Impact of conjunctival folds on central tear meniscus height

PURPOSE. To analyze the effect of temporal and nasal lid–parallel conjunctival folds (LIPCOF) on the central tear meniscus height (TMH). METHODS. Tear meniscus height of 40 eyes of 20 subjects (15 female, median age: 39 years) was evaluated by the Tearscope Plus. Temporal and nasal LIPCOF scores were observed by slit lamp (SL) examination. The cross-sectional LIPCOF area (LA) was measured by a modified Scheimpflug camera. Tear meniscus was colored by fluorescein and TM fluorescence (TMF) was evaluated by SL using a 5-grade pictorial scale. Tear meniscus fluorescence was defined by its intensity, height, and regularity at the LIPCOF area in comparison to the central TMF. Correlations between variables were analyzed by Pearson correlation for parametric data or Spearman rank for nonparametric variables. RESULTS. Inferiorly, central TMH was significantly correlated to temporal LA (Pearson: r = 0.519, P = 0.001) and nasal LA (r = 0.567, P = 0.002). Superiorly, central TMH was significantly correlated with temporal LA (r = 0.352, P = 0.033), but not with nasal LA (r = 0.355, P = 0.075). Temporal LA was significantly correlated with temporal TMF (Spearman rank: r = 0.789, P < 0.001), and nasal LA was significantly correlated to nasal TMF (r =0.415, P = 0.008). Scores of LIPCOF were significantly correlated with TMF scores (Spearman rank: temporal, r = 0.837, P < 0001; nasal, r = 0.609, P < 0.001). Subjective LIPCOF grading was significantly correlated with LA (Spearman rank: temporal, r = 0.707, P < 0.001; nasal, r = 0.515, P = 0.001). CONCLUSIONS. Lid–parallel conjunctival folds impact TMH evaluation. In patients with LIPCOF, the real tear film volume may be smaller than the TMH measurement suggests

The predictive ability of clinical tests for dry eye in contact lens wear

Thirty to fifty percent of contact lens wearers discontinue contact lens wear. Therefore it is essential for the clinician to have a predictive method that can forecast the development of dryness symptoms in contact lens wear. Contact lens wear induces tear film instability leading to increased tear film evaporation and its associated hyperosmolarity. This in turn causes ocular surface inflammation resulting in the release of cytokines, impacting tear mucin production, which further destabilises the tear film. Since this mechanism can only be fully evaluated by an intensive laboratory-based approach, the clinician must rely on assessing those factors easily accessible within the practice situation: tear film stability and mucin loss/epithelial damage. These two factors are inter-related, and investigating one also provides information about the other. For this PhD, these two components of the mechanism have been investigated. This PhD has found that: (1) Bulbar and limbal redness are inter-related using the CCLRU grading scales, a limbal redness grade above 2.5 or a bulbar redness grade above 3.0 may be considered abnormal. (2) Symptomatic, experienced soft contact lens wearers exhibit significantly more lid wiper epitheliopathy (LWE) and lid parallel conjunctival folds (LIPCOF) but not corneal staining, bulbar hyperaemia or decreased Pre-lens break up time (PLBUT). LWE and LIPCOF are significantly correlated, suggesting that both are related to mechanical forces during blinking caused by a deficiency of the mucin layer. (3) LIPCOF and LWE are also positively correlated with symptoms amongst non-contact lens wearers. Using these two tests as a surrogate, the clinician has, for the first time, a useful indication of the mucin layer in contact lens patients. Returning then to the fundamental question&mdash;"Can the development of dryness symptoms in soft contact lens wearers be predicted?" This PhD has found that the clinician can use a combination of currently available tests to meet this question. The optimum combination of tests was found to be LIPCOF Sum plus NIBUT plus OSDI, termed the P-Test. The P-Test shows outstanding potential as a discriminator and predictor of contact lens induced dry eye

Influence of Conjunctival Folds on Calculated Tear Meniscus Volume Along the Lower Eyelid

The final publication is available at Elsevier via 10.1016/j.jtos.2016.04.001. © 2016. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/Purpose: In calculating tear meniscus volume (TMV), tear meniscus height (TMH), radius (TMR) and cross-sectional area (TMA) are usually measured at the center of the lower lid margin, but lid-parallel conjunctival folds (LIPCOFs) are known to influence the tear meniscus regularity. The aim of this study was to analyze the influence of LIPCOFs on TMA measured by optical coherence tomography (OCT) and consequently, the calculated tear meniscus volume (TMV). Methods: Using OCT (Cirrus-HD; Carl Zeiss Meditec, Jena, Germany), the TMH, TMR and TMA in 42 subjects (13M, 29F; mean age 27.3 SD±8.4 years) were measured directly below the pupil center, plus at temporal and nasal locations perpendicularly below the limbus, where LIPCOFs were also evaluated and graded. TMV for the different locations was calculated. Correlations between LIPCOFs and the tear meniscus parameters were analyzed using the Spearman Rank-Order coefficients. Differences between tear meniscus parameters at the different locations were evaluated by the paired t-test. Results: Central TMV (5.30±1.42 x10−2μl/mm) was significantly positively correlated to LIPCOF sum (grade 2.4±1.2) (r=0.422; P<.05). The calculated temporal TMV was greater by 0.53x10−2μl/mm compared to the central TMV (P=.037), while there was no significant difference in tear volume between the other locations.Conclusions: Using OCT it was possible to investigate the influence of LIPCOFs on TMH, TMR, and for the first time on TMA, at central and paracentral positions along the lower lid margin. The presence of LICPOF results in an irregularity of tear meniscus with a difference in the amount of predicted tear volume while measuring TMH or TMR at the different locations

Relationship between corneal sensation, blinking, and tear film quality

Purpose: To examine the possible role of corneal sensitivity and tear film quality in triggering a blink by investigating the relationship between blink rate, central corneal sensitivity threshold (CST), ocular surface temperature (OST), tear meniscus height (TMH), tear film quality (noninvasive tear break-up time [NIBUT]), and tear film lipid pattern under normal conditions. Methods: Forty-two volunteers (average age, 27.76 ± 5.36 years; 11 males) with good ocular health (Ocular Surface Disease Index, <15.0) were recruited for this cross-sectional cohort study. Blink rate, CST (noncontact corneal air gas aesthesiometry, NCCA), minimum and maximum OST in the central and inferior cornea between blinks (thermal infrared camera), TMH, NIBUT, and lipid pattern of the tear film (Keeler Tearscope Plus) were recorded on the right eye only. Results: Median blink rate was 11 blinks/min (interquartile range [IR], 6.95 to 17.05), CST was 0.35 mbars (IR, 0.30 to 0.40), minimum OST in the central cornea was 35.15°C (IR, 34.58 to 35.50), and NIBUT was 34.55 s (IR, 12.45 to 53.80). Moderate but statistically significant correlations were observed between CST and NIBUT (r = 0.535, p < 0.001), CST and blink rate (r = -0.398, p < 0.001), lipid pattern and OST (r = 0.556, p < 0.001), and between CST and OST (r = 0.371, p = 0.008). The correlations between blink rate and NIBUT (r = -0.696, p < 0.001) and between OST and NIBUT (r = 0.639, p < 0.001; Spearman test) achieved higher significance; this was highlighted by the linear regression model where NIBUT and minimum central and inferior OST were identified as significant predictor variables. Conclusions: There is strong evidence for significant interactions between corneal sensitivity, NIBUT, OST, and blink frequency, emphasizing that ocular surface conditions represent a possible important trigger for the initiation of a blink. However, the mechanisms involved in the initiation of a blink are complex, with local ocular sensory input as only one trigger, along with other external influences and internal factors under cortical control

Does air gas aesthesiometry generate a true mechanical stimulus for corneal sensitivity measurement?

Background: Belmonte Ocular Pain Meter (OPM) air jet aesthesiometry overcomes some of the limitations of the Cochet-Bonnet aesthesiometer. However, for true mechanical corneal sensitivity measurement, the airflow stimulus temperature of the aesthesiometer must equal ocular surface temperature (OST), to avoid additional response from temperature-sensitive nerves. The aim of this study was to determine: (A) the stimulus temperature inducing no or least change in OST; and (B) to evaluate if OST remains unchanged with different stimulus durations and airflow rates. Methods: A total of 14 subjects (mean age 25.14 2.18 years; seven women) participated in this clinical cohort study: (A) OST was recorded using an infrared camera (FLIR A310) during the presentation of airflow stimuli, at five temperatures, ambient temperature (AT) +5C, +10C, +15C, +20C and +30C, using the OPM aesthesiometer (duration three seconds; over a four millimetre distance; airflow rate 60 ml/min); and (B) OST measurements were repeated with two stimulus temperatures (AT +10C and +15C) while varying stimulus durations (three seconds and five seconds) and airflow rates (30, 60, 80 and 100 ml/min). Inclusion criteria were age <40 years, no contact lens wear, absence of ocular disease including dry eye, and no use of artificial tears. Repeated measures (analysis of variance) and appropriate post-hoc t-tests were applied. Results: (A) Stimulus temperatures of AT +10C and +15C induced the least changes in OST (−0.20 0.13C and 0.08 0.05C). (B) OST changes were statistically significant with both stimulus temperatures and increased with increasing airflow rates (p < 0.001), and were more marked with stimulus temperature AT +10C. Conclusion: A true mechanical threshold for corneal sensitivity cannot be established with the air stimulus of the Belmonte OPM because its air jet stimulus with mechanical setting is likely to have a thermal component. Appropriate stimulus selection for an air jet aesthesiometer must incorporate stimulus temperature control that can vary with stimulus duration and airflow rate

Lid-parallel conjunctival fold (LIPCOF) morphology imaged by optical coherence tomography and its relationship to LIPCOF grade.

The final publication is available at Elsevier via https://doi.org/10.1016/j.clae.2018.10.025. © 2019. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/Purpose: Lid-parallel conjunctival folds (LIPCOF) are a well-accepted clinical sign in dry eye diagnosis. Commonly, LIPCOF is classified by grading the number of folds observed by slit-lamp microscope. This study investigated the relationship between subjective grading scale and LIPCOF morphology imaged by optical coherence tomography (OCT). Methods: Temporal and nasal LIPCOF of 42 subjects (mean age 27.3±8.4 (SD) years; 13M, 29F) were observed and classified by an experienced optometrist using the Pult LIPCOF grading scale (0: no permanent, lid-parallel conjunctival fold; 1: one fold; 2: two folds, 3: three or more folds). Additionally, LIPCOF cross-sectional area (LIPCOF-A) and fold count (LIPCOF-C), as imaged by OCT (Cirrus HD; Carl Zeiss Meditec, Jena, Germany), were analysed with ImageJ 1.50 (http://rsbweb.nih.gov/ij). Correlations between subjective grading and LIPCOF-A and LIPCOF-C were analysed by Spearman correlation, differences between subjective grading and LIPCOF-C were analysed by Wilcoxon test. Results: For temporal and nasal sectors, mean subjective LIPCOF grade was 1.43±0.86 grade units and 0.57±0.80 grade units, mean LIPCOF-C was 1.67±0.82 folds and 0.69±0.78 folds, and mean LIPCOF-A was 0.0676±0.0236mm2 and 0.0389±0.0352mm2, respectively. Subjective temporal and nasal LIPCOF grade was significantly correlated to LIPCOF-C (r=0.610, p<0.001 and r=0.645, p<0.001, respectively), and to LIPCOF-A (r=0.612, p<0.001 and r=0.583, p<0.001, respectively). LIPCOF-C was not statistical different to subjective LIPCOF grade (p=0.07 and p=0.239; temporal and nasal sectors, respectively). Conclusions: OCT allows for better imaging of finer details of LIPCOF morphology, and especially of LIPCOF area. OCT evaluation of LIPCOF area correlated well with subjective grading and appears to be a promising objective method for LIPCOF classification

Effect of Eye Spray Phospholipid Concentration on the Tear Film and Ocular Comfort

OBJECTIVES: To evaluate the effect of eye spray phospholipid concentration on symptoms and tear film stability. METHODS: High-concentration (Tears Again, Optima Pharma GmbH, Hallbergmoos, Germany) and low-concentration (Ocuvers, Innomedis AG, Germany) phospholipid eye sprays were sprayed onto the closed eyelids of 30 subjects (33.2±1.8 years; 20 women) in a multicentered, prospective, crossover study. Ocular comfort (visual analog scale) and noninvasive tear film stability (NIBUT) of each eye were evaluated before application (along with the Ocular Surface Disease Index), 10 min after application, and 30 min after application. RESULTS: Comfort (high concentration: 68.5±16.4 vs. low concentration: 70.7±14.5 phospholipid) and NIBUT (high concentration: 11.5±4.6 sec vs. low concentration: 11.2±6.0 sec phospholipid) were not different (P>0.3) between sprays before application, but comfort (by 12 points, P=0.001) and NIBUT (by 5 sec, P=0.016) were significantly better with a high-concentration phospholipid spray at both 10 min and 30 min time points than those with the low-concentration phospholipid spray. CONCLUSIONS: The liposomal eye spray with higher concentration of phospholipids significantly improved ocular comfort and tear film stability in contrast to the eye spray with lower concentration of phospholipids, hence practitioners need to choose an appropriate eye spray to maximize the patient benefit

BCLA CLEAR Presbyopia: Management with contact lenses and spectacles

This paper seeks to outline the history, market situation, clinical management and product performance related to the correction of presbyopia with both contact lenses and spectacles. The history of the development of various optical forms of presbyopic correction are reviewed, and an overview is presented of the current market status of contact lenses and spectacles. Clinical considerations in the fitting and aftercare of presbyopic contact lens and spectacle lens wearers are presented, with general recommendations for best practice. Current options for contact lens correction of presbyopia include soft simultaneous, rigid translating and rigid simultaneous designs, in addition to monovision. Spectacle options include single vision lenses, bifocal lenses and a range of progressive addition lenses. The comparative performance of both contact lens and spectacle lens options is presented. With a significant proportion of the global population now being presbyopic, this overview is particularly timely and is designed to act as a guide for researchers, industry and eyecare practitioners alike

Global trends in myopia management attitudes and strategies in clinical practice – 2019 Update

Purpose: A survey in 2015 identified a high level of eye care practitioner concern about myopia with a reported moderately high level of activity, but the vast majority still prescribed single vision interventions to young myopes. This research aimed to update these findings 4 years later. Methods: A self-administrated, internet-based questionnaire was distributed in eight languages, through professional bodies to eye care practitioners globally. The questions examined: awareness of increasing myopia prevalence, perceived efficacy of available strategies and adoption levels of such strategies, and reasons for not adopting specific strategies. Results: Of the 1336 respondents, concern was highest (9.0 ± 1.6; p < 0.001) in Asia and lowest (7.6 ± 2.2; p < 0.001) in Australasia. Practitioners from Asia also considered their clinical practice of myopia control to be the most active (7.7 ± 2.3; p < 0.001), the North American practitioners being the least active (6.3 ± 2.9; p < 0.001). Orthokeratology was perceived to be the most effective method of myopia control, followed by pharmaceutical approaches and approved myopia control soft contact lenses (p < 0.001). Although significant intra-regional differences existed, overall, most practitioners did not consider single-vision distance under-correction to be an effective strategy for attenuating myopia progression (79.6 %), but prescribed single vision spectacles or contact lenses as the primary mode of correction for myopic patients (63.6 ± 21.8 %). The main justifications for their reluctance to prescribe alternatives to single vision refractive corrections were increased cost (20.6 %) and inadequate information (17.6 %). Conclusions: While practitioner concern about myopia and the reported level of activity have increased over the last 4 years, the vast majority of eye care clinicians still prescribe single vision interventions to young myopes. With recent global consensus evidence-based guidelines having been published, it is hoped that this will inform the practice of myopia management in future