identified using standard microbiological techniques. Results. At baseline, 36% of the upper bulbar conjunctivae and 53% of the lower lid margins were contaminated with predominantly gram-positive bacteria. Recovery of samples with positive growth from the upper bulbar conjunctivae decreased during lens wear and ranged from 27 to 14%. The difference was statistically significant at the 12-month visit (14%, p = 0.011). The lower lid margins generally showed similar levels of contamination as at baseline except for less contamination at the 12-month visit (33%) (p = 0.05). Staphylococcus epidermidis and Propionibacterium sp. were the predominant microorganisms isolated from both the sites with and without lens wear. Gram-negative bacteria were infrequent and when isolated, the numbers of colonies were few. Fungus was isolated in a small percent (ranging from 0 to 4.8%) of eyes at various time points. Conclusions. The external ocular surface of children is contaminated with gram-positive bacteria that are resident micro biota. During lens wear, there was a trend for lesser recovery of organisms from the upper bulbar conjunctival samples, but there was no change in the type of microorganisms isolated. At all times, lower lid margins showed consistently greater colonization and is a source of potential contamination of the conjunctival surface.

Recent research showed that the peripheral refractive state is a sufficient stimulus for myopia progression. This finding led to the suggestion that devices that control peripheral refraction may be efficacious in controlling myopia progression. This study aims to understand whether the optical effect of such devices may be affected by near focus. In particular, we seek to understand the influence of accommodation on peripheral refraction and curvature of field of the eye. Refraction was measured in twenty young subjects using an autorefractor at 0° (i.e. along visual axis), and 20°, 30° and 40° field angles both nasal and temporal to the visual axis. All measurements were conducted at 2.5 m, 40 cm and 30 cm viewing distances. Refractive errors were corrected using a soft contact lens during all measurements. As field angle increased, refraction became less hyperopic. Peripheral refraction also became less hyperopic at nearer viewing distances (i.e. with increasing accommodation). Astigmatism (J180) increased with field angle as well as with accommodation. Adopting a third-order aberration theory approach, the position of the Petzval surface relative to the retinal surface was estimated by considering the relative peripheral refractive error (RPRE) and J180 terms of peripheral refraction. Results for the estimated dioptric position of the Petzval surface relative to the retina showed substantial asymmetry. While temporal field tended to agree with theoretical predictions, nasal response departed dramatically from the model eye predictions. With increasing accommodation, peripheral refraction becomes less hyperopic while the Petzval surface showed asymmetry in its change in position. The change in the optical components (i.e. cornea and/or lens as opposed to retinal shape or position) is implicated as at least one of the contributors of this shift in peripheral refraction during accommodation.

The development of silicone hydrogel contact lenses with high oxygen permeabilities is a major step forward in vision correction. This advance in contact lenses material technology provides breakthrough levels of oxygen to the cornea. However, there are still important issues yet to be addressed by researchers, practitioners, and industry. Factors such as adequate correction for all refractive errors, microbial keratitis, comfort, and suitable lens care and lens biocompatibility are discussed from the authors’ perspective.

s / Contact Lens & Anterior Eye 38 (2015) e13–e46 e19 comfortable wear and having Class I UV blocking capability, were developed. Dr. Yu-Chin Lai, Vice President of R&D, Pegavision Corporation in Taiwan. Before joining Pegavision, he had 23 years of career with Bausch & Lomb working on new contact lens materials, IOL’s and processing. He was credited with the inventions of Soflens66, Soflens59 and the successful development of PureVision. He received his doctoral degree in chemistry from University of Florida. He was granted 79 US patents, mostly related to lens materials and processing. He received Industrial Innovation Award from American Chemical Society in 2004. He has over 60 scientific publications, over 70 professional presentations and invited talks. http://dx.doi.org/10.1016/j.clae.2014.11.016

• Rates for CIE, SICS and GNB case contamination for four LCPs when used with balafilcon A (Bausch + Lomb, Rochester, USA) were obtained either from published data or calculated retrospectively. • The four LCPs were o LCP 1 containing sodium chlorite / H2O2: Sauflon Pharmaceuticals, Twickenham, UK. o LCP 2 containing alexidine dihydrochloride / polyquaternium (PQ)-1: Abbott Medical Optics, Inc., Santa Ana, USA. o LCP 3 containing PHMB / PQ-1: Bausch + Lomb, Rochester, USA. o LCP 4 containing PHMB: CIBA Vision, Duluth, USA. PURPOSE

Purpose We develop a new method to compute in situ corneal oxygen uptake during soft-contact-lens (SCL) wear using a micro-polarographic Clark electrode. Methods After steady SCL wear and subsequent removal, a membrane-covered polarographic microelectrode is immediately placed onto the cornea. The resulting polarographic signal is related to the steady-state corneal oxygen uptake rate during soft-contact-lens wear. We devise a new analysis to quantify oxygen uptake into the cornea during lens wear. The proposed procedure is applied to new polarographic data for 10 human subjects with 12 different commercial lenses during open eye. We compare our results with recent theory. Results Average corneal oxygen uptake rates at open eye during SCL wear for 10 subjects wearing 12 different commercial lenses vary from 2 to 10 μL(STP)/cm(2)/h. High oxygen permeability lenses have uptake rates of -10 μL(STP)/cm(2)/h, in close agreement with our previously obtained no-lens human uptake rates of 9 to 13 μL(STP)/cm(2)/h at open eye.(40) Application of the classical data-interpretation procedure to our experimental data gives corneal-uptake results that are approximately three to five times smaller than those obtained with our new interpretation scheme. Conclusions We provide a simple and reliable tool to quantify corneal-oxygen-uptake rates during in vivo soft-contact-lens wear. Comparison of our newly measured in vivo oxygen uptakes to model prediction for SCLs of varying oxygen transmissibility is in good agreement with available theory.

Purpose: Silver-infused contact lenses (CLs) may provide benefits to CL wearers by reducing adherence of potential pathogens to CL surfaces; however, they have the potential to modify the normal ocular biota during wear. This study investigated the effect of silverinfused silicone hydrogel CLs on conjunctival flora over six months of daily wear (DW). Method: A prospective, randomised, doublemasked, contralateral study was conducted. Sixty subjects were randomly assigned to wear silverinfused (galyfilcon A with incorporated silver ions, test) and standard (galyfilcon A, control) silicone hydrogel CLs on a contralateral basis for six months of DW. Prior to assignment of the test and control CLs, all subjects were fitted with etafilcon A daily disposable CLs for a one week wearin period. Conjunctival flora were cultured at screening/pre-baseline (with subjects’ habitual CLs), baseline (after daily disposable wear) and four weeks, three and six months following commencement of test and control CL wear, using sterile calcium alginate swabs moistened with sterile unpreserved 0.9% saline. Results: There were no statistically significant differences between the conjunctivae of test and control eyes in incidence of positive cultures (p>0.05), culture classification grades (p>0.05), microorganism levels (p>0.05) or numbers of different types of microorganisms isolated (p>0.05). Wear of the test CLs did not promote fungal or yeast colonisation of the conjunctivae. The most frequently isolated microorganisms were Gram-positive bacteria considered to be part of the normal ocular flora. Conclusions: Wear of the silver-infused CLs did not result in any statistically or clinically significant alterations to the ocular biota over six months of DW.

Purpose: Silver-infused contact lenses (CLs) may provide benefits to CL wearers by reducing adherence of potential pathogens to CL surfaces; however, they have the potential to modify the normal ocular biota during wear. This study investigated the effect of silverinfused silicone hydrogel CLs on conjunctival flora over six months of daily wear (DW). Method: A prospective, randomised, doublemasked, contralateral study was conducted. Sixty subjects were randomly assigned to wear silverinfused (galyfilcon A with incorporated silver ions, test) and standard (galyfilcon A, control) silicone hydrogel CLs on a contralateral basis for six months of DW. Prior to assignment of the test and control CLs, all subjects were fitted with etafilcon A daily disposable CLs for a one week wearin period. Conjunctival flora were cultured at screening/pre-baseline (with subjects’ habitual CLs), baseline (after daily disposable wear) and four weeks, three and six months following commencement of test and control CL wear, using sterile calcium alginate swabs moistened with sterile unpreserved 0.9% saline. Results: There were no statistically significant differences between the conjunctivae of test and control eyes in incidence of positive cultures (p>0.05), culture classification grades (p>0.05), microorganism levels (p>0.05) or numbers of different types of microorganisms isolated (p>0.05). Wear of the test CLs did not promote fungal or yeast colonisation of the conjunctivae. The most frequently isolated microorganisms were Gram-positive bacteria considered to be part of the normal ocular flora. Conclusions: Wear of the silver-infused CLs did not result in any statistically or clinically significant alterations to the ocular biota over six months of DW.