Mean Schirmer Tear Test Values Research Articles

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...

Ocular findings and reference values for selected ophthalmic diagnostic tests in the macaroni penguin (Eudyptes chrysolophus) and southern rockhopper penguin (Eudyptes chrysocome)

To describe ophthalmic examination findings and standard diagnostic test results in 2 penguin species. Macaroni & Southern Rockhopper Penguins. Complete ophthalmic examinations including Schirmer tear test (STT), modified phenol red thread test (PTT), tonometry, and echobiometry were performed on penguins housed at the Detroit Zoo. Mean and standard deviation of ophthalmic tests are reported and compared for significance using two sample t-tests with significance set at P<0.05. Correlations between variables were assessed using Pearson's correlation coefficient. Cataracts were the most common finding, present in 64% of Macaroni Penguins, and 68% of Rockhopper Penguins. There were anterior segment anomalies in all eyes with cataracts consistent with lens-induced uveitis. The mean modified PTT for the Macaronis was 24.7±6.37mm/15s and 25.1±7.07mm/15s in the Rockhoppers. The mean STT value for the Macaronis was 12.1±5.43mm/min and 11.0±3.96mm/min in the Rockhoppers. Mean intraocular pressure (IOP) for the Macaronis was 21.9±7.05mmHg measured by applanation tonometry and 29.1±7.16mmHg using rebound tonometry. The Rockhoppers had a mean IOP of 20.0±5.77mmHg and 24.1±5.09mmHg for applanation and rebound tonometry, respectively. In both populations, there was a significant difference in IOP measurement between the two instruments. In the Macaroni penguins, the presence of cataracts correlated significantly with increased age and lower IOP readings. Anterior chamber distance and axial globe length were significantly greater in males than in females in both penguin species.

DETERMINATION OF REFERENCE VALUES FOR INTRAOCULAR PRESSURE AND SCHIRMER TEAR TEST IN CLINICALLY NORMAL OSTRICHES (STRUTHIO CAMELUS)

The purpose of this study was to establish normal physiologic reference values for intraocular pressure (IOP) and Schirmer tear test (STT) results in clinically normal ostriches (Struthio camelus). Twenty ostriches of both sexes, 10 juveniles (1.5-2 yr of age) and 10 adults, were included in this study. Complete ophthalmic examination was performed prior to this investigation. STT was performed by inserting a standard sterile STT strip over the ventral lid margin into the ventral conjunctival sac for 60 sec. Following the STT, IOP was measured using applanation tonometry with the Tono-Pen Vet tonometer after topical instillation of one drop of 0.5% proparacaine ophthalmic solution. The mean +/- SD and range of Tono-Pen readings of IOP for all birds was 18.8 +/- 3.5, with a range of 12-24. Mean IOP in juvenile ostriches was 19.7 +/- 3.6. Mean IOP in adult ostriches was 16.9 +/- 2.9. There was no statistically significant difference between young and adult birds (P = 0.07). The mean STT values in the present study were 16.3 +/- 2.5 mm/1 min when measurements from both eyes were averaged. Mean STT in juvenile and adult ostriches was 15.4 +/- 1.8 and 17.2 +/- 2.9 mm/1 min, respectively. There was no statistically significant difference between young and adult birds (P = 0.11). No statistically significant differences between genders were found for any of the results (P > or = 0.41). In conclusion, this study provides normal reference range values for STT and IOP in clinically healthy ostriches.

The Pharmacologic Assessment of A Novel Lymphocyte Function-Associated Antigen-1 Antagonist (SAR 1118) for the Treatment of Keratoconjunctivitis Sicca in Dogs

Keratoconjunctivitis sicca (KCS) is characterized by inflammation and decreased production of tears containing increased levels of cytokines. The release occurs in the setting of conjunctival and lacrimal gland inflammation, potentially mediated by the interaction between lymphocyte function-associated antigen (LFA)-1, a cell surface protein found on lymphocytes, and its cognate ligand intercellular adhesion molecule (ICAM)-1. SAR 1118 is a novel LFA-1 antagonist and may be an effective therapeutic agent for the treatment of KCS. The following studies were performed to assess the in vitro activity of SAR 1118 and to evaluate the clinical efficacy of topical SAR 1118 for the treatment of idiopathic canine KCS. Pharmacodynamics were assessed by measuring the ability of SAR 1118 to inhibit Jurkat T-cell binding with recombinant human ICAM-1 and to inhibit cytokine release from human peripheral blood mononuclear cells (PBMCs) stimulated by staphylococcal enterotoxin B. For the assessment of clinical efficacy, 10 dogs diagnosed with idiopathic KCS were treated with SAR 1118 1% topical ophthalmic solution three times daily for 12 weeks. Schirmer's tear test (STT) was used to measure tear production. SAR 1118 demonstrated concentration-dependent inhibition of Jurkat T-cell attachment, inhibition of lymphocyte activation, and release of inflammatory cytokines, particularly the Th1, Th2, and Th17 T-cell cytokines IFN-γ, IL-2, and IL-17F, respectively. Mean STT values increased from 3.4 mm during week 1 to 5.8 mm at week 12 (P < 0.025). No SAR 1118-related adverse events were observed. SAR 1118 appears to be an effective anti-inflammatory treatment for KCS. Additional studies are warranted to establish the efficacy of SAR 1118 for the treatment of KCS in humans.

Reference values for intraocular pressure and Schirmer tear test in clinically normal Sanjabi sheep

The current study was undertaken to establish reference values for Schirmer tear test (STT) and intraocular pressure (IOP) in the Sanjabi sheep. Twenty apparently healthy Sanjabi sheep with no evidence of ocular disease were used in this study. Tear production was measured by STT by inserting standard sterile Schirmer tear test strip (Ophtechnics Inc., Carson City, NV, USA, Lot number: STR061203) in the ventral conjunctival fornix for 1 min. IOP was measured in both eyes with a Tono-Pen Vet™ (Reichert, Inc. USA). Mean (SD) STT values for all eyes ( n = 40) were 18.52 ± 2.55 mm/min with a range of 13.5–22 mm/min. Comparison of mean STT values between right ( n = 20) and left eyes ( n = 20) showed no differences ( P = 0.88). Mean (SD) IOP values by applanation tonometry were 9.37 ± 2.45 mmHg (range 6–14.5 mmHg). Comparison of mean IOP values between right ( n = 20) and left eyes ( n = 20) showed no differences ( P = 0.59). In conclusion, this study reports STT and IOP findings in Sanjabi sheep, and provide means and ranges for IOP and STT.

Selected Diagnostic Ophthalmic Tests in the Red Kangaroo (Macropus rufus)

The following tests were performed on a total of 20 eyes: Schirmer tear test, intraocular pressure (IOP), assessment of conjunctival flora, and pupillary diameter with application of topical tropicamide in 10 healthy captive red kangaroos (Macropus rufus) under manual restraint. The mean Schirmer tear test value was 22.6 +/- 6.07 mm/min. The mean intraocular pressure was 17.45 +/- 7.23 mm Hg. Values did not differ between eyes or gender for either test, but significant differences were identified for IOP values according to age. The most common bacteria isolated from the conjunctival fornix were Staphylococcus epidermidis (54.5%) and Corynebacterium sp. (18.2%). The mean onset of mydriasis after instillation of 1% tropicamide ophthalmic solution was 16.7 +/- 3.34 min and the mean duration of effect was 17.6 +/- 8.26 hr. The data obtained in this investigation will aid veterinary ophthalmologists and zoo veterinarians to diagnose ocular diseases in the red kangaroo accurately.

Use of phenol red thread tests to evaluate tear production in clinically normal Amazon parrots and comparison with Schirmer tear test findings

To determine phenol red thread test (PRTT) values in eyes of clinically normal Hispaniolan Amazon parrots before and after topical application of an ophthalmic anesthetic agent and compare findings with Schirmer tear test (STT) values. Evaluation study. 24 Amazona ventralis parrots from a research colony. On 4 occasions (1-week intervals), all birds underwent a thorough ophthalmic examination of both eyes, which included (in sequence) performance of a PRTT and an STT; topical ocular application of proparacaine hydrochloride; and performance of another PRTT and another STT. Correlations between PRTT and STT values recorded with and without topical anesthesia were assessed. Without topical anesthesia, mean +/- SD PRTT value was 12.5 +/- 5.0 mm/15 s (range, 1 to 25 mm/15 s). With topical anesthesia, the PRTT value was 12.6 +/- 5.4 mm/15 s (range, 2 to 24 mm/15 s). Without topical anesthesia, mean STT value was 7.9 +/- 2.6 mm/min (range, 0 to 13 mm/min). With topical anesthesia, the STT value was 5.1 +/- 3.3 mm/min (range, 0 to 18 mm/min). The correlation of PRTT and STT values recorded with or without topical anesthesia was weak (r = 0.51 and r = 0.32, respectively). Results indicated that the PRTT and STT were both viable methods for measurement of tear production in Hispaniolan Amazon parrots. Topical application of an ophthalmic anesthetic agent did not have a significant effect on the PRTT values but significantly decreased the STT values.

Effects of feline herpesvirus type 1 on tear film break-up time, Schirmer tear test results, and conjunctival goblet cell density in experimentally infected cats

To determine the effect of feline herpesvirus type 1 (FHV-1) on tear film breakup time (TFBUT) and Schirmer tear test (STT) values in cats with primary experimental infection and to determine the relationship between TFBUT and STT values and conjunctival goblet cell density (GCD). 9 specific-pathogen-free cats of approximately 6 months of age. 6 cats were inoculated with FHV-1; 3 control cats were sham inoculated. Clinical and histologic evidence of conjunctivitis and TFBUT, GCD, and STT values were assessed at multiple times until postinoculation day (PID) 29. In infected cats, mean clinical and histologic conjunctivitis scores peaked at PID 7 and remained above baseline at PID 29. In control cats, these 2 variables did not change from baseline throughout the study. Mean TFBUT declined rapidly in infected cats up to PID 15 and at PID 29 remained less than baseline, less than for control cats, and below reference range values. Mean STT value for infected cats at PID 29 was increased from baseline but was within the reference range and not different from the value for control cats. Mean GCD in infected cats declined precipitously by PID 7 and remained below reference range values at PID 29. Mean GCD in control cats remained unchanged for the duration of the study period. FHV-1 induced qualitative tear film abnormalities in experimentally infected cats, as measured by TFBUT and GCD. Assessment of TFBUT provided a reasonable clinical estimate of GCD.

Upper Lid Blepharoplasty in Patients with LASIK

Purpose: To investigate the changes in tear secretion and tear film stability after upper lid blepharoplasty in patients that had previously undergone excimer laser in situ keratomileusis (LASIK). Methods: We performed carbon dioxide (CO2) laser upper lid blepharoplasty to 18 eyes of 9 patients that had undergone bilateral LASIK at least 18 months before the surgery. Six women and 3 men aged 35 to 52 were included in this group. An additional control group of 18 eyes of similar age patients with no history of LASIK, contact lens usage or dry eye symptoms were studied. We studied the Schirmer tear test values without anesthesia at 5 minutes in both groups before and after the upper lid blepharoplasty procedure. Tear break-up time values were also measured before and 4 weeks after (CO2) laser upper lid blepharoplasty. The Schirmer tear test and tear break-up time values were analyzed statistically using the independent t-test. Results: The mean Schirmer tear test value was 19.07 ± 4.03 mm in both eyes of the patients who had undergone LASIK and upper lid blepharoplasty, and it was 21.07 ± 7.03 mm in the eyes of the control group that only had (CO2) laser upper lid blepharoplasty. The mean tear break-up time value was 21.0 ± 3.55 seconds in the eyes that had LASİK treatment, and it was 21.27 ± 6.79 seconds in the eyes of the control group. There was no statistical difference between the two groups. Conclusion: Because LASIK and blepharoplasty both may cause dry eye symptoms, the possible cumulative effect of these surgeries is a serious consideration. However, dry eye symptoms after LASIK is usually temporary, and we may perform upper lid blepharoplasty to these patients after a certain time interval by closely monitoring their preoperative and postoperative tear function.

Schirmer tear test values and tear film break‐up times in cats with conjunctivitis

(1) To document tear film break-up time (TFBUT) in a group of cats with conjunctivitis; (2) to determine if TFBUTs from cats with conjunctivitis vary significantly from previously established normal values for TFBUT in young cats without ocular disease; (3) to determine if a correlation exists between Schirmer tear test (STT) values and TFBUTs in cats with conjunctivitis; (4) to determine if the TFBUTs in cats with conjunctivitis are influenced by the detection of DNA from feline herpes virus-type 1 (FHV-1), Chlamydophila felis, Mycoplasma spp., and feline calicivirus. Fourteen cats between the ages of 0.8 years to 12 years with active, untreated conjunctivitis and without active keratitis or other ocular or systemic abnormalities were included in this study. Procedures Complete ophthalmic examinations, including TFBUT, were performed on all cats. Polymerase chain reaction (PCR) screening for FHV-1, Chlamydophila felis, Mycoplasma spp., and feline calicivirus was performed on conjunctival swabs from affected eyes and blood samples from all cats. Mean TFBUT for cats in this study was 8.9 (+/- 4.8) s in the right eye (OD) and 8.1 (+/- 4.6) s in the left eye (OS). No correlation existed between mean TFBUTs and mean STT values OD or OS. Conjunctival swabs from seven cats (n = 9 eyes) tested positive via PCR for one of the above infectious agents. Blood samples from nine cats tested positive for FHV-1. Mean TFBUTs for cats from which the DNA from FHV-1 was isolated from the blood were significantly lower than mean TFBUTs for cats from which no such DNA was isolated from the blood. In this study, the mean TFBUT in cats with conjunctivitis was significantly lower than previously established values for clinically healthy cats. This supports the theory that qualitative tear film deficiency, and thus tear film instability, may play a role in the pathogenesis of feline conjunctivitis. Qualitative tear film deficiency may predispose to the development of conjunctivitis or may occur secondarily to this condition.

Decreased tear secretion after laser in situ keratomileusis for high myopia.

To investigate the changes in tear secretion and tear film stability after excimer laser in situ keratomileusis (LASIK) for high myopia. One eye of 28 patients underwent unilateral LASIK for the correction of myopia with spherical equivalent refractions ranging from -6.37 to -18.25 D (mean, -11.98 +/- 3.45 D). Schirmer tear test values without anesthesia at 5 minutes and tear break-up time values were measured 4 weeks after LASIK. Unoperated contralateral eyes were used as a control for each patient. The Schirmer tear test and tear break-up time values were analyzed statistically using the independent t-test. The mean Schirmer tear test value was 16.17 +/- 2.50 mm in the operated eyes and 21.07 +/- 7.03 mm in the unoperated (control) eyes of the same patients (P = .001). The mean tear break-up time value was 21.0 +/- 3.55 seconds in the operated eyes and 21.27 +/- 6.79 seconds in the control eyes (P = .85). Tear secretion decreased following LASIK probably due to decrease in corneal sensitivity, but tear film stability appeared unaltered.