Analysis of the mucosal chemokines CCL28, CXCL14, and CXCL17 in dry eye disease: An in vitro and clinical investigation.

Mucosal chemokines have antimicrobial properties and play an important role in mucosal immunity. However, little is known about their expression on the ocular surface. This study aimed to analyze the expression of the mucosal chemokines CCL28, CXCL14 and CXCL17 in corneal and conjunctival epithelial cells under in vitro dry eye (DE) conditions, and in conjunctival samples from healthy subjects and DE patients. Human corneal epithelial cells (HCE) and immortalized human conjunctival epithelial cells (IM-HConEpiC) were incubated under hyperosmolar (400-500 mOsM) or inflammatory (TNF-α 25 ng/mL) conditions for 6 h and 24 h to measure CCL28, CXCL14, and CXCL17 gene expression by RT-PCR and their secretion by immunobead-based analysis (CCL28, CXCL14) and ELISA (CXCL17). Additionally, twenty-seven DE patients and 13 healthy subjects were included in this study. DE-related questionnaires (OSDI, mSIDEQ and NRS) evaluated symptomatology. Ocular surface integrity was assessed using vital staining. Tactile sensitivity was measured with Cochet-Bonnet esthesiometer, and mechanic and thermal (heat and cold) sensitivity using Belmonte's non-contact esthesiometer. Subbasal nerve plexus and dendritic cell density were analyzed by in vivo confocal microscopy. Conjunctival cells from participants were collected by impression cytology to measure mucosal chemokines gene expression by RT-PCR. Our results showed that HCE and IM-HConEpiC cells increased CCL28, CXCL14, and CXCL17 secretion under hyperosmolar conditions. The gene expression of CCL28 was significantly upregulated in conjunctival samples from DE patients. CCL28 expression correlated positively with symptomatology, corneal staining, heat sensitivity threshold, and dendritic cell density. CXCL14 expression correlated positively with age, ocular pain, conjunctival staining, tactile sensitivity, and image reflectivity. CXCL17 expression correlated positively with corneal staining. These results suggest that corneal and conjunctival epithelial cells could be a source of CCL28, CXCL14, and CXCL17 on the ocular surface and that CCL28 might be involved in DE pathogenesis.

Reliability and agreement of subjective and objective non-invasive break-up time measurements in contact lens wearers.

PURPOSE: To assess the reliability and agreement of non-invasive break-up time (NIBUT) in symptomatic and asymptomatic contact lens (CL) wearers using automatic objective and conventional subjective techniques. METHODS: In this prospective cross-sectional study, soft CL wearers, classified into symptomatic and asymptomatic based on the Contact Lens Dry Eye Questionnaire-8, underwent NIBUT assessment with the CL in situ. The CA-800 Corneal Analyzer and the EasyTear® VIEW+ Tearscope were used for objective and subjective evaluation, respectively. The within-subject repeatability and intraclass correlation coefficient (ICC) were calculated. The agreement between the devices was compared using the Bland-Altman method. RESULTS: A total of 141 CL wearers (51 male and 90 female) with a mean age of 33.6 (SD = 12.2) years were included. The repeatability and ICC values obtained with the CA-800 device when measuring NIBUT were 5.4 s and 58.6% across the whole sample, 4.2 s and 48.8% for the asymptomatic group and 7.1 s and 68.4% for the symptomatic group. When using the subjective method (EasyTear®), the respective repeatability and ICC values were 7.3 s and 32.7% for the whole sample, 6.5 s and 30.4% for the asymptomatic group and 8.6 s and 35.9% for the symptomatic group. The CA-800 device provided significantly (p < 0.001) shorter NIBUT values compared with EasyTear® for the whole sample (3.3 [2.9] vs. 8.1 [3.4] s), the asymptomatic (3.3 [3.0] vs. 7.7 [3.6] s) and the symptomatic (3.8 [2.9] vs. 8.6 [3.0] s) groups. CONCLUSION: Objective (CA-800) NIBUT assessment provides more reliable measurements than the conventional subjective technique using the EasyTear® device. However, CL practitioners should also be aware that the objective method indicates shorter NIBUT values. Symptomatic CL wearers may also need a higher number of NIBUT measurements to obtain reliable estimations.

Reliability of Tear Meniscus Height Measurements in Contact Lens Wearers and Its Relationship With Discomfort Symptoms.

OBJECTIVES: To evaluate the reliability and agreement of tear meniscus height (TMH) measurements performed with a corneal analyzer and optical coherence tomography (OCT) technology in contact lens (CL) wearers and its correlation with contact lens discomfort symptoms. METHODS: Asymptomatic and symptomatic CL wearers classified through the Contact Lens Dry Eye Questionnaire-8 were evaluated with the Corneal Analyzer (Topcon CA-800) and OCT technology (Topcon 3D OCT-2000). The repeatability and intraclass correlation coefficient (ICC) were calculated. The agreement between devices was calculated using the Bland-Altman method. The relationship between TMH measurements and the Contact Lens Dry Eye Questionnaire-8 and Contact Lens Discomfort Index scores was assessed through the Spearman correlation coefficient. RESULTS: Seventy-nine asymptomatic and 42 symptomatic CL wearers aged 34.24±12.50 years were enrolled. The repeatability values obtained for the CA-800 were 0.07 mm in all cases, and the ICC was 0.93 for the whole sample. The CA-800 provided significantly ( P <0.01) higher TMH values than the OCT for the whole sample (0.22±0.08 vs. 0.17±0.06 mm). A weak indirect correlation (ρ=-0.22) between the OCT TMH measurement and Contact Lens Discomfort Index scores was found ( P ≤0.04). CONCLUSION: The CA-800 provides reliable TMH measurements during CL wear; however, they might not be interchangeable with OCT ones. Tear meniscus height measurements might be useful as a complementary sign to detect CL discomfort, but it cannot be used alone as a diagnostic tool.

Inflammation-related molecules in tears of patients with chronic ocular pain and dry eye disease.

The purpose of this study was to analyze inflammation- and pain-related molecules in tears of patients suffering from chronic ocular pain associated with dry eye (DE) and/or a previous corneal refractive surgery (RS). Based on history, symptomatology, and clinical signs, the subjects (n = 180, 51.0 ± 14.7 years, 118 females, 62 males) in this cross-sectional study were assigned to one of five groups: DE and chronic ocular pain after RS (P/DE-RS, n = 52); asymptomatic subjects, i.e., without DE and chronic ocular pain, after RS (A-RS, n = 30); DE and chronic ocular pain without previous RS (P/DE-nonRS, n = 31); DE, no pain, and no previous RS (DE-nonRS, n = 35); and asymptomatic subjects with no previous RS (controls, n = 32). The tear concentrations of 20 cytokines and substance P (SP) were analyzed by immunobead-based assay and enzyme-linked immunosorbent assay, respectively. We found that tear levels of interleukin (IL)-10 and SP were increased in the RS groups. There were significant differences in IL-8/CXCL8 among the five groups. Nerve growth factor (NGF) tear levels were significantly higher in P/DE-RS than in DE-nonRS and controls. IL-9 had the highest percentage of detection in the P/DE-RS and P/DE-nonRS groups, while macrophage inflammatory protein (MIP)-1α, IL-2, and interferon (IFN)-γ were higher in the P/DE-RS, A-RS, and P/DE-nonRS groups. IL-17A was detected only in the A-RS group. Moderate correlations were observed in the A-RS, P/DE-nonRS, DE-nonRS and controls groups. A positive correlation was obtained between growth related oncogene concentration and tear break-up time (rho = 0.550; p = 0.012), while negative correlation was found between monocyte chemoattractant protein-3/CCL7 and conjunctival staining (rho = -0.560; p = 0.001), both in the A-RS group. IL-10 correlated positively with ocular pain intensity (rho = 0.513; p = 0.003) in the P/DE-nonRS group. Regulated on Activation Normal T Cell Expressed and Secreted/CCL5 correlated negatively with conjunctival staining (rho = -0.545; p = 0.001) in the DE-nonRS group. SP correlated negatively with corneal staining (rho = -0.559; p = 0.001) in the controls. In conclusion, chronic ocular pain was associated with higher IL-9 tear levels. IL-10, SP, MIP-1α/CCL3, IL-2, and IFN-γ were associated with previous RS. Higher levels of IL-8/CXCL8, MIP-1α/CCL3, IL-2, and IFN-γ were associated with DE-related inflammation, while NGF levels were related to chronic ocular pain and DE in RS patients. These findings suggest that improved knowledge of tear cytokines and neuromodulators will lead to a more nuanced understanding of how these molecules can serve as biomarkers of chronic ocular pain, leading to better therapeutic and disease management decisions.

Development of a Questionnaire for Detecting Changes in Dry Eye Disease-Related Symptoms.

OBJECTIVES: Determining the changes in symptomatology suffered by dry eye disease (DED) patients after an intervention is difficult because there is only one validated questionnaire specifically designed to measure these changes and it is somewhat complex. This work uses a simplified questionnaire to evaluate the changes in DED-related symptoms. METHODS: A new questionnaire based on a global rating of change scale was designed. The Change in Dry Eye Symptoms Questionnaire (CDES-Q) consists of 2 questions: CDES-Q1 asks for the change in symptoms ("better," "same," or "worse") relative to a determined previous time and CDES-Q2 quantifies this change (range: 0 to +100). To evaluate the CDES-Q, a prospective observational study was performed. At baseline (V1; day-0), DED-related symptoms were evaluated using the ocular surface disease index (OSDI). In the post-treatment visit (V2; day-90), OSDI, Symptoms Assessment Questionnaire in Dry Eye (SANDE) II, and CDES-Q were used. Also, clinical evaluations were performed in each visit. RESULTS: Thirty-six patients were included. At V2, OSDI, SANDE II, and CDES-Q showed a significant reduction in symptoms (-7.17±12.73, P=0.0021; -11.29±20.95, P=0.0035; -25.28±42.28, P=0.0011, respectively). Patients who answered "better" in CDES-Q1 showed a significantly lower SANDE II than those who answered "same" or "worse," while SANDE II did not discriminate between these groups. CONCLUSIONS: CDES-Q can be a useful tool for the evaluation of changes in DED-related symptoms. It is simple and better discriminates patients without changes from those who suffered a worsening than SANDE II.

Ocular Delivery of Polyphenols: Meeting the Unmet Needs.

Nature has become one of the main sources of exploration for researchers that search for new potential molecules to be used in therapy. Polyphenols are emerging as a class of compounds that have attracted the attention of pharmaceutical and biomedical scientists. Thanks to their structural peculiarities, polyphenolic compounds are characterized as good scavengers of free radical species. This, among other medicinal effects, permits them to interfere with different molecular pathways that are involved in the inflammatory process. Unfortunately, many compounds of this class possess low solubility in aqueous solvents and low stability. Ocular pathologies are spread worldwide. It is estimated that every individual at least once in their lifetime experiences some kind of eye disorder. Oxidative stress or inflammatory processes are the basic etiological mechanisms of many ocular pathologies. A variety of polyphenolic compounds have been proved to be efficient in suppressing some of the indicators of these pathologies in in vitro and in vivo models. Further application of polyphenolic compounds in ocular therapy lacks an adequate formulation approach. Therefore, more emphasis should be put in advanced delivery strategies that will overcome the limits of the delivery site as well as the ones related to the polyphenols in use. This review analyzes different drug delivery strategies that are employed for the formulation of polyphenolic compounds when used to treat ocular pathologies related to oxidative stress and inflammation.

Clinical and tear cytokine profiles after advanced surface ablation refractive surgery: A six-month follow-up.

Neuropathic dry eye is one of the most frequently seen complications after corneal refractive surgery, however, its incidence decreases in a significant manner along the first six months postoperative, reaching between 10 and 45% incidence. However, little is known on the inflammatory status of the ocular surface during this recovery process. We aim to analyze the clinical and tear molecule concentration changes along six months after advanced surface ablation for myopia correction, in a prospective study including 18 eyes of 18 subjects who bilaterally underwent advanced surface ablation corneal refractive surgery. Clinical variables (uncorrected distance visual acuity, symptoms, conjunctival hyperemia, tear osmolarity, tear stability, corneal fluorescein staining, conjunctival lissamine staining, Schirmer test, and corneal esthesiometry) and a panel of 23 pro and anti-inflammatory cytokines/chemokines concentration in tears preoperatively and at 1, 3 and 6 months postoperatively were evaluated. We found that uncorrected distance visual acuity improved significantly from baseline at 1-month visit, symptoms improved and tear osmolarity decreased significantly from baseline at 3-month visit and there was a decrease in mechanical corneal threshold between 1-month and 3- and 6-month visits. Regarding tear molecules, IL-4, IL-5, IL-6, IL-13, IL-17A, and IFN-γ tear levels were significantly increased at all the three visits, compared to preoperative levels at V0; IL-2 and VEGF were also significantly increased at 1-month and 6-month visits, but not at 3-month visit, whereas IL-9 IL-10 and IL-12 were only significantly increased at 6-month visit. Although we found that there is a recovery in clinical variables at 6 months postoperatively (i.e. neuropathic dry eye was not developed in the sample), ocular surface homeostasis is not completely restored, as it can be seen by the changes in concentration of some pro and anti-inflammatory molecules measured in tears.

Changes in the tarsal conjunctiva viewed by in vivo confocal microscopy are associated with ocular symptoms and contact lens wear.

PURPOSE: To investigate the effect of soft contact lens (CL) wear on the morphology of the epithelial-lamina propria junction as well as the possible association with symptoms of discomfort. METHODS: Ninety-two subjects were recruited, including 60 soft CL wearers, 16 previous wearers, and 16 non-wearers. Additionally, subjects were classified as symptomatic or asymptomatic using the Contact Lens Dry Eye Questionnaire 8 for the CL wearers (a score ≥ 12 was considered symptomatic) and the Dry Eye Questionnaire 5 for the previous wearers and non-wearers (a score ≥ 5 was considered symptomatic). In vivo confocal microscopy of the tarsal conjunctiva was performed on a single occasion. Papillae density, shortest diameter, longest diameter, area, circularity, lumen/wall brightness ratio, irregularity, reflectivity, inhomogeneous appearance of wall and inhomogeneous appearance of rete ridges were evaluated. Effects of CL wear, symptoms and their interaction were analysed using two-way analysis of variance. Correlations were investigated using Spearman's coefficient. Data are presented as mean (standard deviation) or median [interquartile range]. RESULTS: Contact lens wearers, compared to previous wearers and non-wearers, showed higher circularity [0.65 (0.08) vs 0.59 (0.10) vs 0.57 (0.11), p = 0.003]. Subjects with symptoms, compared to asymptomatic participants, showed higher circularity [0.64 (0.08) vs 0.61 (0.10), p < 0.001] and lower irregularity (1.0 [0.7-2.0] vs 1.3 [1.0-2.3], p = 0.009). For previous wearers, those with symptoms showed greater density (135.4 [107.3-183.3] vs 87.5 [85.4-116.7], p = 0.013) and circularity [0.64 (0.07) vs 0.54 (0.10), p = 0.016]. For non-wearers, those with symptoms showed higher circularity [0.65 (0.08) vs 0.50 (0.08), p < 0.001]. DEQ-5 correlated with circularity (ρ = 0.55, p = 0.001). CONCLUSIONS: Soft CL wear modifies papillae of the epithelial-lamina propria junction into a more rounded shape; however, CL cessation appears to resolve this alteration. Additionally, a more rounded papillae shape is associated with ocular symptoms in subjects not actively wearing CLs.

Reliability of Blotting Techniques to Assess Contact Lens Water Content.

OBJECTIVES: To determine the reliability of wet and modified dry blotting techniques used in the gravimetric method to assess contact lens (CL) water content (WC), the accuracy of both techniques in comparison with the nominal WC, and also their agreement. METHODS: We evaluated hydrated and dry CL mass values and WC using the gravimetric method in 440 daily disposable CLs. Samples assessed corresponded to Dailies Total 1, Dailies AquaComfort Plus, 1-Day Acuvue TruEye, and Biotrue ONEday. Back vertex power ranged from +3.00 diopters (D) to -6.00 D. Within-subject coefficient of variation (CVw) and intraclass correlation coefficients were calculated. Bland-Altman analysis was also performed. RESULTS: The modified dry blotting technique yielded significantly (P≤0.0001) higher hydrated CL mass values. The wet blotting technique provided significantly (P≤0.04) better consistency than the modified dry one. Values of CVw for wet and modified dry blotting techniques ranged from 1.2% to 2.1% and from 3.7% to 5.4%, respectively. As for dry CL mass values, CVw values were not significantly different (P≥0.05) between wet (range: 1.1%-1.9%) and dry (range: 1.0%-5.1%) blotting techniques, except for Dailies AquaComfort Plus (P=0.03). Bland-Altman analysis showed poor agreement between the techniques. The wet blotting technique yielded WC values close (around 1%) to nominal ones, in contrast to modified dry blotting technique (≥2.5%). CONCLUSIONS: The wet blotting technique is not only more reliable than the modified dry one when obtaining hydrated CL mass but also provides more accurate nominal WC measurements. Agreement between the techniques was poor.

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.

Efficacy and Safety of 0.2% Hyaluronic Acid in the Management of Dry Eye Disease.

OBJECTIVES: To evaluate the safety and efficacy of a new artificial tear containing 0.2% hyaluronic acid, as compared with 0.9% saline solution, in mild dry eye patients after 1-month use in a crossover study design with washout periods. METHODS: Overall, 16 mild dry eye patients were included. After a week of washout, every patient used the experimental product (Visaid 0.2%) and the control product (0.9% saline solution), each for a month (3-8 drops daily). Both products were preservative free. The percentage change for the following variables were calculated and analyzed: Ocular Surface Disease Index (OSDI) questionnaire, visual acuity, intraocular pressure, ophthalmoscopy evaluation, biomicroscopy findings, fluorescein corneal staining and lissamine green conjunctival staining, tear breakup time, contrast sensitivity, Schirmer's test, and subject satisfaction. RESULTS: Patients reported an improvement (a significant decrease of -19.5%±27.5%) in OSDI scores after using Visaid 0.2% and a worsening (a significant increase of 19.2%±32.4%) after using 0.9% saline solution; the difference was significant (P=0.0087, Student's t test). Significant changes (P≤0.04, Wilcoxon's test) were found comparing Visaid 0.2% with saline solution for bulbar hyperemia (-39.1%±50.8% vs. 7.8%±12.0%, respectively), corneal staining (-26.0%±53.0% vs. 36.5%±73.3%), conjunctival staining (-54.7%±53.4% vs. -7.8%±47.2%), and subjective satisfaction (26.8%±28.5% vs. -13.3%±22.5%). There were no significant differences in the safety parameters for either solution. CONCLUSION: This clinical trial demonstrates the safety of Visaid 0.2% and its clear benefit over 0.9% saline solution.

Safety and Efficacy of an Artificial Tear Containing 0.3% Hyaluronic Acid in the Management of Moderate-to-Severe Dry Eye Disease.

PURPOSE: To evaluate the safety and efficacy of a new 0.3% hyaluronic acid artificial tear compared with 0.9% saline solution (0.9% NaCl) in moderate-to-severe dry eye patients after 1 month's use. METHODS: A total of 16 patients with moderate-to-severe dry eye were included in this crossover study. After a 1-week washout period, patients used the experimental (Visaid 0.3%) or control solution (0.9% NaCl), selected randomly, applying three to eight drops daily for a month. After another washout period, patients used the other solution in the same way. Percentage of change (ΔY) was calculated and analyzed for (1) safety variables: visual acuity, intraocular pressure, and ophthalmoscopy evaluation; (2) efficacy variable: Ocular Surface Disease Index (OSDI) questionnaire; and (3) secondary variables: biomicroscopy findings, fluorescein corneal staining, lissamine green conjunctival staining, tear breakup time (TBUT), contrast sensitivity, Schirmer test, and subject satisfaction. RESULTS: There were no significant differences in the safety parameters for either solution. After using Visaid 0.3%, patients showed significant improvements in OSDI score (ΔY: -9.66%±10.90), tarsal hyperemia (ΔY: -16.67%±27.89), corneal staining extension (ΔY: -34.90%±42.41), TBUT (ΔY: 13.98%±26.19), and subjective satisfaction (ΔY: 38.06%±47.06). When using 0.9% NaCl, Schirmer test results were significantly worse (ΔY: -11.47%±19.27). A significant difference between the 2 solutions was found in TBUT (ΔY: 13.98%±26.19 vs. 10.15%±42.34, respectively; P=0.0214). CONCLUSION: Visaid 0.3% is a safe product with some benefits over 0.9% NaCl in reducing ocular symptoms and improving some ocular signs in patients with moderate-to-severe dry eye.

Topical Fluorometholone Protects the Ocular Surface of Dry Eye Patients from Desiccating Stress: A Randomized Controlled Clinical Trial.

PURPOSE: To assess the efficacy of topical 0.1% fluorometholone in dry eye disease (DED) patients for ameliorating the worsening of the ocular surface when exposed to adverse environments. DESIGN: Single-center, double-masked, randomized, vehicle-controlled clinical trial. PARTICIPANTS: Forty-one patients showing moderate to severe DED. METHODS: Patients randomly received 1 drop 4 times daily of either topical 0.1% fluorometholone (FML group) or topical polyvinyl alcohol (PA group) for 22 days. Corneal and conjunctival staining, conjunctival hyperemia, tear film breakup time (TBUT), tear osmolarity, and the Symptom Assessment in Dry Eye (SANDE) questionnaire scores were determined at baseline. Variables were reassessed on day 21 before and after undergoing a 2-hour controlled adverse environment exposure and again on day 22. MAIN OUTCOMES MEASURES: Percentage of patients showing an increase 1 point or more in corneal staining and a reduction of 2 points or more (0-10 scale) in SANDE score, after the controlled adverse environment exposure and 24 hours later. RESULTS: After 21 days of treatment, the FML group showed greater improvements in corneal and conjunctival staining, hyperemia, and TBUT than the PA group (P≤0.03). After the adverse exposure, the percentage of patients having a 1-grade or more increase in corneal staining was significantly (P = 0.03) higher in the PA group (63.1% vs. 23.8%, respectively). Additionally, the FML group showed no significant changes in corneal staining (mean, 0.86; 95% confidence interval [CI], 0.47-1.25; vs. mean, 1.05; 95% CI, 0.59-1.51, for visit 2 and 3, respectively), conjunctival staining (mean, 0.95; 95% CI, 0.54-1.37 vs. mean, 1.19; 95% CI, 0.75-1.63), and hyperemia (mean, 0.71; 95% CI, 0.41-1.02 vs. 1.14; 95% CI, 0.71-1.58) after the exposure, whereas for the PA group, there was significant worsening (P≤0.009) in these variables (corneal staining: mean, 1.95; 95% CI, 1.57-2.33 vs. mean, 2.58; 95% CI, 2.17-2.98; conjunctival staining: mean, 1.68; 95% CI, 1.29-2.08 vs. mean, 2.47; 95% CI, 2.07-2.88; hyperemia: mean, 1.95; 95% CI, 1.63-2.26 vs. mean, 2.84; 95% CI, 2.62-3.07). CONCLUSIONS: Three-week topical 0.1% fluorometholone therapy is effective not only in reducing ocular surface signs in DED patients, but also especially in preventing exacerbation caused by exposure to a desiccating stress.

Lack of Agreement among Electrical Impedance and Freezing-Point Osmometers.

PURPOSE: To assess the interchangeability of tear osmolarity measurements between electrical impedance and freezing-point depression osmometers and to analyze inter-eye tear osmolarity variability measured with these osmometers in healthy subjects. METHODS: Tear osmolarity was measured using the TearLab osmometer (OcuSense Inc., San Diego, CA) and the Fiske 210 microsample osmometer (Advanced Instruments Inc., Norwood, MA). We randomly selected one eye in 50 subjects (29 women, 21 men; mean age, 33.16 ± 6.11 years) to analyze whether osmolarity measurements by these osmometers were interchangeable. Both eyes of 25 patients (15 women, 10 men; mean age, 34.32 ± 6.37 years) were included to analyze inter-eye osmolarity variability. RESULTS: The mean tear osmolarity values measured with the TearLab osmometer were higher (305.22 ± 16.06 mOsm/L) than those with the Fiske 210 osmometer (293.40 ± 12.22 mOsm/L), with the intraclass correlation coefficient being 0.23 (p = 0.051). A Bland-Altman plot showed that the systems were not interchangeable because there was a systematic difference, with the limits of agreement being -17.93 to 41.57 mOsm/L. There were no statistically significant differences (p = 0.5006 and p = 0.6533, respectively) between an individual's eyes measured with either osmometer. CONCLUSIONS: Because the TearLab tear osmolarity measurements were higher than those of the Fiske 210 measurements and the limits of agreement were too wide, the two osmolarity values cannot be used interchangeably. In healthy subjects, there is no difference in tear osmolarity between right and left eyes of the same individual measured with both instruments.

Influence of Climate on Clinical Diagnostic Dry Eye Tests: Pilot Study.

PURPOSE: To analyze dry eye disease (DED) tests and their consistency in similar nonsymptomatic population samples living in two geographic locations with different climates (Continental vs. Atlantic). METHODS: This is a pilot study including 14 nonsymptomatic residents from Valladolid (Continental climate, Spain) and 14 sex-matched and similarly aged residents from Braga (Atlantic climate, Portugal); they were assessed during the same season (spring) of two consecutive years. Phenol red thread test, conjunctival hyperemia, fluorescein tear breakup time, corneal and conjunctival staining, and Schirmer test were evaluated on three different consecutive visits. Reliability was assessed using the intraclass correlation coefficient and weighted kappa (κ) coefficient for quantitative and ordinal variables, respectively. RESULTS: Fourteen subjects were recruited in each city with a mean (± SD) age of 63.0 (± 1.7) and 59.1 (± 0.9) years (p = 0.08) in Valladolid and Braga, respectively. Intraclass correlation coefficient and κ values of the tests performed were below 0.69 and 0.61, respectively, for both samples, thus showing moderate to poor reliability. Subsequently, comparisons were made between the results corresponding to the middle and higher outdoor relative humidity (RH) visit in each location as there were no differences in mean temperature (p ≥ 0.75) despite RH values significantly differing (p ≤ 0.005). Significant (p ≤ 0.05) differences were observed between Valladolid and Braga samples on tear breakup time (middle RH visit, 2.76 ± 0.60 vs. 5.26 ± 0.64 seconds; higher RH visit, 2.61 ± 0.32 vs. 5.78 ± 0.88 seconds) and corneal (middle RH, 0.64 ± 0.17 vs. 0.14 ± 0.10; higher RH, 0.60 ± 0.22 vs. 0.0 ± 0.0) and conjunctival staining (middle RH, 0.61 ± 0.17 vs. 0.14 ± 0.08; higher RH, 0.57 ± 0.15 vs. 0.18 ± 0.09). CONCLUSIONS: This pilot study provides initial evidence to support that DED test outcomes assessing the ocular surface integrity and tear stability are climate dependent. Future large-sample studies should support these outcomes also in DED patients. This knowledge is fundamental for multicenter clinical trials. Lack of consistency in diagnostic clinical tests for DED was also corroborated.

Intra- and inter-day variation of cytokines and chemokines in tears of healthy subjects.

Tear levels of certain cytokines/chemokines can potentially serve as biomarkers for dry eye and other ocular surface diseases if they remain stable from day-to-day in healthy eyes. The aim of this study was to determine the normal intra- and inter-day variation of selected tear cytokines/chemokines. Tear samples from 24 young, healthy adults were collected 11:00 AM-1:00 PM (mid-day) and 5:00-7:00 PM (evening) on three non-consecutive days. Concentrations of 18 cytokines/chemokines (EGF, eotaxin, CX3CL1/fractalkine, GM-CSF, IFN-γ, IL-10, IL-1ß, IL-13, IL-17A, IL-1RA, IL-5, IL-6, CXCL8/IL-8, IL-9, CXCL10/IP-10, CCL5/RANTES, TNF-α, and VEGF) were measured by multiplex bead analysis. Ocular surface disease was ruled out by clinical tests. A random-effects ANOVA model was used to evaluate intra- and inter-day effects on cytokine/chemokine levels. Repeatability of intra-subject inter-day measurements was assayed by coefficient of variation. Ten out of the 18 molecules had detectable tear levels in >50% of the subjects. Of those, only IL-10 and IL-1ß levels had significant inter-day variations. EGF, CX3CL1/fractalkine, CXCL10/IP-10, and VEGF were consistently higher in the evening compared to the mid-day measurements. EGF, CXCL10/IP-10, VEGF and CXCL8/IL-8had good intra-subject reproducibility. In conclusion, tear cytokines/chemokines can be measured reproducibly over time, with most not having significant inter-day variability. Some varied significantly depending upon the time of tear collection, and these variations should be taken into account when comparisons are made. The good intra-subject reproducibility for EGF, CXCL10/IP-10, CXCL8/IL-8, and VEGF indicates that these molecules could potentially serve as biomarkers of ocular surface disease.

Clinical characterisation of contact lens discomfort progression.

PURPOSE: This study aimed to assess the subjective and objective differences among the steps of the contact lens discomfort (CLD) progression classification established by the Tear Film & Ocular Surface Society (TFOS) using questionnaires and clinical signs, and to propose a simplified classification. METHODS: Contact lens (CL) wearers were evaluated in a single visit. The Contact Lens Dry Eye Questionnaire (CLDEQ)-8, the Contact Lens Discomfort Index, and Visual Analog Scales for discomfort and dryness were administered. The non-invasive break-up time, the tear film lipid layer thickness, conjunctival hyperaemia and papillae, lid-parallel conjunctival folds, the fluorescein tear film break-up time, corneal and conjunctival staining, lid wiper epitheliopathy, and the Schirmer test were assessed. Sign and symptom scores were compared among TFOS CLD progression steps using analysis of variance or the Kruskal-Wallis H test. Steps 1 and 2 (reduced comfort), and steps 3 and 4 (reduced wearing time) of the TFOS classification were combined to obtain a simplified classification, and the same comparison was performed. A p-value ≤ 0.05 was considered statistically significant. RESULTS: One hundred-fifty CL wearers (97 women and 53 men) aged 34.4 ± 12.6 years were included. In the TFOS classification, there were significant differences between step 0 (no CLD) and the rest of the severity steps for the scores obtained in all questionnaires (p ≤ 0.015). All steps were differentiated (p ≤ 0.032) based on the simplified classification for all questionnaires, except steps 1 and 2 for the CLDEQ-8 and dryness VAS (p = 0.089 and p = 0.051, respectively). There were no differences (all p ≥ 0.06) between the sign scores among the steps of either classification. CONCLUSION: CLD management is encouraged from its first appearance. Simplifying the phases of CLD severity may allow a more accurate classification and a better awareness of the problem by clinicians and CL wearers by using more straightforward simple messages.

Short-Term Efficacy of Ophthalmic Cyclosporine: A 0.1% Cationic Emulsion in Dry Eye Patients Assessed Under Controlled Environment.

INTRODUCTION: To evaluate the short-term efficacy of cyclosporine A (CsA)-0.1% cationic emulsion (CE) in patients with dry eye disease (DED) and mitigation of the inflammatory flares triggered by desiccating stress environments. METHODS: A single-center non-randomized clinical trial was performed at a tertiary care setting. Twenty patients with DED treated with CsA 0.1% CE were exposed to a normal controlled environment (NCE) (23 °C, 50% relative humidity) and an adverse controlled environment (ACE) (23 °C, 10% relative humidity, 0.43 m/s localized airflow) during baseline and the 1- and 3-month visits. Patients underwent the following evaluations: conjunctival hyperemia and staining, corneal fluorescein staining (CFS) using the Oxford and Cornea and Contact Lens Research Unit (CCLRU) scale, meibomian gland (MG) secretion quality, Dry Eye Questionnaire-5, Symptom Assessment in Dry Eye (SANDE II), and Change in Dry Eye Symptoms Questionnaire. Multivariate models were adjusted for statistical analysis. RESULTS: Nineteen women and one man (mean age, 58.9 ± 12.3 years) completed the study. All symptom questionnaires, CFS, conjunctival hyperemia and staining, and MG secretion quality improved (p ≤ 0.003) with 1 month of treatment; improvements were maintained after 3 months (p ≤ 0.02), except for SANDE II (p ≥ 0.07). The CFS worsening (total CCLRU) after baseline ACE exposure (from 8.6 to 10.1) was higher, although not significant (p = 0.64), compared with 1 month (from 5.4 to 5.8) and 3 months (from 5.0 to 5.9) after treatment. CONCLUSION: Topical CsA-0.1% CE improved DED signs and symptoms after 1 month of treatment under controlled environmental conditions. Future studies should confirm the benefit of CsA-0.1% CE in desiccating stress environments. TRIAL REGISTRATION: ClinicalTrials.gov identifier, NCT04492878.

Gene expression changes in conjunctival cells associated with contact lens wear and discomfort.

PURPOSE: This study aimed to analyze the differences in the expression of pain-related genes in conjunctival epithelial cells among symptomatic contact lens (CL) wearers (SCLWs), asymptomatic CL wearers (ACLWs), and non-CL wearers (non-CLWs). METHODS: For this study, 60 participants (20 non-CLWs, 40 CLWs) were enrolled. The CLW group comprised 20 ACLWs and 20 SCLWs according to the Contact Lens Dry Eye Questionnaire short form©. Conjunctival cells were collected using impression cytology, and RNA was isolated and used to determine the expression levels of 85 human genes involved in neuropathic and inflammatory pain. The effects of CL wear and discomfort were evaluated using mixed-effects ANOVA with partially nested fixed-effects model. Gene set enrichment analysis was performed to assign biological meaning to sets of differentially expressed genes. RESULTS: Six genes (CD200, EDN1, GRIN1, PTGS1, P2RX7, and TNF) were significantly upregulated in CLWs compared to non-CLWs. Eleven genes (ADORA1, BDKRB1, CACNA1B, DBH, GRIN1, GRM1, HTR1A, PDYN, PTGS1, P2RX3, and TNF) were downregulated in SCLWs compared to ACLWs. These genes were mainly related to pain, synaptic transmission and signaling, ion transport, calcium transport and concentration, and cell-cell signaling. CONCLUSIONS: CL wear modified the expression of pain- and inflammation-related genes in conjunctival epithelial cells. These changes may be in part, along with other mechanisms, responsible for CL discomfort in SCLWs.