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At least 55 records · Page 3Linked to original sources
PubMed1992

Diurnal tear cycle: evidence for a nocturnal inflammatory constitutive tear fluid.

To investigate the tear film in the closed eye, microliter tear samples were collected without overt reflex stimulation throughout the diurnal cycle, with closed eye samples recovered immediately upon eye opening. Samples were subjected to agarose, polyacrylamide, and two-dimensional electrophoresis, coupled with immunofixation, immunoblot, and lectin blot assays. Major protein constituents were densitometrically and immunologically quantified. Results revealed a distinct progression in composition from reflex to open to closed eye tear samples. Total protein increased from 6.0 to 9.0 to 18.0 mg/ml, secretory IgA increased from less than 0.23 to 0.85 to 8.40 mg/ml, and serum albumin increased from 0.02 to 0.06 to 1.10 mg/ml. In contrast, concentrations of the major reflex tear components (lysozyme, lactoferrin, and tear specific prealbumin) remained essentially static. Immunoblot assay for complement C3 and C3c revealed that eye closure was associated with C3 activation. Results indicate that: (1) the reflex and closed eye tear layers represent opposite extremes in composition and likely origins, with open eye tear film suggesting an intermediate origin; (2) reflex tears are derived from a neurologically inducible lacrimal or accessory gland secretion composed almost exclusively of lysozyme, lactoferrin, tear specific prealbumin, and a minor mixed alpha to beta globulin fraction; (3) upon eye closure, reflex secretion ceases or greatly diminishes, with ongoing slower flow maintained by a constitutive secretion composed almost exclusively of secretory IgA; (4) the closed eye environment induces a subclinical inflammation, accounting in part for the marked rise in albumin concentration. This increase, coupled with that of secretory IgA, may play a critical role in protecting the closed eye environment from pathogens. However, this may render the closed eye environment particularly vulnerable to inflammatory and immune-mediated pathological processes, such as those seen with extended wear soft contact lenses.

Adult↗
PubMed2000

Age, stability of the precorneal tear film and the refractive index of tears.

PURPOSE: To investigate the relationship between age, stability of the precorneal tear film and refractive index of tear samples drawn from a normal population. METHODS: The stability of the precorneal tear film was estimated by measuring the Tear Thinning Time MT) using the Bausch and Lomb keratometer. Microlitre tear samples were obtained from the lower tear meniscus using glass capillary tubes. The refractive index (RI) was measured using a digital electronic Abbe refractometer with an accuracy of +/- 0.00005 units. Measurements were obtained from the right eyes of 110 subjects (55 male and 55 female) ranging in age from 18 to 89 years. They were all healthy, non-contact lens wearing individuals with no history of ocular disease or dry eye symptoms. RESULTS: A significant relationship was found between age (x) and tear stability (TTT) in both genders. Females, TTT = 32.89-0.33x, (Spearman correlation coefficient, r = -0.537, P = 0.0001). Males, TTT = 29.25-0.29x (Spearman correlation coefficient, r = -0.353, P = 0.008). A significant correlation was found between age (x) and refractive index (RI) in females only RI = 1.33815-0.000023x, (Spearman correlation coefficient, r = -0.299, P = 0.027). CONCLUSION: Tear stability is lower in the aged eye regardless of gender. Tear refractive index is lower in the older female eye.

Journal Article↗
PubMed1999

MR imaging for traumatic tears of the rotator cuff: high prevalence of greater tuberosity fractures and subscapularis tendon tears.

OBJECTIVE: The purpose of this study was to determine whether occult bony injuries or other characteristic MR abnormalities are frequent in patients suspected of having traumatic tears of the rotator cuff. SUBJECTS AND METHODS: MR arthrography of the shoulder was performed in 24 consecutive patients with suspected traumatic tears of the rotator cuff. MR findings were analyzed with regard to abnormalities of the supraspinatus, infraspinatus, and subscapularis tendons; and the humeral head. A comparison group of 24 consecutive patients with symptoms of nontraumatic tears of the rotator cuff was included in the investigation. RESULTS: Radiographically occult fractures of the greater tuberosity were found in nine (38%) of 24 patients with clinically suspected traumatic tears of the rotator cuff (seven of which occurred in patients <40 years old). Nine partial-thickness and five full-thickness supraspinatus tears were found in the trauma group. In the comparison group, the corresponding numbers were 13 and 10, respectively. Seven partial lesions of the cranial border of the subscapularis and six complete subscapularis tears (all six in patients >40 years old) were found in the trauma group (nine and one in the comparison group). CONCLUSION: Occult greater tuberosity fractures and complete subscapularis tears are commonly seen on MR images in patients suspected of having traumatic tears of the rotator cuff. Greater tuberosity fractures should be looked for specifically in patients younger than 40 years, and subscapularis tears should be looked for specifically in patients older than 40 years.

Adult↗
PubMed2003

[The accuracy of the clinical diagnosis of meniscal tears with or without associated anterior cruciate ligament tears].

OBJECTIVES: Meniscal tears and anterior cruciate ligament (ACL) tears commonly coexist in sports injuries. The purpose of this study was to analyze the influence of ACL deficiency on our ability to diagnose meniscal tears. METHODS: The study included patients with a clinical diagnosis of medial meniscal tears with (group A; 26 patients; 22 males, 4 females; mean age 26.6 years; range 18 to 67 years) or without (group B; 17 males; mean age 28.2 years; range 19 to 49 years) associated ACL tears. Patients with lesions other than meniscal or ACL tears were excluded. Clinical evaluations were made with the use of medial joint line tenderness, McMurray, and hyperextension tests. Preoperative diagnoses were compared with arthroscopic results and the accuracy of the tests used were calculated. The two patient groups were also compared with regard to the Lysholm scale parameters and total Lysholm scores. Fisher's exact test and Mann-Whitney U-test were used for statistical analysis. RESULTS: Medial joint line tenderness was present in 82% in group A, and 73% in group B. McMurray test was positive in 82% in group A, and 62% in group B; hyperextension test was positive in 73% in group A, and 61% in group B. The total Lysholm scores were significantly different, being 69 in group A, and 61 in group B (p<0.05). CONCLUSION: Our findings suggest that the accuracy of a clinical diagnosis of a meniscal tear is decreased by the presence of an ACL tear. The coexistence of meniscal and ACL tears requires a more careful clinical evaluation and a more frequent need for magnetic resonance imaging.

Adolescent↗
PubMed1991

Effect of topically applied oxymetazoline on tear volume and tear flow in humans.

Vasoconstrictive, alpha-sympathicomimetic eye drops are ophthalmic drugs that are extensively used. However, patients often complain of typical dry eye symptoms, especially after long-lasting application of such eye drops. In the present study, the effect of sympathicomimetic eye drops (0.026% oxymetazoline) on the tear volume and tear flow of 38 healthy individuals was determined quantitatively by means of objective fluorophotometry. Both tear volume and tear flow were found to be significantly (P less than 0.001) decreased up to 6 h after instillation, reaching a minimum 90 min after application (tear volume: -63%; tear flow: -71%). Thus, alpha-sympathicomimetic eye drops containing 0.026% oxymetazoline lead to a marked and protracted decrease in tear volume and tear flow. After frequent or long-lasting application, this fact may be responsible for severe dry eye conditions.

Administration, Topical↗
PubMed1983

The relations between tear fluid concentrations of lysozyme, tear-specific prealbumin and lactoferrin.

A degeneration of the tear gland leads to reduced lysozyme concentrations in the tear fluid. Tear lysozyme concentrations are generally determined by enzymatic methods. Lysozyme determination by radial immunodiffusion has some advantages above the enzymatic assays, and laboratory facilities are not required. The enzymatic properties of lysozyme that favoured its choice as a parameter for tear gland function, influenced to some extent the results of the radial immunodiffusion assay. Therefore we looked among the proteins originating from the lacrimal gland for alternative parameters of tear gland function. In 94 tear samples obtained from a heterogeneous group, ranging from persons with normal lacrimal gland function to severe kerato-conjunctivitis sicca patients, a high degree of correlation was found between lysozyme concentration and that of lactoferrin as well as tear-specific prealbumin. This indicates that the latter two proteins can be used as alternatives for lysozyme in tear gland function tests.

Electrophoresis, Polyacrylamide Gel↗
PubMed2000

Comparison of tear secretion and tear film instability after photorefractive keratectomy and laser in situ keratomileusis.

PURPOSE: To evaluate and compare tear secretion and tear film instability following photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK). SETTING: Department of Ophthalmology, Yonsei University School of Medicine, Seoul, Korea. METHODS: In a prospective study, 36 eyes (21 patients) had PRK and 39 eyes (25 patients) had LASIK to correct myopia. Tear secretion and tear film instability were tested preoperatively and 3 and 6 months postoperatively using Schirmer test values, tear breakup time (BUT) scores, and tear osmolarity. RESULTS: Six months after surgery, the change in Schirmer test values from preoperative levels was -14.57% +/- 6.39% (SD) in the PRK eyes and -23.40% +/- 5.94% in the LASIK eyes and the change in BUT scores, -12.54% +/- 8.28% and -18.79% +/- 13.01%, respectively. The change in tear osmolarity was 14.95% +/- 6.46% and 35.63% +/- 8.51%, respectively. CONCLUSIONS: The decrease in tear secretion was greater after LASIK than after PRK at 6 months. Proper treatment of dry eye is required after LASIK and PRK, particularly in the LASIK postoperative period.

Adult↗
PubMed1992

A classification for dry eyes following comparison of tear thinning time with Schirmer tear test.

In a double-blind study a non-invasive method of examining the stability of the precorneal tear film was used to record tear thinning time on a population of 34 independently diagnosed dry eye patients. The results were compared with those for tear output, as inferred from the standard Schirmer tear test, and a correlation coefficient of 0.20 determined. The mean tear thinning time and Schirmer results for the population sample were 6.87 +/- 2.97 sec, and 5.62 +/- 5.69 mm wetting in 5 min, respectively. From a plot of tear thinning time against Schirmer a simple classification for dry eyes can be made. A Type A with normal tear stability and low output accounting for 14.70% of the dry eyes. A Type B with low tear stability and normal output, also accounting for 14.70% of the dry eyes. A Type C with low stability (less than 9.84 sec), and low output (less than 11.31 mm wetting in 5 min) accounting for 70.60% of the dry eyes.

Adult↗
PubMed1991

[Effect of vasoconstrictor eyedrops on tear volume and tear secretion].

Vasoconstrictive, alpha-sympathicomimetic eye drops are ophthalmic drugs that are extensively used. However, patients often complain of typical dry eye symptoms, especially after long-lasting application of such eye drops. In the present study, the effect of sympathicomimetic eye drops (oxymetazoline 0.026%) on the tear volume and tear flow of 16 healthy individuals was determined quantitatively by means of objective fluorophotometry. Both tear volume and tear flow were found to be significantly (p less than 0.001) decreased 3 h after instillation (tear volume: -52%; tear flow: -31%). Thus, alpha-sympathicomimetic eye drops containing oxymetazoline 0.026% lead to marked and protracted decrease in tear volume and tear flow. After frequent or long-lasting application, this fact may be responsible for severe dry eye conditions.

Adult↗
PubMed2006

Lateral meniscus root tear and meniscus extrusion with anterior cruciate ligament tear.

PURPOSE: To retrospectively determine the prevalence of posterior lateral meniscus root tears (LMRTs), as depicted on magnetic resonance (MR) images, in patients with an anterior cruciate ligament (ACL) tear and to investigate the association of LMRTs with lateral meniscus extrusion and other ligament injuries. MATERIALS AND METHODS: Institutional review board approval was obtained; informed consent was not required. This study was HIPAA compliant. MR images were obtained in 174 male and 119 female patients (mean age, 37 years; age range, 16-87 years) and retrospectively reviewed for LMRT, medial meniscus root tear (MMRT), nonroot meniscus tear, meniscus extrusion, and presence of meniscofemoral ligaments (MFLs). The chi2 and unpaired Student t tests were performed. RESULTS: In 33 patients, 34 meniscus root tears were identified. An LMRT was present in 26 (9.8%) of 264 patients, and an MMRT was present in eight (3.0%) (P=.008). Lateral meniscus extrusion was present in six (23%) of 26 LMRTs and five (2.2%) of 231 patients with normal meniscus roots (P<.001). Complex or deep radial tears were found in three of five cases of lateral meniscus extrusion and normal root. The MFL was not observed in five (19%) of 26 studies of an LMRT. Among these 26 studies of an LMRT, lateral meniscus extrusion was identified in three (14%) of 21 cases in which the MFL was intact and in three (60%) of five cases in which the MFL was not identified (P<.03). Prevalence of an extruded meniscus was seven (88%) of eight for an MMRT and six (23%) of 26 for an LMRT (P=.001). CONCLUSION: Prevalence of LMRTs is greater than that of MMRTs in patients with an ACL tear. LMRTs and complex and radial tears are associated with lateral meniscus extrusion; an absent MFL is more prevalent in patients with LMRTs and when the meniscus is extruded.

Adolescent↗
PubMed1996

Sonographic detection of tears of the anterior portion of the rotator cuff (subscapularis tendon tears).

We studied the value of ultrasonography in identifying tears of the most anterior portion of the rotator cuff (subscapularis tendon tears). Shoulder sonography was performed on 1640 patients with shoulder symptoms, 435 of whom underwent surgery. Among the patients who were operated on, 17 had predominantly or exclusively subscapularis tendon tears; 14 of these were full-thickness and three were partial-thickness tears. Ultrasonography demonstrated 82% (14 of 17) of the subscapularis tendon tears; 86% (12 of 14) of the full-thickness tears and 67% (2 of 3) of the partial-thickness tears were correctly diagnosed with ultrasonography. Sonography can diagnose and show the size of subscapularis tendon tears reliably, but it necessitates that the arm can be externally rotated to the maximum extent when performing the study.

Adult↗
PubMed1991

Effect of eledoisin on tear volume and tear flow in humans as assessed by fluorophotometry.

Topical application of the endekapeptide eledoisin has been reported to increase tear secretion in patients with dry eye. However, to date the efficacy of eledoisin has been proved only by methods that are not easily reproduced and have an enormous intraindividual scatter range (Schirmer test, basic secretion test). In the present study the effect of topically applied eledoisin on tear volume and tear flow was determined quantitatively by means of objective fluorophotometry in 40 subjects, 20 of whom suffered from severe dry eyes. Both tear volume and tear flow were found to be significantly increased up to 2 h after instillation, reaching a maximum 1 h after application (tear volume: +87% and +35% for dry eyes and healthy controls, respectively; tear flow: +250% and +27% for dry eyes and healthy controls, respectively).

Administration, Topical↗
PubMedDate not supplied

Effect of lacrimal punctal occlusion on tear production and tear fluorescein dilution in normal dogs.

OBJECTIVE: To evaluate effects of lacrimal punctal plugs positioned in either the upper, lower, or combination of upper and lower lacrimal canaliculi on plug retention and tolerance; tear production, as measured by the Schirmer tear test; and the dilution of fluorescein within the tear film in normal dogs. MATERIAL AND METHODS: Lacrimal punctal plugs were positioned in the lower, upper, or combination of lower and upper plugs in six laboratory-quality Beagles under topical anesthesia. Retention of plugs was evaluated daily from 8 to 23 days by visual inspection and slit-lamp biomicroscopy. Schirmer tear tests (STT 1 without topical anesthesia) were performed at 48-h intervals. Dilution of fluorescein was determined at 5- and 45-min post-fluorescein instillations once weekly. RESULTS: Lacrimal punctal plugs of 0.4 and 0.6 mm in diameter were retained for 14 (lower plugs: 100%) and 23 days (75%), and for the upper plugs at 8 days less often (75%), and were infrequently locally nonirritating. Combination of lower and upper plugs seemed to adversely affect retention of either plug. When loss of the plugs occurred, a next larger size plug was necessary suggesting some stretching of the lacrimal canaliculi occurred. Pre- and postplug placement STT results indicated no change with lower and combination lacrimal punctal plugs, but decreased levels following upper lacrimal punctal plugs. Tear fluorescein levels at 5 and 45 min in control eye (no punctum plugs) were 3.39% and 0.14%, respectively. With lower, upper, and the combination of lower and upper lacrimal puncta plugs, tear fluorescein levels at 45 min were higher than the controls (lower: 0.76%; upper: 0.45%, and combination 0.56%). CONCLUSION: Lacrimal punctal silicone plugs are retained for 8-23 days in the lower, upper, and combined lower and upper canaliculi at high rates. Effects on STT levels appear limited. Fluorescein within the tear film persists longer with all different positioned lacrimal punctum plugs than in the control eyes.

Animals↗
PubMed2000

Tear secretion and tear film function in insulin dependent diabetics.

BACKGROUND: Diabetic patients often complain of dry eye symptoms, such as burning and/or foreign body sensation. The aim of the present study was to investigate whether diabetes mellitus is correlated with tear film dysfunction and/or tear hyposecretion. METHODS: In 86 consecutive insulin dependent diabetics with retinopathy and 84 non-diabetic controls (age and sex matched) we performed fluorophotometry of tear secretion, the Schirmer test, and impression cytology of the conjunctival epithelium and determined the tear film break up time. RESULTS: When compared with the healthy control group diabetics showed decreased Schirmer test readings (-37%, p <0.001) and significantly more frequent and pronounced signs of conjunctival metaplasia. None of the other values differed between groups. CONCLUSION: In insulin dependent diabetics, reflex tearing was demonstrated to be significantly decreased. In contrast, unstimulated basal tear flow and tear film break up time were found to be normal. However, a majority of insulin dependent diabetics shows distinct signs of conjunctival surface disease.

Aged↗
PubMed2003

Kinetic analysis of tear interference images in aqueous tear deficiency dry eye before and after punctal occlusion.

PURPOSE: Kinetic analysis of sequential tear interference images was used to investigate how the precorneal lipid film spread and distributed in aqueous tear deficiency (ATD) dry eye. METHODS: One eye of 17 patients with ATD was randomly selected for this noncomparative case series. Twelve patients also had noninflamed meibomian gland dysfunction (MGD). Sequential images were digitized and analyzed on computer. Data were further compared in 9 of the 17 cases before and after punctal occlusion (PO). Outcome measures included speed and pattern of lipid spread and resultant lipid layer thickness in the superior, central, and inferior cornea. Intensity and red/green/blue (RGB) color spectra of the tear interference image were compared before and after PO. RESULTS: After lid blinking, it took a longer time (2.2 +/- 1.1 second) to reach a stable lipid film in all eyes with ATD compared with normal subjects (P < 0.0001). Because of this retarded spread, the thickest lipid film was located at the inferior cornea adjacent to the lid margin, with a gradient spreading toward the superior cornea (P = 0.01). As a result, the lipid film was thinner than normal on the superior cornea in 10 of 17 (59%) ATD eyes. Fifteen of 17 eyes (88%) showed vertical streaking, rather than a normal horizontal propagation pattern on the superior cornea. Such a lipid-deficient state and uneven distribution did not correlate with the presence or absence of MGD. The lipid spread time was shortened (P = 0.008), the distribution of the lipid film was more even, and the thickness approached normal in all nine eyes after PO. CONCLUSIONS: In this study, kinetic analysis of tear interference images provided evidence that retardation of lipid spread is, but MGD is not, the main reason for the increased thickness of precorneal lipid film in the inferior cornea of eyes with ATD. As a result, lipid film is deficient in the superior cornea and unevenly distributed, further destabilizing the tear film. The fact that PO significantly improves lipid spread, evenness, and thickness suggests that the performance of lipid film is also dictated by the amount of aqueous tear fluid. These findings provide new insight into the interaction between the lipid film and the aqueous tear fluid.

Adult↗
PubMedDate not supplied

Changes in corneal and conjunctival sensitivity, tear film stability, and tear secretion after strabismus surgery.

PURPOSE: Some patients complain of a foreign body sensation, a burning sensation, or dryness after strabismus surgery. We prospectively investigated the changes in corneal and conjunctival sensitivity, tear film stability, and tear secretion after strabismus surgery. PATIENTS AND METHODS: Corneal and conjunctival sensitivity were assessed with an esthesiometer, tear film breakup time was measured, and the Schirmer test was performed prospectively (preoperatively and 1 week, 1 month, and 3 months postoperatively) in 83 patients (124 eyes) who underwent strabismus surgery at our institution. RESULTS: There were no significant changes in corneal sensitivity, tear film stability, or tear secretion after strabismus surgery (P > .05). Conjunctival sensitivity decreased significantly after strabismus surgery (P < .05). CONCLUSION: Discomfort and dryness after strabismus surgery do not seem to be related to changes in corneal sensitivity, tear film stability, or tear secretion.

Adolescent↗
PubMed1983

Human tear volume, quality and evaporation: a comparison of Schirmer, tear break-up time and resistance hygrometry techniques.

A group of 10 subjects had their tears evaluated by the Schirmer and tear break-up time (TBUT) tests and their rate of tear evaporation measured by resistance hygrometry. No significant relation was found between the evaporation of the tears and the results obtained by either the Schirmer or the TBUT test. No correlation was found between the Schirmer and the TBUT test results. A significant increase in tear evaporation rate was however produced by the instillation of fluorescein during the TBUT test and by the application of Schirmer strips during the Schirmer test. It is concluded that the Schirmer and TBUT tests measure different features of the tears and these features are not related to the rate of tear evaporation.

Adult↗