Phenol Red Thread Research Articles

Investigation of Ocular Tear Ferning in Controlled and Uncontrolled Diabetic Subjects.

To investigate the ocular tear film in controlled and uncontrolled diabetes mellitus (DM) subjects and the relationship between dry eye and diabetes. One hundred twenty-four diabetes adults (65 male and 59 female, with 62 controlled and 62 uncontrolled DM) were assessed by McMonnies dry eye questionnaire, tear break-up time (TBUT), phenol red thread (PRT) test. In addition, tear samples were collected from the lower tear meniscus of right eyes and dried onto glass slides under controlled room temperature (25°C) and humidity (40%). The glass slides were observed using a digital microscopy and the tear ferning (TF) patterns observed were graded based on Masmali TF grading scale. Patients with a HbA1c value below 6.5% were defined as "controlled DM" and those with a HbA1c value above 6.5% were defined as "uncontrolled DM." The Spearman's correlation coefficient was used to determine the relationship between various tests. Several subjects having dry eye varied depending on the test used. McMonnies questionnaire scores suggested that 28 subjects (23%) showed dry eye (score >14.5), of whom 23 subjects (82%) showed uncontrolled diabetes. The TF patterns showed that 44 subjects (35.5%) showed dry eyes (Grade ≥2), of whom 32 subjects (72.7%) showed uncontrolled diabetes. Phenol red thread test found that 46 subjects (37%) showed dry eye (wetting <10 mm), of whom 38 subjects (82.6%) showed uncontrolled diabetes. Tear break-up time found that 57 subjects (46%) showed dry eye (time <10 sec), of whom 45 subjects (78.9%) showed uncontrolled diabetes. In controlled diabetic subjects, TF grades showed medium negative correlations with both TBUT and PRT (-0.374 and -0.349, respectively). In uncontrolled subjects, TF grades have a strong negative correlation with TBUT (-0.539) and a medium negative correlation with PRT (-0.410). Dry eye disease is common in diabetic subjects, particularly in people with poor diabetic control. Uncontrolled blood glucose level seemed to be a risk factor for dry eye syndrome. Tear ferning test showed a correlation between diabetes and dry eye in diabetic subjects and can be used as a reliable test to evaluate the quality of the ocular tear film.

Photophobia and sensations of dryness in patients with migraine occur independent of baseline tear volume and improve following botulinum toxin A injections

BackgroundTo evaluate the efficacy of botulinum toxin A (BoNT-A) in reducing photophobia and dry eye symptoms in individuals with chronic migraine. Additionally, we aimed to evaluate tear film volume as...

Immune Response Targeting Sjögren's Syndrome Antigen Ro52 Suppresses Tear Production in Female Mice.

Autoantibodies reactive against Ro52 are present in 70% of Sjögren’s syndrome patients and are associated with higher disease severity. However, their role in causing aqueous deficient dry eye, a major cause for morbidity in Sjögren’s syndrome, is unclear. To investigate whether immune responses targeting Ro52 contribute towards the dry eye, male and female NZM2758 mice were immunized with recombinant Ro52. Tear production was measured by the phenol red thread test. Sera were analyzed for anti-Ro52 levels by immunoprecipitation. Lacrimal glands were evaluated for inflammatory foci and IgG deposits. Our results showed that, although all mice generated anti-Ro52 antibodies, only females developed a significant drop in tear production. None of the mice developed severe lacrimal gland inflammation, and female mice with anti-Ro52 showed higher levels of IgG deposits within their glands. Passive transfer of anti-Ro52 sera caused reduced tear production in female mice, but not in males. This study demonstrates for the first time that immune responses initiated by Ro52 induce aqueous dry eye, and this may be driven by anti-Ro52 antibodies. Furthermore, the sexual dimorphism in glandular dysfunction suggests that the lacrimal glands in females are more susceptible to autoantibody-mediated injury.

Schirmer's I, modified Schirmer's I, phenol red thread, and paper point tests: a comparative study for tear production measurement techniques in broiler chicks (Gallus gallus domesticus)

Problems with indoor husbandry and immunological challenges are some of the stressors that broilers may face which can affect production. Infectious diseases can compound the effects of excessive concentrations of ammonia causing respiratory and ocular inflammation and increased lacrimal production in broiler chickens. The objectives of this investigation were to establish normal values of tear production in chicks and compare the practicality of the different methods. Palpebral fissure length (PFL) and tear production were evaluated in Cobb 500 chicks at 5 d old and then at 5 d of age by the following methods: modified Schirmer's test I (mSTT1), phenol red cotton thread tear test (PRCTTT), and standardized endodontic absorbent paper point test (EAPPTT). Ten chicks at the age of 5 and 42 d were evaluated for each method. In addition, at 42 d, when the palpebral fissure permitted, a regular-sized Schirmer tear test I (STT1) was performed in another group of 10 chickens. Overall, PFL and the secretion of the aqueous phase of the tear film increased with age. Mean mSTT1 results were 5.00 ± 1.83mm and 10.45 ± 2.58mm for 5- and 42-d-old chicks, respectively. Mean PRCTTT results were 12.37 ± 1.80mm and 25.58 ± 4.8mm for 5- and 42-d-old chicks, respectively. Mean EAPPTT results were 7.13 ± 0.72mm and 12.03 ± 0.92mm for 5- and 42-d-old chicks, respectively. Mean STT1 for 42-d-old chicks was 11.40 ± 2.60mm. Results obtained with endodontic paper points showed the lowest coefficient of variation and investigators found the test easier to perform. These values reported for broilers at different ages may be applied in poultry ophthalmology to help the diagnosis of lacrimal production disorders and to detect early disease symptoms that could cause economic losses in poultry production.

Psychometric Analysis of the SPEED Questionnaire and CLDEQ-8

PurposeThis study reports on the ability of the Standard Patient Evaluation of Eye Dryness (SPEED) questionnaire to detect dry eye (DE) symptoms in contact lens (CL) and non-CL wearers.MethodsThe SPEED questionnaire was administered to all subjects while the Contact Lens Dry Eye Questionnaire-8 (CLDEQ-8) was only administered to CL wearers. Tear meniscus heights (TMH) were measured, and the phenol red thread (PRT) test was conducted. These tests along with self-reported DE were used to identify subjects with dry eye disease (DED). Rasch analysis was performed to evaluate the questionnaires for measurement precision and unidimensionality, and the scores from these Rasch analyses were used to understand their ability to predict measures of DED.ResultsWe enrolled 284 subjects (150 CL and 134 non-CL wearers). Mean subject age was 39.4 ± 14.2 years. Rasch analysis yielded a multidimensional short form of the SPEED questionnaire (8-items) and a unidimensional short form of the CLDEQ-8 (4-item). Scores from both questionnaires were significantly associated with self-reported DE in CL and non-CL wearers. Scores of the 8-item SPEED questionnaire were associated with DED status in non-CL wearers but not in CL wearers while 4-item CLDEQ scores were associated with DED status in CL wearers. TMH or PRT were not associated with either questionnaire in CL or non-CL wearers.ConclusionsThe 8-item SPEED questionnaire demonstrated adequate measurement precision with evidence of quantifying multiple symptoms categories while the 4-item CLDEQ-8 primarily quantified DE symptoms. Questionnaire scores were associated with self-reported DE, which suggests that they may have utility in both populations analyzed.

MyD88 Deficiency Protects Against Dry Eye-Induced Damage.

PurposeDry eye disease (DED) is a multifactorial disease associated with ocular surface inflammation. Toll-like receptors (TLRs) are integral in the initiation of inflammatory signaling. Therefore, we evaluated the effect of TLR-deficiency on dry eye–related ocular surface damage and inflammation using a mouse model of experimental dry eye (EDE).MethodsC57BL/6 wild-type (WT), MyD88−/−, and IL-1R−/− mice were exposed to EDE conditions for 5 days. Tear production was measured by phenol red thread test and ocular surface damage assessed with fluorescein staining. Corneal homogenates were obtained for matrix metalloproteinase (MMP) and cytokine expression analysis by Luminex assay and quantitative PCR. In addition, whole eyes and eyelids were dissected and goblet cells and Meibomian glands were imaged, respectively.ResultsFollowing 5 days of EDE, WT mice had extensive ocular surface staining, while MyD88−/− mice had no increased staining above non-EDE conditions. Similarly, MyD88−/− mice did not have increased corneal MMP-2, 3, or 8 concentrations, as seen with WT mice. MyD88-deficiency also resulted in decreased corneal cytokine levels. In addition, MyD88−/− mice had significantly lower conjunctival goblet cell counts compared with both WT (EDE) and IL-1R−/− (non-EDE) mice. However, there was no difference in Meibomian gland morphology between WT, IL-1R−/−, and MyD88−/− mice.ConclusionsThese studies demonstrate the importance of TLR signaling in dry eye development. Mice lacking TLR signaling, MyD88−/−, were protected from EDE-induced ocular surface damage and inflammatory mediator expression, warranting further investigation into TLR inhibition as a potential therapeutic for DED.

Ocular dryness assessment in Saudi employees working indoors and outdoors.

ObjectiveTo investigate dry eye disease in Saudi employees working in indoor and outdoor environments.MethodsA single-center randomized controlled study was carried out in an optometry clinic, to assess the ocular dryness of 24 male employees (12 indoor and 12 outdoor employees, mean age 36.4±2.5 years). The Ocular Surface Disease Index questionnaire was used to assess ocular dryness. Tear film assessment was carried out using phenol red thread (PRT), tear film osmolarity test, and fluorescein tears breakup time (FTBUT) with slit-lamp biomicroscopy.ResultsBoth indoor and outdoor employees showed mild-to-moderate ocular dryness. A significant difference (P=0.004) was found for the tear quality test (FTBUT) between the indoor (8.58±4.8) and outdoor (5.54±1.3) employees. However, no significant differences for the tear quantity tests (tear osmolarity and PRT) between the indoor and outdoor employees were observed.ConclusionDry eye cases were detected in both groups. This might be due to the hot dry environment in Riyadh and the use of air conditioners commonly used indoors. A significant difference was observed for the tear film stability, which might be due to the effect of environment and/or visual display unit use.

Effect of sedation with butorphanol on variables pertaining to the ophthalmic examination in dogs.

To evaluate whether sedation with intramuscular butorphanol can interfere with different variables of the ocular examination in dogs. Twenty-two beagles without ophthalmic abnormalities. Each dog was examined 20min prior to and again just before administration of butorphanol to establish baseline data. The globe and nictitating membrane position was evaluated, and the following were recorded: menace response, dazzle reflex, corneal blink reflex, phenol red thread tear test (PRT), Schirmer tear test-1 (STT-1), pupil size (PS) measurement, and rebound tonometry. Then, butorphanol was injected intramuscularly at a dose of 0.2mg/kg and these procedures were repeated 10, 20, 30, and 45min postadministration. A sedation score graded 0 to 3 was also established at these time points. Statistical analyses were performed on quantitative data using ANOVA. The sedative effect was not associated with any changes in globe and nictitating membrane position; did not affect the results of the menace response, dazzle reflex, and corneal blink reflex; and had no significant effect on PRT values. However, butorphanol administration was associated with a statistically significant decrease in STT-1 and PS values (P<0.005), and a statistically significant increase in IOP (P<0.05). All these variations remained in the range of normal values. Butorphanol administered intramuscularly at 0.2mg/kg provided a degree of sedation allowing eye examination, but was found to interfere with STT-1, PS, and IOP values among the diagnostic tests studied. However, these values remained within normal limits.

Analysis of basal and reflex human tear osmolarity in normal subjects: assessment of tear osmolarity.

Purpose:The aim of this study is to evaluate the difference between reflex and basal tear osmolarity among healthy normal subjects.Method:The right eyes of 20 healthy normal male subjects aged 20 to 40 years were recruited for this study. The inclusion criteria for the subjects were the Ocular Surface Disease Index questionnaire score of less than 12 and wetting length of the phenol red thread of more than 10 mm. Tear film osmolarity was assessed using TearLab osmometer. Basic tear osmolarity was measured normally without inducing any irritation to the eye. In order to stimulate reflex tear, subjects were asked to open their eye as long as they can till they feel ocular surface irritation (minimum 20 s).Results:The mean score on the Ocular Surface Disease Index questionnaire was 5.5 ± 3. The mean value obtained from the phenol red thread was 21 ± 4.5 mm. There were no statistically significant differences between the osmolarity readings of basal and reflex tear osmolarity (p > 0.05). The mean value was 308 ± 12 and 306 ± 9 mOsm/l for basic and reflex tear osmolarity, respectively.Conclusion:This study found that the osmolarity of the basal and reflex tears fell within the same range. The values found in this study are in agreement with published results for normal subjects.

Relationship Between Dynamic Changes in Expression of IL-17/IL-23 in Lacrimal Gland and Ocular Surface Lesions in Ovariectomized Mice.

An ovariectomized mouse model was constructed to observe the dynamic effects of hormone changes on the expression of interleukin (IL)-17A and IL-23 in the lacrimal glands. The ovariectomized mouse model was constructed by bilateral ovary removal. The concentrations of serum estradiol and testosterone in mouse cardiac blood were detected by radioimmunoassay. Mice in both groups underwent the phenol red cotton thread test and corneal fluorescein staining to assess the ocular surface, whereas Th17 cells in blood and spleen were detected by flow cytometry. IL-17A and IL-23 expression in the lacrimal glands was detected by immunohistochemistry, enzyme-linked immunosorbent assay, and real-time fluorescence quantitative polymerase chain reaction. Serum estradiol and testosterone levels were significantly lower in the ovariectomized group compared with those in the control group. There was lymphocytic infiltration in the lacrimal gland of the ovariectomized group mice. At 6 months after the surgery, aqueous tear production was significantly lower, and statistically significant corneal fluorescein staining was found in the ovariectomized group, compared with that in the control group. In the ovariectomized group, IL-17A and the IL-23 expression in the lacrimal glands and the Th17 expression in the blood and spleen were significantly higher than in the control group. The hormone levels are significantly reduced and lymphocytic infiltration in the lacrimal gland in ovariectomized mice, whereas the frequency of Th17 cells in the blood and spleen and IL-17A and IL-23 expression in the lacrimal glands are increased, leading to reduced tear production and positive fluorescein staining in the cornea.

Tear production and intraocular pressure values in clinically normal eyes of whooper swans (Cygnus cygnus).

The objective of this study was to determine the normal range of tear production and values of intraocular pressure (IOP) in clinically normal eyes of whooper swans (Cygnus cygnus). A total of 86 birds: 81 cygnets (6-10 weeks old) and 5 moulting – adult swans (3-6 years old) were examined in this study. Both eyes of all birds underwent a complete ophthalmic examination, including evaluation of tear production with the phenol red thread test (PRTT) and the assessment of the IOP by rebound tonometry, employing the TonoVet® device. The mean ± standard deviation of PRTT values were as follows: all cygnets (81) 22.59±3.48 mm/15s, male cygnets (45) 22.64±3.54 mm/15s, female cygnets (36) 22.53±3.44 mm/15s. IOP was as follows: all cygnets 11.30±3.55 mmHg, male cygnets 10.93±3.56 mmHg, female cygnets 11.74±3.50 mmHg. No statistically significant differences between right and left eye and between female and male cygnets were found for IOP and PRTT values. This study provides the reference values for the PRTT and IOP in healthy whooper swan cygnets, showing that PRTT determination of the tear production and rebound tonometry to evaluate the IOP methods are practical methods for ophthalmic examination in swans.

Reference Values for Selected Ophthalmic Diagnostic Tests in the Caatinga Parakeet (Eupsittula Cactorum) and Yellow-Chevroned Parakeet (Brotogeris Chiriri)

The aim of the present study was to determine reference values for selected ophthalmic diagnostic tests in the Caatinga Parakeet ( Eupsittula cactorum) and Yellow-chevroned Parakeet ( Brotogeris chiriri). Healthy adults of undetermined gender (15 Caatinga Parakeets and 13 Yellow-chevroned Parakeets), kept at the Triage Center of Wild Animals (CETAS, Salvador, Bahia, Brazil), were used in this investigation. Ophthalmic diagnostic tests were conducted in both eyes, including culture of the conjunctival bacterial flora with antimicrobial susceptibility test, conjunctival cytology, evaluation of tear production by phenol red thread test (PRTT) and endodontic absorbent paper point tear test (EAPPTT), measurements of palpebral fissure length (PFL) and corneal touch threshold (CTT). There was bacterial growth in 97.5% of the evaluated samples, with predominance of Grampositive microorganisms. The antimicrobial susceptibility test showed ciprofloxacin to be the most effective antibiotic. The conjunctival cytology of Caatinga Parakeets demonstrated hypocellularity with a discrete amount of squamous cells, whereas for Yellow-chevroned Parakeets, it presented hypercellularity and predominance of lymphocytes. Medians ± semi-interquartile ranges in Caatinga and Yellow-chevroned Parakeets, respectively, were: 3.51±2.2 and 1.67±1.95 mm·15 s−1 for PRTT; 8.74±2.0 and 5.89±1.48 mm min−1 for EAPPTT; 6.24±3.5 and 6.35±0.27 mm for PFL; and 4.5±1.0 and 3.5±1.95 cm for CTT. The ophthalmic parameters determined in this study may help in the diagnosis of ocular diseases in Caatinga and Yellow-chevroned Parakeets.

Impact of oral vitamin D supplementation on the ocular surface in people with dry eye and/or low serum vitamin D.

To determine the possible association between serum vitamin D levels and dry eye symptoms, and the impact of an oral vitamin D supplement. Three linked studies were performed. (i) 29 older adult participants, (ii) 29 dry eyed participants, and (iii) 2-month vitamin D supplementation for 32 dry eyed/low serum vitamin D levelled participants. All participants were assessed by the Ocular Surface Diseases Index (OSDI) to determine dry eye symptoms, and the phenol red thread test (PRT) and/or Schirmer's tear test, tear meniscus height, non-invasive tear break up time, grading ocular surface redness and fluorescein staining of the cornea to detect the tear quality and ocular surface conditions. Blood samples were collected for serum vitamin D analysis and interleukin-6 (IL-6) levels. Among older adult participants, vitamin D levels were negatively correlated with dry eye symptoms, the severity of dry eye, and associated with tired eye symptom. Vitamin D levels of people with dry eye diagnosis were not correlated with OSDI scores and IL-6 levels; while IL-6 levels showed correlation with tear production. In supplement study, vitamin D levels increased by 29mol/l, while dry eye symptoms and grading of corneal staining appeared significant reductions. No significant changes in IL-6 levels. Low vitamin D levels (<50nmol/l) were associated with dry eye symptoms in older individuals but not those diagnosed with dry eye. Vitamin D supplement increased the vitamin D levels, and improved dry eye symptoms, the tear quality and ocular surface conditions.

OCULAR FINDINGS AND SELECT OPHTHALMIC DIAGNOSTIC TESTS IN CAPTIVE AMERICAN WHITE PELICANS (PELECANUS ERYTHRORHYNCHOS).

The aim of this study was to establish normal ophthalmic parameters for select diagnostic tests in American white pelicans (Pelecanuserythrorhynchos). Twenty-one zoo-housed American white pelicans were manually restrained for noninvasive ocular diagnostic testing and complete ophthalmic examination. Tear production quantification using the phenol red thread test (PRTT), fluorescein staining, and intraocular pressure (IOP) evaluation were performed. In addition, conjunctival aerobic bacterial culture and culture-independent 16S rRNA amplicon sequencing were performed on select eyes. Normal variations and ocular abnormalities detected during complete ophthalmic examination were documented and photographed. Direct pupillary light reflex, menace response, and palpebral reflex were present in all birds. The value (mean ± SD) for PRRT and IOP was 14.9 ± 7.84 mm/15 sec and 9.0 ± 1.41 mm Hg oculus uterque, respectively. Conjunctival culture in nine birds revealed no growth for six birds and Staphylococcus aureus growth in three birds. A high relative abundance of Mycoplasma sp. was detected in all samples based on 16S rRNA sequencing. The normal pelican eye was found to have relative conjunctival hyperemia, absent filoplumes, iris color ranging from light blue to brown, and a subcircular vertically elongated pupil. Ophthalmic abnormalities were noted in 10 of 21 birds. Common findings included corneal fibrosis, cataracts, and asteroid hyalosis. The most common ophthalmic abnormality in this species was cataracts.

A study on meibomian gland disorders and lipid levels in north Indian population

To study meibomian gland disorders (MGD) and lipid levels in north Indian population. Methods: This was a cross-sectional study. A total of 100 clinically diagnosed cases of MGD were included in the study. A detailed history using a Symptom Assessment in Dry Eye (SANDE) questionnaires was taken. Thorough clinical examination using Slit Lamp was performed to confirm the diagnosis of dry eye and for the probable etiology. For this, standard tests like Tear Film break-up time [TFBUT], Schirmer’s test, Phenol Red Thread test were employed. Patients found to have dry eye were evaluated further by slit-lamp biomicroscopy of the lid margins for posterior blepharitis and the degree of meibomian gland dysfunction, if any, was graded. After a complete ocular examination, they were allotted into the groups. Laboratory investigation that was performed in each patient included Serum Fasting Lipid Profile. Results: More than half (59%) of patients were above 45 years of age and 57% were males.Grade II severity of meibomitis was in more than one third of the cases (46%) followed by grade I (42%) and grade III (12%).Borderline cholesterol was in 55% of the cases who had grade II severity of meibomitis. High cholesterol level was found the 50% patients of grade III severity of meibomitis. However, this association was statistically insignificant (p>0.05). High TG was seen 53.5% and 30.2% of grade II and grade III severity of meibomitis. The association between TG level and severity of meibomitis was found to be statistically significant (p=0.0001). There was no significant (p>0.05) association of serum HDL level with severity of meibomitis. However, serum LDL level was found to be significantly (p=0.008) associated with severity of meibomitis. Conclusions: Patients with MGD with history of dyslipidemia may have undiscovered abnormal serum cholesterol, triglycerides and LDL levels.

Pilot Study of a “Large-Eye,” Surgically Induced Dry Eye Rabbit Model by Selective Removal of the Harderian, Lacrimal, and Meibomian Glands

Background/Aims: Establish a reliable rabbit dry eye (DE) model. Methods: An interventional cohort study surgically removing glands contributing to the tear film. Eight rabbits were studied after removal of left lacrimal, Harderian, or both glands. Additional rabbits had Meibomian glands in the left eye thermally obstructed. All were followed for 10 weeks with phenol red thread (PRT) and slit-lamp examination with 2% fluorescein. We assessed corneal sensitivity using a Cochet-Bonnet esthesiometer. Outcome measures were severity/duration of reduced PRT, punctate epithelial erosions (PEE), and histologic evidence of corneal pannus. Results: Fluorescein staining demonstrated signs of dryness including PEE in all of the interventional eyes. The subjective measurement of epithelial erosions correlated with decreased tear production. PRT measurements in the control eyes averaged 31.54 mm (±1.83) and 22.71 mm (±1.60) in the eight left eyes, without loss of corneal sensitivity. Conclusions: Surgical removal of either the Harderian or lacrimal gland results in statistically significant decreases in tear volume and the development of severe DE. Removal of both glands results in the occurrence of a DE of comparable severity/duration to removal of either the lacrimal or Harderian gland alone. Meibomian gland obstruction contributes less to the DE model.

Evaluation of Selected Ophthalmic Diagnostic Tests in Green Iguanas (Iguana iguana)

The objective of this study was to establish reference parameters for different ophthalmic diagnostic tests in green iguanas (Iguana iguana). Median ± semi-interquartile range values of phenol red thread tear test, endodontic absorbent paper point tear test, Schirmer tear test, palpebral fissure length, and intraocular pressure were 3.9 ± 1.7mm/15seconds, 8.5 ± 2.4mm/minutes, 1.0 ± 0.5mm/minutes, 12.4 ± 1.7mm, and 18.0 ± 1.7mm Hg, respectively. Bacterial growth was observed in 18 of 20 conjunctival samples, with a predominance of Gram-positive bacteria (75.8%). Staphylococcus spp. was the most frequently isolated microorganism (39.4%), and a resistance pattern to polymyxin B was demonstrated through antimicrobial susceptibility testing of the bacterial isolates. Median ± semi-interquartile range anterior chamber depth was 1.2 ± 0.2mm and 1.4 ± 0.2mm; vitreous chamber depth, 6.8 ± 0.6mm and 6.8 ± 0.5mm; lens length, 4.4 ± 0.3mm and 4.3 ± 0.3mm; and axial globe length, 12.6 ± 0.8mm and 12.5 ± 0.7mm for the sagittal and dorsal planes, respectively. Conus papillaris length was 6.0 ± 0.3mm and 5.9 ± 0.5mm, whereas the conus papillaris width was measured at 1.1 ± 0.2mm and 1.2 ± 0.2mm, with no difference between the 4.5- and 7.5-hour planes. Hypercellular samples with dense clusters of basaloid and squamous epithelial cells were observed in the conjunctival cytological samples. These results may be helpful for diagnosis and treatment of ocular disorders in green iguanas.

Corneal Nerve Morphology, Sensitivity, and Tear Neuropeptides in Contact Lens Wear.

To determine tear neuropeptide levels in contact lens wearers and non-wearers, and to examine relationships with indices of corneal innervation, tear function, and ocular discomfort. A cross-sectional, single-visit, investigator-masked pilot study. Assessments included Ocular Comfort Index (OCI), central and mid-peripheral corneal nerve density and morphology (HRT-Rostock), corneal sensitivity (Cochet-Bonnet aesthesiometer), tear Substance P and calcitonin gene-related peptide (CGRP) concentration (ELISA), in situ tear osmolarity (TearLab), tear secretion (Phenol Red Thread), and noninvasive tear break-up time (NITBUT; Keeler Tearscope). Groups were compared using independent t-test or Mann-Whitney U test, and regional differences assessed using paired t-tests. Associations were analyzed using Pearson or Spearman correlation. Significance was determined at P < .05. Twenty contact lens wearers (7M:13F, 32 ± 5 years) and 20 non-wearers (7M:13F, 31 ± 5 years) completed the study. OCI score was numerically higher in lens wearers (32.27 ± 5.33) than non-wearers (27.66 ± 9.94). Tear osmolarity was higher [298.0 (IQR 291.0-309.8) vs. 288.5 (282.3-298.3) mOsmol/L; P = .01] whereas NITBUT was lower (9.8 ± 3.4 vs. 13.8 ± 5.6 s; P = .01) in lens wearers compared with non-wearers. Tear neuropeptide concentrations were not different between groups [Substance P 4.29 ng/ml (IQR 1.57-6.05), CGRP 14.89 ng/ml (5.08-59.26)], and there were no differences in nerve morphology or ocular surface sensitivity. Higher nerve density, interconnections, and tortuosity were observed in the central cornea than mid-peripherally (P < .05). OCI score was moderately associated with nerve tortuosity (r = 0.42, P = .01). CGRP was associated with central nerve density (ρ = 0.38, P = .02), as was tear secretion (r = -0.37, P = .02). Nerve interconnections were strongly associated with corneal sensitivity (ρ = 0.64, P < .001). Relationships were demonstrated between nerve density, tear CGRP, and corneal sensitivity. Markers of corneal neurobiology and sensory function do not appear to be altered in contact lens wear despite worse tear function (osmolarity and stability) in lens wearers. This suggests that mechanisms other than overt changes in corneal innervation regulate tear function during lens wear. The relationship between nerve tortuosity and ocular discomfort requires elucidation.

Rapamycin Eye Drops Suppress Lacrimal Gland Inflammation In a Murine Model of Sjögren's Syndrome.

PurposeTo evaluate the efficacy of topical rapamycin in treating autoimmune dacryoadenitis in a mouse model of Sjögren's syndrome.MethodsWe developed rapamycin in a poly(ethylene glycol)-distearoyl phosphatidylethanolamine (PEG-DSPE) micelle formulation to maintain solubility. Rapamycin or PEG-DSPE eye drops (vehicle) were administered in a well-established Sjögren's syndrome disease model, the male nonobese diabetic (NOD) mice, twice daily for 12 weeks starting at 8 weeks of age. Mouse tear fluid was collected and tear Cathepsin S, a putative tear biomarker for Sjögren's syndrome, was measured. Lacrimal glands were retrieved for histological evaluation, and quantitative real-time PCR of genes associated with Sjögren's syndrome pathogenesis. Tear secretion was measured using phenol red threads, and corneal fluorescein staining was used to assess corneal integrity.ResultsLymphocytic infiltration of lacrimal glands from rapamycin-treated mice was significantly (P = 0.0001) reduced by 3.8-fold relative to vehicle-treated mice after 12 weeks of treatment. Rapamycin, but not vehicle, treatment increased tear secretion and decreased corneal fluorescein staining after 12 weeks. In rapamycin-treated mice, Cathepsin S activity was significantly reduced by 3.75-fold in tears (P < 0.0001) and 1.68-fold in lacrimal gland lysates (P = 0.003) relative to vehicle-treated mice. Rapamycin significantly altered the expression of several genes linked to Sjögren's syndrome pathogenesis, including major histocompatibility complex II, TNF-α, IFN-γ, and IL-12a, as well as Akt3, an effector of autophagy.ConclusionsOur findings suggest that topical rapamycin reduces autoimmune-mediated lacrimal gland inflammation while improving ocular surface integrity and tear secretion, and thus has potential for treating Sjögren's syndrome–associated dry eye.

Comparative evaluations of tear secretion in healthy and infectious keratoconjunctivitis Romanov sheep with Schirmer tear test and phenol red thread tear test

The aim of this study is to determine the amount of tear secretion in sheep with infectious keratoconjunctivitis and healthy ones in the Siirt region by Schirmer tear test and phenol red thread tear test. A total of 47 Romanov sheep, consisting of sheep with infectious keratoconjunctivitis (n = 6) and healthy sheep (n = 41), constituted the study material. Phenol red thread tear test followed by Schirmer tear test was performed on both eyes of the animals, properly taken at a control visit on their feet. The Schirmer tear test and phenol red thread tear test values were measured as 18.83 ± 5.29 mm/min and 22.22 ± 6.09 mm/s in the right eyes and 18.41 ± 7.15 mm/min and 20.83 ± 5.72 mm/s in the left eyes, respectively, in healthy animals. The Schirmer tear test and phenol red thread tear test values were measured as 17.33 ± 4.27 mm/min and 18.83 ± 4.36 mm/s in the right eyes and 17.33 ± 7.55 mm/min and 20.17 ± 4.58 mm/s in the left eyes, respectively, in animals with infectious keratoconjunctivitis. The phenol red thread tear test measurement averages were found to be significantly higher than the Schirmer tear test measurement averages (P > 0.05). The amount of normal tear secretion was determined in Romanov breed sheep by the phenol red thread tear test and Schirmer tear test and there was no statistically significant difference in animals with infectious keratoconjunctivitis (P > 0.05).