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Peer-reviewed articles

2016

Moezzi,A. M., Varikooty,J., Schulze,M., Ngo,W., Lorenz,K. O., Boree,D., Jones,L. W. Corneal Swelling with Cosmetic etafilcon A Lenses versus No Lens Wear. Optometry and Vision Science 2016;93,6:619-628. [ Show Abstract ]

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.

Dantam,J., McCanna,D. J., Subbaraman,L. N., Papinski,D., Lakkis,C., Mirza,A., Berntsen,D. A., Morgan,P., Nichols,J. J., Jones,L. W., Mathew,J. H., Cox,S. M., Bickle,K. M., Powell,D. R., Cox,J., Miller,W. L., Wallace-Tucker,A., Charrier,S., Chen,Y. -J, Cardenas,L., Huerta,S., Dionne,K., Maldonado-Codina,C., Plowright,A. J., Howarth,G. F., Chatterjee,N., Smith,S., Dumbleton,K., Schulze,M., Moezzi,A., Luensmann,D., Ngo,W., Paquette,L., Srinivasan,S., Varikooty,J., Johnson,J., Simpson,M., Voss,L., R Microbial contamination of contact lens storage cases during daily wear use. Optometry and Vision Science 2016;93,8:925-932. [ Show Abstract ]

Purpose. To evaluate contact lens (CL) storage case contamination when used with four different CL care solutions during daily wear of three different CL materials. Methods. A parallel, prospective, bilateral, randomized clinical trial (n = 38) was conducted. Subjects were randomly assigned to use one of three CL materials (etafilcon A, senofilcon A, or galyfilcon A) on a daily wear basis. Subsequently, each subject randomly used one of four different CL care solutions (Biotrue, OPTI-FREE PureMoist, RevitaLens OcuTec, and CLEAR CARE) for 2 weeks, along with their respective storage cases. After every 2-week period, their storage cases were collected and the right and left wells of each storage case were randomized for two procedures: (1) microbial enumeration by swabbing the storage case surface and (2) evaluation of biofilm formation (multipurpose solution cases only) using a crystal violet staining assay. Results. More than 80% of storage cases were contaminated when used in conjunction with the four CL care solutions, irrespective of the CL material worn. Storage cases maintained with CLEAR CARE (mean Log colony forming units (CFU)/ well ± SD, 2.0 ± 1.0) revealed significantly (p < 0.001) greater levels of contamination, compared to those maintained with Biotrue (1.3 ± 0.8) and RevitaLens OcuTec (1.2 ± 0.8). Predominantly, storage cases were contaminated with Gram-positive bacteria (= 80%). There were significant differences (p = 0.013) for the levels of Gram-negative bacteria recovered from the storage cases maintained with different CL care solutions. Storage cases maintained withOPTI-FREE PureMoist (0.526 ± 0.629) showed significantly higher biofilm formation (p = 0.028) compared to those maintained with Biotrue (0.263 ± 0.197). Conclusions. Levels of contamination ranged from 0 to 6.4 Log CFU/storage case well, which varied significantly (p < 0.001) between different CL care solutions, and storage case contamination was not modulated by CL materials. © Copyright 2016 American Academy of Optometry.

Berntsen,D. A., Hickson-Curran,S. B., Jones,L. W., Mathew,J. H., Maldonado-Codina,C., Morgan,P. B., Schulze,M. M., Nichols,J. J., Cox,S. M., Bickle,K. M., Powell,D. R., Cox,J., Miller,W. L., Wallace-Tucker,A., Charrier,S., Chen,Y. -J, Cardenas,L., Huerta,S., Dionne,K., Plowright,A. J., Howarth,G. F., Chatterjee,N., Mirza,A., Smith,S., Dumbleton,K., Moezzi,A. M., Luensmann,D., Ngo,W., Paquette,L., Srinivasan,S., Varikooty,J., Johnson,J., Simpson,M., Voss,L., Ryan,L., Careless,N., Smith,A., Subbar Subjective comfort and physiology with modern contact lens care products. Optometry and Vision Science 2016;93,8:809-819. [ Show Abstract ]

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

Schulze,M. -M, Srinivasan,S., Hickson-Curran,S. B., Berntsen,D. A., Howarth,G. F., Toubouti,Y., Morgan,P., Nichols,J. J., Jones,L. W., Mathew,J. H., Cox,S. M., Bickle,K. M., Powell,D. R., Cox,J., Miller,W. L., Wallace-Tucker,A., Charrier,S., Chen,Y. -J, Cardenas,L., Huerta,S., Dionne,K., Maldonado-Codina,C., Plowright,A. J., Chatterjee,N., Mirza,A., Smith,S., Dumbleton,K., Moezzi,A. M., Luensmann,D., Ngo,W., Paquette,L., Varikooty,J., Johnson,J., Simpson,M., Voss,L., Ryan,L., Careless,N., Smith, Lid wiper epitheliopathy in soft contact lens wearers. Optometry and Vision Science 2016;93,8:943-954. [ Show Abstract ]

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. © Copyright 2016 American Academy of Optometry.

Cox,S. M., Berntsen,D. A., Chatterjee,N., Hickson-Curran,S. B., Jones,L. W., Moezzi,A. M., Morgan,P. B., Nichols,J. J., Mathew,J. H., Bickle,K. M., Powell,D. R., Cox,J., Miller,W. L., Wallace-Tucker,A., Charrier,S., Chen,Y. -J, Cardenas,L., Huerta,S., Dionne,K., Maldonado-Codina,C., Plowright,A. J., Howarth,G. F., Mirza,A., Smith,S., Dumbleton,K., Schulze,M., Luensmann,D., Ngo,W., Paquette,L., Srinivasan,S., Varikooty,J., Johnson,J., Simpson,M., Voss,L., Ryan,L., Careless,N., Smith,A., Subbarama Eyelid margin and meibomian gland characteristics and symptoms in lens wearers. Optometry and Vision Science 2016;93,8:901-908. [ Show Abstract ]

Purpose. To describe the lid margin characteristics of contact lens wearers and relate them to comfort during lens wear. Methods. Three study sites enrolled habitual contact lens wearers. Subjects completed the Comfort domain of the Contact Lens User Experience (CLUE) questionnaire, and each eye was graded for the presence of mucocutaneous junction (MCJ) displacement, lid margin irregularity, and lid margin vascularity. Examiners counted the number of meibomian gland (MG) orifices in the central centimeter of the lower eyelid and the number of those that showed pouting/plugging and vascular invasion. MG expressibility was graded according to the Shimazaki schema. Subjects were grouped based on presence/ absence of each characteristic, total number of orifices (=5 vs. 0). Descriptive statistics are reported. A linear model was used to assess the fixed effect of each characteristic on combined CLUE score and each CLUE statement, if the effect on combined CLUE score showed p < 0.10. Results. The study included 203 subjects (67.5% female) with mean age (±SD) of 30.3 ± 9.6 years. The most commonly observed characteristics were orifice pouting/plugging, compromised MG expressibility, and lid margin vascularity (35.0, 30.3, and 20.4%, respectively). MCJ displacement and MG expressibility had an effect on the combined CLUE score such that individual CLUE statements were analyzed (p = 0.01 and p = 0.06, respectively). MCJ displacement had an effect on comfort upon insertion (p = 0.01), comfort after 5 minutes (p = 0.03), end-of-day comfort (p = 0.01), and ability to maintain ocular moisture (p = 0.030). MG expressibility had a significant effect on general comfort (p = 0.01), comfort throughout the day (p = 0.02), and the ability to maintain ocular moisture (p = 0.02). Conclusions. MCJ displacement and MG expressibility have an effect on contact lens comfort. © Copyright 2016 American Academy of Optometry.

Omali,N. B., Heynen,M., Subbaraman,L. N., Papinski,D., Lakkis,C., Smith,S. L., Morgan,P. B., Berntsen,D. A., Nichols,J. J., Jones,L. W., Mathew,J. H., Cox,S. M., Bickle,K. M., Powell,D. R., Cox,J., Miller,W. L., Wallace-Tucker,A., Charrier,S., Chen,Y. -J, Cardenas,L., Huerta,S., Dionne,K., Maldonado-Codina,C., Plowright,A. J., Howarth,G. F., Chatterjee,N., Mirza,A., Dumbleton,K., Schulze,M., Moezzi,A. M., Luensmann,D., Ngo,W., Paquette,L., Srinivasan,S., Varikooty,J., Johnson,J., Simpson,M., Vos Impact of lens care solutions on protein deposition on soft contact lenses. Optometry and Vision Science 2016;93,8:963-972. [ Show Abstract ]

Purpose. To evaluate the effect of four contemporary lens care solutions on total protein, total lysozyme, and active lysozyme extracted from three contact lens materials. Methods. Adapted contact lens wearers were recruited at three sites, and all subjects were randomly assigned to daily wear of either etafilcon A, galyfilcon A, or senofilcon A for 2 weeks. Four lens care solutions (Biotrue, OPTI-FREE PureMoist, RevitaLens OcuTec, and ClearCare) were used by each subject in random order with a new pair of lenses after a washout period between solutions of at least 4 days. After 2 weeks of daily wear, contact lenses were collected for analysis. Proteins were extracted from a subset of contact lenses (n = 568) and total protein, total lysozyme, and lysozyme activity were quantified using a modified Bradford assay, an enzyme-linked immunosorbent assay, and a micrococcal assay, respectively. Results. Higher levels of total protein were extracted from etafilcon A when used with Biotrue compared to other solutions (p = 0.0001). There were higher levels of total lysozyme extracted from galyfilcon A lenses when used with PureMoist than with Biotrue or Clear Care (p < 0.006). Higher total lysozyme was extracted from senofilcon A when used with RevitaLens OcuTec compared to Biotrue (p = 0.002). Lower lysozyme activity was recovered from senofilcon A lenses with RevitaLens OcuTec when compared to all other care solutions (all p < 0.004). When Biotrue, PureMoist, or RevitaLens OcuTec were used, higher total lysozyme was extracted from galyfilcon A compared to senofilcon A(p < 0.01). When RevitaLens OcuTec was used, higher levels of active lysozyme were extracted from galyfilcon A compared to senofilcon A (p = 0.02). Conclusions. The ability of lens care solutions to remove protein from lenses varies depending upon the care solution composition and also the polymeric make-up of the contact lens material. © Copyright 2016 American Academy of Optometry.

2015

Moezzi,A. M., Fonn,D., Varikooty,J., Simpson,T. L. Overnight corneal swelling with high and low powered silicone hydrogel lenses. Journal of Optometry 2015;8,1:19-26. [ Show Abstract ]

Purpose To compare central corneal swelling after eight hours of sleep in eyes wearing four different silicone hydrogel lenses with three different powers. Methods Twenty-nine neophyte subjects wore lotrafilcon A (Dk, 140), balafilcon A (Dk, 91), galyfilcon A (Dk, 60) and senofilcon A (Dk, 103) lenses in powers -3.00, -10.00 and +6.00 D on separate nights, in random order, and on one eye only. The contra-lateral eye (no lens) served as the control. Central corneal thickness was measured using a digital optical pachometer before lens insertion and immediately after lens removal on waking. Results For the +6.00 D and -10.00 D, lotrafilcon A induced the least swelling and galyfilcon A the most. The +6.00 D power, averaged across lens materials, induced significantly greater central swelling than the -10.00 and -3.00 D (Re-ANOVA, p < 0.001), (7.7 ± 2.9% vs. 6.8 ± 2.8% and 6.5 ± 2.5% respectively) but there was no difference between -10.00 and -3.00 D. Averaged for power, lotrafilcon A induced the least (6.2 ± 2.8%) and galyfilcon A the most (7.6 ± 3.0%) swelling at the center (Re-ANOVA, p < 0.001). Central corneal swelling with +6.00 D was significantly greater than -10.00 D lens power despite similar levels of average lens transmissibility of these two lens powers. Conclusions The differences in corneal swelling of the lens wearing eyes are consistent with the differences in oxygen transmission of the silicone hydrogel lenses. In silicone hydrogel lenses central corneal swelling is mainly driven by central lens oxygen transmissibility.

Varikooty,J., Schulze,M. M., Dumbleton,K., Keir,N., Woods,C. A., Fonn,D., Jones,L. W. Clinical performance of three silicone hydrogel daily disposable lenses. Optometry and Vision Science 2015;92,3:301-311. [ Show Abstract ]

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 ofwear) 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 participantscompleted the study. For all visits, themeannoninvasive tear breakup timewas about 1 second longer withDT1 than withC1DandAVTE (p < 0.01).Overall, thewettability 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). Therewere no differences between asymptomatic and symptomatic lenswearers for any of the clinical parameters (all p 9 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 lensYrelated parameters. These results suggest that SiHy DDCLs may be an excellent contact lens modality for the symptomatic patient.

2014

Moezzi,A. M., Fonn,D., Varikooty,J., Simpson,T. L. Overnight corneal swelling with high and low powered silicone hydrogel lenses. Journal of Optometry 2014. [ Show Abstract ]

Purpose: To compare central corneal swelling after eight hours of sleep in eyes wearing four different silicone hydrogel lenses with three different powers. Methods: Twenty-nine neophyte subjects wore lotrafilcon A (Dk, 140), balafilcon A (Dk, 91), galyfilcon A (Dk, 60) and senofilcon A (Dk, 103) lenses in powers -3.00, -10.00 and +6.00 D on separate nights, in random order, and on one eye only. The contra-lateral eye (no lens) served as the control. Central corneal thickness was measured using a digital optical pachometer before lens insertion and immediately after lens removal on waking. Results: For the +6.00 D and -10.00 D, lotrafilcon A induced the least swelling and galyfilcon A the most. The +6.00 D power, averaged across lens materials, induced significantly greater central swelling than the -10.00 and -3.00 D (Re-ANOVA, p < 0.001), (7.7 ± 2.9% vs. 6.8 ± 2.8% and 6.5 ± 2.5% respectively) but there was no difference between -10.00 and -3.00 D. Averaged for power, lotrafilcon A induced the least (6.2 ± 2.8%) and galyfilcon A the most (7.6 ± 3.0%) swelling at the center (Re-ANOVA, p < 0.001). Central corneal swelling with +6.00 D was significantly greater than -10.00 D lens power despite similar levels of average lens transmissibility of these two lens powers. Conclusions: The differences in corneal swelling of the lens wearing eyes are consistent with the differences in oxygen transmission of the silicone hydrogel lenses. In silicone hydrogel lenses central corneal swelling is mainly driven by central lens oxygen transmissibility. © 2013 Spanish General Council of Optometry.

2013

Varikooty,J., Keir,N., Richter,D., Jones,L. W., Woods,C., Fonn,D. Comfort response of three silicone hydrogel daily disposable contact lenses. Optometry and Vision Science 2013;90,9:945-953. [ Show Abstract ]

PURPOSE: To evaluate subjective ocular comfort across the day with three silicone hydrogel daily disposables (SHDDs) in a group of adapted lens wearers. METHODS: Masked subjects (asymptomatic or symptomatic of end-of-day (EOD) dryness with habitual lenses) wore three SHDDs: DAILIES TOTAL1 (DT1), Clariti 1day (C1D), or 1-DAY ACUVUE TRUEYE (AVTE), each for 3 days. On day 2, wearing time (WT) and comfort ratings after insertion, at 4, 8, and 12 hours, and at EOD were recorded. Because not all subjects wore lenses for 12 hours, comfort was analyzed across the day (up to 8 hours, 8 to 12 hours), and a new variable ("cumulative comfort" [CC]) was calculated for EOD. RESULTS: One hundred four subjects completed the study (51 asymptomatic, 53 symptomatic). The two groups had different WTs (mean WT, 14.0 and 12.7 hours, respectively; p < 0.001). Ocular comfort was rated higher in the asymptomatic group throughout the day (p < 0.001). One hundred four subjects wore all three SHDDs for at least 8 hours, whereas 74 (45 asymptomatic, 29 symptomatic) subjects wore them for 12 hours or longer. Comfort ratings were higher with DT1 (least square means [LSM] = 91.0) than with C1D (LSM = 86.5; p < 0.001) and AVTE (LSM = 87.7; p = 0.011) for the first 8 hours and lower with C1D compared with DT1 (p = 0.012) from 8 to 12 hours. Mean EOD (± SD) comfort with the C1D lens was 72 ± 21, lower than both DT1 (mean, 79 ± 17; p = 0.001) and AVTE (mean, 78 ± 21; p = 0.010). Mean CC was higher in the asymptomatic group (mean, 1261 ± 59) compared with that in the symptomatic group (mean, 1009 ± 58; p < 0.001) and higher for DT1 (mean, 1184 ± 258) than C1D (mean, 1094 ± 318; p = 0.002) and AVTE (mean, 1122 ± 297; p = 0.046). CONCLUSIONS: All three SHDDs had average WTs of 12 hours or longer for 1 day. Comfort during the first 12 hours was highest with DT1 (similar to AVTE between 8 and 12 hours) and lowest with C1D. End-of-day comfort was lowest with C1D, and CC was highest for DT1. Cumulative comfort may be a valuable new metric to assess ocular comfort during the day. © 2013 American Academy of Optometry.

2012

Subbaraman,L. N., Glasier,M. -A, Varikooty,J., Srinivasan,S., Jones,L. Protein deposition and clinical symptoms in daily wear of etafilcon lenses. Optometry and Vision Science 2012;89,10:1450-1459. [ Show Abstract ]

Purpose.: To determine the relationship between clinical signs and symptoms and protein deposition over 8 h of wear of etafilcon A lenses in symptomatic and asymptomatic contact lens wearers. Methods.: Thirty adapted soft contact lens wearers (16 symptomatic and 14 asymptomatic) were fitted with etafilcon A lenses. In vivo wettability, non-invasive tear break-up time, and subjective symptoms (vision, comfort, and dryness) were assessed at baseline and after 2, 4, 6, and 8 h. After 2, 4, 6, and 8 h time points, lenses were collected, and total protein, total lysozyme, and active lysozyme deposition were assessed. Results.: There was a significant reduction (p = 0.032) in the non-invasive tear break-up time at 8 h in both groups. In the symptomatic group, there was a significant reduction in subjective comfort and dryness ratings at 6 and 8 h measurement with respect to baseline (p 94% at 8 h). Pearson's correlations between subjective symptoms and protein deposition showed poor correlations for total protein/lysozyme and any subjective factor (r 0.05), and only weak correlations between dryness and % active lysozyme (r = 0.3 to 0.5 for all time points). However, stronger correlations were found between active lysozyme and subjective comfort (r = 0.6 to 0.7; p < 0.001). Conclusions.: In addition to investigating total protein deposited on contact lenses, it is of significant clinical relevance to determine the conformational state of the deposited protein. Copyright © 2012 American Academy of Optometry.

Varikooty,J., Keir,N., Simpson,T. Estimating tear film spread and stability through tear hydrodynamics. Optometry and Vision Science 2012;89,8:e1119-e1124. [ Show Abstract ]

PURPOSE.: The stability and ease of spread of the tear-film over the contact lens surface may be an indicator of contact lens surface dewetting. The present in vivo methods of determining lens dewetting are complex. This study introduces a novel and objective way of determining the upward spread and stability of the tear-film through measurement of tear-film particle dynamics. METHODS.: Ten adapted contact lens wearers wore the same type of contact lens. Using a video camera mounted to a slit-lamp, the tear-film spread over the lens surface was recorded after a blink, at 8× magnification and capture rate of 30 frames per second, at morning after lens insertion, and after 8 h of lens wear. Images from 20 videos, without blinks and without an observable change in fixation were analyzed without any further postprocessing of the images. Using a customized calibrated ImageJ macro for particle tracking, the velocity of naturally occurring reflective particles was determined. The results were analyzed using the R program and ProFit. RESULTS.: The results established that the upward particle velocity was highest immediately after a blink and declined with time. The spread of the tear film measured through upward particle velocity was different on lens insertion than after 8 h of lens wear (p ≤ 0.001). The exponential time constants ± SE were 346.02 ± 29.0 for lens insertion at morning and 1413.13 ± 419.6 after 8 h of lens wear. CONCLUSIONS.: A novel and non-invasive way to measure in vivo spread and stability of the prelens tear-film has been developed. Additional studies are needed to understand whether this simple measure is able to differentiate the performance of different soft contact lenses and how this method may help in the understanding other aspects of lens performance such as non-invasive tear breakup time, surface deposition, and lens comfort. Copyright © 2012 American Academy of Optometry.

2011

Moezzi,A. M., Fonn,D., Varikooty,J., Richter,D. Distribution of overnight corneal swelling across subjects with 4 different silicone hydrogel lenses. Eye and Contact Lens 2011;37,2:61-65. [ Show Abstract ]

Purpose: To determine distribution of central corneal swelling (CCS) across subjects after 8 hr of sleep in eyes wearing silicone hydrogel lenses with various oxygen transmissibility (Dk/t) values and in eyes without lenses. Methods: Twenty-nine neophytes wore lotrafilcon A (Dk, 140), balafilcon A (Dk, 91), galyfilcon A (Dk, 60), and senofilcon A (Dk, 103) lenses in powers -3.00, -10.00, and +6.00 diopters on separate nights, in random order, and on 1 eye only. The contralateral eye (no lens) served as the control. Central corneal thickness was measured using a digital optical pachometer before lens insertion and immediately after lens removal on waking. Results: The average difference between the mean (7%) and the median (6.8%) CCS of all lenses was only 0.2%, suggesting a normal distribution. There was no correlation between the mean and the range of the CCS (r=0.058, P=0.766). Normal CCS distributions were also found with each lens-wearing eye and the control eye (P>0.20 for all). There was a significant correlation between lens-wearing eye and control eye (r=0.895, P<0.001) and between lotrafilcon A and each of the other 3 lenses for mean CCS across the study participants (P<0.001 for all). Conclusions: Distribution of corneal swelling in both lens-wearing eye and control eye followed a normal curve. An individual's corneal swelling response seems to be independent of lens type. © 2011 Lippincott Williams & Wilkins.

2010

Varikooty,J., Keir,N., Woods,C. A., Fonn,D. Measurement of the refractive index of soft contact lenses during wear. Eye and Contact Lens 2010;36,1:2-5. [ Show Abstract ]

Purpose: To determine whether the refractive index (RI) of a soft contact lens can be evaluated using refractometry while the lens remains on the eye and to compare this with more traditional ex vivo RI measurements. Methods: A slitlamp apparatus was modified to incorporate a customized Atago hand refractometer. With a double-masked study design, nine adapted symptomatic soft contact lens wearers wore a contact lens in each eye (lotrafilcon B and etafilcon A) in a randomized order. In vivo RI was determined from the relative Brix scale measurements immediately after lens insertion and after 1 and 10 hr of lens wear. Ex vivo refractometry was performed after 10 hr of lens wear for comparison. Means ± standard errors of the means are reported. Results: In vivo RI values at baseline were 1.422 ± 0.0004 (lotrafilcon B) and 1.405 ± 0.0021 (etafilcon A); after 1 hr of lens wear, values were 1.423 ± 0.0006 and 1.408 ± 0.0007, respectively; and after 10 hr of lens wear, values were 1.424 ± 0.0004 and 1.411 ± 0.0010, respectively. Ex vivo RI values at the end of the 10 hr wearing period were 1.424 ± 0.0003 (lotrafilcon B) and 1.412 ± 0.0017 (etafilcon A). The change in in vivo RI across the day was statistically significant for the etafilcon A lens (repeated-measures analysis of variance, P0.05). Conclusions: This novel adaptation of refractometry was able to measure the RI of soft contact lenses during wear (without lens removal). End of day RI measurements using in vivo and ex vivo refractometry were comparable with each other. Future work is required to determine whether this in vivo method can improve our understanding of the relationships between soft contact lens RI, hydration, on-eye lens performance, and symptomology. Copyright © Contact Lens Association of Ophthalmologists, Inc.

2009

Boone,A., Heynen,M., Joyce,E., Varikooty,J., Jones,L. Ex vivo protein deposition on bi-weekly silicone hydrogel contact lenses. Optometry and Vision Science 2009;86,11:1241-1249. [ Show Abstract ]

Purpose. This study investigated the protein deposition that occurs on daily wear silicone hydrogel (SH) lenses, after 2 weeks of wear. Methods. A total of 40 subjects were divided into equal groups, based on their habitual SH contact lens [CIBA Vision O2OPTIX (O2); Johnson & Johnson ACUVUE ADVANCE with HYDRACLEAR (ADV); Bausch & Lomb PureVision (PV); CIBA Vision Night & Day (ND)]. A randomized, double-masked, cross-over study was conducted in which subjects wore either their habitual SH material or Johnson & Johnson ACUVUE OASYS with HYDRACLEAR PLUS (OAS) for 2 weeks. At the end of the 2-week period, lenses were collected for analysis of total protein, total lysozyme, and percent denatured lysozyme. Results. Total protein was greatest for PV (33 ± 6 μg/lens), with other lenses depositing 0.05). Total lysozyme was also greatest for the PV lens (11 ± 3 μg/lens), with other lenses depositing 0.05). Total lysozyme was also greatest for the PV lens (11 ± 3 μg/lens), with other lenses depositing 0.05). Total lysozyme was also greatest for the PV lens (11 ± 3 μg/lens), with other lenses depositing 0.05). The percentage of lysozyme that was denatured was greatest for ND (90 ± 8%) and lowest for PV (23 ± 10%). The lysozyme extracted from ND and O2 lenses was significantly more denatured than that extracted from the other lens materials (p 0.05) or between ADV, OAS, and PV (p > 0.05). The amount of denatured lysozyme/lens was <3 μg/lens for all materials. Lysozyme as a percentage of the total protein deposited ranged from 32 (PV) to 6% (O2). Conclusions. This study confirms that all SH lenses deposit low levels of protein, and that the amount and percentage of denatured lysozyme can vary, depending on the overall surface charge of the material and absence or type of surface treatment. © 2009 American Academy of Optometry.

Varikooty,J., Simpson,T. L. The interblink interval I: The relationship between sensation intensity and tear film disruption. Investigative Ophthalmology and Visual Science 2009;50,3:1087-1092. [ Show Abstract ]

PURPOSE. To find the relationship between tear film drying and sensation during the interblink period. METHODS. One eye was taped shut, and after a blink the subjects were required to keep the other eye open. Digital video images of the ocular surface (with fluorescein) were obtained using a slit lamp biomicroscope while 23 subjects rated the intensity of the ocular surface sensation by adjusting a one-turn potentiometer to represent the strength of the sensation. They were trained to use the potentiometer before the data were collected. In addition, the characteristics of the sensation as spoken by the subject were recorded. RESULTS. The sensation was generally triphasic, with initial constant sensation and a subsequent biphasic period, with intensity increasing slowly followed by a rapid increase before the subjects blinked (correlations were all r > 0.95). Tear film drying dynamics were also biphasic, and drying and sensation were strongly associated, with a correlation of 0.94 between the break in the bilinear functions of sensation and drying. CONCLUSIONS. The method provides novel information about the development of ocular sensation during ocular surface drying. As evidenced by the complex functions required to adequately describe the relationships, tear film drying and ocular surface sensations are associated in complex ways. © Association for Research in Vision and Ophthalmology.

2008

Varikooty,J., Srinivasan,S., Jones,L. Atypical manifestation of upper lid margin staining in silicone hydrogel lens wearers with symptoms of dry eye. Contact Lens and Anterior Eye 2008;31,1:44-46. [ Show Abstract ]

Purpose: To report an atypical manifestation of upper lid margin staining (ULMS) that occurred in adapted silicone hydrogel (SH) contact lens wearers who complained of ocular surface dryness. Methods: Sequential staining with sodium fluorescein (FL) and lissamine green (LG) strips was performed in 38 SH lens wearers. The "wiper area" of the upper lid was examined with the slit lamp, at 8× and 12× magnifications. Results: Four out of 38 subjects (10.5%) showed fimbriated or "feathery" extensions from the superior margin of the subtarsal fold onto the upper tarsal plate. The extent of these feathery extensions varied between subjects, with a mean (±S.D.) length of 2 ± 0.8 mm. In all cases a broad band of staining with both FL and LG was demonstrated, which extended along the entire length of the lid margin. Conclusion: The staining patterns shown on the subjects' upper lid margins and tarsal plates suggest that ULMS may include more complex variants. The putative tissue damage revealed through the staining, points to a mechanism not simply restricted to the upper lid margin. © 2007 British Contact Lens Association.

2006

Begley,C. G., Himebaugh,N., Renner,D., Liu,H., Chalmers,R., Simpson,T., Varikooty,J. Tear breakup dynamics: A technique for quantifying tear film instability. Optometry and Vision Science 2006;83,1:15-21. [ Show Abstract ]

PURPOSE: The purpose of this study was to develop a novel, quantitative measurement of tear film breakup dynamics (TBUD) to study the phenomenon of tear breakup in dry eye and control subjects and its impact on dry eye symptoms. METHODS: Ten control and 10 dry eye subjects completed the Dry Eye (DEQ) and other questionnaires. After the instillation of sodium fluorescein, subjects kept the tested eye open for as long as possible, similar to a staring contest, while tear film breakup was videotaped (S-TBUD). The maximum blink interval (MBI) and tear breakup time (TBUT) were measured from digital movies by a masked observer. Individual frames of movies were converted to gray-scale images, maps of relative tear film fluorescence were generated, and the total area of tear breakup (AB) of the exposed cornea was quantified. RESULTS: On average, dry eye subjects demonstrated a higher AB and shorter TBUT and MBI, but only the AB was significantly different (p = 0.023). Subjects most often used the descriptors stinging and burning to describe their sensations during staring trials. The AB showed a high correlation between eyes and with some DEQ symptom measures. CONCLUSIONS: These methods allow objective quantification and tracking of the phenomenon of tear breakup. Our results suggest that tear breakup stresses the corneal surface, resulting in stimulation of underlying nociceptors. The tear film of dry eye subjects was less stable than controls. They had a larger AB measured from the last video frame before MBI (i.e., just before blinking) than did controls. This perhaps reflects adaptation to the repeated stress of tear instability in dry eye.

2001

Feng,Y., Varikooty,J., Simpson,T. L. Diurnal variation of corneal and corneal epithelial thickness measured using optical coherence tomography. Cornea 2001;20,5:480-483. [ Show Abstract ]

PURPOSE: To determine the feasibility of optical coherence tomography (OCT) measurement of overnight corneal swelling and de-swelling and, specifically, to examine overnight changes in the corneal epithelium and recovery during the day. METHODS: Ten healthy volunteers were recruited. Corneal OCT imaging was performed at 10:00 PM (baseline), 8:30 AM, and every 2 hours thereafter until 4:30 PM. Either the right or left eye was taped shut (using a gauze pad and surgical tape) until the 8:30 AM session of the next day. Measurements were made along a 1-mm strip centered on the visual axis. RESULTS: At baseline, there were no differences in corneal or epithelial thickness between control and experimental eyes (all p > 0.05). Immediately after patch removal, corneal and epithelial thicknesses of patched eyes were higher than the baseline (all p < 0.05). In patched eyes, the cornea and epithelium swelled 5.5% and 8.1% overnight, respectively (p > 0.05). Two hours later, the epithelial thickness of the experimental eyes recovered to baseline level (p > 0.05), but corneal thickness did not reach to baseline level until 4 hours after patch removal. For control eyes, there were no differences compared with baseline (all p > 0.05). CONCLUSION: Both cornea and corneal epithelium experience proportionately similar amounts of overnight swelling. Recovery of overnight swelling may be slower for the cornea than for the epithelium. OCT provides valuable information about anterior segment morphometry.

Abstracts

2016

Moezzi A, Varikooty J, Luensmann D, Ng A, Schulze M, Karkkainen T, Xu J, Jones L. Open-eye clinical performance of etafilcon a multifocal daily disposable hydrogel contact lenses compared to habitual silicone hydrogel lens wear. Optom Vis Sci 2016;93: E-abstract 165259. [ PDF ]

Jones L, Varikooty J, Schulze M, Keir N. Assessment of contact lens comfort: Single report scores vs cumulative comfort. Asian Cornea and Contact Lens Conference, Hong Kong, 2016.

2015

Panjwani F, Papinski D, Varikooty J, Woods J, Jones L. In-vivo dehydration of stenfilcon A and delefilcon A silicone hydrogel materials. Optom Vis Sci 2015;92: E-abstract 155262. [ PDF ]

2014

Moezzi A, Varikooty J, Schulze M, Ngo W, Lorenz K, Jones L. Open Eye Corneal Swelling with 1-DAY ACUVUE® DEFINE™ and 1-DAY ACUVUE® DEFINE™ with Lacreon® compared to 1-DAY ACUVUE® MOIST®. Invest Ophthalmol Vis Sci 2014;55: E-abstract 4672. [ PDF ]

Moezzi A, Varikooty J, Schulze M, Ngo W, Lorenz K, Boree M. Open-eye corneal swelling with etafilcon A daily disposable hydrogel contact lenses compared to no lens wear. BCLA Clinical Conference and Exhibition, 2014. [ PDF ]

Varikooty J, Woods J, Jones L. Assessment of pre-lens tear film particle velocity measurements in participants wearing daily disposable silicone hydrogel lenses. BCLA Clinical Conference and Exhibition, 2014. [ PDF ]

Berntsen D, Varikooty J, Nichols J, Mathew J, Jones L, Morgan P, Smith S, Hickson-Curran S, Toubouti Y. Soft contact lens wear time and subjective dryness using different contact lens materials and solutions. Optom Vis Sci 2014;91: E-abstract 140085.

2013

Stahl U, Keir N, Varikooty J, Nandakumar K, Keech A, Landers A, Jones L. The effect of recovery periods on end of day comfort. Invest Ophthalmol Vis Sci 2013;54: E-Abstract 5462.

Patel P, Soong F, Varikooty J, Keir N, Jones L. Ocular signs and symptoms in contact lens wearers in a controlled low humidity environmental exposure chamber (LH-EEC), a natural provocation research model. Invest Ophthalmol Vis Sci 2013;54: E-Abstract 5473.

Jones L, Varikooty J, Keir N, Soong F, Patel P. The evaluation of lid wiper epitheliopathy in contact lens wearers in a controlled low humidity environmental exposure chamber. Invest Ophthalmol Vis Sci 2013;54: E-Abstract 5475.

Jones L, Varikooty J, Keir N, Soong F, Patel P. The evaluation of lid wiper epitheliopathy in contact lens wearers in a controlled low humidity enivironmental exposure chamber. Tear Film & Ocular Surface International Conference, Sicily, Italy, 2013.

Patel P, Soong F, Salapatek AM, Varikooty J, Keir N, Jones L. Ocular signs and symptoms in contact lens wearers in a controlled low humidity environmental exposure chamber (LH-EEC) a natural provocation research model. Tear Film & Ocular Surface International Conference, Sicily, Italy, 2013.

Salapatek AM, Soong F, Varikooty J, Keir N, Jones L, Patel P. In-vivo wettability of contact lenses worn in a low humidity environmental exposure chamber (LH-EEC) show comparable changes to traditional field trials. Tear Film & Ocular Surface International Conference, Sicily, Italy, 2013.

Moezzi A, Richter D, Varikooty J, Simpson T. A Novel Method for removing inter-observer Bias in Optical Pachometry. 8th Canadian Optometry Schools Research Conference (COSRC), 2013.

Soong F, Varikooty J, Keir N, Jones L, Patel P. In-vivo wettability of contact lenses worn in a low humidity environmental exposure chamber (LH-EEC) show comparible changes to traditional field trials. Invest Ophthalmol Vis Sci 2013;54: E-Abstract 499.

Varikooty J , Lay B, Keir N, Burdin H, Jones L, Simpson T, Lemp J. The relationship between clinical grading and objective image analysis of lid wiper epitheliopathy. Invest Ophthalmol Vis Sci 2013;54: E-Abstract 5460.

2012

Keir N, Richter D, Varikooty J, Jones L, Woods C, Fonn D. End Of Day Comfort Interpreted Using A Novel Cumulative Comfort Score. Invest Ophthalmol Vis Sci 2012;53:ARVO E-Abstract 4728.

Varikooty J, Keir N, Simpson T. Estimating in-vivo Contact Lens Wettability Through Tear Film Hydrodynamics . Invest Ophthalmol Vis Sci 2012;53:ARVO E-Abstract 6098.

Varikooty J, Keir N, Jones L. Optimization of assessment and grading for lid wiper epitheliopathy. Optom Vis Sci 2012;89:E-abstract 120241.

Schulze M, Varikooty J, Keir N, Jones L. The clinical performance of three contact lens solutions in symptomatic and asymptomatic contact lens wearers. Contact Lens & Anterior Eye 2012;35,S1:e8.

Keir N, Richter D, Varikooty J, Jones L, Woods C, Fonn D. End of day comfort interpreted using a novel cumulative comfort score for symptomatic contact lens wearers. Contact Lens & Anterior Eye 2012;35,S1:e37.

Keir N, Varikooty J, Richter D, Jones L, Woods C, Fonn D. Evaluation of lens surface appearance and ocular physiology with three silicone hydrogel daily disposables. Contact Lens & Anterior Eye 2012;35,S1:e6.

Varikooty J, Keir N, Richter D, Jones L, Woods C, Fonn D. Subjective comfort with three silicone hydrogel daily disposables in symptomatic contact lens wearers. Contact Lens & Anterior Eye 2012;35,S1:e7-e8.

Varikooty J, Keir N, Simpson T. Estimating in vivo contact lens wettability through tear film hydrodynamics. Contact Lens & Anterior Eye 2012;35,S1:e31.

2011

Anderson T, Moezzi A, Varikooty J, Jones L, Woods C, Fonn D. A novel method for measuring contact lens movement and centration using a high speed camera and computer vision. Optom Vis Sci 2011;88:E-abstract 115439.

2010

Heynen M, Lorentz H, Dumbleton K, Varikooty J, Woods C, Jones L. Lipid deposition on senofilcon A silicone hydrogel contact lenses disinfected with 1-step hydrogen peroxide and polyquad/aldox-preserved care regimens. 7th Canadian University Conference in Optometry (Montreal, Canada), 2010.

2009

Fonn D, Moezzi A, Varikooty J. Average and individual overnight central corneal swelling with four different silicone hydrogel lenses. Contact Lens & Anterior Eye 2009;32,5:229.

Keir N, Varikooty J, Woods C, Fonn D. A novel in vivo method for measuring the refractive index of soft contact lenses using refractometry. Contact Lens & Anterior Eye 2009;32,5:229.

Jones L, Heynen M, Joyce E, Lorentz H, Dumbleton K, Varikooty J, Woods C. Tear film deposition on silicone hydrogel contact lenses disinfected with hydrogen peroxide and rub or enhanced no-rub care regimens. Contact Lens & Anterior Eye 2009;32,5:249.

Fonn D, Moezzi A, Varikooty J. Distribution of overnight corneal swelling across subjects with 4 different silicone hydrogel lenses. Invest Ophthalmol Vis Sci 2009;50:E-abstract 5658.

Heynen M, Lorentz H, Dumbleton K, Varikooty J, Woods C, Jones L. Lipid deposition on senofilcon A silicone hydrogel contact lenses disinfected with 1-step hydrogen peroxide and polyquad/aldox-preserved care regimens. Invest Ophthalmol Vis Sci 2009;49:E-abstract 5660.

Woods CA, Varikooty J, Keir N, Fonn D. Investigation of a novel in vivo method for measuring the refractive index of soft contact lenses using refractometry. Invest Ophthalmol Vis Sci 2009;50:E-abstract 5655.

Jones L, Heynen M, Joyce E, Lorentz H, Dumbleton K, Varikooty J, Woods C. Tear film deposition on silicone hydrogel contact lenses disinfected with hydrogen peroxide and rub or enhanced no-rub care regimens. Optom Vis Sci 2009;86:E-abstract 095929.

Moezzi A, Fonn D, Varikooty J, Richter D. Distribution of overnight central corneal swelling with high powered silicone hydrogel lenses. Optom Vis Sci 2009;86:E-abstract 90898.

2008

Fonn D, Moezzi A, Varikooty J, Simpson TL. The effect of oxygen transmissibility on central and peripheral overnight corneal swelling with four different silicone hydrogel lenses. Optom Vis Sci 2008;85: E-abstract 85077.

Moezzi A, Fonn D, Varikooty J, Simpson TL. The effect of lens power on central and peripheral overnight corneal swelling with four different silicone hydrogel lenses. Optom Vis Sci 2008;85: E-abstract 85076.

Jones L, Boone A, Heynen M, Joyce E, Varikooty J. Ex vivo protein deposition on two-weekly daily wear silicone hydrogel contact lens materials. Contact Lens & Anterior Eye 2008;31,5:262-263.

2007

Boone A, Heynen M, Joyce E, Varikooty J, Jones L. Ex vivo protein deposition on two-weekly daily wear silicone hydrogel contact lens materials. Optom Vis Sci 2007;84: E-abstract 075140.

Jones L, Subbaraman LN, Varikooty J, Srinivasan S, Glasier M. Activity of lysozyme deposited on oneday etafilcon contact lenses is correlated with subjective comfort. 14th Scientific Meeting of the International Society for Contact Lens Research (Whistler, Canada), 2007.

Jones L, Subbaraman L, Srinivasan S, Varikooty J, Glasier M. Subjective comfort is correlated with the activity of lysozyme recovered from one-day etafilcon lenses. British Contact Lens Association Annual Meeting, Manchester, England, 2007.

Varikooty J, Srinivasan S, Chan A, Subbaraman L, Woods C, Simpson T, Jones L, Fonn D. Clinical manifestations of upper lid staining in adapted silicone hydrogel lens wearers. British Contact Lens Association Annual meeting (Manchester, UK), 2007.

2006

Subbaraman L, Jones L, Srinivasan S, Varikooty J, Glasier MA. Activity of lysozyme deposited on one-day etafilcon contact lenses is correlated with subjective comfort. Optom Vis Sci 2006;83:E-Abstract 060091.

Varikooty J, Srinivasan S, Subbaraman L, Feng Y, Jones L, Simpson T, Fonn D. The influence of pre-soaking single-use etafilcon contact lenses on ocular comfort in symptomatic and asymptomatic contact lens wearers. Optom Vis Sci 2006;83:E-Abstract 065245.

Srinivasan S, Varikooty J, Subbaraman L, Chan A, Woods C, Simpson T, Jones L, Fonn D. Atypical manifestation of upper lid margin staining in silicone hydrogel lens wearers with symptoms of dry eye. Optom Vis Sci 2006;83:E-Abstract 065255.

Woods J, Woods C, Varikooty J, Jones L, Simpson T, Fonn D. A novel method of recording corneal staining that facilitates parametric analysis. Optom Vis Sci 2006;83: E-Abstract 065236.

Subbaraman LN, Jones L, Srinivasan S, Varikooty J, Glasier MA. Clinical signs & symptoms and protein deposition in one day wear of etafilcon lenses in symptomatic and asymptomatic subjects. Invest Ophthalmol Vis Sci 2006;47: E-Abstract 2400.

Guthrie S, Simpson T, Varikooty J, Fonn D. Background subtraction and contrast enhancement for interferometric images of the human corneal tear film. Invest Ophthalmol Vis Sci 2006;47:E-abstract 2399.

Dumbleton K, Keir N, Varikooty J, Fonn D, Janakiraman P. Toric silicone hydrogel lenses for extended wear. Contact Lens & Anterior Eye 2006;29,4:184.

Rogers R, Jones L, Srinivasan S, Varikooty J, Fonn D. The influence of care regimen composition and wear time on ex vivo wettability of etafilcon contact lenses. Contact Lens & Anterior Eye 2006;29,4:189.

Subbaraman L, Jones L, Srinivasan S, Varikooty J. Clinical signs & symptoms and protein deposition in one day wear of etafilcon lenses in symptomatic & asymptomatic subjects. British Contact Lens Association Annual Meeting, Birmingham, England, 2006.

Keir N, Moezzi A, Fonn D, Varikooty J, Simpson T. Overnight corneal swelling of silicone hydrogel contact lenses with high oxygen transmissibility. Contact Lens & Anterior Eye 2006;29,4:196.

Subbaraman LN, Jones L, Srinivasan S, Varikooty J, Glasier M. The role of protein deposition and surface wettability in symptoms of contact lens-induced dryness during one day wear of etafilcon lenses in symptomatic and asymptomatic subjects. Contact Lens & Anterior Eye 2006;29,4:194-195.

Subbaraman LN, Glasier MA, Srinivasan S, Varikooty J, Jones L. Correlation between clinical signs & symptoms and protein deposition in one day wear of etafilcon lenses in symptomatic and asymptomatic subjects. University of Waterloo Graduate Student Research Conference, 2006.

Varikooty J, Srinivasan S, Subbaraman L, Chan A, Woods C, Jones L, Simpson T, Fonn D. Clinical manifestations of upper lid staining in adapted silicone hydrogel lens wearers. Optom Vis Sci 2006;83:E-abstract 065256.

Subbaraman L, Jones L, Srinivasan S, Varikooty J, Glasier MA. The relationship between protein deposition and clinical signs and symptoms in one day wear of etafilcon lenses in symptomatic and asymptomatic subjects. Canadian Student Health Research Forum (Winnipeg, Canada), 2006.

2005

Dumbleton K, Keir N, Varikooty J, Fonn D. Corneal thickness changes over six months of contralateral extended wear with low and high DK hydrogel lenses. Optom Vis Sci 2005;82: E-Abstract 055109.

Moezzi A, Fonn D, Varikooty J, Simpson T. Overnight corneal swelling of silicone hydrogel contact lenses with high oxygen transmissibility. Optom Vis Sci 2005;82: E-abstract 050083.

Varikooty J, Situ P, Jones L, Fonn D. Clinical performance of alexidine-based and polyquad-based multipurpose solutions when used with daily wear balafilcon lenses. Optom Vis Sci 2005;82: E-abstract 055100.

Jones L, Srinivasan S, Varikooty J, Simpson T. Novel methodologies to investigate patients with symptoms of dry eye. British Contact Lens Association Annual Meeting, Brighton, England, 2005.

Varikooty J. Ocular surface sensations during forced eye opening. International Vision Science and Optometry Conference (EIVOC), Elite School of Optometry, Chennai, India, 2005.

Subbaraman LN, Jones L, Srinivasan S, Varikooty J, Glasier M. The relationship between protein deposition and clinical signs & symptoms in one day wear of etafilcon lenses in symptomatic and asymptomatic subjects. Canadian Student Health Research Forum, 2005.

2004

Varikooty JP, Simpson TL, Jones LW, Fonn D. Subjective sensations reported during the interblink interval reflect different components of ocular surface sensitivity. Invest Ophthalmol Vis Sci 2004;45: E-abstract 99.

2003

Varikooty J, Simpson TL, Fonn D. Changes in ocular surface temperature and redness. Invest Ophthalmol Vis Sci 2003;44: E-Abstract 3752.

2002

Varikooty J, Simpson T, Jones L, Fonn D. Ocular discomfort during tear film drying. Invest Ophthalmol Vis Sci 2002;43: E-abstract 3106.

2001

Varikooty JP, Simpson TL, Jones L, Fonn D. Ocular discomfort during tear drying: A method to simultaneously acquire discomfort ratings, ocular surface video and sensation attributes on a pseudocontinuous scale. Invest Ophthalmol Vis Sci 2001;42,4:s941 #5038.

Varikooty JP, Simpson TL, Jones L, Fonn D. Ocular discomfort during tear drying. International Society for Contact Lens Research, Sun Valley, Idaho, 2001.

2000

Feng Y, Varikooty J, Simpson TL. Diurnal variation of corneal and corneal epithelial thickness measured using optical coherence tomography. Invest Ophthalmol Vis Sci 2000;41,4:s675.

Feng Y, Varikooty J, Simpson TL. Optical coherence tomography measurement of overnight swelling of human cornea and corneal epithelium. Invest Ophthalmol Vis Sci 2000;41,4:s675.

Professional Publications

2014

Varikooty J. Summary: Report of the Subcommittee on Neurobiology. ContactLensUpdate.com 2014.

2012

Varikooty J, Stahl U. Visualization of limbal/conjunctival folliculitis associated with soft contact lens wear. ContactLensUpdate.com 2012.