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.

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

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

Bulbar Redness and Dry Eye Disease: Comparison of a Validated Subjective Grading Scale and an Objective Automated Method.

SIGNIFICANCE: In this study, assessments of conjunctival redness were performed to evaluate whether patients with or without dry eye disease (DED) could be discriminated based on this measure. Our findings suggest that subjectively grading redness by quadrant, as opposed to automated en face measurements, may be more suitable for this purpose. PURPOSE: This study aimed to quantify bulbar redness using the validated bulbar redness (VBR) grading scale and an automated objective method (Oculus Keratograph 5M; K5M) in participants with DED and non-DED controls. METHODS: Participants with DED (Ocular Surface Disease Index score ≥20 and Oxford scale corneal staining ≥2) and controls (Ocular Surface Disease Index score ≤10 and corneal staining ≤1) attended two study visits. In part 1A of visit 1, baseline bulbar redness was graded with the VBR scale in each conjunctival quadrant of both eyes, followed by automated measurements of temporal and nasal redness with the K5M. This was immediately followed by part 1B, during which a topical vasoconstrictor was instilled into both eyes. Redness assessments were repeated 5 and 30 minutes after instillation with both instruments. Participants returned 14 days later for visit 2, where the same assessments as for visit 1A were repeated. RESULTS: Seventy-four participants (50 DED and 24 controls) completed the study. There were statistically significant differences in redness between the DED and control groups when assessed with the VBR scale (14/16 comparisons; all, P < .05), whereas no significant differences in K5M-derived redness between the DED and non-DED groups were found at any location or time point. Both subjective and objective instruments detected statistically significant reductions in redness 5 and 30 minutes after instillation of the vasoconstrictor (all, P < .01). CONCLUSIONS: Although both subjective and objective instruments were sensitive to detecting changes in redness induced by vasoconstriction, statistically significant differences in redness between DED and control groups were only found using the VBR scale.

Efficacy and Safety of Phospholipid Nanoemulsion-Based Ocular Lubricant for the Management of Various Subtypes of Dry Eye Disease: A Phase IV, Multicenter Trial.

PURPOSE: To evaluate the clinical efficacy and safety of propylene glycol/hydroxypropyl-guar (PG-HPG)-based nanoemulsion (Systane® Complete) lubricant eye drops in participants with dry eye disease (DED). PARTICIPANTS AND METHODS: In this phase IV, open-label, single-arm, interventional, multicenter study, adult participants with DED - subtyped into aqueous deficient, evaporative, and mixed dry eye - were instructed to instill one drop of PG-HPG in each eye twice a day for 28 days. Endpoints included change from baseline in tear film break-up time (TFBUT) (primary) and ocular discomfort visual analog scale (VAS) score at Day 14 and TFBUT at Day 28 (secondary). Safety was assessed throughout the study. Data were analyzed for overall patient cohort and by DED subtypes. RESULTS: A total of 134 participants received treatment (mean age: 56.6 years; female: 75.4%). At Day 14, the mean (standard deviation [SD]) TFBUT increased from 2.6 (1.00) seconds at baseline to 4.2 (2.92) seconds (mean change: 1.5 [2.80] seconds); median change was 0.8 seconds (95% CI: 0.52, 1.19) for the overall cohort; the change was maintained at Day 28 (mean change: 1.4 (2.80) seconds, median change: 0.8 seconds (95% CI: 0.49, 1.17). Subgroup analysis showed a mean change (SD) from baseline in TFBUT of 1.1 (2.41) seconds for aqueous deficient, 2.4 (3.17) seconds for evaporative, and 1.2 (2.63) seconds for mixed dry eye at Day 14, respectively. The ocular discomfort VAS score improved (decreased) from baseline at Day 14 (mean [SD] change: -17.3 [24.80]) for the overall cohort, -22.0 [21.73] for aqueous deficient, -17.6 [24.17] for evaporative and -13.1 [27.49] for mixed dry eye subgroups). Adverse events (AEs) were reported in 9 (6.7%) participants. No serious AEs were reported during the study. CONCLUSION: Our study findings demonstrated that PG-HPG-based nanoemulsion lubricant eye drops were effective and well tolerated in participants with DED and all of its subtypes.

Lipid Analysis on Block Copolymer-containing Packaging Solution and Lens Care Regimens: A Randomized Clinical Trial.

SIGNIFICANCE: Lotrafilcon B lenses packaged in and cared for with block copolymer-containing (polyoxyethylene-polyoxybutylene; EOBO) lens care solutions resulted in lower cholesterol extraction than each of the habitual silicone hydrogel lens/multipurpose solution (MPS) regimens tested. PURPOSE: This study aimed to compare the extracted cholesterol of lotrafilcon B lenses packaged in and cared for with EOBO-containing lens care solutions with the extracted cholesterol of habitual silicone hydrogel lenses cared for with MPS not containing EOBO. METHODS: In this prospective, randomized, observer-masked parallel study, habitual wearers of senofilcon C, senofilcon A, comfilcon A, and samfilcon A contact lenses using a non-EOBO MPS were randomized 1:1 to lotrafilcon B lenses packaged in and cared for with EOBO-containing solutions or to their habitual lenses and MPS. Subjects randomized to lotrafilcon B were further randomized to one of two EOBO-containing lens care solutions, OPTI-FREE PUREMOIST or CLEAR CARE PLUS with HydraGlyde (Alcon Laboratories, Inc., Fort Worth, TX). A subset of right eye lenses was collected after wear, and total cholesterol was extracted and measured using a fluorometric enzymatic assay. RESULTS: Of 143 lenses analyzed, 95 were from subjects randomized to their habitual lenses/MPS and 48 to lotrafilcon B + EOBO lenses plus CLEAR CARE PLUS with HydraGlyde or OPTI-FREE PUREMOIST. The mean amounts of cholesterol extracted from lotrafilcon B + EOBO lenses cared for with CLEAR CARE PLUS with HydraGlyde (0.28 ± 0.18 µg/lens) and OPTI-FREE PUREMOIST (0.28 ± 0.48 µg/lens) were significantly lower than those extracted from senofilcon C (4.18 ± 3.25 µg/lens), senofilcon A (2.19 ± 2.69 µg/lens), comfilcon A (2.17 ± 1.47 µg/lens), and samfilcon A (2.07 ± 1.48 µg/lens) lenses used with MPS (P < .0001 each). CONCLUSIONS: Cholesterol sorption was significantly lower in wearers of lotrafilcon B lenses cared for with polyoxyethylene-polyoxybutylene-containing lens care solutions than in users of habitual silicone hydrogel lenses cared for with non-polyoxyethylene-polyoxybutylene MPS.

18F-sodium fluoride bone deposition quantitation with PET in Mice: Variation with age, sex, and circadian rhythm.

AIM: The aim of this study was to establish a data base for normal 18F-sodium fluoride (18F-NaF) bone uptake as a function of age, sex and circadian rhythm in mice. METHODS: In 12 female (F) and 12 male (M) C57BL/6N mice PET images were acquired 90 min after intravenous injection of 20 MBq 18F-NaF for 30 minutes. Each mouse was imaged in follow-up studies at 1, 3, 6, 13 and 21 months of age. In order to assess for physiologic changes related to circadian rhythm, animals were imaged during light (sleep phase) as well as during night conditions (awake phase). Bone uptake is described as the median percentage of the injected activity (%IA) and in relation to bone volume (%IA/ml). RESULTS: A significant smaller bone volume was found in F (1.79 ml) compared to M (1.99 ml; p < 0.001). In sex-pooled data, highest bone uptake occurred at an age of 1 month (61.1 %IA, 44.5 %IA/ml) with a significant reduction (p < 0.001) at age 3 months (43.6 %IA, 23.6 %IA/ml), followed by an increase between 13 (47.3 %IA, 24.5 %IA/ml) and 21 months (52.2 %IA, 28.1 %IA/ml). F had a significantly higher total uptake (F 48.2 %IA, M 43.8 %IA; p = 0.026) as well as a higher uptake per ml bone tissue (F 27.0 %IA/ml; M 22.4 %IA/ml; p < 0.001). A significant impact of circadian rhythm was only found for F at ages of 3 and 6 months with a higher uptake during the sleep phase. CONCLUSION: Circadian rhythm had a significant impact on uptake only in F of 3 and 6 months. Regarding sex, F showed generally higher uptake rates than M. The highest uptake values were observed during bone growth at age 1 month in both sexes, a second uptake peak occurred in elderly F. Designing future bone uptake studies with M, attention must be paid to age only, while in F circadian rhythm and age must be taken into account.

The short-term physiological impact of switching reusable silicone hydrogel wearers into a hydrogel daily disposable multifocal.

Purpose: To evaluate ocular physiological responses to etafilcon A multifocal (etMF) daily disposable (DD) lenses after 4 weeks of wear, when switching from habitual silicone hydrogel (SiHy) daily wear. Method: A single-arm, open-label, bilateral dispensing study was conducted in 39 habitual spherical SiHy wearers (14 hyperopes; 25 myopes). Clinical visits occurred with habitual SiHy (control) at baseline and after 4 weeks of etMF DD open-eye lens wear at exit. Objective limbal/bulbar hyperemia using the Oculus K5M (0-4) and subjective grading of lid wiper epitheliopathy (LWE) (0-4) were tested for non-inferiority (NI), using a margin of 1 grade. Corneal thickness along a 10 mm cord was measured using the Visante OCT and tested for NI using a 30 µm margin. Corneal staining area was graded (0-100%). Results: The least-square mean differences (LSMD) and 95% confidence interval (95% CI) between etMF DD and habitual SiHy in central and peripheral corneal thickness (µm) were 3.64 (-2.0, 9.29) and 3.0 (-7.72, 13.72) in hyperopic, and 3.56 (-0.66, 7.78) and 6.40 (-1.62, 14.42) in myopic subjects. The LSMD (95% CI) for bulbar and limbal hyperemia were -0.08 (-0.19, 0.02) and -0.01 (-0.12, 0.09) in hyperopes, and 0.04 (-0.03, 0.12) and 0.04 (-0.04, 0.11) in myopes. The LSMD (95% CI) for LWE were 0.11 (-0.39, 0.60) and 0.30 (-0.07, 0.67) for hyperopes and myopes, respectively. Conclusions: No clinically significant differences in a variety of physiological responses were found when habitual reusable SiHy daily wear subjects were refitted into hydrogel etMF, when the subjects were followed for 4 weeks.

Lid Wiper Epitheliopathy in Soft Contact Lens Wearers.

PURPOSE: To evaluate lid wiper epitheliopathy (LWE) in soft contact lens (SCL) wearers on initial presentation and after using various SCL and solution combinations. METHODS: LWE was assessed in 253 habitual SCL wearers who attended a screening visit at one of three study sites. LWE was assessed using lissamine green and sodium fluorescein dyes (Korb scale); a final LWE grade was calculated as the averaged LWE grade of the two dyes. Eligible habitual wearers continued into the four study periods, during which they wore one of three SCL types (etafilcon A, galyfilcon A, or senofilcon A) while using each of four care solutions for 10 to 14 days in randomized order. Statistical analyses were performed using linear mixed models, testing for differences in LWE for subject characteristics and between three multipurpose (MPS) test solutions (BioTrue, OPTI-FREE PureMoist, RevitaLens OcuTec) compared to a hydrogen peroxide (Clear Care) control solution. RESULTS: LWE was present in 85% of habitual SCL wearers. LWE was not different for age (p = 0.28), sex (p = 0.99), race (p = 0.34), and comfort (p = 0.38) and not correlated with refractive error (r = 0.07). LWE was lower in habitual senofilcon A wearers (least-squares (LS) mean ± SE = 0.82 ± 0.19) compared to wearers of lotrafilcon B (1.34 ± 0.20; p < 0.02), comfilcon A (1.41 ± 0.21; p < 0.01), and other (1.18 ± 0.16; p < 0.03). Two hundred three participants completed all four study solutions with their assigned lens type; LWE was not different between the MPSs compared to the peroxide control solution across lens materials, except for less LWE for BioTrue (0.88 ± 0.17) versus Clear Care for participants wearing galyfilcon A (1.11 ± 0.18; p < 0.01). CONCLUSIONS: On initial presentation, LWE was present in 85% of habitual wearers and found to be independent of age, sex, race, comfort, and refractive error but dependent on habitual SCL type. There were no clinically meaningful differences in LWE between the MPSs and hydrogen peroxide solution for the three lens types studied.

Subjective Comfort and Physiology with Modern Contact Lens Care Products.

PURPOSE: To compare subjective comfort and ocular physiology with three multipurpose solutions (MPSs) to that of a peroxide-based system with three different soft contact lens materials. METHODS: Habitual soft contact lens wearers (n = 236) were enrolled at three sites and completed a washout period with no contact lens solution for ≥4 days. Subjects were randomly assigned to one of three lens types: etafilcon A, galyfilcon A, or senofilcon A. A new lens of the assigned type was worn for 10 to 14 days each while using one of four care solutions, in random order (A-polyaminopropyl biguanide + polyquaternium, B-POLYQUAD + Aldox, C-alexidine + polyquaternium-1, and D-hydrogen peroxide) with a washout period (≥4 days) between each solution. After each care solution, biomicroscopy was performed and subjective comfort was assessed using the Contact Lens User Experience (CLUE) questionnaire and other instruments including comfortable wear time (CWT). Linear mixed models were used for analysis. Comfort and biomicroscopy signs with each MPS were compared to that of the peroxide solution. RESULTS: Subjective CLUE Comfort score across all lens types with each MPS was not significantly different than with the peroxide solution (p = 0.98). There were no differences in CWT between each MPS and the peroxide solution for any lens type (range of differences: -0.8 to 0.8 h; all p ≥ 0.13). Six MPS/material combinations had no clinically meaningful change in corneal staining versus peroxide (<0.5 units); three combinations could increase staining by up to 0.57 units. Staining was

Corneal Swelling with Cosmetic etafilcon A Lenses versus No Lens Wear.

PURPOSE: To determine if the use of pigments or adding polyvinyl pyrrolidone during the fabrication of 1-DAY ACUVUE DEFINE (AD) brand contact lenses impacts open-eye corneal swelling compared with no lens wear (NLW). METHODS: A partial double-masked, randomized, bilateral crossover study was conducted in 24 Asian subjects using AD, 1-DAY ACUVUE DEFINE with Lacreon (ADL), NLW, and a control lens with no tint (1-DAY ACUVUE MOIST [AM]). Central corneal thickness was measured before insertion and immediately after removal after 8 ± 1 h of open-eye wear using an optical pachymeter in one eye. Corneal thickness along a 10-mm cord was measured in the contralateral eye using the Visante optical coherence tomographer (OCT). Corneal swelling was tested for noninferiority using a 5% margin. The endothelial bleb response was measured at baseline and 20 min after lens insertion using specular microscopy. Subjective grading of corneal staining and limbal/bulbar hyperemia were also monitored. RESULTS: After 8 ± 1 h of open-eye wear, central corneal swelling across the study lenses with either optical pachymeter or OCT methods was negligible. Peripheral corneal swelling least-square mean differences with OCT were -0.03% (95% confidence interval [95% CI], -0.65 to 0.58%) and -0.26% (95% CI, -0.87 to 0.36%) between AD and ADL and the control lens (AM), respectively, and 1.67% (95% CI, 1.06 to 2.29%) and 1.45% (95% CI, 0.84 to 2.06%) between AD and ADL and NLW, respectively. No endothelial blebs were observed. No clinically significant differences were distinguished between the lenses and NLW for corneal staining and limbal/bulbar hyperemia. CONCLUSIONS: After 8 ± 1 h of open-eye wear, central and peripheral corneal swelling along the horizontal meridian with AD, ADL, AM, and NLW were equivalent. These results confirm that the addition of polyvinyl pyrrolidone or pigments to etafilcon A to obtain a limbal ring design have no impact on corneal swelling or limbal/bulbar hyperemia during normal open-eye wear.

Clinical performance of three silicone hydrogel daily disposable lenses.

PURPOSE: To determine the clinical performance of DAILIES TOTAL1 (DT1), Clariti 1Day (C1D), and 1-DAY ACUVUE TruEye (AVTE) silicone hydrogel daily disposable contact lenses (SiHy DDCLs). METHODS: Eligible participants, subdivided into asymptomatic and symptomatic groups, wore each SiHy DDCLs for three consecutive days. Each participant attended three visits (on day 1 at 0 hours; on days 1 and 3 after 8 hours of wear) per lens type. The order of lens wear was randomized, with at least 1 day washout between lenses. Lens-related performance was evaluated by assessing lens surface deposits, wettability, pre-lens noninvasive tear breakup time, lens movement, and centration; ocular response assessments included conjunctival redness, corneal staining, and conjunctival staining and indentation. RESULTS: Fifty-one asymptomatic and 53 symptomatic participants completed the study. For all visits, the mean noninvasive tear breakup time was about 1 second longer with DT1 than with C1D and AVTE (p < 0.01). Overall, the wettability of all three lenses was good; however, DT1 was graded marginally better than the other lenses (both p < 0.01). On day 3, eyes wearing AVTE had significantly more dehydration-induced corneal staining compared with DT1 (AVTE, 24%; DT1, 11%; p < 0.01). After 8 hours, conjunctival staining was different between lenses (greatest with C1D and least with DT1; all p < 0.01). Conjunctival indentation was more prevalent with the C1D lenses (n = 70) compared with DT1 (n = 1; p < 0.01) and AVTE (n = 11; p < 0.01). There were no differences between asymptomatic and symptomatic lens wearers for any of the clinical parameters (all p > 0.05). CONCLUSIONS: Each of the three SiHy DDCLs performed well. Noninvasive tear breakup time was longest and wettability was greater with DT1. C1D had the most conjunctival staining conjunctival indentation. There was no difference between asymptomatic and symptomatic wearers with regard to ocular response and contact lens-related parameters. These results suggest that SiHy DDCLs may be an excellent contact lens modality for the symptomatic patient.

Repeatability of grading meibomian gland dropout using two infrared systems.

PURPOSE: To determine the interobserver and intraobserver repeatability in using the OCULUS Keratograph 4 (K4) and 5M (K5M) to grade meibomian gland (MG) dropout using meibography grading scales. METHODS: The inferior and superior eyelids of 40 participants (35 women, 5 men; mean age = 32 years) were imaged three times each on both instruments. The images were split into one training and two study sets; the latter were graded (four-point meibography scale) by two observers on two separate occasions (24 hours apart) to determine repeatability. Semiobjective quantification of percentage MG dropout was conducted using ImageJ on K4 and K5M images. A finer seven-point meibography scale was used to grade a separate set of K5M images. RESULTS: For the four-point scale, interobserver mean difference (MD) (±SD) was 0.08 (±0.55) on day 1 and 0.13 (±0.50) on day 2, and the concordance correlation coefficient (CCC) was 0.79 and 0.81 on days 1 and 2, respectively. Intraobserver MD (±SD) was 0.04 (±0.54), CCC = 0.79 for observer 1; intraobserver MD (±SD) was -0.09 (±0.60), CCC = 0.74 for observer 2. For the seven-point scale, interobserver MD (±SD) was 0.05 (±0.45), CCC = 0.89 on day 1, and interobserver MD (±SD) was 0.01 (±0.41), CCC = 0.91 on day 2. Intraobserver MD (±SD) was -0.10 (±0.35), CCC = 0.93 for observer 1, and intraobserver MD (±SD) was -0.06 (±0.30), CCC = 0.95 for observer 2. Percentage dropout measured between the K4 and K5M images showed lack of agreement, with 21.8% coefficient of repeatability. There was no significant correlation (r < 0.2; p > 0.05) between meibography score and clinical signs (corneal staining, gland expressibility, telangiectasia, vascularity, lash loss); however, there was a high correlation (r = 0.77; p < 0.05) between meibography score with percentage dropout. CONCLUSIONS: Observers graded from -1 to +1 grade units between and within themselves for a four-point scale, 95% of the time. Although the interobserver and intraobserver repeatability of the K4 and K5M were very similar, a high rate of disagreement in percentage dropout between K4 and K5M images suggests that the two instruments cannot be interchanged. Meibomian gland dropout scores did not correlate significantly with clinical signs. Using a finer scale may be beneficial for detecting change.

Grading bulbar redness using cross-calibrated clinical grading scales.

PURPOSE: To determine the between-scale agreement of grading estimates obtained with cross-calibrated McMonnies/Chapman-Davies (MC-D), Institute for Eye Research (IER), Efron, and Validated Bulbar Redness (VBR) grading scales. METHODS: Modified reference images of each grading scale were positioned on a desk according to their perceived redness (within a 0 to 100 range) as determined in a previous psychophysical scaling experiment. Ten observers were asked to represent perceived bulbar redness of 16 sample images by placing them, one at a time, relative to the reference images of each scale. Only 0 and 100 were marked on the scale, but not the numerical position of the reference images. Perceived redness was taken as the measured position of the placed image from 0 and was averaged across observers. RESULTS: Overall, perceived redness depended on the sample image and the reference scale used (repeated measures ANOVA; P = 0.0008); six sample images had a perceived redness that was significantly different between at least two of the scales. Between-scale correlation coefficients of concordance ranged from 0.93 (IER vs. Efron) to 0.98 (VBR vs. Efron). Between-scale coefficients of repeatability ranged from five units (IER vs. VBR) to eight units (IER vs. Efron) of the 0 to 100 range. CONCLUSIONS: The use of cross-calibrated reference grades for bulbar redness grading scales allows comparison of grading estimates obtained with different scales. Perceived redness is dependent on the dynamic range of the reference images of the scale, with redness estimates generally being found to be higher for scales with a shorter dynamic range.

The conversion of bulbar redness grades using psychophysical scaling.

PURPOSE: To use psychophysical scaling to investigate if the inclusion of reference anchors affected the perceived redness of the reference images of four bulbar redness grading scales and to convert grades between scales. METHODS: Ten participants were asked to arrange printed copies of the McMonnies/Chapman-Davies (6), IER (4), and Efron (5) grading scale images relative to each other, using the stationary but unlabeled 10, 30, 50, 70, and 90 reference images of the validated bulbar redness scale as additional anchors within a given 0 (minimum) to 100 (maximum) redness range (anchored scaling). The position of each image was averaged across observers to represent its perceived redness within this range. Anchored scaling data were then compared with data from a previous study, where the images of all four grading scales had been scaled for the same experimental setup, but with no reference anchors provided (non-anchored scaling). Averaged perceived redness as determined with anchored scaling was used to cross-calibrate grades between scales. RESULTS: Overall, perceived redness of the reference images was significantly different within each scale (repeated measures analysis of variance, all scales p < 0.001). There were differences in perceived redness range and when comparing reference levels between scales. Anchored scaling resulted in an apparent shift to lower perceived redness for all but one reference image compared with non-anchored scaling, with the rank order of the 20 images for both procedures remaining fairly constant (Spearman's ρ = 0.99). CONCLUSIONS: The re-scaling of the reference images in the anchored scaling experiment suggests that redness was assessed based on within-scale characteristics and not using absolute redness scores, a mechanism that can be referred to as clinical scale constancy. The perceived redness data allow practitioners to modify the grades of the scale they commonly use for comparison of their grading estimates with grades obtained with another calibrated scale.

The perceived bulbar redness of clinical grading scales.

PURPOSE: To use a psychophysical scaling method to estimate the perceived redness of reference images of the McMonnies and Chapman-Davies (six reference levels), Institute for Eye Research (four), Efron (five), and Validated Bulbar Redness (five) bulbar redness grading scales. METHODS: Regions of interest were cropped out of the grading scale reference images; three separate image sets (color, grayscale, and binarized) were created for each scale, combining to a total of 20 images per image set. Ten naïve observers were asked to arrange printed copies of the 20 images per image set across a distance of 1.5 m on a flat surface, so that separation reflected their perception of bulbar redness; only start and end point of this range were indicated. The position of each image was averaged across observers to represent the perceived redness for this image, within the 0 to 100 range. Subjective data were compared with physical attributes (chromaticity and spatial metrics) of redness. RESULTS: For each image set, perceived redness of the reference images within each scale was ordered as expected, but not all consecutive within-scale levels were rated as having different redness. Perceived redness of the reference images varied between scales, with different ranges of severity being covered by the images. Perception of redness severity depended on the image set (repeated-measures analysis of variance; all p < or = 0.0002). The perceived redness was strongly associated with the physical attributes of the reference images. CONCLUSIONS: Subjective estimates of redness are based on a combination of chromaticity and vessel-based components. Psychophysical scaling of perceived redness lends itself to being used to cross-calibrate these four clinical scales.

The use of fractal analysis and photometry to estimate the accuracy of bulbar redness grading scales.

PURPOSE: To use physical attributes of redness to determine the accuracy of four bulbar redness grading scales, and to cross-calibrate the scales based on these physical measures. METHODS: Two image-processing metrics, fractal dimension (D) and percentage of pixel coverage (% PC), as well as photometric chromaticity were selected as physical measures, to describe and compare grades of bulbar redness among the McMonnies/Chapman-Davies scale, the Efron Scale, the Institute for Eye Research scale, and a validated scale developed at the Centre for Contact Lens Research. Two sets of images were prepared by using image processing: The first included multiple segments covering the largest possible region of interest (ROI) within the bulbar conjunctiva in the original images; the second contained modified scale images that were matched in size and resolution across scales, and a single, equally-sized ROI. To measure photometric chromaticity, the original scale images were displayed on a computer monitor, and multiple conjunctival segments were analyzed. Pearson correlation coefficients between each set of image metrics and the reference image grades were calculated to determine the accuracy of the scales. RESULTS: Correlations were high between reference image grades and all sets of objective metrics (all Pearson's r >or= 0.88, P

The development of validated bulbar redness grading scales.

PURPOSE: To develop a perceptually and physically based bulbar redness grading scale. METHODS: Digital conjunctival hyperemia photographs were taken using a photo-slit lamp at controlled exposures. Nine participants arranged 25 images on a tabletop over a range of 1.5 m, using separation to represent changes in redness. The position of each image was recorded and normalized for a 0 to 100 scale, and compared to chromaticity of each image obtained using a spectrophotometer. The performance of two versions of the scale (5 and 10 images) and a continuous grading scale was evaluated based on repeatability data collected from nineteen observers who used each scale twice to grade 30 randomly presented images of bulbar redness. RESULTS: Psychophysical scaling was highly correlated between single observers (Pearson's r >or= 0.92, p < 0.05). The averaged subjective grades significantly correlated with chromaticity (r = 0.95 and r = 0.99, p < 0.001 for CIE u* and log u*, respectively). Across all observers, test and retest ratings were highly correlated with either scale (r >or= 0.98), and showed high levels of repeatability expressed by intraclass correlation coefficients (ICC >or= 0.98), correlation coefficients of concordance (CCC >or= 0.96), and coefficients of repeatability (COR

Comparison of an objective method of measuring bulbar redness to the use of traditional grading scales.

PURPOSE: The primary objective was to compare measures of bulbar redness objectively using a photometric method with standard grading methods. Measures of redness were made on 24 participants wearing a silicone hydrogel contact lens in one eye for overnight wear. This report compares hyperaemia after 1 week of daily wear (baseline) with redness measured after 6 months of overnight wear. METHOD: A new method of objectively measuring bulbar conjunctival redness was performed using the Spectrascan650 Photometer by Photo Research under fixed illumination. Photometric measures in CIEu(*) chromaticity values involve the measurement of chromaticity, a physical analogue of redness, greenness and blueness in the image. This method was validated in Part 1 of the study using repeated measurements on the photographic CCLRU scale. In Part 2 of the study, the photographic grading scale (CCLRU) from 0 (none) to 100 (extreme) was used to make the comparison. RESULTS: Part 1 indicated that the photometer provides a repeatable and reliable measure of bulbar redness (CCC=0.989). A moderately strong and significant correlation was found between the CIEu(*) chromaticity values and the analogue data (R=0.795, p=0.000) at each measurement session (from baseline to 1 day, 1 week, and 1, 3 and 6 months of overnight wear). CONCLUSIONS: This new standardized and objective method of measuring bulbar redness has great potential to replace subjective grading scales, especially with multi-centre studies, where variability between investigators occurs. This method may also detect smaller changes between visits or between eyes.