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Crabtree JR, Tannir S, Tran K, Boente CS, Ali A, Borschel GH. Corneal Nerve Assessment by Aesthesiometry: History, Advancements, and Future Directions. Vision (Basel) 2024; 8:34. [PMID: 38804355 PMCID: PMC11130793 DOI: 10.3390/vision8020034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2024] [Revised: 04/28/2024] [Accepted: 05/08/2024] [Indexed: 05/29/2024] Open
Abstract
The measurement of corneal sensation allows clinicians to assess the status of corneal innervation and serves as a crucial indicator of corneal disease and eye health. Many devices are available to assess corneal sensation, including the Cochet-Bonnet aesthesiometer, the Belmonte Aesthesiometer, the Swiss Liquid Jet Aesthesiometer, and the newly introduced Corneal Esthesiometer Brill. Increasing the clinical use of in vivo confocal microscopy and optical coherence tomography will allow for greater insight into the diagnosis, classification, and monitoring of ocular surface diseases such as neurotrophic keratopathy; however, formal esthesiometric measurement remains necessary to assess the functional status of corneal nerves. These aesthesiometers vary widely in their mode of corneal stimulus generation and their relative accessibility, precision, and ease of clinical use. The development of future devices to optimize these characteristics, as well as further comparative studies between device types should enable more accurate and precise diagnosis and treatment of corneal innervation deficits. The purpose of this narrative review is to describe the advancements in the use of aesthesiometers since their introduction to clinical practice, compare currently available devices for assessing corneal innervation and their relative limitations, and discuss how the assessment of corneal innervation is crucial to understanding and treating pathologies of the ocular surface.
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Affiliation(s)
- Jordan R. Crabtree
- Department of Surgery, Indiana University School of Medicine, Indianapolis, IN 46202, USA; (J.R.C.)
| | - Shadia Tannir
- Department of Surgery, Indiana University School of Medicine, Indianapolis, IN 46202, USA; (J.R.C.)
| | - Khoa Tran
- Department of Surgery, Indiana University School of Medicine, Indianapolis, IN 46202, USA; (J.R.C.)
| | - Charline S. Boente
- Department of Ophthalmology, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Asim Ali
- Department of Ophthalmology and Vision Sciences, Hospital for Sick Children, Toronto, ON M5G 1X8, Canada
- Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, ON M5S 1A1, Canada
| | - Gregory H. Borschel
- Department of Surgery, Indiana University School of Medicine, Indianapolis, IN 46202, USA; (J.R.C.)
- Department of Ophthalmology, Indiana University School of Medicine, Indianapolis, IN 46202, USA
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Nosch DS, Käser E, Bracher T, Joos RE. Clinical application of the Swiss Liquid Jet Aesthesiometer for corneal sensitivity measurement. Clin Exp Optom 2024; 107:14-22. [PMID: 37019837 DOI: 10.1080/08164622.2023.2191782] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Accepted: 03/10/2023] [Indexed: 04/07/2023] Open
Abstract
CLINICAL RELEVANCE Corneal sensitivity represents an important indicator for corneal health, its innervation and hence also for ocular disease. It is therefore of great interest from a clinical and research perspective to quantify ocular surface sensation. BACKGROUND The aim of this prospective cross-sectional cohort study was to clinically test the within-day and day-to-day repeatability of the new Swiss Liquid Jet Aesthesiometer, employing small droplets of isotonic saline solution for repeatability, and correlate with the Cochet-Bonnet aesthesiometer in a cohort of participants of two different age groups, based on participant feedback (psychophysical method). METHODS Participants were recruited from two equally, large age groups: group A (18-30 years) and group B (50-70 years). The inclusion criteria were healthy eyes, Ocular Surface Disease Index (OSDI) ≤ 13, and no contact lens wear. Mechanical corneal sensitivity threshold measurements with means of liquid jet and Cochet-Bonnet methods were carried out twice during two visits (a total of four measurements), with a stimulus temperature equal to or slightly above the ocular surface temperature. RESULTS Ninety participants completed the study (n = 45 per age group, average age in group A: 24.2 ± 2.94 years, group B: 58.5 ± 5.71 years). The coefficient of repeatability for the liquid jet method was 2.56 dB within visits and 3.61 between visits. For the Cochet-Bonnet method, it was 2.27 dB within visits and 4.42 dB between visits (Bland Altman with bootstrap analysis). Moderate correlation was observed between the liquid jet and the Cochet-Bonnet method (r = 0.540, p < .001, robust linear regression). CONCLUSIONS Swiss liquid jet aesthesiometry offers a new examiner independent method for corneal sensitivity measurement with acceptable repeatability and moderate correlation with the Cochet-Bonnet aesthesiometer. It offers a large stimulus pressure range of 100-1500 mbar and a precision of 1 mbar. Stimulus intensity can be tuned more precisely and much smaller sensitivity fluctuations may be potentially detected.
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Affiliation(s)
- Daniela S Nosch
- Institute of Optometry, University of Applied Sciences and Arts Northwestern Switzerland (FHNW), Olten, Switzerland
| | | | - Tobias Bracher
- Institute of Optometry, University of Applied Sciences and Arts Northwestern Switzerland (FHNW), Olten, Switzerland
| | - Roland E Joos
- Institute of Optometry, University of Applied Sciences and Arts Northwestern Switzerland (FHNW), Olten, Switzerland
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Merayo-Lloves J, Gómez Martín C, Lozano-Sanroma J, Renedo Laguna C. Assessment and safety of the new esthesiometer BRILL: Comparison with the Cochet-Bonnet Esthesiometer. Eur J Ophthalmol 2023:11206721231210754. [PMID: 37899623 DOI: 10.1177/11206721231210754] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2023]
Abstract
BACKGROUND Corneal sensitivity can decrease by several ocular conditions, such as dry eye or refractive surgery, which favor ocular epithelial lesions and is measured using an esthesiometer. The study's primary objective was to demonstrate the efficacy and safety of the non-contact esthesiometer BRILL, which delivers air pulses to the corneal surface to assess corneal sensitivity. METHODS A single-center, prospective, controlled pilot study was carried out in adult patients with healthy eyes and or with pathology. Corneal sensitivity measurements were made in triplicate for both eyes at three consecutive visits. The esthesiometer BRILL was used in all visits, and on the last visit, the contact esthesiometer Cochet-Bonnet was also used. The results of both devices were compared by transforming them into force values. RESULTS 54 subjects with a mean age of 50.43 (SD 16.55, interval 18-87), 77.78% women, were included. Comparing the forces applied by both esthesiometers in the healthy eyes, in the eyes with pathology in all the groups, and in the dry eyes showed significant differences, p = 0.03603, p = 0.00614, and p = 0.0001, respectively. CONCLUSION The BRILL esthesiometer proved to be an effective and safe tool for non-contact assessment of corneal sensitivity with operator-independent repeatability. The measurements had a good agreement and comparable range with the Cochet-Bonet aesthesiometer measurements in healthy and dry eyes but with no interchangeable values. This portable device can help ophthalmologists and optometrists to diagnose eye pathologies that cause decreased corneal sensitivity and to assess the efficacy of therapy and disease progression.
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Affiliation(s)
- Jesús Merayo-Lloves
- Instituto Universitario Fernández Vega, Oviedo, Spain
- Universidad de Oviedo, Oviedo, Spain
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Nosch DS, Käser E, Bracher T, Joos RE. Age-Related Changes in Corneal Sensitivity. Cornea 2023; 42:1257-1262. [PMID: 36730377 DOI: 10.1097/ico.0000000000003183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Accepted: 09/12/2022] [Indexed: 02/04/2023]
Abstract
PURPOSE The aim of this prospective cross-sectional cohort study was to clinically test whether corneal sensation decreases with age, based on subject feedback (psychophysical method), and whether it correlates with general pain perception. METHODS Subjects were recruited from 2 equally large age groups: group A (18-30 years) and group B (50-70 years; n = 45 per group). The inclusion criteria were healthy eyes, Ocular Surface Disease Index ≤13, and no contact lens wear. Corneal sensitivity threshold (CST) measurements were performed twice during each of the 2 visits, with the aid of the new Swiss liquid jet esthesiometer for corneal sensitivity (SLACS) and Cochet-Bonnet (CB) esthesiometer. A general pain sensitivity score was obtained from all participants. RESULTS Ninety subjects completed the study (n = 45 per age group, average age in group A: 24.2 ± 2.94 years, group B: 58.5 ± 5.71 years). Statistically higher CSTs for age group B were only observed for SLACS (mean difference: 1.58 dB, P < 0.001). No correlation was observed between the pain score and the CSTs obtained with either esthesiometry method (r = 0.11, P = 0.25 for liquid jet and r=-0.076, P = 0.61 CB). CONCLUSIONS A statistically significant decrease in corneal sensitivity was observed for the older age group with SLACS in this study, with CB however only a trend in the same direction was noted. General pain perception was not found to correlate with ocular surface sensation.
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Affiliation(s)
- Daniela S Nosch
- Institute of Optometry, School of Engineering, University of Applied Sciences and Arts Northwestern Switzerland (FHNW), Olten, Switzerland
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Nosch DS, Käser E, Christen A, Schinzel J, Joos RE. Corneal sensitivity in silicone hydrogel and rigid gas permeable contact lens wear. Cont Lens Anterior Eye 2023; 46:101888. [PMID: 37422380 DOI: 10.1016/j.clae.2023.101888] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Revised: 05/08/2023] [Accepted: 06/28/2023] [Indexed: 07/10/2023]
Abstract
PURPOSE The aim of this prospective cross-sectional cohort study was to test the effect of silicone hydrogel (SH) and rigid gas permeable (RGP) contact lens (CL) wear on corneal sensitivity, applying the new Swiss Liquid Jet Aesthesiometer for Corneal Sensitivity (SLACS) and the Cochet-Bonnet (CB) aesthesiometer, based on subject feedback (psychophysical method). METHODS Participants were recruited for three equally large groups: Group A (SH CL), Group B (RGP CL) and Group C (non-CL wearers). Inclusion criteria were healthy eyes and OSDI ≤ 13. Corneal sensory thresholds were determined twice during two visits, with aid of SLACS and CB. RESULTS 96 participants completed the study (n = 33 in groups A and C, n = 30 in group B); average age in group A: 27.42 ± 6.83 years, group B: 36.90 ± 9.68 years and group C: 26.06 ± 6.19 years. No statistically significant difference in corneal sensitivity was observed between the three groups for either method (p = 0.302 for SLACS, p = 0.266 for CB; Kruskal-Wallis rank sum test). Higher CSTs were obtained for males than for females in both CL groups with SLACS, and with CB only in the RGP CL group (p = 0.041 in Group A, p = 0.006 in Group B with SLACS; p = 0.041 in Group B with CB; bootstrap analysis with age correction and gender balancing). No correlation was observed between CL comfort and corneal sensitivity for neither method applied (for SLACS r = 0.097 and p = 0.51, for CB r = 0.17 and p = 0.15; robust linear mixed model). CONCLUSIONS No difference in corneal sensitivity with CL compared to non-CL wear was noted in this study. However, lower levels of corneal sensitivity were observed in the male CL groups, warranting further investigation.
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Affiliation(s)
- Daniela S Nosch
- Institute of Optometry, University of Applied Sciences and Arts Northwestern Switzerland (FHNW), Olten, Switzerland; ELZA Institute AG, Dietikon, Switzerland.
| | - Emanuele Käser
- Institute of Optometry, University of Applied Sciences and Arts Northwestern Switzerland (FHNW), Olten, Switzerland
| | - Alice Christen
- Institute of Optometry, University of Applied Sciences and Arts Northwestern Switzerland (FHNW), Olten, Switzerland; Eye Hospital, Cantonal Hospital Lucerne, Luzern, Switzerland
| | - Julia Schinzel
- Institute of Optometry, University of Applied Sciences and Arts Northwestern Switzerland (FHNW), Olten, Switzerland; ELZA Institute AG, Dietikon, Switzerland
| | - Roland E Joos
- Institute of Optometry, University of Applied Sciences and Arts Northwestern Switzerland (FHNW), Olten, Switzerland
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Nosch DS, Oscity M, Steigmeier P, Käser E, Loepfe M, Joos RE. Working principle and relevant physical properties of the Swiss Liquid Jet Aesthesiometer for Corneal Sensitivity (SLACS) evaluation. Ophthalmic Physiol Opt 2022; 42:609-618. [PMID: 35156726 PMCID: PMC9305237 DOI: 10.1111/opo.12962] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Revised: 01/18/2022] [Accepted: 01/18/2022] [Indexed: 11/29/2022]
Abstract
Purpose To describe and evaluate relevant physical properties of the Swiss Liquid Jet Aesthesiometer for Corneal Sensitivity (SLACS) for ocular surface sensitivity measurement. Methods Characteristics of Liquid Jet (LJ) droplets (consisting of isotonic saline solution) were analysed: vertical and horizontal displacement and speed of LJ droplets were recorded with the aid of the High Speed Photron FASTCAM NOVA S6 camera (stimulus duration: 40 ms). Stimulus mass was assessed for 20 sets of 10 LJs with aid of a microbalance (pressure range of 100–1500 mbar). Results Because continuous flow LJ disintegrated into droplets in the lower pressure range (<700 mbar), pulsed stimuli were applied in order to obtain similar stimulus characteristics across the applied pressure range. For all measurements, very little variability was observed. Vertical and horizontal displacement did not exceed 0.13 mm in either direction. The mass per shot showed an unexpected cubic dependency on pressure. Up to approximately 700 mbar, LJ speed showed an almost linear relationship. For the pressure range of >700–1500 mbar, variability increased and speed decreased compared to the expected in a linear manner. However, this may be caused by the difficulty of identifying pattern changes of LJ droplets from one high speed image frame to the next with increasing stimulus speed, when determining LJ speed via pixel count. Conclusions Swiss Liquid Jet Aesthesiometer for Corneal Sensitivity was shown to deliver fine droplets with a pulsed stimulus mode, in a repeatable manner with precise localisation to the ocular surface. Very little variability was observed in LJ speed and mass for the typical pressure range required for clinical sensitivity measurements.
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Affiliation(s)
- Daniela S Nosch
- Institute of Optometry University of Applied Sciences and Arts Northwestern Switzerland (FHNW) Olten Switzerland
| | - Matthias Oscity
- Institute of Sensors and Electronics University of Applied Sciences and Arts Northwestern Switzerland (FHNW) Windisch Switzerland
| | - Peter Steigmeier
- Institute of Sensors and Electronics University of Applied Sciences and Arts Northwestern Switzerland (FHNW) Windisch Switzerland
| | - Emanuele Käser
- Institute of Optometry University of Applied Sciences and Arts Northwestern Switzerland (FHNW) Olten Switzerland
| | - Markus Loepfe
- Institute of Sensors and Electronics University of Applied Sciences and Arts Northwestern Switzerland (FHNW) Windisch Switzerland
| | - Roland E Joos
- Institute of Optometry University of Applied Sciences and Arts Northwestern Switzerland (FHNW) Olten Switzerland
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Jayakumar V, Simpson TL. Detectability and Bias Indices of Pneumatic Corneal Stimuli Using Signal Detection Theory. Transl Vis Sci Technol 2020; 9:17. [PMID: 33240570 PMCID: PMC7671863 DOI: 10.1167/tvst.9.12.17] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Accepted: 10/09/2020] [Indexed: 12/04/2022] Open
Abstract
Purpose To evaluate the feasibility of using signal detection theory (SDT) in estimating criterion and detectability indices for corneal pneumatic stimuli and test corneal psychophysical data against linking hypotheses from nonprimate physiology using Bayesian analysis. Methods Corneal pneumatic stimuli were delivered using the Waterloo Belmonte esthesiometer. Corneal thresholds were estimated in 30 asymptomatic participants and 1.5× threshold stimuli were used as signals (with 0.4 probability). There were 100-trial mechanical and cold stimulus experiments and 50-trial chemical experiments. Trials were demarcated auditorily and “yes” or “no” recorded after each trial. Cold stimulus experiments were conducted with 0.6 signal probability. Criterion (c), likelihood ratio (lnβ), and d′ were calculated from the yes-no responses. Results Average d′ was 0.59 ± 0.1, 1.65 ± 0.37, and 1.14 ± 0.3 units for cold, mechanical, and chemical stimuli, respectively. Bayes factors obtained using Bayesian analysis of variance mildly favored (BF10 = 1.55) differences between d′s of the stimulus types, with no support for differences in criteria between stimulus types. Multiple comparisons of d′ supported linking hypotheses based on nociception and nerve conductance theories. Conclusions Our experiments are the first to demonstrate the feasibility of estimating SDT indices and test different hypotheses. The conservative strategy (reporting “no” more often) chosen by participants was anticipated due to relatively large proportion of catch trials. Translational Relevance SDT when using pneumatic esthesiometry is vital to evaluate bias in responses of participants. Considering the varied forms of inherent noise in the corneal sensory system, SDT is critical to understand the sensory and decisional characteristics.
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Affiliation(s)
- Varadharajan Jayakumar
- School of Optometry and Vision Science, University of Waterloo, Waterloo, Ontario, Canada
| | - Trefford L Simpson
- School of Optometry and Vision Science, University of Waterloo, Waterloo, Ontario, Canada
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Ehrmann K, Saha M, Falk D. A novel method to stimulate mechanoreceptors and quantify their threshold values. Biomed Phys Eng Express 2018. [DOI: 10.1088/2057-1976/aa9b8d] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Nosch DS, Pult H, Albon J, Purslow C, Murphy PJ. Does air gas aesthesiometry generate a true mechanical stimulus for corneal sensitivity measurement? Clin Exp Optom 2017; 101:193-199. [PMID: 28922696 DOI: 10.1111/cxo.12603] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2016] [Revised: 06/04/2017] [Accepted: 06/10/2017] [Indexed: 11/30/2022] Open
Abstract
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) +5°C, +10°C, +15°C, +20°C and +30°C, 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 +10°C and +15°C) 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 +10°C and +15°C induced the least changes in OST (-0.20 ± 0.13°C and 0.08 ± 0.05°C). (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 +10°C. 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.
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Affiliation(s)
- Daniela S Nosch
- Institute of Optometry, University of Applied Sciences, Olten, Switzerland
| | - Heiko Pult
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, UK.,Optometry and Vision Research, Weinheim, Germany
| | - Julie Albon
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, UK.,Cardiff Institute of Tissue Engineering and Repair, Cardiff, UK
| | - Christine Purslow
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, UK.,Faculty of Health and Human Sciences, Plymouth University, Plymouth, UK
| | - Paul J Murphy
- School of Optometry and Vision Science, University of Waterloo, Waterloo, Ontario, Canada
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Navascues-Cornago M, Maldonado-Codina C, Morgan PB. Mechanical Sensitivity of the Human Conjunctiva. Cornea 2014; 33:855-9. [DOI: 10.1097/ico.0000000000000158] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Armstrong RA. When to use the Bonferroni correction. Ophthalmic Physiol Opt 2014; 34:502-8. [DOI: 10.1111/opo.12131] [Citation(s) in RCA: 1269] [Impact Index Per Article: 126.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2014] [Accepted: 03/13/2014] [Indexed: 12/19/2022]
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Wu Z, Begley CG, Situ P, Simpson T. The effects of increasing ocular surface stimulation on blinking and sensation. Invest Ophthalmol Vis Sci 2014; 55:1555-63. [PMID: 24557346 DOI: 10.1167/iovs.13-13780] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
PURPOSE The purpose of this study was to determine how increasing ocular surface stimulation affected blinking and sensation, while controlling task concentration. METHODS Ten healthy subjects concentrated on a task while a custom pneumatic device generated air flow toward the central cornea. Six flow rates (FRs) were randomly presented three times each and subjects used visual analog scales to record their sensory responses. The interblink interval (IBI) and the FR were recorded simultaneously and the IBI, sensory response, and corresponding FR were determined for each trial. The FR associated with a statistically significant decrease in IBI, the blink increase threshold (BIT), was calculated for each subject. RESULTS Both the mean and SD of IBI were decreased with increasing stimulation, from 5.69 ± 3.96 seconds at baseline to 1.02 ± 0.37 seconds at maximum stimulation. The average BIT was 129 ± 20 mL/min flow rate with an IBI of 2.33 ± 1.10 seconds (permutation test, P < 0.001). After log transformation, there was a significant linear function between increasing FR and decreasing IBI within each subject (Pearson's r ≤ -0.859, P < 0.05). The IBI was highly correlated with wateriness, discomfort, and cooling ratings (Pearson's r ≤ -0.606, P < 0.001). CONCLUSIONS There was a dose-response-like relationship between increased surface stimulation and blinking in healthy subjects, presumably for protection of the ocular surface. The blink response was highly correlated with ocular surface sensation, which is not surprising given their common origins. The BIT, a novel metric, may provide an additional end point for studies on dry eye or other conditions.
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Affiliation(s)
- Ziwei Wu
- School of Optometry, Indiana University, Bloomington, Indiana
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Stapleton F, Marfurt C, Golebiowski B, Rosenblatt M, Bereiter D, Begley C, Dartt D, Gallar J, Belmonte C, Hamrah P, Willcox M. The TFOS International Workshop on Contact Lens Discomfort: report of the subcommittee on neurobiology. Invest Ophthalmol Vis Sci 2013; 54:TFOS71-97. [PMID: 24058137 PMCID: PMC5963174 DOI: 10.1167/iovs.13-13226] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2013] [Accepted: 09/10/2013] [Indexed: 12/26/2022] Open
Abstract
This report characterizes the neurobiology of the ocular surface and highlights relevant mechanisms that may underpin contact lens-related discomfort. While there is limited evidence for the mechanisms involved in contact lens-related discomfort, neurobiological mechanisms in dry eye disease, the inflammatory pathway, the effect of hyperosmolarity on ocular surface nociceptors, and subsequent sensory processing of ocular pain and discomfort have been at least partly elucidated and are presented herein to provide insight in this new arena. The stimulus to the ocular surface from a contact lens is likely to be complex and multifactorial, including components of osmolarity, solution effects, desiccation, thermal effects, inflammation, friction, and mechanical stimulation. Sensory input will arise from stimulation of the lid margin, palpebral and bulbar conjunctiva, and the cornea.
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Affiliation(s)
- Fiona Stapleton
- School of Optometry and Vision Science, University of New South Wales, Sydney, Australia
| | - Carl Marfurt
- Indiana University School of Medicine–Northwest, Gary, Indiana
| | - Blanka Golebiowski
- School of Optometry and Vision Science, University of New South Wales, Sydney, Australia
| | - Mark Rosenblatt
- Weill Cornell Medical College, Cornell University, Ithaca, New York
| | - David Bereiter
- University of Minnesota School of Dentistry, Minneapolis, Minnesota
| | - Carolyn Begley
- Indiana University School of Optometry, Bloomington, Indiana
| | - Darlene Dartt
- Schepens Eye Research Institute, Massachusetts Eye and Ear, Harvard Medical School, Boston, Massachusetts
| | - Juana Gallar
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernandez–Consejo Superior de Investigaciones Cientificas, Alicante, Spain
| | - Carlos Belmonte
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernandez–Consejo Superior de Investigaciones Cientificas, Alicante, Spain
| | - Pedram Hamrah
- Massachusetts Eye and Ear Infirmary, Stoneham, Massachusetts
| | - Mark Willcox
- School of Optometry and Vision Science, University of New South Wales, Sydney, Australia
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