Comparative Analysis of the Osmoprotective Effects of Daily Disposable Contact Lens Packaging Solutions on Human Corneal Epithelial Cells.

Purpose: Contact lens (CL) wear challenges the balance of the ocular surface environment by increasing water evaporation and tear osmolarity. Maintaining ocular surface homeostasis during CL wear remains a goal of lens manufacturers and an important consideration for eye care professionals. The purpose of this study was to measure the metabolic activity and inflammatory responses of a transformed human corneal epithelial cell (THCEpiC) line under hyperosmotic conditions in the presence of CL packaging solutions. Methods: CL packaging solutions sampled from seven daily disposable silicone hydrogel CL blister packages were prepared at 25% and made hyperosmolar (400 mOsm/kg) with NaCl. THCEpiCs were incubated with each solution for 24 hr, after which cell culture supernatants were collected. THCEpiC metabolic activity was determined by an alamarBlue assay. Concentrations in cell culture supernatants of inflammatory cytokine (interleukin [IL]-6) and chemokine (IL-8), as well as monocyte chemoattractant protein-1 (MCP-1), were quantitated by specific enzyme-linked immunosorbent assays. Results: THCEpiC metabolic activity under hyperosmolar conditions decreased in the presence of somofilcon A and senofilcon A solutions (p=0.04 and 0.004, respectively), but no other solution (all p≥0.09). Concentrations of IL-6 increased in the presence of delefilcon A, somofilcon A, narafilcon A, and senofilcon A solutions (all p≤0.001), but no other solution (all p≥0.08), while those of IL-8 increased in the presence of all solutions (all p≤0.03) but kalifilcon A (p>0.99), and those of MCP-1 increased in the presence of delefilcon A, verofilcon A, somofilcon A, and stenfilcon A solutions (all p<0.0001), but no other solution (all p>0.99). Conclusion: CL packaging solutions differ in their capacity to inhibit epithelial inflammation. THCEpiC inflammatory response was less in the presence of a CL packaging solution containing osmoprotectants than in solutions lacking osmoprotectants under moderately hyperosmolar conditions in vitro. Clinical studies are warranted to further substantiate the benefit of osmoprotectants.

Effect of Contact Lens Solutions in Stabilizing the Activity of Tear Lysozyme.

Purpose: Interactions between tear proteins and the interfaces of contact lenses can be complex and can influence contact lens wear success. Tear proteins, including lysozyme, function to maintain the balance of ocular surface homeostasis, as evidenced by the effects of its conformation relative to stabilizing the tear film and its potential impact on corneal epithelial cells. Contact lens manufacturers include components in lens care and blister package solutions to help stabilize the tear film and preserve homeostasis. This in vitro study was performed to evaluate the ability of daily disposable contact lens package solutions to stabilize lysozyme and preserve its native conformation under denaturing conditions. Methods: Lysozyme was added to contact lens solutions sampled from kalifilcon A, etafilcon A, senofilcon A, narafilcon A, nelfilcon A, verofilcon A, delefilcon A, somofilcon A, and stenfilcon A blister packages, then mixed with the protein denaturant sodium lauryl sulfate. Lysozyme activity was evaluated by adding test solutions to a suspension of Micrococcus luteus. Native lysozyme lyses the Micrococcus luteus cell wall, which decreases suspension turbidity. Stabilization of lysozyme activity was determined by comparing suspension turbidity before and after exposure to test solutions. Results: Lysozyme stabilization was 90.7% for kalifilcon A solution, a statistically significant improvement (p < 0.05) compared to phosphate buffered saline (PBS, negative control). No significant improvement was observed with any other contact lens solution (all lysozyme stabilization < 5.00%). Conclusion: The representative tear protein lysozyme was significantly more stable in the novel kalifilcon A contact lens solution containing multiple moisturizers and osmoprotectants than in PBS or other daily disposable contact lens solutions. The lysozyme activity assay provides mechanistic evidence that the kalifilcon A contact lens solution can stabilize proteins under conditions that typically denature proteins, which may contribute to maintaining ocular surface homeostasis.

Clinical Performance of Samfilcon A, a Unique Silicone Hydrogel Lens, on a 7-Day Extended Wear Basis.

PURPOSE: The objective of this study was to evaluate and compare the clinical performance of samfilcon A, a unique, polyvinylpyrrolidone (PVP)-containing, silicone hydrogel contact lens with that of the balafilcon A silicone hydrogel contact lens when worn on a 7-day extended wear basis. SUBJECTS AND METHODS: A total of 669 subjects completed this 12-month, controlled, parallel group, masked, randomized study; of these, 340 wore samfilcon A lenses and 329 balafilcon A lenses. Subjects wore their respective assigned lenses bilaterally on a 7-day extended wear basis. On the seventh night of each wearing week, lenses were removed, cleaned, and disinfected using Biotrue multi-purpose solution (MPS), then re-inserted the following morning. Lenses were replaced with new lenses monthly. At each follow-up visit, investigators completed a slit lamp evaluation, and subjects rated lenses based upon a predefined set of performance criteria. RESULTS: The samfilcon A lens performed comparably to the balafilcon A lens in terms of most graded and ungraded slit lamp findings, differing significantly only for corneal staining Grade 2 or greater, which favored samfilcon A, and anterior segment abnormalities, which favored balafilcon A. Subjects rated both lenses highly when queried about various lens-wearing characteristics. When comparing the number of subjects with findings on either eye on at least one follow-up visit, the two lenses were comparable in many aspects but favored samfilcon A with respect to cleanliness upon removal, overall comfort, comfort at end of day, dryness, vision, vision in low light, vision at end of day, and overall impression (all p < 0.05). CONCLUSION: While subjects rated both highly, samfilcon A lenses worn for 7-day extended wear and replaced on a monthly basis performed comparably to or better than balafilcon A lenses when worn for the same 7-day wear time and replacement cycle.

Satisfaction of astigmatic patients with toric nesofilcon A contact lenses.

PURPOSE: The purpose of this evaluation was to compare the experience of habitual contact lens wearers with that of nonwearers when fitted with a novel toric nesofilcon A contact lens (Biotrue ONEday for Astigmatism lens; Bausch & Lomb Incorporated, Rochester, NY, USA), for wearer comfort, vision, and satisfaction in a real-world setting. MATERIALS AND METHODS: Participating eye care practitioners (ECPs) prescribed toric nesofilcon A lenses to their astigmatic patients as part of their routine clinical practices. Accordingly, 1,253 patients successfully completed the evaluation; of these, 51% wore contact lenses habitually, 41% wore eyeglasses, and 8% had no prior vision correction. All wore the lenses for at least 4 days, and 74% wore them for an average of 9 hours or more per day. After at least 4 days of wear, each patient completed an online survey to evaluate his or her level of satisfaction regarding comfort and vision. As this postmarket evaluation was observational, data were analyzed to determine whether more patients than not agreed with individual statements regarding lens performance, and whether there was any difference in response between habitual contact lens wearers and nonwearers. RESULTS: As a measure of general satisfaction, 96% of patients indicated that their overall opinion of the toric nesofilcon A lens was good to excellent. Further, more patients than not agreed that the lens performed well with regard to all aspects of vision and comfort queried (P<0.001). There was no difference in response between habitual contact lens wearers and nonwearers. CONCLUSION: All astigmatic patients with spherical contact lenses, other toric lenses, or eyeglasses, as well as those who had no prior correction, who had converted to the toric nesofilcon A lens expressed a high level of satisfaction with vision and comfort. ECPs should expect high success rates when converting astigmatic patients to the novel toric nesofilcon A lens.

Evaluation of binocular function among pre- and early-presbyopes with asthenopia.

PURPOSE: Individuals approaching presbyopia may exhibit ocular symptoms as they contend with visual demands of near work, coupled with natural age-related changes in accommodation. Therefore, accommodation and vergence of 30- to 40-year-old, myopic, soft contact lens wearing subjects with symptoms of asthenopia and no history of using multifocal lenses were evaluated. PATIENTS AND METHODS: In this prospective, observational study, 253 subjects with asthenopia were evaluated by 25 qualified practitioners, each at a different clinical site. Subjects were 30-40 years in age, had symptoms of soreness, eyestrain, tired eyes, or headaches with near work, regularly performed 2-3 consecutive hours of near work, and were undiagnosed with presbyopia. Amplitude of accommodation (AC) and near point convergence (NPC) were measured with a Royal Air Force binocular gauge. Triplicate push up and push down AC and NPC measures were recorded, and average AC values were compared to those calculated using the Hofstetter formula (HF). RESULTS: The average AC push up/push down value was significantly better than the HF prediction for this age range (8.04±3.09 vs 6.23±0.80 D), although 22.5% of subjects had mean AC below their HF value (5.36±0.99 D). The average NPC push up/push down value was 12.0±4.69 cm. The mean binocular AC value using the push up measure was significantly better than the push down measure (8.5±3.4 vs 7.6±3.0 D). The mean NPC value using the push up measure was significantly worse than the push down measure (13.0±5.0 vs 11.0±4.7 cm). The most frequent primary diagnosis was ill-sustained accommodation (54%), followed by accommodative insufficiency (18%), and accommodative infacility (12%). CONCLUSION: Based upon a standardized assessment of accommodation and vergence, ill-sustained accommodation was the most frequent diagnosis among this population.

Use of a novel extended blink test to evaluate the performance of two polyvinylpyrrolidone-containing, silicone hydrogel contact lenses.

BACKGROUND: Sustained digital display viewing reduces eye blink frequency and tear film stability. To retain water and preserve a smooth optical surface, contact lens manufacturers have integrated the humectant polyvinylpyrrolidone (PVP) into silicone hydrogel contact lenses. In this study, extended blink time (EBT) was used to assess visual stability over a prolonged blink interval of two PVP-containing silicone hydrogel lenses, samfilcon A (SAM) and senofilcon A (SEN). MATERIALS AND METHODS: This randomized, bilateral, masked, crossover study assessed lens performance in ten subjects after 16 hours of wear. EBT, ie, the time elapsed between cessation of blinking and blur-out of a threshold letter on the acuity chart, was measured. At the end of the wear period, subjects reported duration of computer use and rated visual quality (VQ) and comfort while wearing the assigned lens, and the investigator evaluated lens surface wetting characteristics. Each lens was removed and immediately weighed to determine total water content. RESULTS: EBTs were 10.42 seconds for SAM and 8.04 seconds for SEN (p = 0.015). Subjective ratings of VQ after 16 hours of wear were 84.6 for SAM and 74.4 for SEN (p = 0.049). Comfort ratings were 85.9 for SAM and 80.2 for SEN (p > 0.05). Median times of computer use were 6-8 hours for both lens types. Post blink, 70.0% of SAM and 30.0% of SEN lenses were completely wet (p = 0.021). Total water content after wear was 43.7% for SAM and 35.5% for SEN (p < 0.001). CONCLUSION: EBT measurement indicated more stable vision with the PVP-containing SAM polymer compared with the PVP-containing SEN polymer. The SAM polymer also demonstrated better surface wetting and maintained higher water content after a prolonged period of wear. EBT can be valuable in assessing vision stability of patients after hours of computer use.

Increased concentration of hyaluronan in tears after soaking contact lenses in Biotrue multipurpose solution.

PURPOSE: This study was conducted to determine 1) the concentration of hyaluronan (HA) in the tear films of contact lens (CL) wearers versus non-CL wearers and 2) whether HA sorbed from Biotrue, an HA-containing multipurpose solution (MPS), onto senofilcon A lenses affects the concentration of HA in tears after 2 hours of wear. PATIENTS AND METHODS: Tears of habitual CL wearers and non-CL wearers were collected on Schirmer strips at baseline and after 2 hours of wear of senofilcon A CLs that had first been either rinsed with Sensitive Eyes Saline or soaked in Biotrue MPS for 14 hours. HA concentrations were measured by enzyme-linked immunosorbent assay (ELISA) and adjusted for sample volumes. RESULTS: No difference in baseline concentrations of HA in tears was found between CL wearers and non-CL wearers (P=0.07), nor between males and females (P=0.06). However, age was significantly negatively associated with HA concentration (P<0.01), and mostly, CL wear contributed to a significant association (P<0.01). Among saline-rinsed CL wearers, no change in HA concentration in tears was observed after 2 hours of wear (P=0.38). By contrast, a significant increase in HA concentration was observed in the tears from eyes that had worn CLs soaked in Biotrue MPS when compared to baseline (P=0.01) or to saline-rinsed control (P=0.03). CONCLUSION: 1) In this study population, no difference in baseline concentration of HA was observed between CL wearers and non-CL wearers, and 2) after 2 hours of wear of senofilcon A lenses that were soaked in Biotrue MPS, HA concentrations in the tear films of CL wearers increased.

Evaluation of surface water characteristics of novel daily disposable contact lens materials, using refractive index shifts after wear.

PURPOSE: Contact lens wearers today spend much time using digital display devices. Contact lens manufacturers are challenged to develop products that account for longer periods of time where blink rate is reduced and tear-film evaporation rate is increased, affecting both visual acuity and comfort. Two manufacturers recently introduced novel daily disposable contact lenses with high surface water content. The objective of the present study was to compare surface water characteristics before and after initial wear of recently introduced nesofilcon A and delefilcon A high surface water lenses with those of etafilcon A lenses. PATIENTS AND METHODS: Twenty healthy subjects wore each of the three lens types studied in a randomly determined order for 15 minutes. After each wearing, lenses were removed and the surface refractive index (RI) of each lens was immediately measured. RESULTS: The mean RI of the unworn delefilcon A lens was 1.34, consistent with water content in excess of 80%. After 15 minutes of wear, the surface RI shifted to 1.43, consistent with its reported 33% bulk water content. In contrast, the mean surface RI of the nesofilcon A lens was 1.38, both initially and after 15 minutes of wear, and that of the etafilcon A lens was 1.41 initially and 1.42 after 15 minutes of wear. CONCLUSION: The surface of the delefilcon A lens behaves like a high water hydrogel upon insertion but quickly dehydrates to behave like its low-water silicone-hydrogel bulk material with respect to surface water content during wear, while both nesofilcon A and etafilcon A lenses maintain their water content during initial wear. The nesofilcon A lens appears unique among high water lenses in maintaining high surface and bulk water content during wear. This is important because changes in surface RI due to dehydration are reported to lead to visual aberration affecting user experience.

Meta-analysis of the ocular biocompatibility of a new multipurpose lens care system.

BACKGROUND: The purpose of this paper is to evaluate the biocompatibility of a novel multipurpose solution (MPS) with a dual disinfectant system containing polyaminopropyl biguanide and polyquaternium-1 (Biotrue®) by analysis of biomicroscopy signs and adverse events in six large clinical trials. METHODS: Data from six consecutive, prospective clinical trials conducted from February 2008 to March 2010 were combined for meta-analysis. Subjects used the new MPS daily for periods of 2 weeks to 6 months. Slit-lamp signs were graded at each follow-up visit using an ordinal scale (0, one; 1, trace; 2, mild; 3, moderate; 4, severe). Analysis for biocompatibility included tracking of greater than grade 2 slit-lamp findings and number of adverse events. RESULTS: A total of 1,567 subjects (3,134 eyes) and 81 clinical investigators participated in the six studies, with 1,499 subjects completing the studies. Based on subject days in the studies, there were 72,904 exposures to the MPS and 7,212 biomicroscopy examinations. The completion rate for the studies was 96.3%. Per observation incidence of any finding greater than grade 2 at the follow-up visits were: corneal staining 0.08%, limbal injection 0.04%, bulbar injection 0.04%, tarsal conjunctiva abnormality 0.09%, and neovascularization 0.01%. There were no other slit-lamp signs greater than grade 2 and no statistically significant difference between hydrogels and silicone hydrogels for any finding. There were no reports of adverse events during the trials. CONCLUSION: Analysis of over 72,000 daily exposures and 7,212 eye examinations showed that the novel MPS exhibited excellent biocompatibility in subjects using daily wear hydrogel or silicone hydrogel lenses.

Tear cytokine response to multipurpose solutions for contact lenses.

PURPOSE: An increased risk of corneal infiltrative events has been noted with the use of certain contact lenses and multipurpose solutions (MPS). This study was designed to evaluate tear cytokine assay as a sensitive, objective, and quantitative measure of the ocular surface response to contact lens/MPS and to consider the assay's clinical relevance in the context of other measures of ocular surface response. METHODS: Two MPS, ReNu® Fresh™ (RNF) and Opti-Free® RepleniSH (OFR), were used with daily wear silicone hydrogel contact lenses in a randomized, prospective crossover study involving 26 subjects. Clinical data collection (conjunctival hyperemia, ocular surface sensitivity, solution induced corneal staining (SICS) test score, and subjective responses) and tear cytokine assays were conducted masked. Responses were tracked as change from baseline throughout the experimental schedule. RESULTS: SIMILAR RESPONSE PATTERNS FOR SEVERAL INFLAMMATORY CYTOKINES WERE SEEN THROUGHOUT BOTH PHASES: subjects who received OFR in Phase I had mean tear concentrations that were generally higher than those of the RNF Phase I group. OFR Phase I subjects had significant (P < 0.01) increases over baseline at day 1 and/or following washout for 13 cytokines (cc chemokine ligands [CCL] 3, CCL5, CCL11, granulocyte-macrophage colony-stimulating factor [GM-CSF], interferon [INF]-γ, interleukin [IL]-2, IL-4, IL-5, IL-6, IL-13, IL-15, IL-17, tumor necrosis factor [TNF]-α). These changes were not observed in RNF Phase I subjects, even though SICS test scores increased. Phase I OFR subjects also had increased dryness, while RNF Phase I subjects had decreased bulbar hyperemia. No changes were detected with respect to limbal hyperemia or surface sensitivity thresholds. CONCLUSION: The tear cytokine assay can detect and differentiate contact lens/MPS induced increases in inflammatory cytokines. Changes in cytokine levels were consistent with measurement of hyperemia and dryness but not with SICS scores, thereby suggesting a proinflammatory response to OFR compared to RNF that is not related to SICS test score. Tear cytokine profiles may be useful for reconciling clinical relevance of test results and in revealing signaling involved in the development of corneal infiltrative events.

Assessment of patient and practitioner satisfaction with Biotrue™ multi-purpose solution for contact lenses.

PURPOSE: Consumer product companies often use in-home studies to gain consumer insights on product performance. Satisfaction surveys completed in the office have been shown to overestimate satisfaction ratings. The purpose of this study was to evaluate the consumer acceptance of a novel multi-purpose solution (Bausch & Lomb Biotrue multi-purpose solution) through the use of a unique Internet survey and a measurement of practitioner satisfaction through in-office evaluations. METHODS: Contact lens users were converted to an unbranded, investigational-labeled Biotrue multi-purpose solution. Independent practitioners from 15 investigational sites enrolled patients. Following 7 days of use, subjects completed an Internet survey to capture their perspectives regarding the product. After 2 weeks of use, the investigators exited the subjects. RESULTS: Of the 300 subjects enrolled, 291 (97%) completed the Internet survey. Ninety percent rated Biotrue multi-purpose solution "excellent," "very good," or "good" for overall opinion. Significantly more subjects rated Biotrue multi-purpose solution better than their habitual product. Use of Biotrue multi-purpose solution did not affect the fitting characteristics (centration/movement) or surface wetting of the lens. Throughout the evaluation, there were no adverse events reported. Slit lamp examinations revealed that 99.2% of eyes had minimal findings (no findings or trace or mild findings). With 600 eyes enrolled in the study, practitioners agreed that 95.2% of the eyes appeared healthy throughout the study. CONCLUSIONS: Use of Internet surveys can be an effective method to gain patient perspectives regarding new products dispensed by eye care practitioners. There was a high level of satisfaction with Biotrue multi-purpose solution.

Upper and lower tear menisci on contact lenses.

PURPOSE: The purpose of this study was to measure upper and lower tear menisci on contact lenses using real time optical coherence tomography (OCT). METHODS: Both eyes of 20 adapted contact lens wearers were imaged when they wore two types of silicone hydrogel lenses, balafilcon A on one eye and galyfilcon A on the other eye. The height, radius, and area of upper and lower tear menisci were obtained before, immediately after, and 20 minutes after lens wear on two consecutive days. On a third visit, the lenses were switched between eyes and an investigative lubricant was instilled after 4 hours of lens wear. OCT images were obtained as before and additionally at 1 and 4 hours after lens insertion. Imaging was also conducted immediately after lubricant instillation and 20 minutes post-instillation. RESULTS: There were no significant differences in the measured variables between lenses (P > 0.05) and between consecutive visits (P > 0.05). The menisci around both eyelids immediately after lens insertion were significantly greater than that before (P < 0.005). By 20 minutes after lens insertion, all variables had returned to baseline values and remained that way for at least 4 hours. Immediately after the instillation of the lubricant at 4 hours, meniscus variables increased (P < 0.001), but recovery to baseline occurred within 20 minutes. CONCLUSIONS: It is feasible to use OCT in the measurement of both upper and lower tear menisci on contact lenses in situ. Tear menisci increased on insertion of contact lenses and on instillation of lubricants. However baseline values were re-established with 20 minutes.