Daytime Changes in Tear Film Parameters and Visual Acuity with New-Generation Daily Disposable Silicone Hydrogel Contact Lenses-A Double-Masked Study in Symptomatic Subjects.

This prospective, double-masked, contralateral study aimed to analyze and compare daytime changes in pre-lens tear film (PLTF) stability and optical quality in symptomatic subjects wearing two contact lenses (CL). A secondary goal was to assess the performance of the PLTF by using dynamic topography techniques and analyzing surface asymmetry and irregularity indexes (SAI and SRI, respectively). Measurements were conducted on 20 symptomatic subjects (OSDI score > 13). Participants were fitted contralaterally and randomly with spherical Delefilcon A and Stenfilcon A CLs and underwent a series of measurements over 3 consecutive days: three in the morning (after 1-2 h of CL wear) and three in the afternoon (after 7-9 h of CL wear). High- and low-contrast visual acuity (HCVA and LCVA, respectively), pre-lens NIBUT, and dynamic topography were assessed. The contralateral fit of the two lenses allowed a direct and better comparison between them since they were exposed to the same conditions during the day. Consequently, both lenses demonstrated similar performance in HCVA, LCVA, and PLTF stability, with no statistically significant differences between them, although some fluctuations were observed throughout the day. Dynamic topography proved sensitive in evaluating temporal changes in the PLTF. The SRI index showed greater sensitivity to topographic changes due to lacrimal destabilization, making it potentially valuable for evaluating dry eye patients.

Inflammatory status predicts contact lens discomfort under adverse environmental conditions.

PURPOSE: To characterize and predict the clinical and tear molecular response of contact lens (CL) wearers exposed to a controlled adverse desiccating environment (CADE). METHODS: Objective and subjective variables and tear cytokine levels were evaluated of monthly silicone hydrogel CL wearers pre- and post-90 min of CADE exposure. Unsupervised hierarchical agglomerative clustering based on relative change from baseline values was used to identify response profiles (clusters). A multiple logistic regression model was used to identify cluster membership predictors. RESULTS: Forty-seven CL wearers were divided into 3 clusters having similar age (mean: 27.7 ± 7.7 years) and sex distribution. All of them showed a significant (p ≤ 0.05) increase in limbal hyperemia and staining after CADE exposure. Additionally, Cluster-1 (n = 22, 46.8%) membership was characterized by a significant (p ≤ 0.05) higher worsening of corneal and limbal staining, increased CL wear symptoms, and reduced epidermal-growth-factor and increased interleukin (IL)-4 and IL-6 tear levels. Cluster-2 (n = 22, 46.8%) showed no changes (p > 0.05) in symptoms after CADE; however, their IL-12p70, monocyte-chemoattractant-protein-1 and regulated-on-activation, normal-T-cell-expressed-and-secreted (RANTES) post-exposure tear levels significantly (p ≤ 0.05) increased. Finally, Cluster-3 (n = 3, 6.4%) mainly showed significant higher blink rate (78.1 ± 21.7) during CADE. Corneal staining and tear IL-12p70 levels were identified as Cluster-1 membership predictors. CONCLUSIONS: Most of silicone hydrogel CL wearers exposed to CADE showed a worsening of the ocular surface integrity and an upregulated tear inflammatory status. However, only half of them reported worsening of CL wear symptoms. These CL wearers were detected based on corneal integrity and tear inflammatory status. These findings can help reduce CL wear discontinuation and drop out.

Ocular response to environmental variations in contact lens wearers.

PURPOSE: To assess the influence of different indoor environments simulated in an environmental chamber on soft contact lens (CL) wearers. METHODS: Fifty-four CL wearers were grouped based on their symptoms while wearing their CLs. Subjects were fitted with two different CL types, conventional hydrogel (Omafilcon A) and silicone hydrogel (comfilcon A), and exposed to two controlled indoor environmental conditions, standard [50% relative humidity (RH), 23°C, 930 mb of atmospheric pressure] and adverse (in-flight air cabin environment: 5% RH, localised air flow, 23°C, 750 mb atmospheric pressure), for 90 min in an environmental chamber, making a total of four visits. Symptoms, tear osmolarity, pre-lens tear breakup time (PLBUT), phenol red thread test, visual acuity, bulbar and limbal hyperaemia, corneal and limbal staining, and CL dehydration were assessed using repeated measures analysis of variance. A linear mixed model was used to analyse the effect of environment, CL type, discomfort-based grouping, and time on blink rate. RESULTS: Environment was found to significantly (p ≤ 0.018) affect limbal and bulbar hyperaemia, PLBUT, tear osmolarity, and CL dehydration. Likewise, CL type significantly (p ≤ 0.04) affected nasal and total corneal staining, limbal conjunctival staining, CL dehydration, comfort, and blurred vision. The environment, CL type, and time had significant effects (p ≤ 0.0001) on the blink rate. CONCLUSIONS: Ocular surface integrity and blink rate in CL wearers depend on the environment CL users are exposed to, as well as on the soft CL type that they are wearing. Tight control of environmental conditions can contribute to a better understanding of CL-related discomfort.

Effect of Environmental Conditions on the Concentration of Tear Inflammatory Mediators During Contact Lens Wear.

PURPOSE: To analyze the influence of environmental conditions on the concentrations of tear inflammatory mediators during contact lens (CL) wear. METHODS: Fifty-four CL wearers completed 4 visits combining the bilateral use of omafilcon A or comfilcon A CL and a 90-minute exposure to 2 environmental conditions: standard [50% relative humidity (RH), 23°C, 930 mb] or adverse (5% RH, localized air flow, 23°C, 750 mb). Four microliters of tears was collected by capillarity from each subject. Changes in concentration of epidermal growth factor (EGF); interleukin (IL)-1 receptor antagonist, IL-1ß, IL-2, IL-4, IL-6, and IL-8; tumor necrosis factor (TNF) α; monocyte chemoattractant protein-1; and matrix metalloproteinase (MMP)-9 were analyzed. The effects of the environment, CL type, and symptoms were evaluated using a 3-way mixed analysis of variance with repeated measures. RESULTS: Under the standard condition, EGF significantly increased [0.36; 95% confidence interval (CI), 0.08 to 0.64], and IL-1ß (-0.48; 95% CI, -0.84 to -0.12) and IL-2 (-0.48; 95% CI, -0.87 to -0.09) significantly decreased. Under the adverse condition, IL-6 significantly increased (0.35; 95% CI, 0.09 to 0.62). Comparing conditions, EGF change was significantly lower (P = 0.02) and IL-1ß, IL-2, IL-6, and TNF-α changes were significantly higher (P ≤ 0.04) under the adverse condition. Additionally, IL-1ß significantly decreased with comfilcon A (-0.51; 95% CI, -0.88 to -0.15), being significantly lower (P = 0.01) than the change with omafilcon A (0.06; 95% CI, -0.23 to 0.35). CONCLUSIONS: The secretion of several tear inflammatory mediators during CL wear differs depending on the environmental conditions and the CL type used. These outcomes might help to understand the effect of the environment and CL materials on the ocular surface of CL wearers.

Effect of the osmolarity change in multipurpose solutions induced by an improper contact lens case cleaning procedure.

PURPOSE: To determine whether variations in multipurpose disinfecting solution (MPDS) storage osmolarity from inappropriate contact lens (CL) case cleaning affect ocular surface integrity and wearer comfort. METHODS: There were twenty contact lens cases (study CLCs) in the study group. Ten were filled with ReNu Multiplus(®) and 10 with SoloCare Aqua™ (MPDS-1 and -2, respectively) and kept closed for 8h; the cases were then emptied and kept open for air-drying for 16h. This procedure was carried out every day for two months. Storage solution osmolarity was measured on days 0, 15, 30, 45 and 60. Ten subjects were then fitted with both month-old lenses stored in the study CLCs and with new lenses stored in new cases with fresh solution for 24h (control CLCs). Symptoms, tear osmolarity and percentage of subjects whose conjunctival hyperaemia and ocular surface staining scores changed were determined after 1h of wear. RESULTS: Study CLC osmolarity increased in both solutions after two months (p<0.05). For MPDS-1 there were differences in stinging between study CLCs and control CLCs after 10min of CL wear (p=0.04), and in comfort after 10 (p=0.035) and 60min wear (p=0.042). Significant (p<0.05) differences between study CLC and control CLC groups were also found for MPDS-2 in limbal hyperaemia (study: 50% change; control: 0% change) and bulbar and corneal staining (study: 80% change; control: 20% change). CONCLUSION: The stored-MPDS osmolarity increase caused by air-drying the CLCs could affect the ocular surface. This increase might reduce lens wear comfort.

Clinical and Molecular Inflammatory Response in Sjögren Syndrome-Associated Dry Eye Patients Under Desiccating Stress.

PURPOSE: To evaluate the response of the lacrimal function unit in Sjögren syndrome (SS)-associated dry eye patients exposed to 2 simulated daily life environmental conditions. DESIGN: Prospective crossover pilot study. METHODS: Fourteen female SS dry eye patients were exposed for 2 hours to a controlled normal condition (23 C, 45% relative humidity, and air flow 0.10 m/s) and a controlled adverse condition that simulates desiccating stress (23 C, 5% relative humidity, and air flow 0.10 m/s). The following dry eye tests were performed before and after the exposure: tear osmolarity, phenol red thread test, conjunctival hyperemia, fluorescein tear break-up time, corneal fluorescein staining, conjunctival lissamine green staining, and Schirmer test. Levels of 16 molecules were analyzed in tears by multiplex immunobead analysis. RESULTS: Clinical evaluation showed lacrimal functional unit impairment after the desiccating stress: significantly increased tear osmolarity (315.7 ± 3.0 vs 327.7 ± 5.1 mOsm/L, P = .03), conjunctival hyperemia (1.3 ± 0.1 vs 1.6 ± 0.1, P = .05), and corneal staining in temporal (3.5 ± 0.5 vs 4.7 ± 0.4, P = .01) and nasal (3.6 ± 0.5 vs 4.5 ± 0.5, P = .04) areas. Tear concentrations increased for interleukin-1 receptor antagonist (16 557.1 ± 4047.8 vs 31 895.3 ± 5916.5 pg/mL, P = .01), interleukin-6 (63.8 ± 20.2 vs 111.5 ± 29.6 pg/mL, P = .02), interleukin-8 (2196.1 ± 737.9 vs 3753.2 ± 1106.0 pg/mL, P = .03), and matrix metalloproteinase-9 (101 515.6 ± 37 088.4 vs 145 867.1 ± 41 651.5 pg/mL, P = .03). After the simulated normal condition, only a significant increase in nasal corneal staining (2.9 ± 0.5 vs 3.6 ± 0.5, P = .03) was observed. CONCLUSIONS: Even a short exposure to a desiccating environment can produce a significant deterioration of the lacrimal function unit in female SS dry eye patients. The often unnoticed exposure to these conditions during daily life may increase inflammatory activity rapidly, triggering an ocular surface deterioration.

Corneal Sensitivity and Inflammatory Biomarkers in Contact Lens Discomfort.

PURPOSE: The aim of this study was to analyze whether symptoms of discomfort in hydrogel contact lens (HCL) wearers were associated with changes in corneal sensitivity or levels of tear inflammatory mediators. METHODS: Sixty-six subjects were included: 47 HCL wearers, further divided into 24 symptomatic and 23 asymptomatic wearers by the Contact Lens Dry Eye Questionnaire short form and 19 non-contact lens wearers. At least 24 h after HCL removal, we obtained scores from the Ocular Surface Disease Index and mechanical, hot, and cold corneal thresholds using a Belmonte esthesiometer. We collected 4 µl of tears with a capillary micropipette and measured levels of 12 inflammatory markers using a bead-based array: epidermal growth factor, fractalkine, interleukin-10 (IL-10), IL-1ß, IL-1 receptor antagonist, IL-2, IL-4, IL-6, IL-8, monocyte chemoattractant protein 1, tumor necrosis factor-α, and matrix metalloproteinase 9. RESULTS: There were no significant differences between groups in corneal sensitivity thresholds and levels of tear molecules. The following significant correlations were found in the total sample pooled: Ocular Surface Disease Index correlated with mechanical threshold (p < 0.01; rho = -0.324) and epidermal growth factor (p < 0.01, rho = -0.330), and mechanical threshold correlated with heat threshold (p < 0.01, rho = -0.321). CONCLUSIONS: Twenty-four hours after HCL removal, symptoms of discomfort in HCL wearers are not related to changes in corneal sensitivity or tear inflammatory mediator levels. This might indicate either that HCL wear has no effect on these parameters or that ocular surfaces recover from HCL-caused effects during the first hours after HCL removal. However, there were correlations for associations between symptoms, corneal sensitivity, and some molecules in tears.

End-of-day dryness, corneal sensitivity and blink rate in contact lens wearers.

PURPOSE: To study the relationship among the variables intensity of the end-of-day (EOD) dryness, corneal sensitivity and blink rate in soft contact lens (CL) wearers. METHODS: Thirty-eight soft CL wearers (25 women and 13 men; mean age 27.1±7.2 years) were enrolled. EOD dryness was assessed using a scale of 0-5 (0, none to 5, very intense). Mechanical and thermal (heat and cold) sensitivity were measured using a Belmonte's gas esthesiometer. The blink rate was recorded using a video camera while subjects were wearing a hydrogel CL and watching a film for 90 min in a controlled environmental chamber. RESULTS: A significant inverse correlation was found between EOD dryness and mechanical sensitivity (r: -0.39; p=0.02); however, there were no significant correlations between EOD dryness and thermal sensitivity. A significant (r: 0.56; p<0.001) correlation also was observed between EOD dryness and blink rate, but no correlations were found between blink rate and mechanical or thermal sensitivity. CONCLUSIONS: CL wearers with higher corneal sensitivity to mechanical stimulation reported more EOD dryness with habitual CL wear. Moreover, subjects reporting more EOD dryness had an increased blink rates during wear of a standard CL type. The increased blink rate could act to improve the ocular surface environment and relieve symptoms.

Dry eye exacerbation in patients exposed to desiccating stress under controlled environmental conditions.

PURPOSE: To determine if controlled environmental conditions can induce acute exacerbations of signs and symptoms in dry eye and asymptomatic subjects. DESIGN: Prospective cross-sectional study. METHODS: Nineteen patients with dry eye and 20 asymptomatic controls were exposed to controlled low humidity (5% relative humidity, desiccating environment) for 2 hours in our Controlled Environmental Research Laboratory at the University of Valladolid. The patients completed the Single-Item Score Dry Eye Questionnaire and the following diagnostic tests were performed before and after exposure: tear osmolarity, phenol red thread test, conjunctival hyperemia, fluorescein tear film break-up time, Schirmer test, and ocular surface vital staining. Sixteen molecules in the tears samples were analyzed by multiplex bead analysis. RESULTS: After exposure, the patients and controls had a significant (P ≤ .003) increase in corneal staining (from 0.68 ± 0.15 to 1.16 ± 0.14 and from 0.50 ± 0.15 to 1.30 ± 0.19, respectively), significantly decreased (P ≤ .01) fluorescein tear film break-up time values (from 2.78 ± 0.56 seconds to 1.94 ± 0.24 seconds and from 2.81 ± 0.24 seconds to 2.13 ± 0.19 seconds, respectively), and significantly increased (P ≤ .03) matrix metalproteinase 9 tear levels (from 10 054.4 ± 7326.6 pg/mL to 25 744.5 ± 13 212.4 pg/mL and from 10 620.5 ± 4494.3 pg/mL to 16 398.7 ± 5538.3 pg/mL, respectively). In the control group, the epidermal growth factor tear levels decreased significantly (P = .007; from 1872.1 ± 340.7 pg/mL to 1107.1 ± 173.6 pg/mL), and interleukin 6 levels increased significantly (P < .001; from 29.6 ± 5.8 pg/mL to 54.3 ± 8.3 pg/mL) after exposure. CONCLUSIONS: Adult patients with mild-to-moderate dry eye and asymptomatic subjects of similar ages can experience acute exacerbation in an environmental chamber that resembles the sudden worsening that patients with dry eye experience daily.

Influence of environmental factors in the in vitro dehydration of hydrogel and silicone hydrogel contact lenses.

PURPOSE: To analyze in vitro the influence of different environmental conditions on the dehydration pattern of seven currently marketed hydrogel (Hy) and silicone hydrogel (Si-Hy) contact lenses (CL). METHODS: Three Hy and four Si-Hy CLs were evaluated. CLs were exposed to four different relative humidity (RH) conditions (5%, 30%, 50%, and 70%) and two air flow (AF) rates (0 and 2.75 m/seg) within an environmental chamber. Dehydration was assessed using the gravimetric method. Data were taken at baseline, 5, 10, 15, 20, 30, 45, 60, 90, and 120 minutes of exposure. Dehydration rate (DR), valid dehydration (VD) and stabilization time were calculated. RESULTS: The interaction between RH, AF and the type of the CL material had a significant effect (p ≤ 0.03) on DR up to 60 minutes. The maximum differences in VD values among CL occurred around 15 minutes exposure varying from 25.16% to 42.75%. Stabilization time was quicker under the 5%RH with AF condition than under 70% RH without AF one for most CLs. CONCLUSIONS: Lower RH seems to increase CL dehydration being further accelerated with the AF presence. The dehydration pattern is material dependent, thus current marketed CLs behave differently under several controlled environmental conditions. Future in vivo studies should confirm these outcomes.

Influence of a controlled environment simulating an in-flight airplane cabin on dry eye disease.

PURPOSE: To evaluate symptoms, signs, and the levels of 16 tears inflammatory mediators of dry eye (DE) patients exposed to an environment simulating an in-flight air cabin in an environmental chamber. METHODS: Twenty DE patients were exposed to controlled environment simulating an in-flight airplane cabin (simulated in-flight condition [SIC]) of 23°C, 5% relative humidity, localized air flow, and 750 millibars (mb) of barometric pressure. As controls, 15 DE patients were subjected to a simulated standard condition (SSC) of 23°C, 45% relative humidity, and 930 mb. A DE symptoms questionnaire, diagnostic tests, and determination of 16 tear molecules by multiplex bead array were performed before and 2 hours after exposure. RESULTS: After SIC exposure, DE patients became more symptomatic, suffered a significant (P ≤ 0.05) decrease in tear stability (tear break up time) (from 2.18 ± 0.28 to 1.53 ± 0.20), and tear volume (phenol red thread test), and a significant (P ≤ 0.05) increase in corneal staining, both globally (0.50 ± 0.14 before and 1.25 ± 0.19 after) and in each area (Baylor scale). After SSC, DE patients only showed a mild, but significant (P ≤ 0.05), increase in central and inferior corneal staining. Consistently, tear levels of IL-6 and matrix metalloproteinase (MMP)-9 significantly increased and tear epidermal growth factor (EGF) significantly decreased (P ≤ 0.05) only after SIC. CONCLUSIONS: The controlled adverse environment conditions in this environmental chamber can simulate the conditions in which DE patients might be exposed during flight. As this clearly impaired their lacrimal functional unit, it would be advisable that DE patients use therapeutic strategies capable of ameliorating these adverse episodes.