Limbal and Bulbar Hyperaemia in Normal Eyes

Determining initial ocular comfort differences between 0.7% olopatadine and 0.035% ketotifen fumarate

PURPOSE

To compare the ocular comfort at application of topical, over-the-counter, 0.7% olopatadine and 0.035% ketotifen fumarate anti-allergy eye drops.

METHODS

This study recruited participants who were minimally symptomatic based upon Standard Patient Evaluation of Eye Dryness (SPEED) questionnaire scores (≤3 units) and who had minimal between-eye inter-ocular comfort differences as judged by visual analog scale scores (VAS; ≤7 units). Baseline comfort was evaluated by eye with a VAS. One drop of 0.7% olopatadine or 0.035% ketotifen fumarate was then applied to the right eye with the alternative drop being immediately applied to the left eye. Participants were next evaluated with the same comfort VAS by eye at drop application, and then at 30 s, 1 min, and 2 min post-application. LogMAR visual acuities and bulbar conjunctival redness were evaluated pre- and post-drop application to judge initial changes.

RESULTS

This study enrolled 159 participants who had a mean ± SD age of 26.3 ± 7.7 years, and 78.6% of the participants were female. The VAS found that the 0.7% olopatadine drop was more comfortable than the 0.035% ketotifen fumarate drop at all time-points. There were no between-eye differences in LogMAR visual acuities, yet bulbar redness was significantly less in 0.7% olopatadine treated eyes compared 0.035% ketotifen fumarate treated eyes.

CONCLUSION

This study found that topically applied 0.7% olopatadine drops were initially more comfortable than 0.035% ketotifen fumarate drops.

Review of 20 years of soft contact lens wearer ocular physiology data

BACKGROUND

Since the introduction of Silicone hydrogel (SiHy) contact lenses 20 years ago, industry has continued to modify lens materials, designs, lens care products and manufacturing processes, striving to improve contact lens physiological performance, comfort, and convenience for wearers. The purpose of this study was to investigate whether the ocular health of habitual soft contact lens wearers today is better than it was in previous decades.

METHODS

Baseline ocular physiology data for 3624 participants from a The Brien Holden Vision Institute clinical trials database were retrospectively reviewed. Records were grouped into 3 time periods; A: >2 decades ago (1997-1999), B: one decade ago (2009-2014) and C: recent years (since 2015). Physiology data for both neophytes and habitual contact lens wearers included; bulbar, limbal and upper palpebral conjunctival redness, corneal and conjunctival staining and conjunctival indentation from contact lenses.

RESULTS

Corneal staining levels are similar between neophytes and contact lens wearers at time points A and C but worse for contact lens wearers at time point B. Limbal redness was greater in contact lens wearers than in neophytes at time point A but at time points B and C they are not different to the non-contact lens wearing population. In recent years, most ocular physiological variables in habitual contact lens wearers are similar to neophytes.

CONCLUSIONS

While there have been changes over the past two decades in ocular physiological responses to contact lens wear, it appears that ocular health with current day contact lens wear is similar to no lens wear in most respects.

CLEAR - Effect of contact lens materials and designs on the anatomy and physiology of the eye

This paper outlines changes to the ocular surface caused by contact lenses and their degree of clinical significance. Substantial research and development to improve oxygen permeability of rigid and soft contact lenses has meant that in many countries the issues caused by hypoxia to the ocular surface have largely been negated. The ability of contact lenses to change the axial growth characteristics of the globe is being utilised to help reduce the myopia pandemic and several studies and meta-analyses have shown that wearing orthokeratology lenses or soft multifocal contact lenses can reduce axial length growth (and hence myopia). However, effects on blinking, ptosis, the function of Meibomian glands, fluorescein and lissamine green staining of the conjunctiva and cornea, production of lid-parallel conjunctival folds and lid wiper epitheliopathy have received less research attention. Contact lens wear produces a subclinical inflammatory response manifested by increases in the number of dendritiform cells in the conjunctiva, cornea and limbus. Papillary conjunctivitis is also a complication of all types of contact lenses. Changes to wear schedule (daily disposable from overnight wear) or lens materials (hydrogel from SiHy) can reduce papillary conjunctivitis, but the effect of such changes on dendritic cell migration needs further study. These changes may be associated with decreased comfort but confirmatory studies are needed. Contact lenses can affect the sensitivity of the ocular surface to mechanical stimulation, but whether these changes affect comfort requires further investigation. In conclusion, there have been changes to lens materials, design and wear schedules over the past 20+ years that have improved their safety and seen the development of lenses that can reduce the myopia development. However, several changes to the ocular surface still occur and warrant further research effort in order to optimise the lens wearing experience.

Thirty years of 'quiet eye' with etafilcon A contact lenses

Frequent replacement contact lenses made from the etafilcon A hydrogel lens material were introduced onto the market over 30 years ago, and etafilcon A remains the most widely used hydrogel lens material today. Although the prescribing of silicone hydrogel lenses is increasing, millions of lens wearers globally have been wearing hydrogel lenses for many years and exhibit a physiologically-stable 'quiet eye', with a low profile of adverse events. Hydrogel lenses are demonstrated to maintain a low inflammatory response and infection risk profile during daily wear, which in the case of etafilcon A, may be related to its low modulus, and the naturally-protective, anti-microbial, non-denatured lysozyme absorbed into the lens from the tear fluid. Although improved corneal physiology from decreased hypoxia with silicone hydrogel lenses is well accepted, equivalent levels of corneal oxygenation are maintained during daily wear of low to medium powered hydrogel lenses, which do not impede the daily corneal de-swelling process, and do not induce clinically significant changes in ocular health. Therefore, hydrogel lenses remain an important alternative for daily wear in modern contact lens practice.

The short-term physiological impact of switching reusable silicone hydrogel wearers into a hydrogel daily disposable multifocal

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.

Investigating the Short-term Effect of Eyelid Massage on Corneal Topography

PURPOSE

The aim of this study was to evaluate the short-term effect of eyelid massage, after the use of warm compresses, on corneal topography.

METHODS

Corneal topography was evaluated on 20 subjects (mean age, 47.0 [SD ±17.3] years) using the Oculus Keratograph (Oculus, Wetzlar, Germany). Corneal eccentricity (Epsilon) was compared between topography measurements before eyelid warming (using warm compresses) (T1), after eyelid warming (T2), directly after eyelid massage (T3), and 30 minutes after eyelid massage (T4). Differences in corneal eccentricity between the enrolment measurement (T1) and consecutive measurements (T1-4) were analyzed. The contralateral eye-treated by warm compresses, but not by eyelid massage-was the control. Visual acuity (decimal), bulbar conjunctival hyperemia, and corneal staining (Cornea and Contact Lens Research Unit grading scale) were evaluated at T1 and T4 to assess clinical safety.

RESULTS

No significant differences were found between consecutive eccentricity measurements overall and with the central radii (repeated-measures analysis of variance, P > .238 (massaged eyelid: Epsilon T1: 0.48 [95% confidence interval, ±0.07], T2: 0.49 [±0.05], T3: 0.49 [±0.06], T4: 0.48 [±0.06]; horizontal radii T1: 7.76 [±0.13] mm, T2: 7.74 [±0.13] mm, T3: 7.75 [±0.13] mm, T4: 7.76 [±0.13] mm; vertical radii T1: 7.56 [±0.12] mm, T2: 7.55 [±0.10] mm, T3: 7.54 [±0.10] mm, T4: 7.58 [±0.11] mm). Decimal visual acuity significantly improved at the end of the study (massaged eyelid: T1: 1.1 [±0.1]; T4: 1.3 [±0.1]; P < .032). No significant differences were detected between the consecutive evaluation of corneal staining (Wilcoxon test; P > .285). Redness was not significantly different between time points (repeated-measures analysis of variance; P = .187) in the colateral eyes. Hyperemia was significantly reduced in the massaged eyes (T1: 2.0 grade units [±0.3]; T4: 1.9 [±0.3]; P = .021).

CONCLUSIONS

Eyelid warming followed by eyelid massage appears to be a safe procedure, without any clinically relevant short-term effects on the cornea.

Corneal Swelling with Cosmetic etafilcon A Lenses versus No Lens Wear

Purpose

To determine if the use of pigments or adding polyvinyl pyrrolidone during the fabrication of 1-DAY ACUVUE DEFINE (AD) brand contact lenses impacts open-eye corneal swelling compared with no lens wear (NLW).

Methods

A partial double-masked, randomized, bilateral crossover study was conducted in 24 Asian subjects using AD, 1-DAY ACUVUE DEFINE with Lacreon (ADL), NLW, and a control lens with no tint (1-DAY ACUVUE MOIST [AM]). Central corneal thickness was measured before insertion and immediately after removal after 8 ± 1 h of open-eye wear using an optical pachymeter in one eye. Corneal thickness along a 10-mm cord was measured in the contralateral eye using the Visante optical coherence tomographer (OCT). Corneal swelling was tested for noninferiority using a 5% margin. The endothelial bleb response was measured at baseline and 20 min after lens insertion using specular microscopy. Subjective grading of corneal staining and limbal/bulbar hyperemia were also monitored.

Results

After 8 ± 1 h of open-eye wear, central corneal swelling across the study lenses with either optical pachymeter or OCT methods was negligible. Peripheral corneal swelling least-square mean differences with OCT were −0.03% (95% confidence interval [95% CI], −0.65 to 0.58%) and −0.26% (95% CI, −0.87 to 0.36%) between AD and ADL and the control lens (AM), respectively, and 1.67% (95% CI, 1.06 to 2.29%) and 1.45% (95% CI, 0.84 to 2.06%) between AD and ADL and NLW, respectively. No endothelial blebs were observed. No clinically significant differences were distinguished between the lenses and NLW for corneal staining and limbal/bulbar hyperemia.

Conclusions

After 8 ± 1 h of open-eye wear, central and peripheral corneal swelling along the horizontal meridian with AD, ADL, AM, and NLW were equivalent. These results confirm that the addition of polyvinyl pyrrolidone or pigments to etafilcon A to obtain a limbal ring design have no impact on corneal swelling or limbal/bulbar hyperemia during normal open-eye wear.

Assessing ocular bulbar redness: a comparison of methods

PURPOSE

We consider whether quantification of ocular bulbar redness, using image processing of relative Red-channel activity (Red-value), can be applied to a clinical sample and how this approach compares to an automated bulbar redness grading technique (Oculus Keratograph 5M, R-scan).

METHODS

Red-values from dry eye patients (n = 25) were determined using image processing of digital photographs over the nasal bulbar conjunctiva. Red-values were compared with subjective grades from six clinicians who graded the images using the IER scale. We considered the level of agreement between the Red-value and automated bulbar redness scores from the commercial instrument (R-scan). Scoring variability for each technique was assessed using the geometric coefficient of variation (gCoV, %). Agreement between techniques was considered with Bland-Altman analyses.

RESULTS

Red-values showed a strong linear relationship (R(2) = 0.99) to the R-scan. The Red-value had least variability (gCoV = 0.97%, 95% CI: 0.76-1.35%). The IER grade showed a linear relationship with Red-value (R(2) = 0.99), bound by a floor effect; it did not discriminate changes in redness below a threshold of 1.75 units (Red-value = 33.0%), after which it paralleled the redness returned by the R-scan. Intra-method variability for the redness returned by the R-scan (gCoV = 9.84%, 95% CI: 7.60-13.94%) and IER grades (gCoV = 7.30%, 95% CI: 1.73-10.31%) was similar (p > 0.05). Bland-Altman analysis showed the R-scan was consistently biased towards lower absolute redness scores than the IER.

CONCLUSIONS

Digital imaging processing, using relative Red-channel activity, was the least variable of the three techniques. The R-scan and IER showed similar intra-observer variability. The linear relationship between R-scan and Red-value suggests that the R-scan could be derived using similar methods.

Assessment of Bulbar Redness with a Newly Developed Keratograph

PURPOSE

To determine the validity and reliability of the clinical assessment of bulbar redness (BR) using a newly developed corneal topographer.

METHODS

This is a cross-sectional diagnostic evaluation study. The BR scores [Oculus Index (OI)] from 30 eyes of 26 patients with different degrees of conjunctival hyperemia were assessed and scored automatically using a new method: a keratograph equipped with scanning and scoring software. The values obtained via this system were correlated with three image-based comparative subjective scales: the Institute for Eye Research (IER), the Efron, and the Validated Bulbar Redness (VBR) grading scales. The IER and Efron scores were interpolated to 0.1 unit, and the VBR scores were interpolated to 1 unit. We also evaluated the repeatability of each method and the level of agreement between the OI score and the scores achieved using the three other image-based methods.

RESULTS

There was a significant correlation between the OI score and the scores obtained with the IER (r = 0.921, p < 0.001), Efron (r = 0.958, p < 0.001), and VBR (r = 0.965, p < 0.001) scales. The intraobserver intraclass correlation coefficients were 0.947, 0.874, 0.810, and 0.920 for the OI, IER, Efron, and VBR, respectively, and the intraobserver coefficients of repeatability were 13.924, 16.111, 17.684, and 16.900, respectively. Furthermore, the interobserver intraclass correlation coefficients were 0.889, 0.880, 0.884, and 0.881 for the OI, IER, Efron, and VBR, respectively, and the interobserver coefficients of repeatability were 15.934, 16.366, 22.059, and 21.373, respectively.

CONCLUSIONS

The OI is an objective and reliable method for scoring BR. Its reproducibility was the highest of all the four modalities. The keratograph is recommended, therefore, as a suitable alternative for BR assessment.

Automated grading system for evaluation of ocular redness associated with dry eye

Background

We have observed that dry eye redness is characterized by a prominence of fine horizontal conjunctival vessels in the exposed ocular surface of the interpalpebral fissure, and have incorporated this feature into the grading of redness in clinical studies of dry eye.

Aim

To develop an automated method of grading dry eye-associated ocular redness in order to expand on the clinical grading system currently used.

Methods

Ninety nine images from 26 dry eye subjects were evaluated by five graders using a 0–4 (in 0.5 increments) dry eye redness (Ora Calibra™ Dry Eye Redness Scale [OCDER]) scale. For the automated method, the Opencv computer vision library was used to develop software for calculating redness and horizontal conjunctival vessels (noted as “horizontality”). From original photograph, the region of interest (ROI) was selected manually using the open source ImageJ software. Total average redness intensity (Com-Red) was calculated as a single channel 8-bit image as R – 0.83G – 0.17B, where R, G and B were the respective intensities of the red, green and blue channels. The location of vessels was detected by normalizing the blue channel and selecting pixels with an intensity of less than 97% of the mean. The horizontal component (Com-Hor) was calculated by the first order Sobel derivative in the vertical direction and the score was calculated as the average blue channel image intensity of this vertical derivative. Pearson correlation coefficients, accuracy and concordance correlation coefficients (CCC) were calculated after regression and standardized regression of the dataset.

Results

The agreement (both Pearson’s and CCC) among investigators using the OCDER scale was 0.67, while the agreement of investigator to computer was 0.76. A multiple regression using both redness and horizontality improved the agreement CCC from 0.66 and 0.69 to 0.76, demonstrating the contribution of vessel geometry to the overall grade. Computer analysis of a given image has 100% repeatability and zero variability from session to session.

Conclusion

This objective means of grading ocular redness in a unified fashion has potential significance as a new clinical endpoint. In comparisons between computer and investigator, computer grading proved to be more reliable than another investigator using the OCDER scale. The best fitting model based on the present sample, and usable for future studies, was C4=−12.24+2.12C2HOR+0.88C2RED:C4 is the predicted investigator grade, and C2HOR and C2RED are logarithmic transformations of the computer calculated parameters COM-Hor and COM-Red. Considering the superior repeatability, computer automated grading might be preferable to investigator grading in multicentered dry eye studies in which the subtle differences in redness incurred by treatment have been historically difficult to define.

The relationship between clinical signs and dry eye symptoms

PURPOSE

To evaluate (i) the relationship between traditional and new clinical tests (lid-wiper epitheliopathy (LWE), lid-parallel conjunctival folds (LIPCOF)) and dry eye symptoms in non-contact lens wearers, and (ii) that a combination of these tests can improve predictive ability for the development of dry eye symptoms.

METHODS

Tear meniscus height (TMH), non-invasive break-up time (NIBUT), ocular hyperaemia, LIPCOF, phenol red thread test (PRTT), corneal and conjunctival staining, and LWE grades were observed in a cohort of 47 healthy, non-lens wearers (male=17, female=30, median age=35 years, range=19-70). Symptoms were assessed using the Ocular Surface Disease Index (OSDI).

RESULTS

LWE was significantly correlated to both temporal and nasal LIPCOF (0.537 -0.248, P < 0.001). Significant correlations were found between NIBUT and TMH (r=0.461, P=0.001) and PRTT (r = 0.640, P < 0.001). OSDI scores were significant correlated to NIBUT, TMH, PRTT, LIPCOF, and LWE (r>∣0.31∣; P<0.05). Significant discriminators of OSDI+/- were NIBUT (area under the receiver operative characteristic curve (AUC)=0.895), TMH (0.715), PRTT (0.781), LIPCOF (temporal/nasal/Sum 0.748/0.828/0.816), and LWE (0.749). Best predictive ability was achieved by combining NIBUT with nasal LIPCOF (AUC=0.944).

CONCLUSIONS

The individual tests NIBUT, TMH, PRTT, LIPCOF, and LWE were significantly, but moderately, related to OSDI scores. The strongest relationship appeared by combining NIBUT with nasal LIPCOF.