Effect of a Novel Omega-3 and Omega-6 Fatty Acid Supplement on Dry Eye Disease: A 3-month Randomized Controlled Trial.

SIGNIFICANCE: Supplementing diet with a novel combination of omega-3 and omega-6 fatty acids significantly improved symptoms in extremely symptomatic participants with dry eye disease (DED). PURPOSE: This study aimed to determine the effect of daily intake of a novel combination of essential fatty acids on signs and symptoms of DED. METHODS: Participants with moderate to severe DED were enrolled in a prospective, randomized, double-masked parallel group study. Participants ingested either the treatment supplement containing omega-3 and omega-6 fatty acids (1200 mg eicosapentaenoic acid, 300 mg docosahexaenoic acid, 150 mg γ-linoleic acid) or the placebo (coconut and olive oil) daily for 3 months. To determine compliance, Omega-3 Index blood tests were conducted. At baseline and at 1 and 3 months, the following assessments were conducted: Ocular Surface Disease Index (OSDI) questionnaire and Symptom Assessment Questionnaire in Dry Eye, noninvasive tear breakup time, tear meniscus height, tear osmolarity, ocular redness, surface staining, Schirmer test, and meibography. RESULTS: Fifty participants (mean ± standard deviation baseline OSDI score, 52.2 ± 16.5) completed the study: 24 randomized to treatment and 26 randomized to placebo. Although there was an improvement in OSDI score at 3 months for both groups (treatment: -13.4 points, P = .003; placebo: -7.8 points, P = .02), participants with baseline OSDI scores >52 demonstrated an even larger significant improvement in symptoms with the treatment at 3 months compared with baseline (n = 13, -20.8 points, P = .002). There were no significant changes in any of the ocular assessments at 1 or 3 months (all P > .05). After 3 months, Omega-3 Index increased by 34% in the treatment group (baseline, 5.3 ± 0.8; 3 months, 8.0 ± 2.1; P < .001) and did not change in the placebo group (baseline, 4.8 ± 0.8; 3 months, 4.8 ± 0.6; P = .95). CONCLUSIONS: Supplementation with eicosapentaenoic acid, docosahexaenoic acid, and γ-linoleic acid resulted in a significant and clinically meaningful improvement of dry eye symptoms in extremely symptomatic participants with DED (OSDI ≥52).

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.

Visual Performance of a Multifocal Contact Lens versus Monovision in Established Presbyopes.

PURPOSE: To compare subjective and objective visual performance of the Air Optix Aqua Multifocal lens to monovision in a group of subjects requiring a medium level of reading-addition power. METHODS: Fifty participants with reading additions between 1.25 and 2.00 diopters (inclusive) were randomized into a prospective, crossover clinical trial. They wore monovision and multifocals for 2 weeks in a randomized order. High- and low-contrast logMAR (logarithm of the minimum angle of resolution) acuity and stereopsis were measured at the beginning and end of each period. During each phase, participants performed specific tasks followed by subjective rating surveys and also completed satisfaction rating surveys on days 3, 7, and 12; all were transferred in real time using BlackBerry smartphones. A general rating survey was completed at the dispensing and 2-week visits. RESULTS: Forty-nine participants completed the study (mean age, 52 years). Distance and near high- and low-contrast acuities were significantly better (p < 0.05) with monovision at all visits. High-contrast intermediate acuity was only better (p < 0.05) with multifocals after 2 weeks. Stereopsis was equivalent after 2 weeks, but better (p < 0.05) with multifocals at dispensing. Subjective ratings were generally equivalent between modalities although there was a trend for multifocals to be rated higher for focus changing and driving, whereas monovision tended to be rated higher for near tasks. For both corrections, the satisfaction survey showed no significant change between days 3, 7, and 12, and the general survey showed that comfort was maintained but subjective vision ratings decreased significantly over the 2 weeks. Twenty-five participants (51%) preferred multifocals, 18 (37%) preferred monovision, and the remaining 6 (12%) declared both unacceptable. CONCLUSIONS: In this cohort, distance and near acuities were better with monovision, whereas the subjective ratings tended to favor the Air Optix Aqua Multifocal, with the exception of near performance. Preference was statistically similar between both corrections, with a trend toward preferring the multifocal.

Evaluation of Lag of Accommodation with Full-Field Diffusion Optics Technology™ (DOT) Contrast Management Spectacle Lenses in Emmetropic Children.

Purpose: To evaluate the impact on the lag of accommodation (LOA) in emmetropic children after short-term wear of full-field Diffusion Optics TechnologyTM (DOT) spectacle lenses, designed to modulate retinal contrast to control myopia progression. Patients and Methods: This was a single-visit, prospective, randomized, subject-masked study of emmetropes (ametropes ±1.00D or less in each meridian) with no history of myopia control treatment. Unaided logMAR visual acuity was measured, and ocular dominance was determined using the sighting method. In a randomized order, participants wore plano full-field contrast management (DOT) spectacles (no clear central aperture) or control spectacles (standard single vision spectacle lenses). Each participant was given 5 minutes for adaptation to the respective lenses before open field autorefraction measurements were taken at 6 meters and 40 cm. Ten measurements were taken for each eye. Data were evaluated from the right eye and the dominant eye separately. Results: A total of 30 participants (20 females and 10 males) with a mean age of 10.4 ± 2.8 (7 to 17) years completed the study. There was no significant difference in right eye mean LOA with contrast management spectacles 0.57 ± 0.39D versus control spectacles 0.62 ± 0.34D; Wilcoxon test, p = 0.37. For dominant eyes, LOA values were 0.60 ± 0.40D and 0.68 ± 0.33D with contrast management spectacles and control spectacles, respectively (p = 0.14). Additionally, no significant difference was observed in mean LOA between males and females or between age groups (7-11 years vs 12-17 years) for either right or dominant eyes with contrast management or control spectacles (all p > 0.05). Conclusion: Full-field contrast management spectacle lenses had no significant effect on LOA compared to standard single vision spectacle lenses, indicating no differential impact on accommodative response over the short period of lens wear tested.

Relationships Between Success Factors in Daily Disposable Multifocal Contact Lenses.

Purpose: To explore links between subjective comfort and vision in habitual multifocal soft contact lens (MFCL) wearers when refit with daily disposable MFCLs, to determine which factors are relevant for success with MFCLs and evaluate consistency between MFCLs of different designs. Patients and Methods: This work examined subjective measures in a randomised, participant masked, bilateral wear crossover study at five optometry practices. Fifty-eight habitual MFCL wearers wore stenfilcon A multifocal (stenA-MF; CooperVision Inc) and delefilcon A multifocal (delA-MF; Alcon) for two-weeks. Subjective ratings included satisfaction with comfort and vision and agreement questions. Results: Agreement with "I would like to wear this MFCL in the future" was taken to indicate success with each MFCL; agreement was significantly higher with stenA-MF. There was strong correlation between agreement responses for "I would like to wear this MFCL in the future" and "MFCL met my needs for vision" with both lenses (p<0.01). However, it was only with stenA-MF, which had higher agreement responses to both statements (p<0.05), that responses to these two statements correlated with satisfaction with end-of-day (EOD) comfort (p<0.01). These differences in correlations between the two lenses are seemingly driven by greater satisfaction with stenA-MF for near and intermediate vision (p<0.05). Conclusion: Subjective vision and comfort were only correlated when vision met the needs of most participants. Meeting participants' needs for vision correlated strongly with wanting to wear a MFCL. Results indicate that meeting vision needs is more important than meeting comfort needs when influencing whether presbyopic patients continue wearing MFCLs.

Determination of the Minimal Clinically Important Difference (MCID) for Ocular Subjective Responses.

Purpose: To determine the minimal clinically important difference (MCID) for contact lens (CL)-related subjective responses and explore whether MCID values differ between subjective responses and study designs. Methods: This was a retrospective analysis of data from seven one-week bilateral crossover studies and 14 one-day contralateral CL studies. For comfort, dryness, vision, or ease of insertion, participants rated on a 0-100 visual analogue scale (VAS) and indicated lens preference on a five-point Likert scale featuring strong, slight, and no preferences. For each criterion, four MCID estimates were calculated and averaged: mean VAS score difference for "slight preference," lower limit of 95% confidence interval VAS score difference for "slight preference," difference in mean VAS score difference between "slight" and "no preference" and 0.5 standard deviation of VAS scores. Results: The four calculation methods generated a small range of MCID values. For bilateral studies, the averaged MCID was 7.2 (range 5.4-8.8) for comfort, 8.1 (5.2-10.6) for dryness, 7.1 (5.5-9.3) for vision and 7.6 (6.0-10.5) for ease of insertion. For contralateral studies, the averaged MCID was 6.9 (6.1-7.6) for comfort at insertion and 7.5 (6.8-8.2) for end-of-day comfort. Conclusions: This work demonstrated very similar MCID values across subjective responses and study designs, in a population of habitual soft CL wearers. In all cases, MCID values were on average seven units on a 0 to 100 VAS. Translational Relevance: This work provides MCID values which are important for interpreting ocular subjective responses and planning clinical studies.

Control of myopia using diffusion optics spectacle lenses: 4-year results of a multicentre randomised controlled, efficacy and safety study (CYPRESS).

AIMS: To evaluate the myopia control efficacy of Diffusion Optics Technology (DOT) spectacle lenses in children over a 4-year treatment period. METHODS: CYPRESS Part 1 (NCT03623074) was a 3-year multicentre, randomised, controlled, double-masked trial comparing two investigational spectacle lens DOT designs (Test 1, Test 2) and standard single vision Control lenses in 256 North American children aged 6-10 years. Children completing Part 1 (n=200) were invited to enrol in CYPRESS Part 2 (NCT04947735) for an additional 1-year period. In Part 2, Test 1 (n=35) and Control groups (n=42) continued with their original lens assignment and the Test 2 group (n=21) were crossed over to Test 1 (DOT 0.2) lenses. The co-primary endpoints were change from baseline in axial length (AL) and cycloplegic spherical equivalent refraction (cSER). RESULTS: Test 1 spectacle lenses demonstrated superiority to the Control in both co-primary endpoints: with a difference between means (Test 1-Control) of -0.13 mm for AL (p=0.018) and 0.33 D for cSER (p=0.008) in Part 1 and -0.05 mm for AL (p=0.038) and 0.13 D for cSER (p=0.043) in Part 2. Comparing treatment effects in Part 1 and 2 suggests that COVID-19 public health restrictions negatively impacted treatment efficacy in study years 2 and 3. CONCLUSION: DOT 0.2 spectacle lenses are safe and effective at reducing myopia progression, with additional benefit evident in year 4 of wear. These results support the hypothesis that a mild reduction in retinal contrast can slow myopia progression in young children. The unprecedented disruption in participant schooling and lifestyle during the COVID-19 pandemic may have depressed treatment efficacy in Part 1.

BCLA CLEAR Presbyopia: Evaluation and diagnosis.

It is important to be able to measure the range of clear focus in clinical practice to advise on presbyopia correction techniques and to optimise the correction power. Both subjective and objective techniques are necessary: subjective techniques (such as patient reported outcome questionnaires and defocus curves) assess the impact of presbyopia on a patient and how the combination of residual objective accommodation and their natural DoF work for them; objective techniques (such as autorefraction, corneal topography and lens imaging) allow the clinician to understand how well a technique is working optically and whether it is the right choice or how adjustments can be made to optimise performance. Techniques to assess visual performance and adverse effects must be carefully conducted to gain a reliable end-point, considering the target size, contrast and illumination. Objective techniques are generally more reliable, can help to explain unexpected subjective results and imaging can be a powerful communication tool with patients. A clear diagnosis, excluding factors such as binocular vision issues or digital eye strain that can also cause similar symptoms, is critical for the patient to understand and adapt to presbyopia. Some corrective options are more permanent, such as implanted inlays / intraocular lenses or laser refractive surgery, so the optics can be trialled with contact lenses in advance (including differences between the eyes) to better communicate with the patient how the optics will work for them so they can make an informed choice.

Evaluating the Performance of Verofilcon A Daily Disposable Contact Lenses in a Group of Heavy Digital Device Users.

Purpose: The purpose of this study was to evaluate the performance of verofilcon A daily disposable contact lenses (CL) in CL wearers who identified themselves as heavy digital device users. Patients and Methods: This prospective, non-masked, open-label study enrolled CL wearers who reported ≥6 hours digital device use per day. Participants were dispensed with the verofilcon A study lenses for 14±2 days, to be worn for at least 5 days a week and 10 hours per day, while continuing their normal routine of digital device use. Participants rated the lens performance at the Day 14 visit using a 0-100 (with 100 being best) scale. Ratings were completed at lens insertion, after 6 hours of digital device use, just before CL removal and for overall experience. Participants also completed a 4-point (strongly agree/disagree, slightly agree/disagree) Likert scale-based questionnaire. Results: Thirty-two participants were eligible and completed the study (27 females; age 25.8 ± 6.0 years, ranging from 19 to 40). Overall lens performance ratings at the Day 14 visit (mean ± standard deviation) for comfort, dryness, and clarity of vision were 91 ± 11, 88 ± 11, and 92 ± 9, respectively. Subjective ratings were stable throughout the day with no significant differences after insertion, after 6 hours of digital device use and before CL removal (all p>0.05). The majority of participants agreed that the study lenses performed well, provided good all-day comfort (28/32; p<0.01) and good all-day vision (29/32; p<0.01). Participants also agreed that after ≥6 hours of digital device use they were satisfied with CL comfort (27/32; p<0.01), vision (29/32; p<0.01) and that the lenses provided good performance (26/32; p<0.01). Conclusion: Verofilcon A lenses were found to perform well, with high ratings for comfort, dryness and vision that remained high throughout the day, during extensive digital device use.

Use of a photographic manipulation tool to assess corneal vascular response.

PURPOSE: Corneal vasculature change in contact lens wearers has been linked to the level of hypoxia within the cornea.To assess the impact a treatment has on limbal vessels, a sensitive method of measurement and quantification is required. METHODS: A group of 21 highly myopic, hydrogel wearers, with preexisting signs of corneal hypoxia, were enrolled into a study where they wore sifilcon A penetrated hydrogel lenses (Dk/t ± 117), on a daily wear basis for 9 months. At all scheduled visits, photographs were taken of the superior, inferior, temporal, and nasal limbal regions which were then imported into Adobe Photoshop. A red-free filter was applied to enhance the contrast of the blood columns. In each quadrant, the length of the longest visible blood column was measured and the blood columns that penetrated 0.5 mm into the cornea were counted. A control group of 11 non-lens wearers was recruited. Their photographs were taken at the beginning of the study and 9 months later. An independent, masked observer assessed the photographs. RESULTS: There was a significant decrease in the maximum penetration of the blood column in all quadrants (p = 0.001) from baseline to the 9-month visit (e.g., superior: baseline 0.84 ± 0.39 mm; 9 months 0.63 ± 0.20 mm). There was also significant reduction in the number of visible blood columns longer than 0.5 mm in each quadrant (p = 0.001) from baseline to 9 months in all quadrants (e.g., superior: baseline 14.0 ± 8.2; 9 months 6.5 ± 6.0). The control group showed no change over time for the maximum blood column length (p = 0.638) or the number of columns 0.5 mm (p = 0.341). CONCLUSIONS: A group of highly myopic subjects exhibited reduction in the maximum length and number of blood columns in the cornea when ref it with a highly permeable silicone hydrogel material. The use of photography, along with Adobe Photoshop software, provides a reliable way of measuring corneal vascular responses over time.

Exploring the factors which impact overall satisfaction with single vision contact lenses.

PURPOSE: To explore the impact of subjective factors (lens handling, comfort and vision) on overall single vision contact lens satisfaction. METHODS: Correlation analysis of a prospective, randomised, double-masked, bilateral crossover study involving 55 adapted lens wearers fitted with somofilcon A (SiHy) (clariti® 1 day, CooperVision) and etafilcon A (Hy) (1 DAY ACUVUE® MOIST, Johnson & Johnson Vision) was conducted. Subjective ratings of lens handling, comfort and vision collected after 1 week of lens wear for each lens type were correlated with overall satisfaction. Data were analysed by combining data for both lens types and also for each lens separately. RESULTS: For the combined analysis, significant correlations (p < 0.01) were found between subjective ratings of overall satisfaction and ratings of handing for application (r = 0.64), handling for removal (r = 0.50), comfort upon application (r = 0.59), comfort at end of day (r = 0.61), overall satisfaction with comfort (r = 0.88) and overall satisfaction with vision (r = 0.64). Correlation analysis of the per lens data showed that lens specific correlations of overall satisfaction with handling for lens application varied greatly with lens material (SiHy: r = 0.26, p = 0.05 vs Hy: r = 0.72, p < 0.01). Correlation strength of comfort upon application/at end of day with overall satisfaction also varied with lens material (Application: SiHy: r = 0.40 vs Hy: r = 0.61; End of day: SiHy: r = 0.76 vs Hy: r = 0.58; all p ≤ 0.01). CONCLUSION: Overall satisfaction was significantly correlated with the specific subjective evaluations of handling, vision and comfort. Correlations of overall satisfaction and ease of handling for each lens type suggest that, for habitual contact lens wearers, dissatisfaction with handling at the time of lens application can play a major role in overall dissatisfaction with a lens. Handling for application had a similar correlation (r) value as vision, suggesting that handling for application should not be underestimated when considering overall patient satisfaction.

International multi-centre study of potential benefits of ultraviolet radiation protection using contact lenses.

PURPOSE: To examine the effects of long-term ultraviolet radiation (UVR) blocking wearing contact lenses on ocular surface health, eye focus and macular pigment. METHOD: 210 pre-presbyopic patients were recruited from Birmingham UK, Brisbane Australia, Hong Kong China, Houston USA and Waterloo Canada (n = 42 at each site). All patients had worn contact lenses for ≥ 5 years, half (test group) of a material incorporating a UVR-blocking filter. Ocular health was assessed using slit-lamp biomicroscopy and UV autofluorescence. Accommodation was measured subjectively with a push-up test and overcoming lens-induced defocus. Objective stimulus response and dynamic measures of the accommodative response were quantified with an open-field aberrometer. Macular pigment optical density (MPOD) was assessed using heterochromatic flicker photometry (MPS II). RESULTS: The two groups of participants were matched for age, sex, race, body-mass-index, diet, lifestyle, UVR exposure, refractive error and visual acuity. Limbal (p = 0.035), but not bulbar conjunctival redness (p = 0.903) was lower in eyes that had worn UVR-blocking contact lenses compared to controls. The subjective (8.0 ± 3.7D vs 7.3 ± 3.3D; p = 0.125) and objective (F = 1.255, p = 0.285) accommodative response was higher in the test group, but the differences did not reach significance. However, the accommodative latency was shorter in eyes that had worn UVR-blocking contact lenses (p = 0.003). There was no significant different in MPOD with UVR filtration (p = 0.869). CONCLUSIONS: Blocking the transmission of UVR is beneficial in maintaining the eye's ability to focus, suggesting that presbyopia maybe delayed in long-term UVR-blocking contact lenses wearers. These lenses also provide protection to the critical limbal region.

Ocular health of children wearing daily disposable contact lenses over a 6-year period.

PURPOSE: To report on the ocular health and safety of children fit with soft hydrogel daily-disposable contact lenses, and followed for 6-years in a double-masked clinical trial investigating the performance of a dual-focus contact lens designed to control myopia progression. METHODS: Children aged 8-12 years, naïve to contact lens wear, were enrolled across four international sites. During years 1-3, children were randomised to either MiSight® 1 day or Proclear® 1 day (both omafilcon A, CooperVision, Inc.). The lenses were identical in material and geometry except for the front optical zone design. At the end of year-3, all those wearing Proclear 1 day were switched to MiSight 1 day, therefore all wore MiSight 1 day in years 4-6. Subjects agreed to wear the lenses at least 10-hours/day, 6-days/week. After dispensing, study visits were at 1-week, 1-month, 6-months and every 6-months until 6-years. At each visit, ocular measurements and subjective responses were recorded. Biomicroscopy used 0-4 grading scales; grade 0 represented no findings. RESULTS: 144 children were enrolled: 69F:75M; mean age 10.1 years; mean cycloplegic spherical-equivalent refraction -2.11D; ethnicities included 34 East-Asian, 12 West-Asian, and 79 Caucasian. 92 completed the 6-years. Only three subjects discontinued due to an ocular adverse event (AE). No contact lens related AEs were classified as serious. The incidence rate of infiltrative AEs was 0.61% (6.1/1000 wearing-years; 95%CI: 0.24%-1.57%). The most common biomicroscopy findings were limbal, bulbar and tarsal hyperaemia and tarsal roughness. 99% of all biomicroscopy findings were grade-1 or lower. After 6-years of lens wear, ocular health by biomicroscopy was similar to pre-lens wear. CONCLUSIONS: Across the 6-years, there were no contact lens related serious AEs and biomicroscopy showed no significant changes. Results suggest that children this age can successfully wear daily-disposable hydrogel contact lenses with minimal impact on ocular physiology.

Geographic distribution of corneal staining in symptomatic dry eye.

PURPOSE: To describe the geographic distribution of corneal fluorescein staining across the five corneal zones, among non contact lens wearers who report symptoms of dry eye and determine which corneal zone most frequently exhibited the worst staining. METHODS: Prior studies conducted at the Centre for Ocular Research & Education, Canada, were reviewed for inclusion in the analysis. Each study assessed dry eye symptoms using OSDI and also assessed corneal fluorescein staining in five corneal zones. For each subject, the corneal zones were ranked 1-5 according to their relative staining grade, Rank-1 representing the highest grade. RESULTS: Data from 13 studies and 368 subjects were included. The total number of zones assigned Rank-1 (worst) staining was 449 (across 264 subjects). The inferior zone had the most Rank-1 counts of all zones at 193/43%, which involved 52.5% of all subjects. The nasal zone had 77/17% involving 20.9% of subjects, followed by the temporal (69/15.5%, 18.8% subjects) and superior zones (63/14%, 17.1% subjects). The central zone had the lowest count of Rank-1 designations, at only 47/10.5%, involving 12.8% of subjects. Bayesian analysis was used to generate distributions of the credible proportions of subjects likely to present with staining in a single peripheral zone, with or without central zone staining. It illustrated that staining in a peripheral zone without central staining was more credible. The worst single zone staining was most likely to present in the inferior zone (67.9%), followed by the nasal zone (11.3%), the superior zone (9.2%), and the temporal zone (5.6%). CONCLUSION: In the presence of dry eye symptoms, the inferior zone typically presents the most severe grade of corneal staining, more likely without central zone staining. This knowledge is valuable when developing a strategy to treat dry eye signs, as the inferior corneal zone has the highest grade of staining thus has the potential to exhibit the greatest reduction in staining post-treatment.

Protein deposition on a lathe-cut silicone hydrogel contact lens material.

PURPOSE: To determine the quantity of total protein, total lysozyme, and the conformational state of lysozyme deposited on a novel, lathe-cut silicone hydrogel (SiHy) contact lens material (sifilcon A) after 3 months of wear. METHODS: Twenty-four subjects completed a prospective, bilateral, daily-wear, 9-month clinical evaluation in which the subjects were fitted with a novel, custom-made, lathe-cut SiHy lens material. The lenses were worn for three consecutive 3-month periods, with lenses being replaced after each period of wear. After 3 months of wear, the lenses from the left eye were collected and assessed for protein analysis. The total protein deposited on the lenses was determined by a modified Bradford assay, total lysozyme using Western blotting and the lysozyme activity was determined using a modified micrococcal assay. RESULTS: The total protein recovered from the custom-made lenses was 5.3 +/- 2.3 microg/lens and the total lysozyme was 2.4 +/- 1.2 microg/lens. The denatured lysozyme found on the lenses was 1.9 +/- 1.0 microg/lens and the percentage of lysozyme denatured was 80 +/- 10%. CONCLUSIONS: Even after 3 months of wear, the quantity of protein and the conformational state of lysozyme deposited on these novel lens materials was very similar to that found on similar surface-coated SiHy lenses after 2 to 4 weeks of wear. These results indicate that extended use of the sifilcon A material is not deleterious in terms of the quantity and quality of protein deposited on the lens.

Early symptomatic presbyopes--what correction modality works best?

PURPOSE: To compare the performance of a low-addition silicone hydrogel multifocal soft lens with other soft lens correction options in a group of habitual soft lens wearers of distance correction who are symptomatic of early presbyopia. METHOD: This clinical study was designed as a prospective, double-masked, randomized, crossover, dispensing trial consisting of four 1-week phases, one for each of the correction modalities: a low-addition silicone hydrogel multifocal soft lens, monovision, habitual correction, and optimized distance visual correction. The prescriptions of all modalities were finalized at a single fitting visit, and the lenses were worn according to a randomized schedule. All lenses were made from lotrafilcon B material. A series of objective vision tests were conducted: high- and low-contrast LogMAR under high- and low-room lighting conditions, stereopsis, and critical print size. A number of other data collection methods used were novel: some data were collected under controlled laboratory-based conditions and others under "real-world" conditions, some of which were completed on a BlackBerry hand-held communication device. RESULTS: All participants were able to be fit with all four correction modalities. Objective vision tests showed no statistical difference between the lens modalities except in the case of low-contrast near LogMAR acuity under low-lighting levels where monovision (+0.29 +/- 0.10) performed better than the multifocal (+0.33 +/- 0.11, P=0.027) and the habitual (+0.37 +/- 0.12, P<0.001) modalities. Subjective ratings indicated a statistically better performance provided by the multifocal correction compared with monovision, particularly for the vision associated with driving tasks such as driving during the daytime (93.3 +/- 8.8 vs. 84.2 +/- 23.7, P=0.05), at nighttime (88.8 +/- 11.7 vs. 74.9 +/- 23.6, P=0.001), any associated haloes or glare (92.0 +/- 10.6 vs. 78.0 +/- 22.8, P=0.003), and observing road signs (90.1 +/- 11.8 vs. 79.4 +/- 20.2, P=0.027). Preference for the multifocal compared with monovision was also reported when watching television (95.0 +/- 6.4 vs. 82.6 +/- 20.1, P=0.001) and when changing focus from distance to near (87.0 +/- 13.4 vs. 66.1 +/- 32.2, P<0.001). CONCLUSIONS: For this group of early presbyopes, the AIR OPTIX AQUA MULTIFOCAL--Low Add provided a successful option for visual correction, which was supported by the results of subjective ratings, many of which were made during or immediately after performing such activities as reading, using a computer, watching television, and driving. These results suggest that making a prediction of "success or not" based on consulting room acuity tests alone is probably unwise.

A novel scale for describing corneal staining.

The assessment of corneal staining is a commonly conducted procedure in both clinical practice and as part of various research studies. Different grading scales are employed by many clinicians and researchers to undertake this procedure for corneal staining comparisons between eyes, products and over time. This paper describes the development and use of a grading scale for corneal staining undertaken at an academic research site. The scale involves assessment of three factors across five corneal zones: type, area and depth. Staining type and area are graded on a 0-100 scale, and depth is graded on a 0-4 scale. These factors can be combined to create a three- or two-factor staining grade, or the factors may be reported individually. An additional benefit of this scale is that the staining scores may be reported by zone as "zone staining scores" or the scores of zones may be combined to provide an overall corneal "global staining score".

Myopia prevalence in Canadian school children: a pilot study.

PURPOSE: A pilot study to determine the prevalence of myopia, proportion of uncorrected myopia and pertinent environmental factors among children in a suburban region in Canada. METHODS: Refraction with cycloplegia and ocular biometry were measured in children of two age groups. Myopia was considered at a spherical equivalent refraction (SER) ≤-0.50 D in at least one eye. Parents completed a questionnaire that captured the child's daily activities. RESULTS: A total of 166 children completed the study (83 aged 6-8 and 83 aged 11-13). Myopia prevalence was 17.5% among the overall group, 6.0% among ages 6-8 and 28.9% among ages 11-13. Mean subjective SER in myopic children was -1.10 D (95% confidence interval (CI), -0.34 to -1.86 D) at ages 6-8 and -2.44 D (95% CI, -1.71 to -3.18 D) at ages 11-13. In this study, 34.5% of the myopic children were uncorrected, which represented 6.0% of the entire group of children. Mean axial length (AL) increased by 1.03 mm from ages 6-8 (mean 22.62 mm; 95% CI, 22.45 to 22.79 mm) to ages 11-13 (mean 23.65 mm; 95% CI, 23.45 to 23.84 mm; p < 0.01). The correlation coefficient between AL and SER was -0.618 (p < 0.01). Binary logistic regression between outdoor time and the prevalence of myopia showed that one additional hour of outdoor time per week lowered the odds of a child having myopia by 14.3% (p = 0.007). CONCLUSION: Myopia prevalence increased from 6% at ages 6-8 to 29% at ages 11-13. Thirty-five per cent of the myopes in this study were uncorrected. More time outdoors may be beneficial to protect against myopia onset.

The responses of visual cortical neurons encode differences across saccades.

Primate vision consists mostly of periods of stable fixation separated by rapid saccadic eye movements. Each saccade brings a new scene onto the retina, and each new scene results in a burst of activity in the neurons of visual cortex. It might be expected that the activity of these neurons should only represent what is on the retina now, much as a video camera hooked up to a television only displays what the camera is currently pointed at. However, we show here that this is not the case. Recording from 25 primary visual cortical neurons in an awake primate demonstrated that the responses to the saccade-induced presentation of a stimulus within a neuron's receptive field (RF) are typically suppressed by the presence of a stimulus in the RF before the saccade. Flashing stimuli on with the eyes stationary showed, on average, suppressive effects of similar magnitude, suggesting that the mechanism is simple adaptation. However, while the mechanism may be simple, the implications for the operation of the visual system are not. The activity of visual cortical neurons does not represent just the current retinal image, but also the differences between the current retinal image and the previous one. These results suggest that the current approach of studying the visual system, which concentrates on determining the relationship between a single stimulus and a single response, may have to be modified to take into account the timing of retinal image changes that occurs in normal vision.

The influence of lens conditioning on signs and symptoms with new hydrogel contact lenses.

BACKGROUND: Daily disposable contact lenses are considered to be the pinnacle of safe contact lens wear, yet it has been suggested that it takes some period of wear for the lens surface to reach optimal compatibility with the ocular surface. This study assesses the influence of brief treatment with a conditioning drop on the ocular response to new contact lenses over a single day of wear. METHODS: The study was a single-masked, paired (contralateral) comparison of the signs and symptoms with wear of new Acuvue 2 contact lenses pretreated with a conditioning agent containing carboxymethylcellulose (carmellose, CMC) against new lenses inserted directly from the blister pack. Sixty-one subjects participated in the study, of whom 59 were considered eligible for data analysis. Subjects were also divided into symptomatic and asymptomatic lens wearers based on their overall comfort level in lens wear. Symptoms and signs were recorded at lens delivery and following eight hours of wear. RESULTS: A set of slitlamp signs, comprising corneal staining (p <0.05), limbal redness (p <0.05), bulbar conjunctival hyperaemia (p <0.05), bulbar conjunctival staining (p <0.01) and palpebral conjunctival redness (p <0.05) showed small but statistically significant (p <0.05) end-of-day mean values in favour of the lens that was conditioned with the rewetting agent. These data were supported by the proportion of subjects showing lower gradings with conditioned lenses versus unconditioned lenses, as follows: corneal staining (35 per cent versus 12 per cent, p <0.05), limbal redness (43 per cent versus 22 per cent, p <0.05), bulbar conjunctival hyperaemia (50 per cent versus 15 per cent, p <0.05), bulbar conjunctival staining (46 per cent versus 30 per cent, p <0.1) and palpebral conjunctival hyperaemia (28 per cent versus 17 per cent, NS). For those subjects reporting symptoms with lens wear (n=12), there was a statistically significant (p <0.05) preference in terms of comfort as a result of preconditioning. CONCLUSIONS: The results of the investigation suggest that use of a conditioning agent can provide a more physiologically suitable environment for a new lens, thereby reducing the clinical signs associated with lens discomfort. The protocol used here, which is based on a statistical paradigm using standard pictorial grading scales, allows high sensitivity in detecting small changes in ocular parameters.