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PubMed1981

Basal and reflex human tear analysis. II. Chemical analysis: lactoferrin and lysozyme.

Unstimulated basal tears and stimulated tears were collected from normal controls, keratoconjunctivitis sicca (KCS) patients, and contact lens (CL) wearers. Basal tear volume (Periopaper) and reflex tear volume (Schirmer Strip) were measured and tears eluted from their respective strip with a TMED-acetic acid buffer. Lactoferrin and lysozyme concentrations were measured in the eluates. Concentration of lysozyme in basal tears was: 65 +/- 43 mg% in normals; 44 +/- 26 mg% in KCS, and 81 +/- 50 mg% in CL wearers. Concentration of lysozyme in reflex tears was: 160 +/- 73 mg% in normals, 74 +/- 41 mg% in KCS, and 186 +/- 83 mg% in CL wearers. Concentration of lactoferrin in basal tears was 137 +/- 102 mg% in normals, 154 +/- 82 mg% in KCS, and 157 +/- 80 mg% in CL wearers. Concentrations of lactoferrin in reflex tears was: 327 +/- 187 mg% in normals; 171 +/- 69 mg% in KCS, and 302 +/- 160 mg% in CL wearers. The lactoferrin concentration in all tear samples was consistently higher (1.6-3.5 times) than lysozyme. In basal tears, lactoferrin concentrations were not significantly different in the three groups. In reflex tears, however, lactoferrin was significantly lower in KCS than normal or CL wearers. The concentration of lysozyme in both basal and reflex tears was significantly lower in the KCS when compared to normal or CL wearers. Lysozyme and lactoferrin concentrations in both basal and reflex tears were similar in CL wearers and normal controls. The sampling and elution of basal and reflex tears as described appears to be a feasible technique for analysis of lysozyme and lactoferrin concentrations by the electroimmunodiffusion technique and has potential diagnostic value.

Contact Lenses↗
PubMed2004

The effect of prematurity on tear production.

PURPOSE: To evaluate the effect of the birth weight and the postconceptional age on the tear production of preterm and term newborn infants and to evaluate the changes in tear production during the first two months of life. SUBJECTS--METHODS: Both eyes of medically stable term and preterm infants were included in the study. Based on postconceptional age and birth weight, we divided preterm infants into three groups. Then, we measured the basal and reflex tear secretions of both eyes by Schirmer tests before and after instillation of topical anesthetic agent. We performed initial tear measurements on the second day of life (between first 24 hours to first 48 hours after birth): and at 2 weeks, 4 weeks and 8 weeks after birth. RESULTS: We tested a total of 138 infants (63 preterm and 75 term), 72 males and 66 females. Schirmer-1-test of preterm and terms on the 2nd day of life revealed a mean basal tear secretion (BTS) of 4.8 +/- 4.1 and 8.8 +/- 3.2 mm, respectively (p < 0.0001). The mean reflex tear secretion (RTS) within 48 hours of life was 6.1 +/- 3.9 mm and 10.3 +/- 4.4 mm in preterm and term infants, respectively (p < 0.0001). The mean values of both basal and reflex tear secretion were significantly lower in the preterm than the term infants during the first two months of the life. In preterm infants, both basal and reflex tear secretions were found to be highly correlated with postconceptional age (r: 0.79 and 0.74, respectively, both p values: 0.001); however, there was a weak correlation with birth weight (r: 0.16 and 0.19, respectively, both p values: 0.01). Statistically significant differences for both BTS and RTS existed among the three postconceptional age groups: there were no such difference among the three different birth weight groups. We found no gender or laterality dependent (side of the eyes) differences in the tear production (both p values >0.05). CONCLUSIONS: Preterm infants have significantly reduced tear secretion compared with term infants. Postconceptional age, rather than birth weight, seems to be more correlated with the tear secretion. Sex and laterality does not appear to have an effect on tear production in infants. Tear production of preterm infants is significantly reduced than that of term infants during the first two months of life. Term infants increased their tear production significantly in each examination during the neonatal period while the preterms increase tear production significantly only at mean postconceptional age of eight and a half (8.5) months.

Birth Weight↗
PubMed2005

Effect of artificial tears on visual performance in subjects with dry eye.

PURPOSE: Disruption of the anterior refracting surface of the eye (i.e., the tear layer) reduces visual performance. Tear layer breakup occurs soon after a blink in contact lens wearers and patients with dry eye. This study determined whether artificial tears stabilize the tear film and improve visual performance in contact lens wearers who also exhibit a dry eye. METHODS: Five subjects with mild to moderate dry eye (probably as a result of an evaporative dry eye) during spectacle and contact lens wear were fitted with a Focus Night & Day hydrogel lens for this study. A temporal, two-alternative, forced-choice paradigm was used to measure contrast sensitivity. The stimuli were vertically oriented sine wave gratings (between 0.5 and 14 cpd) presented for 16.67 msec. The stimuli were presented at two different times after blink detection: 2 sec after blink detection (i.e., before tear layer breakup) or 4 sec after tear film breakup. Four conditions were investigated at 4 sec after tear layer breakup: 1) without artificial tears added, 2) with Clerz2 (Alcon, Fort Worth, TX) instilled, 3) with Sensitive Eyes (Bausch & Lomb, Rochester, NY), and 4) with GenTeal (Novartis, Basel, Switzerland) applied. The artificial tears were instilled at 10-min intervals during the data collection. The short-term visual effects of drop instillation were also investigated by continually monitoring contrast sensitivity for a 14-cpd grating after a single-drop administration. RESULTS: High spatial frequency contrast sensitivity and visual acuity were found to be reduced after tear film breakup in the absence of supplementation with artificial tears. For the group data (and four of five subjects), the instillation of Sensitive Eyes improved the contrast sensitivity and visual acuity to the level attained before tear breakup, thus prolonging visual performance. Clerz2 and GenTeal did not produce any enhancement in visual performance. A short-term decrease in contrast sensitivity was also observed with a single administration of Clerz2 and GenTeal. CONCLUSIONS: This study indicates that there was a benefit of Bausch & Lomb Sensitive Eyes tear supplementation on visual performance in subjects with an evaporative dry eye. This may be the result of 1) aqueous supplementation in these subjects and/or 2) the minimal tear layer disruption found with Sensitive Eyes drop administration. The results suggest that practitioners need to identify those patients who can benefit from the use of appropriate artificial tear supplements.

Adult↗
PubMed1996

Transforming growth factor beta-1 and beta-2 in human tear fluid.

PURPOSE: To evaluate human tear fluid for transforming growth factor beta isoforms 1 and 2 (TGF-beta1 and TGF-beta2). METHODS: To accomplish this, human tears were evaluated for TGF-betas by quantitative antibody sandwich ELISA (sELISA), mink lung epithelial cell (MLEC) growth inhibition bioassay and western blotting. Various physical and chemical treatments were used to activate TGF-beta in these assays. RESULTS: TGF-betas could not be detected in untreated or heated tears by sELISA; however, mean TGF-beta1 concentrations of 2.32 ng/ml were detected in acid-activated tears by sELISA. Furthermore, 10.54 ng/ml of TGF-beta1 and 2.98 ng/ml of TGF-beta2 were detected in tears treated with the mucolytic agent, acetylcysteine. Total TGF-beta bioactivity in human tears measured by the MLEC assay was found to be 13.04 ng/ml in untreated tears and 24.85 ng/ml in acid-activated tears. Approximately one-half TGF-beta in tear specimens was biologically active (mean = 52%, range 39-71%). Total tear TGF-beta bioactivity could be completely neutralized by recombinant human TGF-beta1 latency associated peptide (rh TGF-beta1 LAP). Mean neutralization of tear TF-beta bioactivity was 83% by TGF-beta1-specific antisera, and was 13% by TBF-beta2-specific antisera. Immunoreactive TBF-beta bands at approximately 12.5 and 95 kD were observed in immunoblots of reduced acidified tears. A high molecular weight (MW) TGF-beta band (>203 dD) was noted in untreated tears; however, this band disappeared following treatment with acetylcysteine. CONCLUSIONS: The results of these studies indicate that TGF-beta1 and TGF-beta2 are present in human tear fluid, and TGF-beta1 is the predominant isoform. There appear to be factors in human tears capable of binding TGF-beta.

Acetylcysteine↗
PubMed1998

Inflammatory cytokines in normal human tears.

PURPOSE: To elucidate inflammatory cytokine levels in normal human tears, we investigated the concentrations of interleukin-1alpha (IL-1alpha), interleukin-1beta (IL-1beta), interleukin-6 (IL-6), and interleukin-8 (IL-8) both in basal tears and reflex tears of normal healthy eyes. METHODS: Tear samples were collected from 270 healthy, normal volunteers with no past history of ocular surface disease; the total number of eyes was 295. All tear samples were collected in graduated disposable microcapillaries from the conjunctival cul-de-sac. Reflex tear stimulation was carried out by inserting an applicator into each volunteer's nose. Cytokine levels in basal tears and reflex tears were determined by ELISA. Tears were not diluted, and pooled samples were used for the cytokine assays. RESULTS: In basal tears, the concentrations of IL-1alpha, -1beta, -6 and -8 were 10.9 +/- 1.2, 12.9 +/- 2.3, 226.2 +/- 29.6 and 731.4 +/- 116.2 pg/ml, respectively. In reflex tears, IL-1beta was not detectable, and the concentrations of IL-1alpha, -6 and -8 were 9.3 +/- 2.7, 11.6 +/- 1.6 and 276.1 +/- 47.5 pg/ml respectively. IL-1beta, -6 and -8 levels in reflex tears were significantly lower than those in basal tears, except for IL-1alpha. CONCLUSIONS: In the present study, the normal concentration range of inflammatory cytokines in human basal tears was clarified, as a baseline for further studies to examine the levels of these cytokines in tears during disease states.

Adult↗
PubMed2002

Correlation between type of discoid lateral menisci and tear pattern.

This study analyzed the relationship between type of discoid lateral menisci and tear pattern. There were 108 consecutive cases (103 patients) with discoid lateral meniscus tear treated by arthroscopy. Regarding type of discoid meniscus (Watanabe's classification), 38 cases were "complete" and 70 cases "incomplete." There was no Wrisberg type. Tear patterns were classified into simple horizontal, complicated horizontal, longitudinal, radial, degenerative, and complex tear. The relationship between tear pattern and type of discoid menisci was statistically highly significant. Simple horizontal tear was found only in the complete type of case, and radial, degenerative, and complex tears were found only in the incomplete type of case. In the longitudinal tear, however, we found no correlation between tear pattern and type of discoid meniscus. In addition, the extent of meniscal resection was dependent on the tear pattern. Subtotal or total meniscectomy was performed significantly more frequently in longitudinal and complex tears. In radial and degenerative tears only partial meniscectomy was carried out. Complicated horizontal tears showed no difference in extent of resection. Among the 13 cases of simple horizontal tears partial meniscectomy was performed in 12 cases. These findings about relationship between the type of discoid menisci and tear pattern could be useful in planning operation and deciding extent of resection.

Adolescent↗
PubMed2007

Classification and localization of acetabular labral tears.

OBJECTIVE: The purpose of this study was to compare the findings on hip MR arthrography (MRA) with the published MRA and arthroscopic classifications of hip labral tears and to evaluate a clock-face method for localizing hip labral tears. DESIGN/PATIENTS: We retrospectively reviewed 65 hip MRA studies with correlative hip arthroscopies. Each labrum was evaluated on MRA using the classification system of Czerny and an MRA modification of the Lage arthroscopic classification. In addition, each tear was localized on MRA by using a clock-face description where 6 o'clock was the transverse ligament and 3 o'clock was anterior. These MRA findings were then correlated with the arthroscopic findings using the clock-face method of localization and the Lage arthroscopic classification of labral tears. RESULTS: At MRA, there were 42 Czerny grade 2 and 23 grade 3 labral tears and 22 MRA Lage type 1, 11 type 2, 22 type 3 and 10 type 4 tears. At arthroscopy, there were 10 Lage type 1 flap tears, 20 Lage type 2 fibrillated tears, 18 Lage type 3 longitudinal peripheral tears and 17 Lage type 4 unstable tears. The Czerny MRA classification and the modified MRA Lage classification had borderline correlation with the arthroscopic Lage classification. Localization of the tears using a clock-face description was within 1 o'clock of the arthroscopic localization of the tears in 85% of the patients. CONCLUSIONS: The Lage classification, which is the only published arthroscopic classification system for hip labral tears, does not correlate well with the Czerny MRA or an MRA modification of the Lage classification. Using a clock-face description to localize tears provides a way to accurately localize a labral tear and define its extent.

Acetabulum↗
PubMed2005

The use of axial reconstructed images from three-dimensional MRI datasets for morphological diagnosis of meniscal tears of the knee.

INTRODUCTION: In recent years, three-dimensional (3D) MRI has been utilized to detect meniscal tears and has displayed several advantages over 2D MRI. The diagnostic performance to discriminate the type of meniscal tears by 2D MRI (sagittal and coronal images) and axial images from 3D MRI datasets has not been reported yet. The aim of the present study is to evaluate the efficacy of the axial reconstructed images from 3D MRI datasets for the morphological diagnosis of meniscal tears of the knee. MATERIALS AND METHODS: Seventy-four menisci in 37 patients who underwent arthroscopic surgery of the knee were studied. All patients were examined by 2D sagittal and coronal MRI and by axial images from 3D MRI datasets prior to surgery. First, we compared the diagnostic performance for meniscal tears by 2D sagittal and coronal MRI to that by axial images from 3D MRI datasets as judged by arthroscopic findings. Second, we compared the correlation of tear types presumed from 2D sagittal and coronal MRI to arthroscopy with those presumed from axial images from 3D MRI datasets to arthroscopy. RESULTS: For the diagnostic performance of meniscal tears on 2D MRI, the sensitivity, specificity and accuracy were 93.5%, 88.4% and 90.5%, respectively. On axial images from 3D MRI, the sensitivity, specificity and accuracy were 96.8%, 79.1% and 86.5%, respectively. Nine cases were false-positive on axial images, while 5 cases were false-positive on 2D images. Correlations to arthroscopy were 100% by both scans for longitudinal tears and discoid meniscus tears. Only 29% were correctly diagnosed by 2D sagittal and coronal images for radial tears, however, all radial tears could be correctly diagnosed by axial images. All horizontal tears were correctly diagnosed on 2D sagittal and coronal images, while none of the horizontal tears could be correctly diagnosed from axial images. CONCLUSION: Axial images from 3D MRI datasets were useful in the diagnosis of radial tears, but two limitations are noted concerning the use of axial images. First, medial menisci should be carefully read on axial slices because of the relatively high rate of false-positives on medial menisci. Second, axial images cannot discriminate horizontal tears from other types of meniscus tears.

Adolescent↗
PubMed2006

Fate of anterior capsule tears during cataract surgery.

PURPOSE: To determine the incidence of anterior capsule tears, at what stage of surgery they occurred, and their intraoperative behavior. SETTING: Ambulatory surgery center, Cincinnati Eye Institute, Cincinnati, Ohio, USA. METHODS: This 5-year retrospective study was of patients having phacoemulsification with posterior chamber intraocular lens (IOL) implantation complicated by unplanned peripheral extension of the capsulorhexis tear or a radial anterior capsule tear. The operative notes and a videotape of the surgery were reviewed. The stage at which the tear was initially observed and when it extended were identified, as was whether the tear extended to the posterior capsule. Anterior vitrectomy and the design and location of the IOL implanted were also analyzed. RESULTS: A discontinuous anterior capsulorhexis or a break in the anterior capsule rim was observed in 21 eyes of 2646 cases, for an overall incidence of 0.79%. Anterior capsule tears were identified during ophthalmic viscosurgical device injection in 1 eye, capsulorhexis in 13 eyes, hydrodissection in 2 eyes, phacoemulsification in 3 eyes, irrigation/aspiration (I/A) in 1 eye, and implantation of a prosthetic iris device in 1 eye. Seven of the 13 tears identified during the capsulorhexis were managed by redirecting the second edge of the "safety" capsulorhexis to incorporate the tear. In 14 eyes, the tear in the anterior capsule extended into the zonules; 4 of these tears were limited. Ten tears extended around the equator and through the posterior capsule, occurring during the hydrodissection in 1 eye, phacoemulsification in 2 eyes, I/A in 1 eye, and IOL implantation in 6 eyes. An anterior vitrectomy was required in 4 eyes that had posterior capsule involvement. Endocapsular fixation of a 1-piece acrylic IOL was achieved in 18 eyes. Three eyes required implantation of a 3-piece acrylic IOL in the ciliary sulcus. CONCLUSIONS: Extension of an anterior capsule tear can complicate cataract surgery at any stage. Extension of the tear through the posterior capsule occurred in almost half the eyes with an anterior capsule tear, often requiring an anterior vitrectomy. Managing an anterior capsule tear can be challenging yet compatible with implantation of a posterior chamber IOL.

Capsulorhexis↗
PubMed2006

Imaging factors related to rotator cuff tear in patients with deltoid contracture.

BACKGROUND: Bony deformity and muscular malfunction around the shoulder induced by deltoid contracture may influence rotator cuff function and lead to subsequent tearing. The purpose of this study was to investigate the imaging and clinical factors related to rotator cuff tear in patients with deltoid contracture. METHODS: We retrospectively reviewed 48 shoulders in 44 patients with magnetic resonance imaging diagnosis of deltoid contracture and surgically-proven rotator cuff tear. These shoulders were subdivided into partial-thickness and full-thickness tear groups. Another 17 shoulders in 17 patients with deltoid contracture but no evident rotator cuff tear were included as the control group. The characteristics, including age, gender and imaging features, of these three groups were compared. RESULTS: Two patients who underwent initial operations for cuff tears required secondary operations for distal release of deltoid contracture. The age of patients with full-thickness tear was significantly greater than that of patients with partial-thickness tear or without tear. The winging angle of the glenoid (WAG) in the full-thickness tear group was significantly greater than that in the partial-thickness tear group. Patients with partial-thickness tear also had greater WAG than those without tear. However, WAG was not significantly correlated with the fibrotic size or age of the patient. CONCLUSION: In patients with deltoid contracture, age and WAG are associated with the development of rotator cuff tear. To prevent the occurrence of rotator cuff tear, early surgical release of deltoid contracture is highly recommended, especially in patients with greater WAG.

Adult↗
PubMed1996

Site and size of rotator-cuff tear. Findings at ultrasound, double-contrast arthrography, and computed tomography arthrography with surgical correlation.

RATIONALE AND OBJECTIVES: The authors discuss findings of ultrasound (US), double-contrast arthrography (AG), and contrast computed tomography arthrography (CTA) in assessing precise site and size of rotator-cuff tears. METHODS: Eighty-six patients were compared prospectively in a masked fashion; the results of surgery were studied in 25 patients and the results of arthroscopy were studied in 61 patients. RESULTS: Ultrasound detected 80% (8 of 10) of the partial-thickness tears and 90% (18 of 20) of the full-thickness tears. Arthrography and CTA had identical results with 70% sensitivity (7 of 10) in partial-thickness tears; AG showed 90% (18 of 20) and CTA 95% (19 of 20) of the full-thickness tears. Arthrography had two false-positive findings, and US and CTA had one each. The size of a tear could be evaluated correctly with AG in 30% (9 of 30), with US in 70% (21 of 30) and with CTA in 76% (23 of 30). More extensive tears were encountered at US than had been found at surgery in 2% (2 of 86) and less extensive tears in 9% (8 of 86); CTA depicted more extensive tears in 2% (2 of 86) and less extensive tears in 6% (6 of 86), respectively. The site of a tear could be evaluated with AG in 30% (9 of 30); US and CTA showed the site correctly in every patient in which the tear could be diagnosed. CONCLUSION: Ultrasound and CTA were equally accurate in diagnosing and evaluating the size and site of rotator-cuff tears. Double-contrast AG was less accurate in the diagnosis of tears and the size and site of tears clearly could be assessed worse.

Adult↗
PubMed2004

The occurrence of anular tears and their relation to lifetime back pain history: a cadaveric study using barium sulfate discography.

STUDY DESIGN: The occurrence of anular tears and general disc degeneration of the lumbar spine was studied in relation to the lifetime frequency of back pain. SUMMARY OF BACKGROUND DATA: Although anular tears and ruptures are common targets for diagnostic and therapeutic approaches, the relationship between disc findings and back pain has been weak or nonexistent. METHODS: The data comprised barium sulfate discograms of lumbar spine levels from 157 male cadavers. The extent of "anular tears" and "general disc degeneration" based on posterior-anterior and side views were evaluated separately using a 4-point scale. Lifetime history of back pain occurrence and work were obtained from the families of 86 cadavers. To assess whether the risk of back pain changed with the severity of findings or the level of disc, we applied trend tests and proportional-odds logistic models for occurrence data. RESULTS: In early adulthood, the risk of anular tears was 0.6 to 0.7, whereas at retirement age, tears were practically unavoidable. The risk of full anular tears with barium sulfate leaking ("leaking" tear) was estimated to be 0.10 and 0.35 among the men in the age groups of 20 to 49 and 50 to 59 years, respectively. The risk of "leaking" tears was greatest at the L5-S1 levels. There were less severe degenerative findings associated with sedentary occupation but no differences between driving and physically light and heavy occupations. Overall, the risk of any anular tears and any general degeneration as defined was similar. The frequency of back pain had a highly significant relation to the occurrence of tears (model-based P = 0.0009). With a "leaking" tear, the model-based estimate of the risk of frequent lifetime back pain was 0.42, with an "outer" tear the risk was 0.20, and with no tears or "inner" tears the risk was 0.10 (the observed prevalence was 0). The effect of occupational loading was of borderline significance (P = 0.045). CONCLUSION: Anular degeneration of the lumbar discs appear earlier and are more clearly related to back pain than previously thought, most probably due to the better sensitivity of the BaSO4 discography method to detect tears.

Adult↗
PubMed2003

The clinical importance of meniscal tears demonstrated by magnetic resonance imaging in osteoarthritis of the knee.

BACKGROUND: Meniscal tears are frequently found during magnetic resonance imaging of osteoarthritic knees. However, the prevalence and clinical relevance of these tears have not been determined. This study was designed to investigate the relationship between meniscal tears and osteoarthritis and between such tears and pain in patients with osteoarthritis. METHODS: Magnetic resonance imaging and plain radiography of the knee were performed in a group of 154 patients with clinical symptoms of knee osteoarthritis and a group of forty-nine age-matched asymptomatic controls. Pain scores (according to a 100-mm visual analog scale) and functional scores (according to the Western Ontario and McMaster University Osteoarthritis Index [WOMAC]) were determined for ninety-one of the patients with symptomatic osteoarthritis. Meniscal tears were defined as tears extending to an articular surface as seen on magnetic resonance imaging. RESULTS: A medial or lateral meniscal tear was a very common finding in the asymptomatic subjects (prevalence, 76%) but was more common in the patients with symptomatic osteoarthritis (91%) (p < 0.005). In the group with symptomatic osteoarthritis, a higher Kellgren-Lawrence radiographic grade was correlated with a higher frequency of meniscal tears (r = 0.26, p < 0.001), and men had a higher prevalence of meniscal tears than did women (p < 0.01). However, there was no significant difference with regard to the pain or WOMAC score between the patients with and those without a medial or lateral meniscal tear in the osteoarthritic group (p = 0.8 to 0.9 for all comparisons). The power of the study was 80% to detect a difference in the WOMAC scores of 15 points and a difference in the scores on the visual analog scale of 16 mm. CONCLUSIONS: Meniscal tears are highly prevalent in both asymptomatic and clinically osteoarthritic knees of older individuals. However, osteoarthritic knees with a meniscal tear are not more painful than those without a tear, and the meniscal tears do not affect functional status. These data do not support the routine use of magnetic resonance imaging for the evaluation and management of meniscal tears in patients with osteoarthritis of the knee. LEVEL OF EVIDENCE: Diagnostic study, Level I-1 (testing of previously developed diagnostic criteria in series of consecutive patients [with universally applied reference "gold" standard]). See p. 2 for complete description of levels of evidence.

Age Factors↗
PubMed1993

MR diagnosis of meniscal tears of the knee: importance of high signal in the meniscus that extends to the surface.

OBJECTIVE: The presence of intrameniscal signal in contact with the surface is a commonly used criterion for the diagnosis of meniscal tear. This signal presumably represents the actual tear in the meniscus. However, some menisci with signal that contacts the surface are noted to be intact at arthroscopy whereas other menisci that have no signal in contact with the surface are found to be torn. We investigated the relationship between the presence of a meniscal tear at arthroscopy and the location within the menisci of signal that contacted the surface. We hypothesized that patterns were present that would improve the accuracy of MR diagnosis of a meniscal tear. MATERIALS AND METHODS: We reviewed the MR and arthroscopic findings from 200 consecutive patients who had both knee MR examinations and knee arthroscopy. There were 108 medial and 58 lateral meniscal tears on arthroscopy. Each MR examination was reviewed for three aspects of intrameniscal signal: the number of images showing signal possibly or definitely contacting the surface, the specific surfaces involved, and the signal location. The coronal and sagittal images were evaluated separately. We correlated each of these features with the presence of a meniscal tear at arthroscopy. RESULTS: Menisci with signal possibly contacting the surface had the same frequency of tears (three tears in 33 menisci) as menisci without signal contacting the surface (15 tears in 194 menisci). More than 90% of menisci with signal contacting the surface on more than one image were torn, but only 55% of medial and 30% of lateral menisci with such signal on only one image were torn. In the torn menisci with signal contacting the surface, such signal was seen only on sagittal MR images in 31% of the medial menisci and 45% of the lateral menisci. Sixteen percent of the torn lateral menisci had signal contacting the meniscal surface in only the anterior two thirds of the meniscus, whereas this was true in only 2% of the torn medial menisci. Distinct patterns were not seen in the association between tears and signal contacting either the superior or the inferior surface. CONCLUSION: We found definite patterns in the location of intrameniscal signal that comes in contact with the meniscal surface. These patterns vary in the frequency of associated meniscal tears. Although menisci with internal signal in contact with the surface are usually torn, a tear is less likely if such signal is present on only one image. Tears may be identifiable on only one image plane. Tears in the anterior horn of the lateral meniscus are not uncommon. Knowledge of these patterns should help in the MR diagnosis of meniscal tears.

Adolescent↗
PubMed2004

Detection of meniscal tears and marrow lesions using coronal MRI.

OBJECTIVE: The usefulness of coronal images in addition to sagittal images for detection of additional meniscal injuries or bone lesions has been questioned. Some authors believe meniscal tears are rarely seen only in the coronal plane. We performed a retrospective review of coronal and sagittal MR images of the knee to determine whether coronal imaging resulted in the detection of any additional meniscal tears or bone lesions when compared with sagittal MRI of the knee alone. MATERIALS AND METHODS: Two musculoskeletal radiologists retrospectively reviewed 200 consecutive sets of MR images of the knee by consensus. Both observers recorded their retrospective findings on sagittal proton density images, sagittal and coronal T2-weighted images, and coronal T1-weighted images. Findings recorded were those of meniscal tears, bone marrow abnormalities, and bone lesions. RESULTS: On these 200 consecutive sets of MR images of the knee, 114 meniscal tears were shown. Ninety-three meniscal tears were shown on sagittal proton density images only. One hundred fourteen meniscal tears were seen on sagittal proton density and coronal T1- and T2-weighted images. Use of coronal images resulted in the confident detection of 21 additional meniscal tears not well seen on sagittal proton density images alone. Twelve of the 21 additional meniscal tears were seen on coronal T1- and T2-weighted images. Nine of the 21 additional meniscal tears were seen only on coronal T1-weighted images. Most of these additional meniscal tears were in the body of the meniscus. These 21 additional meniscal tears were confirmed arthroscopically. Eight marrow lesions were well characterized only on coronal T1-weighted images. Five were osteochondral lesions, one was an intraosseous hemangioma, and two were microfractures. CONCLUSION: Coronal MR images of the knee allowed better detection and characterization of some meniscal tears than sagittal images alone. Radial meniscal tears, bucket-handle tears, and horizontal tears in the body of the meniscus may be difficult to characterize in the sagittal plane alone. Use of coronal T1-weighted images, rather than coronal T2-weighted or sagittal proton density images alone, allows accurate characterization of some additional marrow lesions. The addition of a T1-weighted sequence in the coronal plane adds only 1 min 30 sec to the scanning time.

Adolescent↗
PubMed2003

Analysis of rabbit tear proteins by high-pressure liquid chromatography/electrospray ionization mass spectrometry.

The aim of this study was to develop a fast and reliable analytical procedure for the display of the protein components of tears that can be used to differentiate the status of the ocular surface. Using this new procedure, we analyzed the tear protein components following a corneal wound in the rabbit. Calibrated 10-microL glass, fire-polished capillary micropipettes were used to collect tears from New Zealand White rabbits prior to and daily for 9 days following a unilateral 6-mm diameter centrally placed anterior keratectomy. Tear proteins were eluted by a reversed-phase high-performance liquid chromatography (RP-HPLC) column and the tear protein profile was monitored by electrospray ionization (ESI) mass spectrometry positive total ion current (TIC) chromatography. Tear proteins were reliably separated into 17 peaks, each of which contained one or a number of protein components. The molecular weight of each protein component was determined by on-line ESI. Major tear protein components, lactoferrin, lysozyme (minimally detectable in rabbit tears), albumin, lipocalin, lipophilin and beta2-microglobulin, were tentatively identified by this method. Based on the mass spectrometric data, beta2-microglobulin was found to be glycosylated with N-acetylhexosamine. ESI-positive TIC chromatograms and mass spectra revealed comparative differences in the tear protein spectra after corneal wounding. One day after wounding, rabbit lysozyme with a molecular weight of 14,717 Da was found to be 8-fold higher in the tears of wounded eyes when compared with tears from unwounded eyes. It dropped back to normal 3 days after wounding. The expression of an unidentified tear protein with the molecular weight of 16,060 Da was also elevated after corneal wounding and returned to normal level by day 5. In this study, LC/ESI-MS was developed as a fast, reproducible and simple method for the identification and analysis of many of the protein components of the tears. Importantly, this technique also allows quantification of each component resolved in the chromatogram. This method is very suitable for mapping peptides and proteins (<80 kDa) in tears.

Animals↗
PubMed1994

Of an extracellular matrix in human pre-corneal tear film.

A theory relating viscosity to fluid flow rates in human tear film was developed and from that theory arises a relationship between viscosity, tear-film thickness and vertical drainage rates at the air-tear interface. Human tears were collected in capillary tubes at rates, on average, of less than 1 microliter min-1. Protein concentration was slightly higher than values reported in the literature and electrophoretic distributions of tear-film proteins were normal. Viscosity of the tear films were measured at 35 degrees C (physiological temperature). Vertical flow rates of tear film were measured in the inter-blink period either by observing the movement of lipid plaques at the air-tear interface or by observing naturally occurring contaminant specs (size around 1 micron). Tear film vertical flow rates were at least an order of magnitude lower than those predicted from collected tear-fluid viscosity measurements. It was concluded that collected tears are not representative of the whole pre-corneal tear film and that the tear film includes a fluid flow-inhibiting matrix whose structural components have a longer time-constant of exchange than the soluble proteins of the collected tear fluid.

Adult↗
PubMed2000

[Imaging of the microarchitecture and dynamics of the break-up phenomena of the preocular tear film with the aid of laser scanning microscopy].

BACKGROUND: Sufficient and regular wetting of the cornea with a normal preocular tear film is an essential requirement for the accurate visual functioning of the eye. Multiple factors may cause tear film instability. Measuring the break-up time of the preocular tear film is a necessary, clinically reliable means for evaluating tear film stability. We designed a new instrument to observe the preocular tear film at high magnification which can contribute to the in vivo imaging of the physiological and pathophysiological dynamics of the tear film and its break-up phenomena. MATERIALS AND METHODS: To image the tear film phenomena at sufficient magnification (x200) we used a confocal laser scanning microscope. Modification of an additional adaptor allows the tear film to be imaged at high magnification. This study evaluated the dynamics and microarchitecture of the break-up phenomena in the preocular tear film of normal patients and patients with "dry eye". RESULTS: Laser scanning microscopy allows high magnification imaging of the preocular tear film and evaluation of a number of break-up mechanisms. The dynamics and structure of the tear film was analyzed and documented. Based on our observations we formulate a new hypothesis on the break-up mechanism of the preocular tear film caused by alterations in the epithelial surface, for example, an elevation or tear film microparticle. By evaluating video sequences in the fluorescence and reflection modus of the laser scanning ophthalmoscope we also found early thinning of the aqueous layer simultaneously with an intact lipid layer covering the aqueous layer. CONCLUSION: Additional criteria result from using high-magnification microscopy, for example, laser scanning microscopy. This method reveals more microstructures of the corneal surface and the preocular tear film. The morphological representation of break-up phenomena leads to a better understanding of the underlying mechanisms and can be used for further investigations. Confocal laser scanning microscopy supplements the examination facilities and can be used in addition to slit lamp microscopy and to diagnose "dry eye".

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