Limbal Hyperemia Research Articles

Tear‐borne interleukin 1‐beta and transforming growth factor‐beta and its relationship with clinical parameters in neophytes contact lens wearers

Aims/Purpose: To determine the presence of Interleukin 1‐beta (IL1‐β) and Transforming growth factor‐beta (TGF‐β) in the tears of neophytes contact lens wearers; and investigate the relationship between their concentration, tear stability, and ocular physiology findings.Methods: In this clinical trial, 12 neophytes (5 males, 24.0 ± 5.0 years) were dispensed with delefilcon A contact lenses. Physiological responses (bulbar and limbal hyperemia), non‐invasive tear break‐up times, and tear sample collections were obtained in the morning (before lens insertion; 9–10 a.m.) and afternoon (before lens removal; 7–8 p.m.) of the same day. The tear samples were assayed for IL1‐β and TGF‐β concentrations using Enzyme‐Linked Immunoabsorbent Assay kits. A parallel control group of 11 individuals (6 males, 25.0 ± 5.0) was also assessed to determine the levels of the biomarkers in the tears of non‐contact lens wearers.Results: Patients wore lenses for an average of 7:20 [6,9] h. Bulbar and limbal hyperemia increased throughout the day (p < 0.001). Tear break‐up times were lower in the afternoon compared to the morning assessment (4.7 ± 2.0 Vs. 12.2 ± 8.8 seconds; p < 0.001). The IL1‐β levels were higher in neophytes compared to controls (3.2 ± 4.7 Vs. 0.1 ± 0.1 ρg/ml; p = 0.05) but only in the afternoon. A significant correlation was found between IL1‐β concentration, bulbar (r = 0.405, p = 0.008), and limbal hyperemia (r = 0.499, p = 0.027) in the morning period. No substantial changes were reported for TGF‐β.Conclusions: The use of contact lenses might alter the IL1‐β regulatory mechanisms and disturb ocular surface homeostasis. However, more clinical evidence is needed to understand this phenomenon.

Efficacy of five-flash intense pulsed light therapy technique in patients with meibomian gland dysfunction

ABSTRACT Clinical relevance Meibomian gland dysfunction is the main cause of evaporative dry eye disease and can lead to ocular discomfort and ocular surface damage. Early diagnosis and management of this condition can prevent its impact on patients ‘visual health and quality of life. Background In the last decade, intense pulsed light therapy (IPL) has been introduced as a therapeutic option for patients with meibomian gland dysfunction (MGD). Various treatment modalities and protocols have been reported to increase the efficacy of this technique. This study aimed to assess the efficacy of a novel five-flash IPL technique in combination with home-based therapy and to compare it with conventional home care alone in patients with MGD. Methods In a randomised controlled trial, 100 symptomatic MGD patients were enrolled. The treatment group underwent three sessions of a five-flash IPL therapy. For all participants, eyelid warming, lid hygiene and lubricant therapy was prescribed. Ocular surface parameters were compared for control and treatment groups. Results Ocular Surface Disease Index (OSDI), non-invasive keratograph tear break up time (NIKBUT), fluorescein TBUT, MG expressibility, meibum quality and tear osmolarity were improved at follow up visits in both groups (p < 0.05). On day 75, NIKBUT was significantly higher in the IPL group (p = 0.045). The IPL treatment effect was not statistically significant (p > 0.05), except for bulbar and limbal hyperaemia (p = 0.02 and p = 0.02). In both groups, younger patients showed more improvement in NIKBUT (p = 0.02, r = −0.32; p < 0.001, r = −0.52). Conclusion IPL therapy combined with conventional home-based therapy, and home care alone are both effective for patients with MGD. IPL may have an additional role in the improvement of ocular hyperaemia.

The Influence of Work Environment Factors on the OcularSurface in a One-Year Follow-Up Prospective Clinical Study.

The purpose of this study was to assess the effect of environmental working conditions on the symptoms and signs of dry eye disease and to examine whether and how those conditions impact the ocular surface. Methods: This single-center, prospective clinical study with a 1-year follow-up included 150 patients. The following parameters were evaluated: non-invasive keratograph break-up time (NIKBUT), tear meniscus height (TMH), and conjunctival and limbal hyperemia. We also performed staining of the surface of the eye for simulated fluorescein images, Schirmer’s test I, assessment of Meibomian gland dysfunction (MGD), and an Ocular Surface Disease Index (OSDI) questionnaire. Results: In the OW (office workers) group, in people working >4 h at the computer, the NIKBUT before work and the Schirmer test results were statistically significantly lower than in people working <4 h. The conjunctival hyperemia result before work was statistically significantly higher for people working >4 h at a computer in both groups and after work in the MW (medical workers) group. Low relative air humidity in the building and air-conditioned rooms negatively affects the tear film, causing the symptoms of dry eye disease. At the 1-year follow-up, there was a statistically significant reduction in conjunctival and limbal hyperemia in the OW group as well as a statistically significant reduction in TMH at the first examination before and after work, and in the second examination after 1 year in both groups. Conclusions: Environmental factors such as reduced relative air humidity, increased air temperature, and decreased illumination have a negative impact on the ocular surface.

Does placebo effect exist in contact lens discomfort management?

PurposeTo study the effect of daily disposable contact lens (DDCL) refitting in monthly contact lens (CL) wearers suffering from contact lens discomfort (CLD), and to assess if there is a placebo effect associated with this CLD intervention. MethodsSymptomatic CL wearers, according to the Contact Lens Dry Eye Questionnaire 8 (CLDEQ-8 ≥ 12 points), were divided into two groups. The study group was provided with DDCLs (delefilcon A) and the control group with a masked pair of their habitual monthly CLs (placebo effect) and were assessed after one month. Then, the control group was provided with the same DDCLs and evaluated one month later. The symptoms were recorded with the CLDEQ-8 and global rating of change scale (GRCS). Non-invasive tear break-up time (NITBUT), conjunctival hyperaemia, fluorescein staining, and lid wiper epitheliopathy (LWE) were evaluated. Changes between visits, groups, and the effect of each intervention were analysed. ResultsThirty-one participants (mean age: 23.2 ± 5.3 years) were recruited. The study group (n = 14) showed an improvement of -39.6 ± 25.8 % (p < 0.001) in CLDEQ-8 and 31.3 ± 14.6 points in GRCS (p < 0.001) after one month of DDCL use, while no changes in clinical tests were found. In the control group (n = 17), symptoms improved significantly after wearing the masked monthly CL (CLDEQ-8: -26.1 ± 31.0 %, p = 0.03; GRCS: 14.9 ± 17.0, p = 0.002), however a worsening in bulbar (26.5 ± 40.0 %; p = 0.02) and limbal hyperaemia (21.6 ± 34.7 %, p = 0.02) and an improvement of -19.1 ± 37.0 % (p = 0.049) in LWE was found. When the control group was fitted with the DDCL, improvements in GRCS (20.5 ± 25.5, p = 0.02), NITBUT (37.9 ± 42.3 %, p = 0.002), and conjunctival staining (-47.1 ± 59.9 %, p = 0.005) were noted. ConclusionsRefitting symptomatic monthly CL wearers with Delefilcon A DDCL is effective in reducing symptoms related to CLD. However, clinicians and researchers must be aware of the existence of a placebo effect when assessing the effectiveness of any CL refitting.

Inflammatory status predicts contact lens discomfort under adverse environmental conditions

PurposeTo characterize and predict the clinical and tear molecular response of contact lens (CL) wearers exposed to a controlled adverse desiccating environment (CADE). MethodsObjective 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. ResultsForty-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. ConclusionsMost 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.

Optimising subjective anterior eye grading precision

PurposeTo establish the optimum grading increment which ensured parity between practitioners while maximising clinical precision. MethodsSecond year optometry students (n = 127, 19.5 ± 1.4 years, 55 % female) and qualified eye care practitioners (n = 61, 40.2 ± 14.8 years, 52 % female) had 30 s to grade each of bulbar, limbal and palpebral hyperaemia of the upper lid of 4 patients imaged live with a digital slit lamp under 16× magnification, diffuse illumination, with the image projected on a screen. The patients were presented in a randomised sequence 3 times in succession, during which the graders used the Efron printed grading scale once to the nearest 0.1 increment, once to nearest 0.5 increment and once to the nearest integer grade in a randomised order. Graders were masked to their previous responses. ResultsFor most grading conditions less than 20 % of clinicians showed a ≤0.1 difference in grade from the mean. In contrast, more than 50 % of the student graders and 40 % of experienced graders showed a difference in grade from the mean within 0.5 for all conditions under measurement. Student precision in grading was better with both 0.1 and 0.5 grading increments than grading to the nearest unit, except for limbal hyperaemia where they performed more accurately with 0.5 unit increment grading. Limbal grading precision was not affected by grading step increment for experienced practitioners, but 0.1 and 0.5 grading increments were both better than the 1.0 grading increment for bulbar hyperaemia and the 0.1 grading increment was better than the 0.5 grading increment and both were better than the 1.0 grading increment for palpebral hyperaemia. ConclusionAlthough narrower interval scales maximise the ability to detect smaller clinical changes, the grading increment should not exceed one standard deviation of the discrepancy between measurements. Therefore, 0.5 grading increments are recommended for subjective anterior eye physiology grading (limbal, bulbar and palpebral redness).

Ocular surface response and subjective symptoms associated to lens care solutions in Palestine

PurposeTo compare the biocompatibility and subjective symptoms of four multipurpose solutions marketed in Palestine with hydrogel contact lenses. Methods50 habitual soft contact lens wearers were recruited in this interventional crossover study. Subjects were asked to attend the optometry clinic five times. A new pair of hydrogel lenses (Bioxifilcon-B) were fitted each time. This pair was soaked randomly overnight in one of the following four-multipurpose solutions (NEOPLUS®, AvizorUnicaSensitive®, ReNuMultiPlus® and COMPLETERevitaLens®) which contain different disinfecting agents (PHMB, Phx, PAPB, and PQ-1+Alexidine, respectively), or non-preserved saline. At each visit, corneal staining, ocular redness and subjective symptoms were assessed. ResultsThe percentage of corneal staining increased significantly (P≤0.050) after soaking the lenses with PHMB (86%), PAPB (64%) and Phx (32%) based-solutions. However, a non-significant increase was noticed after the use of PQ-1+Alexidine based solution (30%, P=0.083). Ocular redness evaluation showed a significant increase (P≤0.050) in limbal hyperemia after the use of all solutions, while bulbar redness was significantly increased after the use of biguanide-based solutions (P≤0.050). The subjective assessment analysis showed a non-significant change in comfort, dryness, photophobia and scratchiness (P≥0.050) at 2-h intervention using all solutions, except for the PHMB based solution which showed a significant change in subjective symptoms (P≤0.050). ConclusionThe combination of Bioxifilcon-B hydrogel contact lenses and solution containing PHMB, PAPB and Phx-disinfectants induced a significant increase in corneal staining after 2h of CL-wear with a higher severity when the PHMB-based solution was used, while the PQ-1+Alexidine-based solution did not. Only the PHMB-based solution triggered a significant change in subjective symptoms which might which suggests that it might be related to the severity of staining rather than the induction of staining.

&lt;p&gt;The short-term physiological impact of switching reusable silicone hydrogel wearers into a hydrogel daily disposable multifocal&lt;/p&gt;

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.

The ability of the Contact Lens Dry Eye Questionnaire (CLDEQ)-8 to detect ocular surface alterations in contact lens wearers.

To study whether some ocular surface alterations could be associated with contact lens (CL) wearers suffering from CL discomfort (CLD) detected using the Contact Lens Dry Eye Questionnaire (CLDEQ)-8. Forty-one soft CL wearers further classified into symptomatic CL wearers (SCLW) and asymptomatic CL wearers (ACLW) by the CLDEQ-8, and 20 non CL wearers (NCLW) were included. Tear osmolarity, slit-lamp biomicroscopy findings, tear film break-up time, corneal and conjunctival staining, and Schirmer test were performed 24 h after CL removal. Data were compared among groups using the analysis of variance and the Student t-test or the Kruskal-Wallis H and the Mann-Whitney U tests, applying the Bonferroni correction. Correlations between the CLDEQ-8 and the clinical signs were performed using the Spearman correlation coefficient. Twenty-four SCLW, 17 ACLW and 20 NCLW were recruited. There were significant differences among groups for tear osmolarity (p < 0.001), limbal hyperaemia (p = 0.014), and tarsal hyperaemia (p = 0.031). Pairwise comparisons revealed that SCLW and ACLW had higher tear osmolarity (p < 0.003, both comparisons) and limbal hyperaemia (p = 0.027 and p = 0.048, respectively) than NCLW. Moreover, SCLW had higher tarsal hyperaemia (p = 0.030) than NCLW. No significant correlations were found (p > 0.05). The CLDEQ-8 was ineffective to detect clinical alterations between SCLW and ACLW; therefore, the use of questionnaires alone remains being the best approach to detect CLD. The role of the tarsal conjunctiva in the development of CLD should be analyzed in future studies.

Assessment of Ocular Surface Damage during the Course of Type 2 Diabetes Mellitus

Purpose To investigate the impact of disease duration on the ocular surface during the course of type 2 diabetes mellitus compared with nondiabetic controls. Methods One hundred twenty diabetic patients were divided into three groups according to disease duration: less than 5 years, 5–10 years, and over 10 years. All eyes were imaged using a corneal topographer (Oculus Keratograph 5M). Tear film measurements and meibography were also recorded. Meibomian gland changes were scored from 0 to 6 (meiboscore). Results The noninvasive breakup time first (NIKBUT-1st) and noninvasive breakup time average (NIKBUT-avg) were significantly shorter in the over 10 years diabetic group compared with the control group (P=0.0056 and P=0.010, resp.). Tear meniscus height (TMH) was significantly lower in the over 10 years diabetic group compared with the control group (P=0.0016) and the 5 years group (P=0.0061). We also found that more patients in the over 10 years diabetic group showed bulbar and limbal hyperemia compared with the control group (bulbar hyperemia: P=0.049; limbal hyperemia: P=0.026). The meiboscore in the over 10 years diabetic group was significantly higher compared with the other three groups (P < 0.05). Bulbar hyperemia showed a significant negative correlation with NIKBUT-1st in the over 10 years diabetic group (r=−0.35 and P < 0.05). Conclusion Ocular surface damage in long-term type 2 diabetes is more severe than that in patients with shorter disease duration.

Clinical comparison of optimum and large diameter soft contact lenses.

To compare the clinical performance of large diameter lenses with optimally fit lenses in the same material and monocurve back surface design. In a four-visit, randomised, bilateral, crossover, study, 25 myopic subjects wore optimum diameter lenses (control) and large diameter lenses (test) in random succession for 1 week each. Both study lenses were made of methafilcon A and of an identical design. Trial fittings with Frequency 55 (Coopervision) lenses modified with a design algorithm were used to determine the appropriate custom-made study lenses. The least squares mean scores (±SE) for overall comfort and end-of-day comfort (0-10 scale) were 7.57 ± 0.33 vs. 7.42 ± 0.33 (P = 0.59) and 7.00 ± 0.31 vs. 7.27 ± 0.32 (P > 0.05) for the optimum and large diameter lenses, respectively. There were no significant differences in mean (±SE) gradings for limbal hyperaemia (1.23 ± 0.11 vs. 1.19 ± 0.11, 0-4 scale, P = 0.60) and corneal staining (1.79 ± 0.25 vs. 2.04 ± 0.25, P = 0.39). Conjunctival staining was greater for the optimum lens: 1.80 ± 0.28 vs. 0.93 ± 0.28 (0-4 scale, P = 0.001). With regard to lens fit, the large diameter lenses showed significantly less post-blink movement (0.22 ± 0.01 vs. 0.16 ± 0.01 mm, P = 0.004), and greater total decentration (0.15 ± 0.02 vs. 0.21 ± 0.02 mm, P = 0.010). However, there was no significant difference in the key fit variable of tightness on push-up (46 ± 0.69% vs. 48 ± 0.69%, 0-100 scale, P = 0.12). The findings suggest that larger than optimal soft lenses may be worn without detriment to either comfort or ocular physiology, provided an optimal fit is otherwise maintained.

Daily Wear Contact Lenses Manufactured in Etafilcon A Are Noninferior to Two Silicone Hydrogel Lens Types With Respect to Hypoxic Stress.

This study hypothesized that a traditional high-water contact lens of moderate oxygen transmissibility (Dk/t) is noninferior to common silicone hydrogel (SH) lenses worn for daily wear with respect to measures of hypoxic stress. Thirty-six habitual contact lens wearers completed wear of three lens types worn in a randomized order: etafilcon A (ACUVUE 2, control), lotrafilcon B (Air Optix Aqua), and comfilcon A (Biofinity). Central corneal thickness (CT) and limbal hyperemia were measured >2 hr after waking and after 6 to 8 hr of wear on days 1 and 7. Endothelial bleb formation was measured on day 1 of each lens type. Noninferiority of etafilcon A, with respect to the other two lens types, was assumed if the following difference margins of equivalence were met: <1.5% for corneal swelling, <0.5 grade for limbal hyperemia, and <1% area of endothelial blebs. Outcomes were modeled using generalized linear mixed modeling techniques. All lenses showed reductions in least-square mean estimates of CT on both days: etafilcon A -0.26% at day 1 and -0.31% at day 7; lotrafilcon B -1.11% at day 1 and -1.06% at day 7; comfilcon A -0.63% at day 1 and -0.84% at day 7. The difference in mean swelling between etafilcon A and lotrafilcon B was 0.85% at day 1 (95% confidence interval [0.4%-1.3%]) and 0.75% at day 7 (0.3%-1.2%). The difference in mean swelling between etafilcon A and comfilcon A was 0.37% at day 1 (-0.1% to 0.8%) and 0.53% at day 7 (0.1%-1.0%). For limbal redness, etafilcon A fell within 0.1 grade of lotrafilcon B and 0.18 grade of comfilcon A. For endothelial bleb formation, etafilcon A fell within 0.45% of lotrafilcon B and 0.23% of comfilcon A. The etafilcon A control lens resulted in corneal deswelling throughout the day as did the SH lens types. Limbal hyperemia and endothelial bleb formation with all lenses were negligible, and noninferiority assumptions were met between the lens types for all outcomes. Equivalence of etafilcon A with respect to the two SH lenses for three measures of hypoxic stress was demonstrated.

Clinical Severity Classification using Automated Conjunctival Hyperemia Analysis Software in Patients with Superior Limbic Keratoconjunctivitis

ABSTRACTPurpose: Digitization of clinical observation is necessary for assessing the severity of superior limbic keratoconjunctivitis (SLK). This study aimed to use a novel quantitative marker to examine hyperemia in patients with SLK.Materials and Methods: We included six eyes of six patients with both dry eye disease and SLK (SLK group) and eight eyes of eight patients with Sjögren syndrome (SS group). We simultaneously obtained the objective finding scores by using slit-lamp examination and calculated the superior hyperemia index (SHI) with an automated conjunctival hyperemia analysis software by using photographs of the anterior segment. Three objective finding scores, including papillary formation of the superior palpebral conjunctiva, superior limbal hyperemia and swelling, and superior corneal epitheliopathy, were determined. The SHI was calculated as the superior/temporal ratio of bulbar conjunctival hyperemia by using the software. Fisher’s exact test was used to compare a high SHI (≥1.07) ratio between the SLK and SS groups. P-Values < 0.05 were considered statistically significant.Results: The SHI (mean ± standard deviation) in the SLK and SS groups was 1.19 ± 0.50 and 0.69 ± 0.24, respectively. The number of patients with a high SHI (≥1.07) was significantly higher in the SLK group than in the SS group (p < 0.05). The sensitivity and specificity of the SHI in the differential diagnosis between SS and SLK were 66.7% and 87.5%, respectively. An analysis of the association between the objective finding scores and SHI showed that the SHI had a tendency to indicate the severity of superior limbal hyperemia and swelling score in the SLK group.Conclusion: The SHI calculated using the automated conjunctival hyperemia analysis software could successfully quantify superior bulbar conjunctival hyperemia and may be a useful tool for the differential diagnosis between SS and SLK and for the quantitative follow-up of patients with SLK.

Corneal confocal microscopy assessment in contact lens discomfort

PurposeThe aim of this study was to analyze whether symptoms of discomfort in CL wearers were associated to changes in the nerve morphology and/or the density of dendritic cells in the corneal sub‐basal nerve plexus.MethodsSixty subjects were included: 20 symptomatic CL wearers (SCLW), 20 asymptomatic CL wearers (ACLW), and 20 non wearers (NCLW). Ocular Surface Disease Index (OSDI), visual acuity, tear osmolarity, biomicroscopy findings, tear film break‐up time, corneal and conjunctival staining, Schirmer test, and confocal microscopy were performed. In the confocal images number and density of nerves, density of nerve branches, grade of nerve tortuosity, and density of dendritic cells were analyzed.ResultsOSDI and lid roughness was higher in the SCLW group (p=0.S009 and p=0.04, respectively), limbal hyperaemia was raised in the ACLW group (p=0.S009), and tear osmolarity was increased in both CL wearers groups (p=0.000), in comparison with the NCLW group. Subjects were divided into low and high density of dendritic cells using a 75 cells/mm2 cut‐off. This distribution was significantly different (p=0.04) between the CL wearers (21 and 19 subjects had low and high cell density, respectively) and the NCLW group (16 and 4, respectively). The CL type was significantly different (p=0.011) between CL wearers with low (4 and 17 subjects wear conventional and silicone hydrogel CLs, respectively) and high (11 and 8, respectively) cell density.ConclusionsSymptoms of discomfort in CL wearers seem not to be related to changes in the nerve morphology or density of dendritic cells in the corneal sub‐basal nerve plexus.

Ocular response to environmental variations in contact lens wearers.

To assess the influence of different indoor environments simulated in an environmental chamber on soft contact lens (CL) wearers. 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, 930mb of atmospheric pressure] and adverse (in-flight air cabin environment: 5% RH, localised air flow, 23°C, 750mb atmospheric pressure), for 90min 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. 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. 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.

Interpreting the corneal response to oxygen: Is there a basis for re-evaluating data from gas-goggle studies?

When anoxia (0% oxygen) is created within a gas-tight goggle, ocular physiological responses, including corneal swelling, limbal hyperaemia and pH change, are known to vary, depending on the presence or absence of a low, oxygen transmissibility contact lens. A new theory is proposed to account for this discrepancy based on the concept of lid derived oxygen, whereby oxygen originating from the vascular plexus of the palpebral conjunctiva supplements that available to the ocular surface in an open, normally blinking eye, even when the surrounding gaseous atmosphere is anoxic. The effect of a lid derived contribution to corneal oxygenation was assessed by using existing experimental data to model open-eye, corneal swelling behavior as a function of atmospheric oxygen content, both with and without the presence of a contact lens. These models predict that under atmospheric anoxia, contact lens wear results in 13.2% corneal swelling compared with only 5.4% when the lens was absent. Lid derived oxygen acts to provide the ocular surface in the non-contact lens wearing, normally blinking, open-eye with up to 4.7% equivalent oxygen concentration, even within the anoxic environment of a nitrogen filled goggle. Correcting for lid derived oxygen eliminates previously observed discrepancies in corneal swelling behavior and harmonizes the models for the contact lens wearing and gas-goggle cases. On this basis it is proposed that true anoxia at the ocular surface cannot be achieved by atmospheric manipulation (i.e. a gas-goggle) alone but requires an additional presence, e.g. a low, oxygen transmissibility contact lens, to prevent access to oxygen from the eyelids. Data from previously conducted experiments in which the gas-goggle paradigm was used, may have been founded on underestimates of the real oxygen concentration acting on the ocular surface at the time and if so, will require re-interpretation. Future work in this area should consider if a correction for lid derived oxygen is necessary.

Effects of wearing a daily disposable lens on tear film: a randomised controlled trial

PurposeContact lens‐induced dry eye is commonly encountered, although its extent is not well documented with daily disposable lenses. A novel type of contact lens system incorporating moisturising agent (alginic acid) has been developed. The aim of this study was to evaluate the effect of wearing daily 2‐hydroxyethyl methacrylate disposable contact lenses for seven days on tear stability, conjunctival and limbal redness and dry eye symptoms. Then, we aimed to determine whether lens solutions containing alginic acid had any influence on tear parameters.MethodsThis was a seven‐day parallel group double‐masked clinical trial of previous contact lens wearers, where participants were randomly assigned to wearing SEED 1dayPure moisture contact lenses with (n = 15) or without alginic acid (n = 15). Tear lipid layer thickness (LLT), non‐invasive tear break‐up time (NIBUT), conjunctival redness, corneal fluorescein staining, tear break‐up time and Schirmer I readings were measured. Symptom severity and frequency were evaluated and combined using a global score from visual analogue scales.ResultsThe mean age and standard deviation of the participants was 25 ± 3.8 years. There were 24 females and six males. After reintroduction of contact lens wear for one week, there was significant improvement in the global symptom score; however, this may not be clinically significant. There were small and clinically insignificant changes in limbal and conjunctival hyperaemia but no significant changes in lipid layer thickness, Schirmer I and NIBUT in overall participants. The use of alginic acid in lens solutions did not affect these parameters compared to control lenses (p > 0.05).ConclusionsAfter seven days of wearing a modern daily disposable lens, there was no significant deterioration of tear function in a group of young contact lens wearers. In this short‐term study, there was no evidence of significant benefit of lens solutions containing alginic acid used with HEMA lenses.

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

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. 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. 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). The stored-MPDS osmolarity increase caused by air-drying the CLCs could affect the ocular surface. This increase might reduce lens wear comfort.

Anterior eye health recording.

To survey eye care practitioners from around the world regarding their current practice for anterior eye health recording to inform guidelines on best practice. The on-line survey examined the reported use of: word descriptions, sketching, grading scales or photographs; paper or computerised record cards and whether these were guided by proforma headings; grading scale choice, signs graded, level of precision, regional grading; and how much time eye care practitioners spent on average on anterior eye health recording. Eight hundred and nine eye care practitioners from across the world completed the survey. Word description (p<0.001), sketches (p=0.002) and grading scales (p<0.001) were used more for recording the anterior eye health of contact lens patients than other patients, but photography was used similarly (p=0.132). Of the respondents, 84.5% used a grading scale, 13.5% using two, with the original Efron (51.6%) and CCLRU/Brien-Holden-Vision-Institute (48.5%) being the most popular. The median features graded was 11 (range 1-23), frequency from 91.6% (bulbar hyperaemia) to 19.6% (endothelial blebs), with most practitioners grading to the nearest unit (47.4%) and just 14.7% to one decimal place. The average time taken to report anterior eye health was reported to be 6.8±5.7 min, with the maximum time available 14.0±11 min. Developed practice and research evidence allows best practice guidelines for anterior eye health recording to be recommended. It is recommended to: record which grading scale is used; always grade to one decimal place, record what you see live rather than based on how you intend to manage a condition; grade bulbar and limbal hyperaemia, limbal neovascularisation, conjunctival papillary redness and roughness (in white light to assess colouration with fluorescein instilled to aid visualisation of papillae/follicles), blepharitis, meibomian gland dysfunction and sketch staining (both corneal and conjunctival) at every visit. Record other anterior eye features only if they are remarkable, but indicate that the key tissue which have been examined.

Kornea Kroslink Sonrası Kullanılan İki Farklı Tip Bandaj Kontakt Lensin Karşılaştırılması

Objective: To compare the efficiacy of two types of silicone hydrogel bandage contact lenses (BCLs) after corneal collagen crosslinking (CXL) in keratoconus patients. Material and Methods: In this prospective study, 36 keratoconus patients received CXL in both eye. Each patient received a BCL composed of balafilcon A (Pure Vision; Bauch&Lomb) (14.0 diameter, 8.6 base curve) in 1 eye and lotrafilcon B (Air Optix Aqua; Ciba Vision) (14.2 diameter, 8.6 base curve) in the fellow eye. Patients were masked to the lens type in each eye. Postoperative medication regimen was the same with both eye. Epithelial defect size, contact lens debris, conjunctival and limbal hyperemia, reepithelization and responses to a subjective-comfort questionnaire were assessed postoperatively at 1, 3, and 5 days. A paired Student's t test and chi-square tests were used when appropriate. Results: Seventy-two eyes of 36 keratoconus patients who underwent CXL were analyzed. There was no statistically significant difference in epithelial defect size, conjunctival or limbal hyperemia between the 2 lenses at any postoperative visit. Three days postoperatively, re-epithelization was complete in 77.8% of eyes (28 eyes) in the balafilcon A group and 83.3% of the eyes (30 eyes) in the lotrafilcon B group. Lens deposition and patient discomfort was significantly higher with the balafilcon A group 5 days postoperatively (p<0.01 for both comparisons). Conclusion: There were no differences in corneal re-epithelization between the 2 types of BCLs (p>0.01). However, lens deposition and patient discomfort was higher with balafilcon A (p<0.01).