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At least 91 records · Page 5Linked to original sources
PubMed2004

Genetic influences in the aetiology of tears of the rotator cuff. Sibling risk of a full-thickness tear.

From a retrospective, cohort study of 205 patients diagnosed with full-thickness tears of the rotator cuff, we determined, using ultrasound, the prevalence of such tears in their 129 siblings. Using 150 spouses as controls, the relative risk of full-thickness tears in siblings versus controls was 2.42 (95% CI 1.77 to 3.31). The relative risk of symptomatic full-thickness tears in siblings versus controls was 4.65 (95% CI 2.42 to 8.63). The significantly increased risk for tears in siblings implies that genetic factors play a major role in the development of full-thickness tears of the rotator cuff.

Adult↗
PubMed2003

Differentiation of lipid tear deficiency dry eye by kinetic analysis of tear interference images.

OBJECTIVE: To use kinetic changes to characterize tear interference images in patients with lipid tear deficiency (LTD) dry eye. METHODS: We used a DR-1 camera to digitize and analyze sequential images of tear interference on the central 8 mm of the cornea at the start of complete blinking in 11 healthy volunteers and 8 patients with LTD and noninflamed meibomian gland dysfunction. MAIN OUTCOME MEASURES: We studied tear lipid spread time and pattern, stability of the lipid after spread, and distribution of thickness in a prospective, case-control study. RESULTS: On complete lid closure, the lipid spread was horizontal in healthy eyes but vertical in LTD (P<.001). Mean +/- SD lipid spread time was 0.36 +/- 0.22 seconds in healthy eyes but 3.54 +/- 1.86 seconds in LTD (P<.001). Conventional DR-1 grading could not distinguish these groups (P =.32). Mean +/- SD lipid film thickness in healthy eyes was 74.5 +/- 6.9 nm, thicker than the 43.8 +/- 10.6 nm in LTD (P<.001), and this result was confirmed by qualification with intensity histogram (P<.001). CONCLUSIONS: Kinetic analysis of the tear interference revealed distinctive differences in the time and pattern of lipid spread and the distribution and stability of resultant lipid thickness between healthy subjects and patients with LTD. This method can be coupled with others for formulating effective therapies for patients with dry eye.

Adult↗
PubMed2004

Relationship between tear volume and tear meniscus curvature.

OBJECTIVE: To investigate the relationship between tear volume and tear meniscus curvature by means of the video meniscometer. METHODS: Eleven eyes of 11 patients with severe dry eye were studied (all female; mean +/- SD age, 66.2 +/- 7.7 years; 7 left eyes and 4 right eyes), each of whose puncta had been therapeutically occluded. Four instillations of balanced salt solution were given at intervals of 1 minute in each studied eye, with the concentration increasing in 5-microL steps from 5 to 20 microL. Before and after the instillation of balanced salt solution, tear meniscus changes were recorded by video meniscometer and radius of the meniscus was calculated from the printed images by means of the concave mirror formula. RESULTS: The mean radius of the meniscus increased linearly with increased drop volume (r(2) = 0.65, P<.001), with mean +/- SD radius values of 0.24 +/- 0.08 mm at baseline and 0.48 +/- 0.13, 0.62 +/- 0.13, 0.84 +/- 0.26, and 1.00 +/- 0.32 mm after separate instillations of 5, 10, 15, and 20 microL of balanced salt solution, respectively. For each subject, a significantly different slope defining the relationship between instilled volume and meniscus radius was seen (0.016-0.063 mm/ microL; mean +/- SD, 0.039 +/- 0.015 mm/ microL), which was thought to depend on the difference in capacity of the fluid reservoir over the ocular surface. CONCLUSIONS: This study confirmed that the volume of instilled eyedrops is linearly related to the resulting radius of the tear meniscus, suggesting that this radius is a useful measure in monitoring the tear volume. This is likely to have implications both for dry eye diagnosis and for confirming the efficacy of punctal occlusion in this condition.

Aged↗
PubMedDate not supplied

Effects of trimethoprim-sulfadiazine on tear production and the fluctuations of Schirmer tear test values in horses.

The objectives of this study were to observe the effects of trimethoprim-sulfadiazine on equine tear production and to determine normal fluctuations in Schirmer tear test (STT) values in horses. A randomized, placebo-controlled, blinded clinical trial measuring STT values in 15 horses over an 8-week period was performed. The treatment group (eight horses) received 30 mg/kg trimethoprim-sulfadiazine orally once a day and the control group (seven horses) received placebo (flour) at the same time. All horses were housed outdoors throughout the study. Schirmer tear test values were measured at 0, 2, 4, 6 and 8 weeks, and 4 weeks after discontinuation of treatment. There were no significant differences in tear production between the treated and control groups. Fluctuations in STT were observed and may result from individual and environmental variations. Trimethoprim-sulfadiazine did not decrease tear production in the horses in this study. Horses normally experience periodic fluctuations in STT values.

Administration, Oral↗
PubMedDate not supplied

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

OBJECTIVES: (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. ANIMALS STUDIED: 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. RESULTS: 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. CONCLUSIONS: 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.

Animals↗
PubMed1989

Biomicroscopy of the tear film: the tear film of the pekingese dog.

Polarised light biomicroscopy was used to examine the normal pre-corneal tear film in 21 eyes of 12 pekingese dogs. The purpose of the study was to examine the influence of excessive exophthalmos on the pre-corneal tear film in the dog. The majority of the animals were found to have high levels of ocular surface contamination by particulate material and plaques of viscous mucus. Other abnormalities included surface lipid with an abnormal granular (three dogs) or 'curdled' (two dogs) appearance; excessive thinning of the lipid layer of the tear film; and the presence of dark globular structures in two dogs, which were presumed to be abnormal meibomian lipid. Break up of the tear film was observed in one dog. Grossly, a thread of viscous mucus was frequently observed along the margin of the lower eyelid. It is postulated that this thread forms because of the excessively exophthalmic conformation of the breed, which prevents the normal access of effete mucus and entrapped debris to the lower conjunctival fornix. The combination of the above factors in the pekingese is suggested as the mechanism whereby the tear film has a reduced stability, thus enhancing the risk from factors more usually considered to initiate corneal ulceration in the breed. The possible adverse effects of lid splitting for the mass removal of distichiae in exophthalmic dogs is discussed.

Animals↗
PubMed1995

Poor mixing of microdrops with the tear fluid reduces the accuracy of tear flow estimates by fluorometry.

The initial rapid fall in tear film fluorescence after instilling a 1 microliter drop of fluorophore could be a result of stimulated tear flow or of distribution of the dye throughout the tear fluid present in the conjunctival sac. An attempt was made to decide this by comparing the fall in fluorescence of two different fluorophores instilled at an interval of several minutes. In fact, very few patterns of initial rapid loss were found, but it was noted that there was usually a strong gradient of fluorescence from side to side across the cornea that took several minutes to dissipate. It seems that lateral mixing of a microdrop with the tear fluid is not instantaneous and that caution should be exercised in interpreting such measurements to estimate the total volume of tear fluid.

Conjunctiva↗
PubMed1975

Evaluation of tear formation in the dog, using a modification of the Schirmer tear test.

The Schirmer tear test for the measurement of tear formation in the dog was done according to 2 procedures: Schirmer I (the conventional procedure) and SCHIRMER II (with topical anesthesia and drying of the ventral conjunctival fornix. Results from 97 normal dogs averaged 21.0 mm wetting/minute (standard deviation (sd) plus or minus 4.2 mm) for the Schirmer I test and 11.6 mm wetting/minute (sd plus or minus 6.1 mm) for the Schirmer II test. When atropine was injected subcutaneously in 50 dogs (0.02 mg/kg, wetting/minute averaged 9.36 mm (Schirmer I) AND 4.32 MM (Schirmer II). Two dogs in each of 3 groups had either the lacrimal gland, gland of the membrane nictitans, or both excised. Changes in tear formation were evaluated by Schirmer I and II tear tests, as well as after parenteral administration of atropine. The lacrimal gland, the gland of the membrama mocotams. amd tje accessory lacrimal glands and mucous cells were found to contribute 6.17, 35.2, and 3.1%, respectively, to tear formation.

Animals↗
PubMed1991

Effect of preservatives in artificial tear solutions on tear film evaporation.

It has been suggested that certain preservatives in artificial tears may affect the stability of the tear film lipid layer. In the present study, tear film evaporation rate (TER) was measured with a modified Servomed Evaporimeter to determine whether preservatives affected tear stability. Two solution combinations were compared in a cross-over study of eight non-contact lens wearers. These combinations consisted of identical solutions, one preserved with either benzalkonium chloride (0.004%) or chlorobutanol (0.5%), the other non-preserved. Grouped data analysis showed no significant difference in TER with either solution combination. Individuals showed differences, but these were not related to the preservative. It is suggested that these concentrations of chlorbutanol and benzalkonium chloride did not affect the stability of the tear film lipid layer as indicated by an altered TER.

Adult↗
PubMedDate not supplied

Six surgery-correlated sonographic signs for rotator cuff tears: emphasis on partial-thickness tear.

The purpose of the study is to correlate the sonographic signs of rotator cuff tears (RCTs) with surgical findings, with emphasis on partial-thickness tear. We prospectively performed ultrasonography (US) on 50 patients with suspected RCTs and comparison with operative findings. Six US signs, which included "nonvisualization", "focal depression", "focal thinning", "focal hypoechoic cleft", "floating bright spots" and "focal heterogeneous hypoechogenicity" in rotator cuffs (RCs), were emphasized, but only "focal heterogeneous hypoechogenicity" favored partial-thickness tear (10/14, 71%). All the other five signs, including "floating bright spots" (not pointed out in literatures), were suggestive of full-thickness tear. The overall sensitivity, specificity, positive predictive value, negative predictive value and accuracy for US to detect RCTs were 95%, 90%, 97%, 82% and 94%, respectively. US is effective to detect RCTs and differentiate full- from partial-thickness tear.

Adolescent↗
PubMed2003

Assessment of tear concentrations on therapeutic drug monitoring. III. Determination of theophylline in tears by gas chromatography/mass spectrometry with electron ionization mode.

A simple and sensitive method for the quantitation of theophylline (TP) in tears and plasma developed using gas chromatography/electron-impact ionization/mass spectrometry. Tears were collected by non-invasive Schirmer method. Plasma was pipetted on a Schirmer tear test strip (cutting to 5 mm x 5 mm). Then, TP was converted directly into its pentafluorobenzoyl amide derivative without the need to perform any extraction from the biological fluid absorbed on Schiemer test paper and was quantified by gas chromatography-selected ion recordings with electron ionization mode. The concentrations in tears [C]t correlated very well with those of the free form in the plasma [Cf]p and those of the total form in the plasma [Cb+f]p. The ratios between TP concentrations in tears and plasma (free and total form) were as follows: [C]t/[Cb+f]p=0.53+/-0.20; [C]t/[Cf]p=1.21+/-0.19; [Cf]p/[Cb+f]p=0.44+/-0.14. The ratios of [C]t/[Cb+f]p, [C]t/[Cf]p and [Cf]p/[Cb+f]p were in good agreement with the previously published data.

Journal Article↗
PubMed1990

Urokinase-type plasminogen activator in rabbit tears. Comparison with human tears.

Plasminogen activator activity was determined in stimulated normal rabbit tears, and was identified as being due to urokinase using specific antibodies. The activator activity is about 100-fold higher in rabbit tears than in human tears. The molecular weight of the activator was determined by fibrin zymography to be 40-50 kDa. However, a multiband pattern of urokinase-type antigen ranging in molecular weight from 60-70 kDa to 200 kDa was detected by immunoblotting. The 60-70 kDa protein was resistant to reduction. The antigen concentration is more than 100-fold higher than the concentration expected from the activity measurement, indicating that most of the urokinase in rabbit tears is in inactive form, such as in inhibitor or receptor complexes.

Animals↗
PubMed2006

Prospective controlled study of vapor pressure tear osmolality and tear meniscus height in nasolacrimal duct obstruction.

PURPOSE: To determine tear osmolality (TO) and tear meniscus height (TMH) in patients with functional (FNLDO) and primary acquired (PANDO) nasolacrimal duct obstruction. Additionally, to determine the effect of successful dacryocystorhinostomy surgery on these tear parameters. DESIGN: Prospective case-controlled interventional case series. METHODS: Up to 20 microl of basal tears were collected from 20 age- and gender-matched control subjects, 33 patients with FNLDO, 28 patients with PANDO, and 31 patients after successful dacryocystorhinostomy. TMH was measured with videoreflective dacryomeniscometry, and TO was measured with vapor pressure osmometry. RESULTS: Thirty-nine percent of the patients with FNLDO (13/33) elected to undergo dacryocystorhinostomy surgery, compared with 64% of the patients with PANDO (18/28; P = .09). TMH was significantly higher in the disease groups (FNLDO median, 630 +/- 187 microm; PANDO median, 620 +/- 210 microm) compared with the control subjects (median 262 +/- 50 microm; P < .01). In those patients who underwent surgery, TMH was slightly higher in FNLDO than PANDO (P = .08), and TMH reduced significantly after surgery (P < .05). Mean TO in the control subjects was 313 +/- 17 mmol/kg, in FNLDO was 309 +/- 19 mmol/kg, and in PANDO was 315 +/- 24 mmol/kg (P > .05). TO was similar in those patients who progressed to surgery compared with the total group and was unaffected by surgery. CONCLUSION: TO was similar in normal control subjects and in the watery eye group and was unchanged after dacryocystorhinostomy surgery. Despite the slightly higher TMH in patients with FNLDO, a higher proportion of patients PANDO elected to have surgery. Relative to FNLDO, patients with PANDO who progressed to surgery had lower TMH and normal TO, which suggests that a complete lacrimal drainage obstruction induces negative feedback that results in no reduction in TO.

Aged↗
PubMed1998

The influence of tear proteins on the film stability of rabbit tear extracts.

This study was undertaken to gain an understanding of the significance of tear proteins in stabilizing the tear film. Either a sigma agonist, N,N-dimethyl-2-phenylethylamine HCl (AF2975), or a sigma antagonist, haloperidol, was administered to rabbit eyes in order to increase or decrease protein secretion, respectively. At 0, 10 and 60 minutes after instillation, tear proteins were extracted from Schirmer strips and measured for total protein. A portion of the extract was used for separating five major protein fractions using size-exclusion HPLC. Total protein extract or individual protein fractions were measured for surface tension by the horizontal capillary method and for in vitro break up time (in vitro BUT), a newly designed procedure. A statistically significant decrease was measured for surface tension and a concomitant increase was measured for in vitro BUT for the total protein samples at 10 and 60 minutes after instillation of AF2975 compared to the vehicle treated eye. The results for haloperidol yielded an increase in surface tension and an decrease in in vitro BUT. When the tear proteins were separated into five major fractions, only the 23 minute protein fraction was found to decrease surface tension and increase in vitro BUT following AF2975 administration. Haloperidol, a sigma antagonist, showed an exact opposite effect for the total protein and the 23 minute protein fraction.

Animals↗
PubMed1999

Changes in tear flow and tear film stability after photorefractive keratectomy.

PURPOSE: To investigate the changes in tear flow and tear film stability after photorefractive keratectomy (PRK) for myopia. MATERIAL AND METHOD: One eye of 32 patients underwent unilateral PRK procedure for the correction of myopia ranging from -1.50 to -6.00 diopters (D) (mean -3.65 +/- 1.55 D). Schirmer test values and break-up time (BUT) scores were measured 6 weeks after the PRK procedure. Unoperated, contralateral eyes were used as control eyes for each patient. The Schirmer test scores and BUT values were statistically analyzed using independent t test. RESULTS: The mean Schirmer test value was 14.45 +/- 7.79 mm in the operated eyes. It was 28.83 +/- 5.89 in the control eyes. The decrease in Schirmer test value was statistically significant (t = 8.28, p = 0.0001). The mean BUT scores were 13.19 +/- 5.09 s in the operated eyes and 27.83 +/- 9.31 s in the control eyes. The decrease was statistically significant (t = 7.86, p = 0.0001). CONCLUSION: PRK causes a decrease in tear flow and tear film stability that is probably caused by decreased corneal sensation after PRK.

Adult↗
PubMed1990

Effect of artificial tear solutions and saline on tear film evaporation.

The effect on tear evaporation of two artificial tear solutions is compared with that of an equal volume of saline instilled into the eye. Changes in tear evaporation rates (TER) were measured with a modified Servomed Evaporimeter in a cross-over study of nine subjects. Initial increases in TER were found with all three solutions; however, slight evidence exists for a faster return to baseline with artificial tear solutions.

Analysis of Variance↗
PubMed2006

Tear meniscus height, lower punctum lacrimale, and the tear lipid layer in normal aging.

PURPOSE: The purposes of this study are to investigate the tear meniscus height (TMH), lipid layer, and critical dimensions of the lower punctum lacrimale (DPL) in normal human subjects over a large age range; and to determine the shape and general characteristics of the lower punctum lacrimale in a normal population. METHODS: TMH and DPL were measured using a graticule set at the eyepiece of a slit lamp biomicroscope (magnification 32x). Lipid layer was assessed by interferometry (Tearscope, Keeler). Only one eye (right) of each subject was assessed. All subjects were normals without any tear-related disorders and/or symptoms. RESULTS: Four hundred forty-four subjects were assessed (268 females, age range, 6-91 years; 176 males, age range, 6-91 years). Mean (+/-standard deviation) TMH in females was 0.19 mm (+/-0.11) and in males was 0.19 mm (+/-0.10). TMH was related to age (x): in females, TMH=0.13+0.0009x (r=0.2393, p<0.001); in males, TMH=0.14+0.0008x (r=0.2492, p<0.001). TMH increased from 0.15 mm (+/-0.06) in the young (<20 years) to 0.21 mm (+/-0.10) in the elderly (>80 years). The punctum was closed in 10.8%, slit shaped in 24.3%, oval in 5.4%, and round in 59.5% of all cases. Mean age and TMH of those presenting with closed puncta was significantly higher than those presenting with open puncta (p<0.001). Mean (+/-standard deviation) area of open puncta was 0.008 mm (+/-0.013) in females and 0.010 mm (+/-0.018) in males. The difference was not significant. Diameter of round puncta was inversely related to age in females (r=-0.4985, n=149, p<0.001) but not within the males. A total of 14.6% of females and 12.5% of males presented with no discernible lipid layer. Lipid layer tended to be thinner in older subjects (one-way analysis of variance, F=6.667, p<0.001). There was no clear relationship between TMH and the lipid layer. CONCLUSIONS: There is a gradual increase in TMH and shift in size and shape of the punctum lacrimale with advancing years. Age-related changes in the lipid layer are expected to reduce tear volume by way of increased evaporation. On balance, it would appear any effects on tear volume by a thinning lipid layer are outweighed by changes in the puncta.

Adolescent↗