Schirmer Tear Test Strips Research Articles

Comparison of the Effects of 0.1% Fluorometholone and 1% Prednisolone on Intraocular Pressure and Schirmer Tear Test in Equine Eye.

This research was performed to compare the effects of prednisolone and fluorometholone on intraocular pressure (IOP) and Schirmer tear test (STT) in the normal equine eye. Sixteen normal mares aged between 6 and 10 years were used for this study. Horses were randomly assigned to two groups. Eight horses in the first group received 0.2 mL of topical 1% prednisolone in one eye and the contralateral eye was used as control (0.2 mL of saline was instilled). The second group received 0.2 mL of 0.1% fluorometholone in a randomly selected eye and the contralateral eye served as control and received 0.2 mL of saline. STT values and IOP were determined using STT strips and rebound, respectively, at the baseline, and 30-, 60-, 90-, and 180-minutes post eyedrop instillation. Mean (SD) IOPs at the baseline in the treated eyes of the first and second groups were 28.5 (5.4) and 27.5 (4.9) mm Hg, respectively. STT values at the baseline in the treated eyes of the first and second groups were 26.0 (1.8) mm/min and 24.0 (4.0) mm/min, respectively. Neither prednisolone nor fluorometholone caused significant changes in the IOP during 3 hours of monitoring (P > .05). There were no significant differences in the mean levels of STT in the control and treatment eyes, either between groups or within each group (P > .05). In conclusion, one dose (0.2 mL) of 1% prednisolone or 0.1% fluorometholone after 3 hours did not alter the IOP and STT in healthy horses. Further research for a longer period on normal horses and horses with uveitis is warranted.

The glycoproteomics of hawk and caiman tears

BackgroundGlycoproteins are important tear components that participate in the stability of the ocular surface. However, the glycopeptides that are present in the tears of wild animals have not yet been described. This work aimed to describe the glycoproteomic profile of roadside hawk (Rupornis magnirostris) and caiman (Caiman latirostris) tears.MethodsTears collected from 10 hawks and 70 caimans using Schirmer tear test strips were used in this study. The samples were submitted to trypsin digestion and separated using a reverse-phase column coupled to a mass spectrometer associated to a nanospray ionization source. The glycoproteins were categorized as: cellular components, biological processes and molecular function, according to the UniProt Knowledgebase.ResultsAs shown by the liquid chromatography–mass spectrometry, all glycopeptides found were classified as N-type. Of the 51 glycoproteins that were identified in the hawk tear film, the most abundant were ovotransferrin, globulins and complement system proteins. In the caiman tear film, 29 glycoproteins were identified. The most abundant caiman glycoproteins were uncharacterized proteins, ATPases, globulins and proteasome components. Ontological characterization revealed that the glycoproteins were extracellular, and the most identified molecular function was endopeptidase activity for both species.ConclusionGlycoproteins are abundant in the tear film of the bird and reptile species studied herein, and all these molecules were shown to have N-type modifications. Location at the extracellular space and an endopeptidase inhibitor activity were the main cell component and molecular function for both species, respectively. These profiles showed differences when compared to human tears, are possibly linked to adaptive processes and can be the basis for further studies on the search of disease biomarkers.

Tear Film Proteome of Healthy Domestic Cats.

The aim of this study was to investigate the proteins found in tear film of healthy domestic cats. Schirmer tear test strips were used to collect tear samples of twelve healthy cats, which were mixed, centrifuged, and placed in a single 1.5 mL microtube that was frozen at −20°C, until analysis by two-dimensional polyacrylamide gel and mass spectrometry associated with high-performance liquid chromatography. The resulting spectra were analyzed and compared with the Swiss-Prot search tool. Forty peptides were detected in the analyzed protein fragments of 90 spots, with 16 proteins identified. Of these, the authors confirmed what has been already found in other studies: lactotransferrin, serum albumin, allergenic lipocalins, and neutrophil gelatinase-associated lipocalin. Others were considered novel in tear film samples of all species: cyclin-dependent protein kinase, serine/arginine repetitive matrix protein, apelin receptor, secretory protein related to C1q/TNF, Wee1, α-1,4 glucan phosphorylase, and WD repeat domain 1. The network was divided into 11 clusters, and a biological function was assigned. Most of the proteins have functions in the defense and maintenance of feline ocular surface homeostasis. Serum albumin is a bottleneck protein, with a high betweenness value. This paper is a pioneer in reporting, in-depth, the tear film proteome of domestic cats.

The porcine corneal surface bacterial microbiome: A distinctive niche within the ocular surface

PurposeThe ocular surface microbiome has been described as paucibacterial. Until now, studies investigating the bacterial community associated with the ocular surface through high-throughput sequencing have focused on the conjunctiva. Conjunctival samples are thought to reflect and be representative of the microbiome residing on the ocular surface, including the cornea. Here, we hypothesized that the bacterial community associated with the corneal surface was different from those of the inferonasal and superotemporal conjunctival fornices, and from the tear film.MethodsBoth eyes from 15 healthy piglets were sampled using swabs (inferonasal fornix, superotemporal fornix, and corneal surface, n = 30 each) and Schirmer tear test strips (STT, n = 30). Negative sampling controls (swabs and STT, n = 2 each) and extraction controls (n = 4) were included. Total DNA was extracted and high-throughput sequencing targeting the 16S rRNA gene was performed. Bioinformatic analyses included multiple contamination-controlling steps.ResultsCorneal surface samples had a significantly lower number of taxa detected (P<0.01) and were compositionally different from all other sample types (Bray-Curtis dissimilarity, P<0.04). It also harbored higher levels of Proteobacteria (P<0.05), specifically Brevundimonas spp. (4.1-fold) and Paracoccus spp. (3.4-fold) than other sample types. Negative control STT strip samples yielded the highest amount of 16S rRNA gene copies across all sample types (P<0.05).ConclusionsOur data suggests that the corneal surface provides a distinct environmental niche within the ocular surface, leading to a bacterial community compositionally different from all other sample types.

تعیین مقدار قابل ارجاع برای اندازهگیری میزان اشک چشم با استفاده از نوار آزمایش اشکی (STT) در اسبچه خزر

BACKGROUND: The Schirmer tear test (STT) is widely used in both human and veterinary ophthalmology. Two types of STTs have been developed: STT I and STT II. OBJECTIVES: The purpose of this research was to determine the reference value for measuring tear production of the Caspian horse by using the Schirmer tear test strip. METHODS: Twenty apparently healthy male and female Caspian horses, aged between 2 and 15 years old and weighing between 192±32 Kg were selected. After physical examination and reviewing the horse's health history and assuring their health, the Schirmer tear test was performed. To produce a higher volume of tears in horses, compared to other animal species, we used the Schirmer tear strip (Schirmer‐ Eickemeyer®, Germany), for 30 seconds instead of one minute in the lower conjunctival sac. In this study, we investigated the effect of age and gender on tear production in the Caspian horse, as well as the comparison between the left and right eyes tear production. RESULTS: The study shows that the results of STT I in the study animals illustrated the mean±SD STT I value was 23.38±3.6 mm/min (range, 15–30 mm/30s). Based on the results of this study, the variants of age and gender had no significant effects on the STT1 results in the Caspian horses. No significant difference was noted between the amount of tear production in the left and right eyes. CONCLUSIONS: Considering the importance of rapid diagnosis of dry eye syndrome and preventing its subsequent disorders such as Keratoconjunctivitis Sicca, the results of this study can be used as the reference value in the future to measure the amount of moisture of caspian horses of the Caspian horse.

Schirmer strip wetting length varies by commercial manufacturer.

To determine whether wetting length of Schirmer tear test (STT) strips varies by commercial manufacturer of test. Ten normal female beagle cross-breed dogs. Schirmer tear test strips from four commercial manufacturers were used to assess wetting lengths in-vitro when exposed to a set volume of water over 1minute. Digital photography was used to assess the total surface area of Schirmer strips from each manufacturer. Schirmer tear test type 1 was performed on normal dogs over 1minute with STT strips from the same four commercial manufacturers in a randomized crossover design. ANOVA was used to detect differences between strips from different manufacturers. Significant differences in wetting length were found between STT strips from different manufacturers in-vitro (P<.0001) and in-vivo (P<.0001). STT wetting lengths for the in-vitro experiments (mean±SD) were 21.2±0.8mm (Amcon Laboratories), 27.8±2.7mm (Merck Animal Health), 30.0±1.7mm (HUB pharmaceuticals), and 31.5±2.3mm (Gulden Ophthalmics). STT wetting lengths for the experiments in live dogs (mean±SD) were 17.5±3.4mm (Amcon Laboratories), 24.8±3.9mm (Merck Animal Health), 26.5±3.7mm (HUB pharmaceuticals), and 24.0±3.9mm (Gulden Ophthalmics). The surface area of STT strips were found to vary between different manufacturers. Schirmer tear test type 1 results in dogs are affected by choice of STT strip commercial manufacturer. It is proposed that guidelines are created for the standardization of future STT strip production.

An Objective Measure of Vaginal Lubrication in Women With and Without Sexual Arousal Concerns

Changes in vaginal blood flow and lubrication are primary components of physiological sexual arousal in women. Despite the existence of well-established tools for measuring vaginal blood flow, there is not yet a consistently implemented measure of physiological lubrication. To address this methodological gap, researchers have begun examining the utility of litmus test strips, primarily in sexually healthy women. The present study builds on this work by examining the utility of an alternative tool, the Schirmer Tear Test strips, in women with (n = 32) and without (n = 32) sexual arousal concerns. Significant increases in physiological lubrication were found in response to a sexual film, and these changes were moderately correlated with self-reported genital arousal (r = .41) and lubrication (r = .30). No between-group differences in lubrication were observed. These results indicate the Schirmer Tear Test strips are sensitive enough to detect increases in lubrication and may be valuable in clinical and research assessments of female sexual arousal.

The use of tear ferning test in cats for evaluation of ocular surface

BackgroundThe tear film is a trilaminar fluid composed mainly of lipids, electrolytes, proteins and water. It is responsible for lubrication, nutrition and protection against microbial and toxic agents. Disruption of any these components may weaken the ocular surface, making it more susceptible to disease. Increasing evidence suggests that qualitative tear film deficiencies are an important predisposing factor or cause of some of the most common and challenging ocular diseases in cats, including conjunctivitis, corneal ulcer, spontaneous chronic corneal epithelial defects (SCCED), pigmentary keratitis, corneal sequestrum and dry eye syndrome. The aim of this study was to describe the tear ferning test in healthy cats and to compare the results by using two grading scales for humans. Tear samples were collected using Schirmer tear test (STT) strips from 60 healthy cats, and, after centrifuging the strips to obtain the samples, the aliquot was placed on clean microscope glass until it dried and the tear ferning patterns were observed under a polarized light microscope and classified according to the Rolando and Masmali grading scales.ResultsFerning patterns in the lower grades showed full crystallization with high density, without gaps between the ferns and branches, forming several nuclei that were easily distinguished. According to the Rolando scale, 50% (60/120), 46.6% (56/120) and 3.4% (4/120) of eyes showed type I, II and III patterns, respectively. According to the Masmali scale, 15% (18/120), 56.6% (68/120 eyes) and 28.4% (34/120) of eyes showed grade 0, 1 and 2 patterns, respectively. No difference was observed between the right and left eyes for both Rolando (P = 0.225) and Masmali (P = 0.683) scales.ConclusionsThe tear ferning test is a qualitative test that can be used in cats as a complementary evaluation of the ocular surface. While the Rolando scale showed an increased prevalence of types I and II, the Masmali scale showed an increased prevalence of grades 1 and 2. This can be attributed to the species-specific differences between human and feline tear film. So Masmali grade 2 can be considered a normal tear pattern for the species, because all the cats used in study were clinically healthy. For this reason, future complementary studies are necessary for comparing healthy eyes and eyes with different ocular surface disease in cats. Both scales can be feasible options for grading tear crystallization in cats, but as Rolando scale included 96.6% of the samples in the 2 types that are considered normal for humans, we think that this scale seemed to be more precise to classify crystallization pattern in cats. The crystallization patterns observed in this study can form the basis for standardizing ocular surface parameters in cats.

Human Lacrimal Production Rate and Wetted Length of Modified Schirmer's Tear Test Strips.

PurposeTo assess and compare the wetting kinetics of sheathed and unsheathed Schirmer's tear test (STT) strips, and to determine the repeatability of 5-minute wetted length (WL) and basal tear production rate (BTPR).MethodsSeventeen subjects underwent two sheathed and unsheathed STTs each for both eyes on four visits on separate days. After administration of topical anesthetic, WLs were measured every 30 seconds for 5 minutes, and BTPRs were calculated for sheathed strips. Limits of agreement (LoA), difference-versus-mean plots (DVM), and the coefficient of repeatability (CR) assessed WL and BTPR repeatabilities. Variance estimates were used to calculate sample sizes for future study.ResultsFor the unsheathed STT, the mean (SD) difference in WLs between visits was 0.74 (5.05) mm, LoA were [−9.17, 10.64], and CR was 9.17 mm; for the sheathed STT, the mean (SD) intervisit difference was 0.16 (5.94) mm, LoA were [−11.49, 11.8], and CR was 10.53 mm. Eight of 48 sheathed STTs and 20 of 44 unsheathed STTs showed constant WL for the final 90 seconds of the test. The mean (SD) difference between repeated visits for BTPR was approximately 0.0 μL/min, LoA were [−1.82, 1.82], and CR was 1.91 μL/min.ConclusionsRepeatability of sheathed and unsheathed 5-minute WL and BTPR is inadequate for measuring within-subject changes, but is sufficient for group studies with moderate sample sizes. Constant WL for the final 90 seconds with the eight sheathed STT measurements suggests varying BTPR, whereas constant WL with the unsheathed STT can be explained by balancing evaporation and BTPR.Translational RelevanceRepeatability of the modified STT is evaluated clinically to establish quantitative BTPRs rather than inference from a strip WL.

Use of endodontic paper points and Schirmer strips for measurement of tear flow in red-lored parrots (&lt;em&gt;Amazona autumnalis&lt;/em&gt;)

Ocular diseases are sub-diagnosed in bird species, partly because of limited diagnostic methods and lack of reference data. Placement of Schirmer tear test strips in the bottom of the conjunctival sac of birds for tear flow measurement can prove to be difficult, whereas paper tips commonly used for dental procedures may be easier to use, due to a more adequate size and shape. Hence, the aim of this study was to assess and compare tear flow values, using ABC Dental® # 30 color paper tips and TearFloTM Test strips in Red-lored Parrots (Amazona autumnalis) (n = 26). Captive birds of undetermined sex were housed in groups under similar environmental conditions and fed the same diet. All animals were deemed healthy through remote and physical examinations. Average tear flow values of 0.6365 ± 0.032 cm/min and 0.5942 ± 0.032 cm/min were obtained with the Schirmer strips test and the endodontic tips respectively. Lack of difference in observed values between measurement techniques (p = 0.3629) indicates that endodontic tips may be a good alternative for tear flow assessment in Red-lored parrots. In addition, endodontic tips are more cost effective and may be less invasive. This study stresses the need to establish species specific ophthalmic reference values for clinical practice in birds, since differences have been reported even in specimens within the same genus.Figure 1. Measurement of tear flow in Red-lored parrots using TearFloTM Test Strips

Proteomic analysis of tear fluid reveals disease-specific patterns in patients with Parkinson's disease – A pilot study

BackgroundThe diagnosis of Parkinson's disease (PD) is still challenging and biomarkers could contribute to an improved diagnostic accuracy. Tear fluid (TF) is an easily accessible body fluid reflecting pathophysiological changes in systemic and ocular diseases and is already used as a biomarker source for several ophthalmological disorders. Here, we analyzed the TF of patients with PD and controls (CTR) to describe disease-related changes in TF and identify putative biomarkers for the diagnosis of PD. MethodsUnstimulated TF samples of a pilot cohort with 36 PD patients and 18 CTR were collected via Schirmer tear test strips and then analyzed via a Bottom-up liquid chromatography electrospray ionization tandem mass spectrometry (BULCMS) workflow, followed by functional analysis encompassing protein-protein interaction as well as cellular component and pathway analysis. ResultsBULCMS analysis lead to the identification of 571 tear proteins (false discovery rate, FDR < 1%), whereby 31 proteins were exclusively detected in the PD group and 7 only in the CTR group. Whereas 21 proteins were significantly increased in the PD versus CTR groups, 19 proteins were significantly decreased. Core networks of proteins involved in immune response, lipid metabolism and oxidative stress were distinctly altered in PD patients. ConclusionsTo our best knowledge, this is the first description of TF proteome in PD patients. Tear protein level alterations suggest the contribution of different disease-related mechanisms in ocular pathology in PD and propose candidate proteins to be validated as potential biomarkers in larger cohorts.

Effects of intravenous romifidine, detomidine, detomidine combined with butorphanol, and xylazine on tear production in horses

SummarySedation facilitates the ocular examination in horses. Alpha2‐adrenoceptor agonists are commonly used in equine practice. If the eye is painful, the combination of an α2‐adrenoceptor agonist and butorphanol provides a greater analgesic effect. Unfortunately, little is known about the effects of α2‐adrenoceptor agonists on equine Schirmer tear test I (STT I) values. The aim of the study was to assess the effects of intravenous romifidine, detomidine, detomidine combined with butorphanol, and xylazine on the STT I values in horses. Forty healthy client‐owned Italian saddle horses were enrolled. Horses received 0.04 mg/kg bwt of romifidine or 15 μg/kg bwt of detomidine or 10 μg/kg bwt of detomidine combined with 10 μg/kg bwt of butorphanol or 0.7 mg/kg bwt of xylazine intravenously. The Schirmer tear test strip was inserted into the lateral third side of the inferior conjunctival fornix for 1 min in each eye. The STT I measurements were performed before sedation and at 5, 15, 30, 60, 120 and 180 min after the administration of sedation. The data were analysed by ANOVA. Romifidine did not affect the STT I values. Detomidine significantly reduced the STT I values at 15 min (18.17 ± 0.97 mm/min). The combination of detomidine and butorphanol significantly reduced the STT I values at 30 and 60 min (17.44 ± 0.99, 15.81 ± 0.99 mm/min). Xylazine significantly increased the STT I values at 5, 15 and 30 min (25.17 ± 0.99, 26.72 ± 0.99, 28.07 ± 0.99 mm/min). The STT I values at 180 min were similar to those before sedation. These results suggest that the administration of xylazine or detomidine alone or combined with butorphanol is associated with significant changes in aqueous tear production, whereas romifidine does not affect the STT I values. Romifidine is therefore suitable for chemical restraint to measure tear production in horses.

Determination of reference values for intraocular pressure and Schirmer tear test results in clinically normal domestic donkeys (Equus asinus)

This study was conducted to establish normal reference range for the Schirmer tear test (STT) and intraocular pressure (IOP) in clinically normal donkeys for use in clinical practice. Sixteen adult...

Comparison of the Schirmer tear test I values after placement in ventral and dorsal conjunctival fornices in healthy cats.

The objective of this study was to compare the Schirmer tear test I values obtained from placement of Schirmer tear test (STT) strips in ventral and dorsal conjunctival fornices and to investigate any correlation between age, body weight and STT values in clinically normal cats. Twenty-eight intact adult domestic shorthair and Persian cats were used in this study. The cats were gently physically restrained in a sternal position, and a Schirmer tear strip was placed on each eye in the ventral conjunctival fornix at one-third of the distance from the temporal to nasal canthus for 60 s. Then, the wetted portion of the strips was measured as mm/min (L-STT I). After 48 h, the same procedure was performed on each eye in the dorsal conjunctival fornix (U-STT I). Mean ± SD STT values of the ventral and dorsal conjunctival fornices were 20.80 ± 2.25 mm/min (range 14-25 mm/min; 95% confidence interval [CI] 19.92-21.67) and 18.28 ± 2.27 mm/min (range 15-22 mm/min; 95% CI 17.39-19.16) in all of the study population, respectively. A significant difference was found between STT values obtained from the ventral and dorsal conjunctival fornices ( P <0.001). There was no correlation between the age and body weight of the animals and STT I values. This study compared the STT I values of the dorsal and ventral conjunctival fornices in cats. The difference was significant between the L-STT I and U-STT I values; however, the L-STT I and U-STT I values were within normal reference intervals. The U-STT I data have diagnostic value that might be of benefit in cases where there is a problem in the ventral conjunctival fornix.

Tear sample collection in ocular allergy

SummaryPurposeTo evaluate four different methods of tear collection in healthy participants.MethodsFour methods used for tear collection were evaluated in both eyes of 20 healthy participants. Methods tested: capillary tubes (CT), capillary tubes with instillation of saline (CT saline), Schirmer's Tear Test Strips (STTS) and Polyvinyl Alcohol sponges (PVA). Volume, duration of collection, participant‐reported discomfort, concentration and mass of histamine were evaluated.ResultsWith CT saline the largest volume was collected in the shortest time. A significantly higher concentration of histamine was found in samples collected with STTS compared to CT saline (p = 0.04) and PVA (p = 0.02). CT and CT saline were associated with no or mild discomfort in 95% and 90%, STTS and PVA with moderate or severe discomfort in 70% and 85%.ConclusionFor collection of tear fluid for the measurement of histamine the CT saline method was found to be a technically easy and quick method of obtaining sufficient volumes of tear fluid, with low discomfort for participants.

Reference values and repeatability of the Schirmer tear tests I and II in domesticated, clinically normal dromedary camels (Camelus dromedarius).

To determine the normal values and repeatability for Schirmer tear test (STT) in clinically normal dromedary camels and to analyze the influence of the age and gender on these values. Thirty clinically normal dromedary camels of different ages (calves, immature, and mature). Schirmer tear tests I and II were performed using commercial STT strips. Three measurements were obtained from each eye over three consecutive weeks, and the variance of these measurements was determined. Mean values and coefficient of variation of STT I and STT II for the right and left eyes varied significantly among camel groups (P < 0.05). For STT I, the most frequently recorded values were >14-18, > 22-26, and >30-34 mm/min in calves, immature camels, and mature camels, respectively. For STT II, however, the most frequently recorded values were 7-14, >10-18, and >26-30 mm/min, respectively. The interassay coefficients of variation were 1.7-14.4% and were significantly lower in mature camels than in calves and immature camels (P < 0.05). Age was positively correlated with STT I (r = 0.81) and STT II values (r = 0.88). No significant variations were found between genders. This preliminary study reports STT I and II values and repeatability in normal dromedary camels. This information may assist veterinary practitioners in complete ophthalmic examinations and in accurate diagnosis of ocular surface diseases affecting the tear film in this species.

Measurement of tear production and intraocular pressure in ducks and geese.

The purpose of this study was to establish a reference value of tear production and intraocular pressure in clinically normal ducks and geese. The study population consisted of forty-eight ducks (24 males and 24 females) and fifty-two geese (26 males and 26 females). Birds were gently physically restrained in dorsoventral position without any pressure to the head and neck. Tear secretion and intraocular pressure were measured using 5-mm-wide Schirmer tear test strips and TonoVet® rebound tonometer, respectively. Overall mean ± 2SD STT and IOP values of all eyes were 6.2 ± 2.2 mm/min and 10.2 ± 2.2 mmHg, respectively, for the ducks; 5.5 ± 2.6 mm/min and 9.1 ± 2.0 mmHg, respectively, for the geese. There was no statistically significant difference in IOP between left eye and right eye or between males and females in ducks (P = 0.56, P = 0.63) and geese (P = 0.23, P = 0.22). Analysis of variance revealed that there were no significant differences in the STT and IOP between the breeds in ducks (P = 0.49, P = 0.68) and geese (P = 0.14, P = 0.26). Results of this study may be beneficial for the diagnosis and therapeutic monitoring of ducks and geese affected with Keratoconjunctivitis sicca, glaucoma, and uveitis.

Preliminary evaluation of tear production in dogs hospitalized in an intensive care unit

To determine the tear production in dogs admitted to an intensive care unit (ICU). Prospective observational study from November 2010-September 2011. Private emergency and referral hospital. Thirty healthy control dogs and 30 dogs hospitalized in an ICU for treatment of systemic illness without previously diagnosed ophthalmic disorders and no recent history of anesthesia. Enrollment was based on availability of the ophthalmologist within 24 hours of admission to the ICU. Tear production was measured utilizing Schirmer tear test strips (STT) in healthy control animals as well as in hospitalized canine patients. All patients received an ophthalmic examination by a board-certified veterinary ophthalmologist within 24 hours of admission to the ICU. Lubrication with artificial tear gel every 2-4 hours as needed was implemented after STT was measured. Average tear productions in the control and canine ICU populations were 24.5 mm/min and 13.2 mm/min, respectively. This was found to be statistically significant (P < 0.001). Furthermore, there was a trend toward a decrease in tear production in patients with kidney disease and a trend toward normal tear production in patients with cardiac disease but the sample size was likely too small to enable detection of a statistically significant difference. This study demonstrates a decrease in tear production in canine ICU patients. While further study is warranted to determine how different diseases impact tear production, these finding support the implementation of frequent ocular lubrication in all ICU patients.

Comparison of two methods of tear sampling for protein quantification by Bradford method

The aim of this study was to compare two methods of tear sampling for protein quantification. Tear samples were collected from 29 healthy dogs (58 eyes) using Schirmer tear test (STT) strip and microcapillary tubes. The samples were frozen at -80ºC and analyzed by the Bradford method. Results were analyzed by Student's t test. The average protein concentration and standard deviation from tears collected with microcapillary tube were 4.45mg/mL ±0.35 and 4,52mg/mL ±0.29 for right and left eyes respectively. The average protein concentration and standard deviation from tears collected with Schirmer Tear Test (STT) strip were and 54.5mg/mL ±0.63 and 54.15mg/mL ±0.65 to right and left eyes respectively. Statistically significant differences (p&lt;0.001) were found between the methods. In the conditions in which this study was conducted, the average protein concentration obtained with the Bradford test from tear samples obtained by Schirmer Tear Test (STT) strip showed values higher than those obtained with microcapillary tube. It is important that concentration of tear protein pattern values should be analyzed according the method used to collect tear samples.

Correlation between corneal sensitivity and quantity of reflex tearing in cows, horses, goats, sheep, dogs, cats, rabbits, and guinea pigs

Guinea pigs have a very low threshold of corneal sensitivity and at the same time nearly no reflex tearing compared to dogs, cats, and horses. The question arose whether there is a general correlation between corneal sensitivity and the quantity of reflex tearing. Totally 160 animals of 8 different species (20 animals per species) were investigated. The corneal touch threshold (CTT) was measured with a Cochet-Bonnet esthesiometer. The palpebral fissure length (PFL) was measured with a calliper ruler. The Schirmer tear test (STT) was modified by adapting the width of the STT strip to the PFL of every species. For the STT II, 0.4% oxybuprocaine was applied. Corneal touch threshold: Cows (1.67 g/mm(2)), horses (1.23 g/mm(2)), sheep (1.13 g/mm(2)), goats (1.44 g/mm(2)), dogs (2.16 g/mm(2)), and cats (1.33 g/mm(2)) show similar CTT values. In contrast, rabbits (6.21 g/mm(2)) and guinea pigs (7.75 g/mm(2)) show a significantly lower CTT. Tear Production Difference STT I - STT II: Rabbits have the greatest decline in tear production with 38.4%, followed by sheep (33.3%), dogs (31.1%), cats (24.7%), cows (23.7%), horses (18.0%), and goats (14.0%). Guinea pigs have no decline, but a slight increase of -16.0%. Correlation CTT and STT II - STT I Difference: Pearson's correlation coefficient shows a small, but significant correlation. The coefficient of determination can only forecast a value with 7.1% certainty. The high variance and low reproducibility of results suggest that the measuring devices are inappropriate to assess the evaluated parameters. Therefore, no assured correlation between the corneal sensitivity and the quantity of reflex tearing could be found.