Mertzanis,P., Abetz,L., Rajagopalan,K., Espindle,D., Chalmers,R., Snyder,C., Caffery,B., Edrington,T., Simpson,T., Nelson,J. D., Begley,C. The relative burden of dry eye in patients' lives: Comparisons to a U.S. normative sample Investigative Ophthalmology and Visual Science 2005;46(1):46-50 [ Show Abstract ]

PURPOSE. To assess the relative burden of dry eye in daily life by comparing Short Form-36 (SF-36) responses from individuals with and without dry eye against U.S. norms. METHODS. Assessment of 210 people, 130 with non-Sjögren's keratoconjunctivitis sicca (non-SS KCS), 32 with Sjögren's Syndrome (SS), and 48 control subjects. The study population data and published normative SF-36 data were compared. Dry eye severity was assessed by recruited severity (control, non-SS KCS, SS), patient self-report (none, very mild/mild, moderate, severe/extremely severe), and clinician-report (none, mild, moderate, severe). Age- and gender-matched norms were compared with all defined severity groups. RESULTS. Compared with the norms, control subjects scored higher on all SF-36 scales. Effect size (ES) ranged from 0.15 to 0.52. Non-SS KCS patients had lower Role-Physical (ES = -0.07), Bodily Pain (ES = -0.08), and Vitality (ES = -0.11) scores, indicating more dry eye impact on those areas versus the norm. All SF-36 scale scores except Mental Health (ES = 0.12) were lower in the SS group than the adjusted norm (ES range: -0.16 to -0.99). Regardless of severity classification, mild patients consistently had lower Role-Physical and Bodily Pain scores than the norm, suggesting impact on daily roles (ES < 0.2). Patients with moderately severe disease also experienced less vitality and poorer general health. The group with severe disease scored lower than the norm across all domains (ES range: -0.14 to -0.91) except Role-Emotional (ES = 0.13) and Mental Health (ES = 0.23). CONCLUSIONS. These results indicate dry eye's negative impact on everyday life, particularly in daily activities. Further research using disease-specific measures to examine dry eye's impact is underway.

Mirzapour,P., McCanna,D. J., Jones,L. In vitro analysis of the interaction of tear film inflammatory markers with contemporary contact lens materials Contact Lens Anterior Eye 2021;44(5):101430 [ Show Abstract ]

Purpose
Several clinical studies have suggested that reusable silicone hydrogel contact lens materials exhibit a two-times increased rate of corneal infiltrative events compared to reusable hydrogels. One potential factor contributing to this complication relates to the differential uptake of tear film-based pro-inflammatory cytokines. The purpose of this study was to use an in vitro assay to investigate whether four pro-inflammatory cytokines differed in their uptake onto six contemporary contact lens materials.

Methods
Conventional hydrogel (etafilcon A, omafilcon A) and silicone hydrogel (balafilcon A, comfilcon A, senofilcon A, somofilcon A) contact lens materials were soaked in solutions containing pro-inflammatory cytokines IL-1β, IL-6, IL-8 and TNF-α. Samples of the soaking solutions were collected over various time points and analyzed using the Meso Scale Discovery system, which served as a measurement of cytokine uptake onto the contact lens materials.

Results
Both conventional hydrogels (etafilcon A, omafilcon A) and two of the four silicone hydrogels tested (balafilcon A, comfilcon A), exhibited some uptake of IL-1β, IL-8 or TNF-α (p 0.05). There was no uptake of IL-6 onto any of the contact lens materials investigated (p > 0.05).

Conclusion
The contact lens materials tested did not exhibit any uptake of IL-6 and furthermore, did not exhibit more than 10 ± 3 % to 25 ± 12 % uptake of IL-1β, IL-8 or TNF-α. Numerous factors could contribute to the reported increase in corneal infiltrative events with reusable silicone hydrogel materials, however, based on these results, it appears that uptake of these four cytokines are unlikely to contribute to this finding.

Mishra,S. K., Baidya,S., Bhattarai,A., Shrestha,S., Homagan,S., Rayamajhee,B., Hui,A., Willcox,M. Bacteriology of Endotracheal Tube Biofilms and Antibiotic Resistance: A Systematic Review Journal of Hospital Infection 2024;147(May):146-157 [ Show Abstract ]

Background
Bacteria commonly adhere to surfaces and produce polymeric material to encase the attached cells to form communities called biofilms. Within these biofilms, bacteria can appear many times more resistant to antibiotics or disinfectants. This systematic review explores the prevalence and microbial profile associated with biofilm production of bacteria isolated from endotracheal tubes and its associations with antimicrobial resistance.

Methods
A comprehensive search was performed on databases PubMed, Embase, and Google Scholar for relevant articles published between January 1, 2000 and December 31, 2022. The relevant articles were exported to Mendeley Desktop 1.19.8 and screened by title and abstract, followed by full text screening based on the eligibility criteria of the study. Quality assessment of the studies was performed using the Newcastle-Ottawa Scale (NOS) customized for cross-sectional studies. Furthermore, the prevalence of antimicrobial resistance in biofilm-producers isolated from endotracheal tube specimens was investigated.

Results
Twenty studies encompassing 981 endotracheal tubes met the eligibility criteria. Pseudomonas spp. and Acinetobacter spp. were predominant isolates among the biofilm producers. These biofilms provided strong resistance against commonly used antibiotics. The highest resistance rate observed in Pseudomonas spp. was against fluoroquinolones whereas the least resistance was seen against piperacillin-tazobactam. A similar trend of susceptibility was observed in Acinetobacter spp. with a very high resistance rate against fluoroquinolones, third-generation cephalosporins and carbapenems.

Conclusion
Endotracheal tubes were associated with colonisation by biofilm forming bacteria with varying levels of antimicrobial resistance. Biofilms may promote the occurrence of recalcitrant infections in endotracheal tubes which need to be managed with appropriate protocols and antimicrobial stewardship. Research focus should shift towards meticulous exploration of biofilm-associated infections to improve detection and management.

Moezzi,A. M., Fonn,D., Simpson,T. L. Overnight corneal swelling with silicone hydrogel contact lenses with high oxygen transmissibility Eye and Contact Lens 2006;32(6):277-280 [ Show Abstract ]

PURPOSE. To compare central corneal swelling after 8 hours of sleep in eyes wearing 2 different silicone hydrogel lenses with high oxygen transmissibility. METHODS. Twenty neophyte subjects were randomly assigned to wear a comfilcon A lens (CooperVision Inc) in one eye and a lotrafilcon A lens (CIBA Vision) in the contralateral eye for an 8-hour overnight period. The study was repeated with another 20 neophyte subjects wearing comfilcon A in one eye only and no lens in the contralateral control eye. Central corneal thickness was measured with optical pachometry before lens insertion, immediately after lens removal on waking, at 20 and 40 minutes, 1 hour, 2 hours and 3 hours. RESULTS. There was no significant difference between the amount of overnight central corneal swelling induced by the 2 lenses (4.1% ± 1.9% with comfilcon A vs. 4.0% ± 1.7% with lotrafilcon A; P>0.05). The swelling of the comfilcon A lens-wearing eyes was significantly higher than that found in the non-lens-wearing contralateral eyes (4.5% ± 2.1% vs. 3.0% ± 1.7%; P<0.05). CONCLUSIONS. The same amount of overnight corneal swelling was induced by the 2 study lenses. The higher overnight swelling observed with the comfilcon A lenses compared to the non-lens-wearing eyes is similar to that reported in the literature for studies using lotrafilcon A lenses. © 2006 Lippincott Williams & Wilkins, Inc.

Moezzi,A. M., Fonn,D., Simpson,T. L., Sorbara,L. Contact lens-induced corneal swelling and surface changes measured with the Orbscan II corneal topographer Optometry and Vision Science 2004;81(3):189-193 [ Show Abstract ]

Purpose. The purpose of this study was to measure central and topographical corneal swelling in response to contact lens wear and eye closure, to determine whether the swelling induced by soft and polymethyl methacrylate (PMMA) lenses is different, and to determine whether the anterior and/or posterior corneal shape alters with corneal swelling. Methods. An Orbscan II corneal topographer was used to measure corneal swelling and the shape of the anterior and posterior corneal surfaces of 16 neophytes before and after wearing soft and PMMA contact lenses with near-zero oxygen transmissibility. The lens-wearing eye was patched for 3 h. Results. The mean 15.1% ± 3.8% (±SD) central corneal swelling with soft lenses was significantly > 12.6% ± 4.1% with PMMA lenses. Topographical corneal swelling was significantly greater with soft vs. PMMA lenses. However, the difference between central and peripheral corneal swelling was much greater with PMMA lenses. With both lenses, the cornea swelled significantly more in the center than the periphery. The anterior best-fit sphere radius remained unchanged in response to soft lenses (0.00 ± 0.04 mm) and steepened slightly but significantly with PMMA lenses (-0.04. ± 0.05 mm). The posterior best-fit sphere radius flattened significantly with both lenses (0.12 ± 0.07 mm with soft and 0.14 ± 0.08 mm with PMMA lenses). Conclusions. Corneal swelling (greater centrally than peripherally) flattens the posterior surface of the cornea and is independent of lens type. Although the anterior best-fit sphere radius steepened with PMMA, the magnitude is probably clinically unimportant. Both lens types produced greater central vs. peripheral corneal swelling. However, the soft lens induced significantly greater overall swelling than PMMA. Because their oxygen transmission was the same, these results suggest that there is lateral diffusion of oxygen from the peripheral area of the cornea (that is not covered by the lens) toward the center.

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.

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;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. © 2013 Spanish General Council of Optometry.

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.

Moezzi,A. M., Sin,S., Simpson,T. L. Novel pachometry calibration Optometry and Vision Science 2006;83(6):E366-E371 [ Show Abstract ]

PURPOSE: The purpose of this study was to develop a simple method for cross-calibrating instruments that measure corneal thickness. METHODS: Fourteen rigid lenses of different thicknesses were manufactured using a material with refractive index of 1.376. Center thickness of the lenses (CT) was measured using a computerized optical pachometer (OP), two optical coherence tomographers (OCTs), and a confocal microscope (CM). Accuracy of measurements was compared between the four instruments. RESULTS: Before calibrating the machines, there was a significant effect of the measurement device (p < 0.05). The differences between instruments were eliminated (p > 0.05) after applying calibration equations for each device. In addition, after each instrument was calibrated with lenses of 1.376 refractive index, there was no significant difference (p > 0.05) between measured values of lens center thickness by OP, each OCT, CM, and the physical center thickness of the lenses. CONCLUSIONS: Using calibration lenses with the same refractive index as the cornea (1.376) allows rapid and simple calibration of the pachometers so that corneal thickness measurements from different devices can be used interchangeably.

Moezzi,A. M., Varikooty,J., Luensmann,D., Schulze,M., Ng,A. Y., Karkkainen,T., Xu,J., Jones,L. The short-term physiological impact of switching reusable silicone hydrogel wearers into a hydrogel daily disposable multifocal Clinical Ophthalmology 2019;13:1193-1202 [ Show Abstract ]

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.

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.

Moezzi,A., Hutchings,N., Fonn,D., Simpson,T. L. Mixed Model Analysis of Between-Subject Variability in Overnight Corneal Swelling and Deswelling With Silicone Hydrogel Lenses Invest Ophthalmol Vis Sci 2018;59(6):2576-85 [ Show Abstract ]

PURPOSE: To model between subject variability of corneal swelling (CS) and deswelling after overnight wear of silicone hydrogel (SiHy) contact lenses.

METHODS: A total of 29 neophyte subjects wore 12 SiHy lenses with central transmissibility range of 31 to 211 Dk/t units on separate nights, in random order, and on one eye only. The contralateral eye served as the control. Central corneal thickness was measured using digital optical pachymetry before lens insertion, immediately after lens removal on waking, then 20, 40 minutes, 1, 2, and 3 hours later. Mixed modelling was conducted for simultaneous analysis of group and between-subject effects of CS and deswelling.

RESULTS: The best model for overnight CS versus Dk/t was linear with a random intercept showing constant between-subject differences in CS for different Dk/t values. The best fit for corneal deswelling versus time was a curvilinear random intercept and random slope model. About 90% of the total between-subject deswelling variance in either lens or control eyes was due to the intercept variability with much less (∼10%) being due to the variability of the individual deswelling rate (slope). Subject age, sex, and ametropia were not predictors of individual corneal swelling in the swelling versus Dk/t analysis. Age, however, was a significant (inverse) predictor of the rate of corneal deswelling, only in lens-wearing eyes.

CONCLUSIONS: A large proportion of variability in corneal swelling is because of subject-specific differences in corneal response to hypoxia. This shows that "low swellers" and "high swellers" actually do exist.

Mohammadi,S., Eslami,S., Jones,L., Gorbet,M In vitro tear replenishment system: assessing drug delivery from contact lens biomaterials through corneal epithelial monolayer and multilayer under replenishment conditions
Drug Delivery and Translational Research 2024;Online ahead of print [ Show Abstract ]

There is a need to develop improved in vitro ocular models for biocompatibility and drug delivery studies to assess the potential of in vivo performance of contact lenses. By using an in vitro corneal epithelial cell model combined with a tear replenishment method, this study aimed to investigate the delivery of the glaucoma drug latanoprost from contact lenses and compare the dynamic release results to no-replenishment (immersion) conditions. Corneal epithelial cells were grown as a monolayer or multilayer on curved cellulose cell culture inserts. Three contact lens materials (balafilcon A; senofilcon A; etafilcon A), soaked for 24 h in latanoprost, were placed on the curved cornea models (CCM) and drug concentration was determined on the basal (diffusion/transport) and apical (supernatant) sides after 1, 4, 8 and 12 h. The in vitro tear replenishment was achieved via intermittent flow of a tear solution over the CCM at a rate of 1 mL/hour. A zero-order kinetic was observed for basal drug concentration over the 12 h period. Similar basal and apical drug concentrations were observed with monolayer and multilayer CCM, except for the etafilcon A material. The apical release of latanoprost was significantly lower under replenishment compared to no-replenishment conditions. These results demonstrate the role that a dynamic release model will have in predicting the amount of drug that can be released from a contact lens into the tear film and the critical role of a cell monolayer in in vitro drug delivery studies.

Mohammadi,S., Jones,L., Gorbet,M. Extended latanoprost release from commercial contact lenses: In vitro studies using corneal models PLOS ONE 2014;9(9):e106653 [ Show Abstract ]

In this study, we compared, for the first time, the release of a 432 kDa prostaglandin analogue drug, Latanoprost, from commercially available contact lenses using in vitro models with corneal epithelial cells. Conventional polyHEMA-based and silicone hydrogel soft contact lenses were soaked in drug solution ( solution in phosphate buffered saline). The drug release from the contact lens material and its diffusion through three in vitro models was studied. The three in vitro models consisted of a polyethylene terephthalate (PET) membrane without corneal epithelial cells, a PET membrane with a monolayer of human corneal epithelial cells (HCEC), and a PET membrane with stratified HCEC. In the cell-based in vitro corneal epithelium models, a zero order release was obtained with the silicone hydrogel materials (linear for the duration of the experiment) whereby, after 48 hours, between 4 to 6  of latanoprost (an amount well within the range of the prescribed daily dose for glaucoma patients) was released. In the absence of cells, a significantly lower amount of drug, between 0.3 to 0.5 , was released, (). The difference observed in release from the hydrogel lens materials in the presence and absence of cells emphasizes the importance of using an in vitrocorneal model that is more representative of the physiological conditions in the eye to more adequately characterize ophthalmic drug delivery materials. Our results demonstrate how in vitro models with corneal epithelial cells may allow better prediction of in vivo release. It also highlights the potential of drug-soaked silicone hydrogel contact lens materials for drug delivery purposes.

Mohseni,M., Shokrollahi,P., Barzin, J. Gelatin/O-carboxymethyl chitosan injectable self-healing hydrogels for ibuprofen and naproxen dual release International Journal of Biological Macromolecules 2024;263, Part 1(April):Art No 130266 [ Show Abstract ]

Recently, a significantly greater clinical benefit has been reported with a combination of glucosamine sulfate and nonsteroidal anti-inflammatory drugs (NSAIDs) compared to either treatment alone for the growing osteoarthritis (OA) disease. So, this study introduces hydrogels using O-carboxymethyl chitosan (O-CMC, structurally akin glucosamine glycan), and Gelatin type A (GA) in a 1:2 ratio with β-glycerophosphate (βGPh) at varying percentages (5 %, 12.5 %, and 15 %). We show that hydrogel properties, adaptable for drug delivery or tissue engineering, can be fine-tuned based on OCMC:βGPh ratio. CMC/GA/βGPh-12.5 exhibited a swelling rate of 189 %, compressive stress of 164 kPa, and compressive modulus of 3.4 kPa. The self-healing hydrogel also exhibited excellent injectability through a 21-gauge needle, requiring only 5 N of force. Ibuprofen and Naproxen release from CMC/GA/βGPh-12.5 and CMC/GA/βGPh-15 of designed dimensions (bi-layer structures of different diameter and height) were measured, and drug release kinetics were estimated using mathematical equations (MATLAB and polyfit program). CMC/GA/βGPh-12.5 demonstrated significant antibacterial effects against E. coli and S. aureus, a high cell survival rate of 89 % against L929 fibroblasts, and strong cell adhesion, all indicating biocompatibility. These findings underscore potential of these hydrogels as promising candidates for treating inflammatory diseases such as osteoarthritis.

Morgan,P. B., Efron,N., Helland,M., Itoi,M., Jones,D., Nichols,J. J., van der Worp,E., Woods,C. A. Twenty first century trends in silicone hydrogel contact lens fitting: An international perspective Contact Lens and Anterior Eye 2010;33(4):196-198

Morgan,P. B., Efron,N., Helland,M., Itoi,M., Jones,D., Nichols,J. J., van der Worp,E., Woods,C. A. Demographics of international contact lens prescribing Contact Lens and Anterior Eye 2010;33(1):27-29

Morgan,P. B., Efron,N., Helland,M., Itoi,M., Jones,D., Nichols,J. J., van der Worp,E., Woods,C. A. Global trends in prescribing contact lenses for extended wear Contact Lens and Anterior Eye 2011;34(1):32-35

Morgan,P. B., Murphy,P. J., Gifford,K. L., Gifford,P., Golebiowski,B., Johnson,L., Makrynioti,D., Moezzi,A. M., Moody, K., Navascues-Cornago,M., Schweizer,H., Swiderska,K., Young,G., Willcox,M. CLEAR - Effect of contact lens materials and designs on the anatomy and physiology of the eye Contact Lens Anterior Eye 2021;44(2):192-219 [ Show Abstract ]

This paper outlines changes to the ocular surface caused by contact lenses and their degree of clinical significance. Substantial research and development to improve oxygen permeability of rigid and soft contact lenses has meant that in many countries the issues caused by hypoxia to the ocular surface have largely been negated. The ability of contact lenses to change the axial growth characteristics of the globe is being utilised to help reduce the myopia pandemic and several studies and meta-analyses have shown that wearing orthokeratology lenses or soft multifocal contact lenses can reduce axial length growth (and hence myopia).

However, effects on blinking, ptosis, the function of Meibomian glands, fluorescein and lissamine green staining of the conjunctiva and cornea, production of lid-parallel conjunctival folds and lid wiper epitheliopathy have received less research attention. Contact lens wear produces a subclinical inflammatory response manifested by increases in the number of dendritiform cells in the conjunctiva, cornea and limbus. Papillary conjunctivitis is also a complication of all types of contact lenses. Changes to wear schedule (daily disposable from overnight wear) or lens materials (hydrogel from SiHy) can reduce papillary conjunctivitis, but the effect of such changes on dendritic cell migration needs further study. These changes may be associated with decreased comfort but confirmatory studies are needed. Contact lenses can affect the sensitivity of the ocular surface to mechanical stimulation, but whether these changes affect comfort requires further investigation.

In conclusion, there have been changes to lens materials, design and wear schedules over the past 20+ years that have improved their safety and seen the development of lenses that can reduce the myopia development. However, several changes to the ocular surface still occur and warrant further research effort in order to optimise the lens wearing experience.

Morgan,P., Efron,N., Woods,C. A., Jones,D. A., Jones,L., Nichols,J. International trends in prescribing multifocal and monovision soft contact lenses to correct presbyopia (2000–2023): An update Contact Lens Anterior Eye 2024;Online ahead of print [ Show Abstract ]

Purpose: Numerous multifocal soft contact lenses have been introduced into clinical practice over the past half century. The purpose of this work is to update earlier surveys by describing international trends in multifocal and monovision soft lens fitting for presbyopia between 2000–2023, inclusive.

Method: An annual contact lens prescribing survey was sent to eye care practitioners in up to 71 countries between 2000–2023. Data relating to 52,580 soft daily wear lens fits to presbyopes (those ≥45 years of age) undertaken in 20 countries returning reliable longitudinal data were analysed in respect of multifocal and monovision soft daily wear lens fits.

Results: Overall, multifocal and monovision soft daily wear lens prescribing to presbyopes has more than doubled over the course of this survey, from 26.4 % of standard soft daily wear lens fits in 2000 to 61.1 % in 2023 (p < 0.0001). There were significant differences between countries in presbyopia soft daily wear lens prescribing (p < 0.0001). Of all soft daily wear fits to males, 45.1 % were multifocal and monovision soft lenses, compared with 52.7 % for females (p < 0.0001). When considered as the proportion of lenses fitted by age, multifocal soft lens fitting peaked between 50–65 years, followed by a precipitous drop until 85–90 years of age, and then an increase beyond 90 years of age. Analysis of 13,014 recent soft lens fits to presbyopes (2019–2023) revealed the following fitting proportions: multifocal lenses – 51 %; monovision – 10 %; and non-presbyopia fitting – 39 %.

Conclusion: There has been a substantial increase in soft contact lens correction of presbyopia using multifocal and monovision corrections throughout the 24 years of this survey. A significant number of soft contact lens-wearing presbyopes are not receiving a presbyopia contact lens correction.

Morgan,P., Efron,N., Woods,C. A., Jones,D. A., Jones,L., Nichols,J. International trends in daily disposable contact lens prescribing (2000–2023): An update Contact Lens Anterior Eye 2024;Online ahead of print [ Show Abstract ]

Purpose
Daily disposable contact lenses offer numerous benefits in terms of ocular health and wearer convenience. The purpose of this work is to update earlier surveys by describing global trends in daily disposable lens fitting between 2000 and 2023.

Method
An annual contact lens prescribing survey was sent to eye care practitioners in up to 71 countries between 2000 and 2023, inclusive. Data relating to 265,106 daily wear soft lens fits undertaken in 20 countries returning reliable longitudinal data were analysed in respect of daily disposable lens fitting.

Results
Overall, daily disposable lens prescribing increased over time, from 17.1 % of daily wear soft lens fits in 2000 to 46.7 % in 2023 (p < 0.0001). There were significant differences between countries in daily disposable lens prescribing (p < 0.0001), and between the percentage of males fitted with daily disposable lenses, as a proportion of all daily wear soft lenses (37.2 %), compared to females (35.2 %) (p < 0.0001). Daily disposable lens wearers are slightly younger at fitting than reusable soft lens wearers (31.0 vs 31.2 years, respectively) (p < 0.0001), although this difference is not clinically meaningful. Analysis of 50,240 daily wear soft lenses fitted recently (2019–2023) were found to be prescribed for the following replacement frequencies: daily – 47 %; monthly – 42 %; 1–2 weekly – 9 %; and ≥3 monthly – 2 %.

Conclusion
There has been a substantial increase in daily disposable lens fitting throughout the first 24 years of this century. The gradual nature of this increase is commensurate with the staged introduction of daily disposable lens designs and expanded parameter ranges over the survey period.

Morgan,P., Efron,N., Woods,C. A., Jones,D. A., Jones,L., Nichols,J. International trends in prescribing extended wear soft contact lenses (2000–2023): An update Contact Lens Anterior Eye 2024;Online ahead of print [ Show Abstract ]

Purpose
Extended wear has long been considered as the ultimate contact lens modality in terms of user convenience. The purpose of this work is to update earlier surveys by describing international trends in extended wear soft lens fitting between 2000 and 2023, inclusive.

Method
An annual contact lens prescribing survey was sent to eye care practitioners in up to 71 countries between 2000 and 2023, inclusive. Data relating to 282,142 soft contact lens fits undertaken in 20 countries returning reliable longitudinal data were analysed in respect of extended wear soft lens fitting.

Results
Over the duration of the work there was a very small decrease in the prescribing of extended wear soft lenses (p < 0.0001). More detailed inspection shows that prescribing of these lenses steadily increased from 5.8 % of all soft lens fits in 2000 to 11.6 % in 2007, then steadily decreased to 5.2 % in 2023. Of all soft contact lenses prescribed to males, 9.2 % were fitted for extended wear, compared with 6.7 % for females (p < 0.0001). The mean age of extended wear soft lens wearers at fitting was 34.7 ± 14.7 years, compared to 31.1. ± 14.10 years for daily soft lens wearers (p < 0.0001). Analysis of 1,948 recent extended wear soft lens fits (2019–2023, inclusive), in terms of material type, revealed that, on average, 86 % and 14 % of extended wear soft lenses were fitted using silicone hydrogel and hydrogel materials, respectively.

Conclusion
A modest increase in extended wear soft lens prescribing from 2000 to 2007 corresponded with the introduction of high oxygen transmissibility silicone hydrogel lenses. However, prescribing of this lens type declined thereafter, probably due to ongoing concerns over their increased rate of microbial keratitis, resulting in a prescribing rate in 2023 (5.2%) that was little different to that observed in 2000 (5.8%).

Muntz,A., Subbaraman,L. N., Sorbara,L., Jones,L. Tear exchange and contact lenses: A review Journal of Optometry 2015;8(1):2-11 [ Show Abstract ]

Tear exchange beneath a contact lens facilitates ongoing fluid replenishment between the ocular surface and the lens. This exchange is considerably lower during the wear of soft lenses compared with rigid lenses. As a result, the accumulation of tear film debris and metabolic by-products between the cornea and a soft contact lens increases, potentially leading to complications. Lens design innovations have been proposed, but no substantial improvement in soft lens tear exchange has been reported. Researchers have determined post-lens tear exchange using several methods, notably fluorophotometry. However, due to technological limitations, little remains known about tear hydrodynamics around the lens and, to-date, true tear exchange with contact lenses has not been shown. Further knowledge regarding tear exchange could be vital in aiding better contact lens design, with the prospect of alleviating certain adverse ocular responses. This article reviews the literature to-date on the significance, implications and measurement of tear exchange with contact lenses.

Muntz,A., Subbaraman,L.N., Craig,J. P., Jones,L. Cytomorphological assessment of the lid margin in relation to symptoms, contact lens wear and lid wiper epitheliopathy Ocular Surface 2020;18(2):214-220 [ Show Abstract ]

Purpose: Lid wiper epitheliopathy (LWE) is insufficiently understood from a cytological perspective. This study explored the relationship between lid margin cytomorphology, LWE, contact lens wear, and lens-related symptoms. Methods: Habitual, symptomatic (n = 20) and asymptomatic (n = 20) soft, rigid gas permeable (n = 18) and non-contact lens wearers (n = 19) were enrolled. LWE was graded using lissamine green and the Korb scale. Subjective symptoms were assessed using the Ocular Surface Disease Index and the Contact Lens Dryness Evaluation Questionnaire. Impression cytology samples obtained from the central upper and lower lid margins of both eyes stained histologically to highlight keratinization and imaged using high-resolution microscopy. A masked investigator digitally delimited and measured the average sagittal width of the lid wiper conjunctiva and mucocutaneous junction using ImageJ. Results: The upper lid wiper conjunctiva measured 424 ± 171 μm, 404 ± 75, 667 ± 219 and 266 ± 64 in asymptomatic soft, symptomatic soft, rigid and non-contact lens wearers, respectively. The corresponding lower lid wiper conjunctivae measured 141 ± 57 μm, 232 ± 150, 519 ± 212 and 225 ± 102, which was significantly narrower than that of the upper eyelid in most cases (p < 0.05). Symptoms were not associated with lid margin changes; however, rigid lens wear and clinical LWE were associated with histologically enlarged lid wiper conjunctival areas and increased keratinization. Conclusion: A novel, exploratory account of histological measures of LWE and cytomorphological change associated with contact lens wear suggests mechanical or frictional cellular insult is occurring at the lid wiper conjunctiva.

Muntz,A., van Doorn,K., Subbaraman,L. N., Jones,L. W. Impression cytology of the lid wiper area Journal of Visualized Experiments 2016 (114): [ Show Abstract ]

Few reports on the cellular anatomy of the lid wiper (LW) area of the inner eyelid exist and only one report makes use of cytological methods. The optimization of a method of collecting, staining and imaging cells from the LW region using impression cytology (IC) is described in this study. Cells are collected from the inner surface of the upper eyelid of human subjects using hydrophilic polytetrafluoroethylene (PTFE) membranes, and stained with cytological dyes to reveal the presence of goblet cells, mucins, cell nuclei and various degrees of pre- and parakeratinization. Immunocytochemical dyes show cell esterase activity and compromised cell membranes by the use of a confocal scanning laser microscope. Up to 100 microscopic digital images are captured for each sample and stitched into a high-resolution, large scale image of the entire IC span. We demonstrate a higher sensitivity of IC than reported before, appropriate for identifying cellular morphologies and metabolic activity in the LW area. To our knowledge, this is the first time this selection of fluorescent dyes was used to image LW IC membranes. This protocol will be effective in future studies to reveal undocumented details of the LW area, such as assessing cellular particularities of contact lens wearers or patients with dry eye or lid wiper epitheliopathy. © 2016 Journal of Visualized Experiments.