Tear-Derived Exosome Proteins Are Increased in Patients with Thyroid Eye Disease

Exosomes contain proteins, lipids, RNA, and DNA that mediate intercellular signaling. Exosomes can contribute to the pathological processes of various diseases, although their roles in ocular diseases are unclear. We aimed to isolate exosomes from tear fluids (TF) of patients with Thyroid eye disease (TED) and analyze the exosomal proteins. TFs were collected from eight patients with TED and eight control subjects. The number of TF exosomes were measured using nanoparticle-tracking analysis. The expression of specific proteins in the purified exosome pellets were analyzed using a Proteome Profiler Array Kit. Cultured normal orbital fibroblasts were incubated with TF exosomes from patients with TED and control subjects, and changes in inflammatory cytokine levels were compared. TF exosomes from TED patients showed more exosomes than the control subjects. The expression levels of exosomal proteins vitamin D-binding (VDB) protein, C-reactive protein (CRP), chitinase 3-like 1 (CHI3L1), matrix metalloproteinase-9 (MMP-9), and vascular adhesion molecule-1 (VCAM-1) were significantly increased in patients with TED, compared to those of controls. Orbital fibroblasts exposed to TF exosomes from patients with TED showed significantly higher levels of interleukin (IL)-6, IL-8, and monocyte chemoattractant protein-1 (MCP-1) production than those treated with control TF exosomes. Specific proteins showed higher expression in exosomes from TED patients, implying that they may play keys roles in TED pathogenesis.

Ophthalmological Aspects in Allogenic Bone Marrow Transplantation: Sjögren-Like Syndrome in Graft-Versus-Host Disease

PURPOSE

A major complication of allogenic bone marrow transplantation (BMT) is graft-versus-host disease (GVHD), characterized principally by involvement of the eyes, producing a Sjögren-like syndrome (SLS). This study assessed the predictive role of the eye involvement in the onset of GVHD.

METHODS

Thirty-five patients transplanted for hematological malignancies were routinely examined for ocular manifestation of dry eye. Examination includes the Schirmer I test, break-up time, Lissamine Green staining, fluorescein test, lactoferrin test and impression cytology. A threshold was established for quantitative analysis of SLS.

RESULTS

Fifteen of 35 patients (40%) developed SLS during long-term follow-up. Ten of these (77%) developed acute or chronic GVHD.

CONCLUSIONS

The possible etiology of SLS includes three factors: total body irradiation, ocular toxicity of chemotherapy and GVHD. A correlation was found between poor-prognosis GVHD and the occurrence of SLS.

Tear Histamine and Histaminase during the Early (Epr) and Late (Lpr) Phases of the Allergic Reaction and the Effects of Lodoxamide

The objectives of this study were two-fold: to identify tear histamine content and its relationship to changes in tear histaminase activity during the early (EPR) and late phases (LPR) of the allergic reaction induced by a conjunctival provocation test (CPT) and to evaluate the effects of lodoxamide on histamine release and allergic signs and symptoms during EPR and LPR. A baseline CPT was administered to 20 allergic patients with no baseline signs or symptoms of allergy. Clinical signs and symptoms were evaluated after 20 minutes and 6 hours. Tear samples were taken after 5-10 minutes and after 6 hours for subsequent analyses of cytology and histamine content (ELISA). Patients were then randomly assigned to receive lodoxamide or placebo four times daily for one week in a double-masked fashion. A second CPT was done after this therapy and the same parameters were re-evaluated. During EPR, tear histamine increased significantly with respect to baseline values (p < 0.05). During LPR, tear histamine increased significantly (p < 0.05) only in histamine inactivated samples. Histaminase enzymes were also significantly less active during the EPR (5.5 +/- 0.7) than the LPR (9.9 +/- 2.3) and at baseline. Histamine levels significantly correlated with allergic signs and symptoms (p < 0.05) only during the EPR. Lodoxamide significantly reduced histamine release during EPR (p < 0.05), allergic signs and symptoms during both EPR (p < 0.001) and LPR (p < 0.005), and tear cytology counts during LPR. In conclusion, greater histaminase activity may account for the smaller amount of tear histamine generally found during LPR, while these enzymes seem to play less of a role during the surge of histamine release and activity in the EPR. Lodoxamide was shown to ideally inhibit various aspects of the allergic reaction: clinical signs and symptoms in both the early and late phases, the primarily EPR-related peak of histamine release, and the primarily LPR-related changes in tear cytology.

Cellular changes in tears associated with keratoconjunctival responses induced by nasal allergy

BACKGROUND

Allergic keratoconjunctivitis occurs in a primary form, caused by an allergic reaction localized in the conjunctiva, and in a secondary form, induced by an allergic reaction originating in the nasal mucosa. Various hypersensitivity mechanisms involved in the keratoconjunctivitis forms result in different keratoconjunctival response types.

PURPOSE

To investigate the cytologic changes in tears during the secondary immediate (SIKCR), late (SLKCR), and delayed (SDYKCR) keratoconjunctival responses.

METHODS

In 61 patients, comprising 20 SIKCRs, 23 SLKCRs, and 18 SDYKCRs, nasal provocation tests (NPTs) with allergens and 61 phosphate-buffered control challenges were repeated and supplemented with cell counting in the tears.

RESULTS

The SIKCR (P<0.01), appearing 10-120 min after the NPT, was associated with increased eosinophil and mast cell counts in tears. The SLKCR (P<0.01), appearing 5-12 h after the NPT, was accompanied by increased counts of eosinophils, neutrophils, basophils, and conjunctival epithelial and goblet cells. The SDYKCR (P<0.05), appearing 24-48 h after NPT, was associated with increased counts of lymphocytes, neutrophils, monocytes, basophils, conjunctival epithelial, corneal epithelial and goblet cells.

CONCLUSIONS

The SIKCR, SLKCR, and SDYKCR, induced by nasal allergy, were associated with different cellular profiles in the tears. The cells, except mast, epithelial and goblet cells, displaying no intracellular changes, migrated probably from the conjunctival capillaries, in response to the factors released during the primary allergic reaction in the nasal mucosa and subsequently penetrating into the conjunctiva. These results demonstrate a causal role of nasal allergy and diagnostic value of NPT combined with recording of ocular features and cellular profiles in tears in some keratoconjunctivitis patients.

Automatic assessment of tear film break-up dynamics

Dry eye syndrome is a common disorder of the tear film which affects a remarkable percentage of the population. The Break-Up Time (BUT) is a clinical test used for the diagnosis of this disease, which computes the time the first tear film break-up appears. This work describes a fully automatic methodology to compute the BUT measurement and evaluate the break-up dynamics until the final blink. This analysis provides useful additional information for the assessment of tear film stability.

Development of a new grading scale for tear ferning

PURPOSE

This paper reports on the development of a new tear ferning (TF) subjective grading scale, and compares it with the Rolando scale.

METHOD

TF patterns obtained from tear film samples collected from normal and dry eye subjects in previous studies were collated into a large image library. From this library, 60 images were selected to represent the full range of possible TF patterns, and a further sub-set of 15 images was chosen for analysis. Twenty-five optometrists were asked to rank the images in increasing order between extreme anchors on a scale of TF patterns. Interim statistical analysis of this ranking found 7 homogeneous sub-sets, where the image rankings overlapped for a group of images. A representative image (typically the mean) from each group was then adopted as the grade standard. Using this new 7-point grading scale, 25 optometrists were asked to grade the entire 60 image library at two sessions: once using the 4-point Rolando scale and once using the new 7-point scale, applying 0.25 grade unit interpolation.

RESULTS

Statistical analysis found that for the larger image set, the Rolando scale produced 3 homogeneous sub-sets, and the 7-point scale produced 5 homogeneous sub-sets. With this refinement, a new 5-point TF scale (Grades 0-4) was obtained.

CONCLUSIONS

The Rolando grading scale lacks discrimination between its Type I and II grades, reducing its reliability. The new 5-point grading scale is able to differentiate between TF patterns, and may provide additional support for the use of TF for both researcher and clinician.

Non-contact Confocal Microscopy of the Tear Film in Unoperated Eyes

PURPOSE

The NIDEK ConfoScan4 (CS4) is a digital scanning slit confocal microscope. The corneal structure and tear film can be viewed, magnified, measured, and photographed at magnifications up to 500x, in vivo, in a noninvasive manner. The objective of this study was to evaluate and illustrate various conditions related to dry eye using the CS4 confocal microscope with the 20x noncontact lens.

METHODS

The CS4 was used to evaluate the natural tear film in 58 eyes of 29 patients with normal examinations, allergic conjunctivitis, nonspecific conjunctivitis, and dry eyes. In a subset of this patient population, subjective and objective findings were used to classify mild, moderate, and severe dry eye disease states. The usefulness of confocal microscopy as an objective tool to diagnose and manage different tear film-related ocular disease was also evaluated.

RESULTS

The differences in tear film composition were visible using confocal microscopy. Photographs demonstrate confocal noncontact 20x microscopy as a diagnostic tool.

CONCLUSIONS

Noncontact confocal microscopy is a valuable tool in the diagnosis and treatment of dry eye syndrome and other ocular states such as allergic and nonspecific conjunctivitis. It provides a simple and effective way to observe, classify, and treat the tear film. As investigators visualize and learn more, understanding of this structure will continue to improve.

Trypsin Inhibitory Capacity in Vernal Keratoconjunctivitis

PURPOSE

To study tear trypsin inhibitory capacity (T-TIC), serum trypsin inhibitory capacity (S-TIC) and their relationship to matrix metalloproteinases (MMP)-1 and -9 in patients with vernal keratoconjunctivitis (VKC).

METHODS

In the first phase of the study, inactivation of alpha-1 antitrypsin (AAT) by MMP-1 and -9 was investigated in vitro. Subsequently, tear samples were collected after clinical evaluation from 14 patients with active VKC and 15 normal control subjects. Tear cytology was performed on all samples. Levels of T-TIC and S-TIC were determined by spectrophotometry, whereas levels of tear pro-MMP-1, pro-MMP-9, and active MMP-1 and -9 were determined by enzyme-linked immunosorbent assay (ELISA).

RESULTS

MMP-1 and -9 inactivated AAT in vitro. S-TIC was significantly higher (P < 0.0001), and T-TIC (P < 0.0001) significantly lower in VKC samples. Tear levels of pro-MMP-1 and pro-MMP-9, and the activity of MMP-1 and -9 was significantly greater in patients with VKC than in healthy subjects (P < 0.0001). There was no significant correlation between T-TIC, MMP-1, and MMP-9 activity. In addition, T-TIC was not correlated to the total clinical score or to single clinical sign scores.

CONCLUSIONS

In this study, tear trypsin inhibitory capacity was shown to be reduced and tear MMP-1 and -9 activity increased in patients with VKC. Although T-TIC did not correlate with VKC severity, a local reduced inhibitory capacity of ATT may facilitate or prolong conjunctival inflammation in VKC.

A pilot study on the infiltrating cells and cytokine levels in the tear of fungal keratitis patients

AIM

To determine the cellular profile and cytokine levels in the tear fluid of fungal keratitis patients.

MATERIALS AND METHODS

Tear samples were collected from six fungal keratitis patients (Group I) from active stages of the disease up to resolution. Tears collected from the following served as controls: uninfected fellow eye (Group II A) of Group I, patients undergoing cataract surgery (Group II B) and acute conjunctivitis (Group II C). The cellular profile was evaluated. Interleukines (IL-6, IL-8 and IL-1beta) were estimated using sandwich enzyme immunoassay. Statistical analysis was carried out using nonparametric two-sample median test.

RESULTS

Polymorphonuclear leukocytes (PMN) were the predominant infiltrating cells in Group I. During the initial stages of fungal infection, levels of IL-6 and IL-8 in the tear samples were found to be significantly increased when compared with Group II A (P=0.019 for IL-6, P<0.001 for IL-8). This was also true for IL -8 (P=0.008) levels in Group I and Group II B). While IL-6 levels decreased significantly towards healing, IL-8 remained slightly elevated even after healing. These cytokines were at the base level in Group II A. Lymphocytes and PMN were present in equal proportions in Group II C, which showed elevated levels of cytokines but not to the extent of Group I.

CONCLUSION

This horizontal study indicates that understanding the nature of the inflammatory response in the tears of fungal keratitis patients is of considerable interest and warrants further investigations.

Interferometric imaging of the full thickness of the precorneal tear film

A method is described for recording interference images from the full thickness of the precorneal tear film (PCTF). Simultaneous images are recorded by two video cameras. One camera responds to broadband spectral illumination and records interference from the superficial lipid layer of the tear film. The other camera uses narrowband illumination and records interference from both the lipid layer and the full thickness of the PCTF. Thus the full-thickness interference fringes are derived from the difference between, or ratio of, narrowband broadband images. This method has the potential for evaluating the role of both tear film flow and evaporation in tear film thinning and breakup. It therefore may be applied to the analysis of dry eye disease.

Th1- and Th2-type cytokines in chronic ocular allergy

BACKGROUND

Previous reports have suggested that Th2-type cytokines are important in the pathogenesis of ocular allergic diseases. The purpose of this study is to measure levels and mRNA expression of Th1- and Th2-type cytokines in patients with active vernal keratoconjunctivitis (VKC) and atopic keratoconjunctivitis (AKC).

METHODS

Tear samples and tear-isolated cells were obtained from 9 healthy participants (CT--controls), 28 VKC, and 6 AKC patients. IL-4, IL-13, and interferon gamma (IFNgamma) tear levels were determined by ELISA, and IL-4 and IFNgamma tear cell mRNA expression by RT-PCR. Effects of these cytokines on IL-6 and IL-8 secretion, and on ICAM-1 expression by conjunctival fibroblasts, were evaluated by ELISA and flow cytometry respectively.

RESULTS

Interleukin-4 tear levels were increased in VKC and AKC compared with CT, but only IFNgamma significantly correlated with corneal involvement. An IL-4/13-dominant profile was found in 50% of VKC and in 17% of AKC patients, while a IFNgamma-dominant profile was found in 18% of VKC and in 17% of AKC patients. IL-4 and IFNgamma transcripts were detected in tear cells from 11 out of 12 VKC patients. IFNgamma upregulated expression of ICAM-1 on conjunctival fibroblasts and the secretion of IL-6 and IL-8.

CONCLUSIONS

Although both IL-4 and IFNgamma are detected in tears, only IFNgamma levels correlated with disease severity and upregulated ICAM-1 on conjunctival fibroblasts, suggesting the role of IFNgamma in the inflammatory phase of chronic allergic eye diseases.

[Morphometric analysis of the structure of tear and aqueous humor in senile cataract]

The parameters of the wedge dehydrated samples of aqueous humor and tear taken from patients with senile cataract were compared by a morphometric assay. Computer-aided processing of the images of the test biological fluids was made on a Morphotest-1 hardware-software complex. The study has provided evidence for the uniformity of distribution of major structural components in the dehydrated samples of tear and aqueous humor in each specific examinee. This fact opens up possibilities for studying the signs of different intraocular pathological conditions from the morphological pattern of tear.

Evaluating Tear Film Stability in the Human Eye With High-Speed Videokeratoscopy

High-speed videokeratoscopy (HSV) is an emerging technology that has the potential to acquire information on the dynamics of corneal topography and tear-film behavior. We show that the surface regularity and asymmetry indices, which are traditionally used for characterizing the stability of precorneal tear film, have limitations in the context of HSV because they are highly sensitive to natural ocular microfluctuations. To overcome this problem, we propose a new microfluctuation-independent surface indicator. It is based on the root-mean-square of the error of the parametric model fit to the surface. Further, we develop techniques for estimating the tear film build-up and break-up times. The tear film build-up time estimator is based on the proposed RMS fit surface indicator while the tear film break-up time estimator is derived directly from a set of consecutive HSV digital images, without the need for estimating the resulting corneal surface.

Curvature sensor for the measurement of the static corneal topography and the dynamic tear film topography in the human eye

A system to measure the topography of the first optical surface of the human eye noninvasively by using a curvature sensor is described. The static corneal topography and the dynamic topography of the tear film can both be measured, and the topographies obtained are presented. The system makes possible the study of the dynamic aberrations introduced by the tear film to determine their contribution to the overall ocular aberrations in healthy eyes, eyes with corneal pathologies, and eyes wearing contact lenses.

Double lateral shearing interferometer for the quantitative measurement of tear film topography

A lateral shearing interferometer designed and built for the study of the precorneal tear film topography dynamics and its effect on visual performance is presented. Simple data processing algorithms are discussed and tested on data illustrating different tear topography features: postblink tear undulation, tear breakup, eyelid-produced bumps and ridges, bubbles, and rough precontact lens tear surfaces.

Detection of neutrophils in late-onset interface inflammation associated with flap injury after laser in situ keratomileusis

OBJECTIVE

To report a case with late-onset interface inflammation associated with traumatic flap injury at 7 months after laser in situ keratomileusis (LASIK) and to describe the type of infiltrating cells in the tears of the patient.

METHODS

Interventional case report. A 24-year-old male patient who underwent uneventful LASIK on both eyes received blunt trauma from the tip of a shoe in the left eye 7 months after surgery. The corneal flap of his left eye was lacerated across the pupillary area. Inflammatory cells were observed under the lacerated flap segment. Tear fluid was collected from his left eye 3 days after the injury and assessed by tear cytology. For controls, tears of 2 patients who underwent LASIK and developed no interface inflammation were collected the next day after their surgeries and examined.

RESULTS

Tear fluid of the patient with interface inflammation contained numerous neutrophils. Tears of control patients contained only a few epithelial cells and cell debris but no inflammatory cells. The inflammation was decreased by systemic and topical steroids. However, irregular astigmatism caused by stromal scarring remained, resulting in decreased best-corrected visual acuity.

CONCLUSIONS

Interface inflammation can be caused by late-onset flap injury. Neutrophils detected in the tears may reflect a major component of cells infiltrating the interface after LASIK.

Double-masked, randomized, placebo-controlled clinical study of the mast cell-stabilizing effects of treatment with olopatadine in the conjunctival allergen challenge model in humans

OBJECTIVE

The purpose of this study was to assess the effects of olopatadine on the release of mast cell-derived mediators after conjunctival allergen challenge(CAC) in humans.

METHODS

This was a double-masked, randomized, placebo-controlled clinical trial. Subjects with a clinical history of seasonal allergic conjunctivitis (but no current symptoms or treatment at baseline) were studied. At visit 1, subjects underwent bilateral CAC with increasing doses of allergen every 15 minutes until a significant clinical reaction was obtained, then were evaluated at 15 minutes and 5 hours after CAC. At visit 2 (2 weeks later), subjects were rechallenged to confirm the allergic response. Subjects exhibiting positive reactions at both visits (at both 15 minutes and 5 hours) were randomized and instructed to treat 1 eye with olopatadine and the contralateral eye with placebo (commercially available artificial ears) in a double-masked fashion twice daily for the 5 days immediately preceding visit 3. At visit 3, bilateral CAC was performed with the same dose as at visit 2. Itching and redness were recorded. Tear cytology for inflammatory cell counts(ie, neutrophils, eosinophils, and lymphocytes) was carried out using precolored slides, and cell numbers were counted at 400x magnification. Tear histamine was assessed using radioimmunoassay histamine measurement. Intercellular adhesion molecule (ICAM)-1/CD54 monoclonal antibody was used for immunohistochemical staining of conjunctival epithelial cells obtained by impression cytology. Slides were examined by 3 masked investigators and redness was classified on a scale of 0 (absent) to 3 (very intense).

RESULTS

Ten subjects completed the trial. Olopatadine significantly reduced postchallenge itching and redness compared with placebo (P < 0.01 and P < 0.03,respectively). Olopatadine also reduced the number of neutrophils and the total number of cells at 30 minutes (both P = 0.015), and the number of eosinophils(P < 0.001), neutrophils (P < 0.004), lymphocytes (P = 0.011), and total number of cells (P = 0.001) at 5 hours postchallenge compared with placebo. Tear histamine levels were significantly lower after challenge in the eyes pretreated with olopatadine compared with placebo (mean [SD], 7 [8] vs 22 [12] nmol/L; P = 0.04). Olopatadine significantly reduced tear histamine levels compared with those measured in the same eyes after CAC at visit 2 (P = 0.001), whereas placebo did not affect histamine levels. Olopatadine also significantly reduced ICAM-1 expression compared with placebo at 30 minutes and 5 hours postchallenge(P < 0.03 and P < 0.01, respectively).

CONCLUSION

In the present study, olopatadine significantly reduced the levels of histamine, cellular infiltrate, and ICAM expression compared with placebo after CAC, suggesting that it reduced the release of mast cell-derived mediators in humans. This inhibition of mediator release correlated with reduction of itching and redness.

Pharmacological mechanism of topical lodoxamide treatment in vernal keratoconjunctivitis: a flow-cytometric study

The aim of this study was to investigate the possible effect of lodoxamide 0.1% ophthalmic solution (LOS) on tear T lymphocytes, especially Th2 (T helper 2 subgroup of helper T lymphocytes), in the tear specimens of patients with vernal keratoconjunctivitis (VKC) and to explore the mechanism of the anti-allergic effect of this drug. Twenty-eight active VKC patients were randomly divided into two groups each containing 14 patients. We obtained tear samples from all patients at the beginning of the study. LOS was prescribed to the study group (group A), but the controls (group B) received placebo over the course of 6 weeks. Tear samples were also collected from all patients following a 6-week course of treatment with either LOS or placebo. The percentages of Th1, Th2 and Th cells in the tear samples were measured by using a flow-cytometric technique and the results were compared to each other by using Wilcoxon matched-pairs signed-rank and Mann-Whitney U tests. We found that LOS treatment decreased the percentages of Th2 and Th cells in the tears of group A patients, while placebo had no effect on these values. Th1 cell count in the tears of both groups of patients did not show any significant change between the pre- and posttreatment stages. Our data suggest that LOS exerts, at least, some part of its anti-allergic effect via decreasing the Th2 cell number in the tears of VKC patients.

Mechanisms and comparison of anti-allergic efficacy of topical lodoxamide and cromolyn sodium treatment in vernal keratoconjunctivitis

PURPOSE

To explore the mechanism of action of topical lodoxamide and cromolyn sodium treatment in vernal keratoconjunctivitis (VKC) and to compare the efficacy of these drugs to each other.

DESIGN

Single-investigator, masked, randomized, clinical trial.

PARTICIPANTS

Twenty male and 10 female patients between the ages of 6 and 19 years, who were diagnosed as having active VKC, were enrolled in this study.

INTERVENTIONS

The patients were randomly divided into two equal groups (groups A and B). Group A patients received topical lodoxamide ophthalmic solution 0.1% (LOS); topical cromolyn sodium ophthalmic solution 4% (CSO) was prescribed to group B patients in a dose of two drops four times daily.

MAIN OUTCOME MEASURES

The eye symptom severity scores and clinical signs of the patients were evaluated both in the pre- and post-treatment periods. In addition to the clinical data, conjunctival impression cytologic specimens were obtained from patients both before and after treatment. Impression cytologic specimens were stained using immunohistochemical methods to detect the percentages of CD4(+), CD8(+), CD45RA(+), and CD23(+) cells. Statistical analyses were performed within and between groups.

RESULTS

The percentages of CD4(+) and CD23(+) cells in tear samples of patients in groups A and B were significantly higher in the pretreatment stage than post-treatment stage. In the post-treatment stage, group A patients had significantly lower CD4(+) and CD23(+) cell values compared with group B patients. Patient symptom scores and clinical signs were at a significantly lower level after treatment with either LOS or CSO in both groups A and B compared with their pretreatment values. Moreover, group A patients had significantly lower symptom scores and clinical signs than group B patients in the post-treatment stage.

CONCLUSIONS

Clinical superiority of LOS over CSO may be linked to its greater effect on the CD4(+) cells, because CD4(+) cells plays a pivotal role in the pathogenesis of VKC.

Evaluation of DNA damage in exfoliated tear duct epithelial cells from individuals exposed to air pollution assessed by single cell gel electrophoresis assay

The search for relevant target cells for human monitoring purposes has increased during the last few years. Cells such as sperm, buccal or nasal and gastric epithelium are being used. In this study, we report the use of exfoliated tear duct epithelial cells as a potential material for human biomonitoring studies, since these cells are a target for environmental pollutants. We employed the alkaline single cell gel electrophoresis (SCGE) assay to evaluate for differences in the basal level of DNA damage between young adults from the south (exposed mainly to high levels of ozone) and from the north (exposed principally to hydrocarbons) regions of Mexico City. We found an increase in DNA migration in tear duct epithelial cells from individuals who live in the southern part of the city compared to those living in the northern part. Moreover, young people who live in the southwest part of the city with the highest values of ozone presented the highest values of DNA damage. These results show the feasibility of using exfoliated tear duct epithelial cells in human biomonitoring studies.

Efficacy of lodoxamide eye drops on tear fluid cytology of patients with vernal conjunctivitis

A double-masked, randomized, placebo-controlled study was conducted to evaluate the effectiveness of lodoxamide tromethamine 0.1% eyedrops in preventing inflammatory cell accumulation in the tear fluid of patients with vernal conjunctivitis. A 1-week baseline period was followed by 4 weeks of treatment with either lodoxamide tromethamine 0.1% ophthalmic solution or placebo in 30 symptomatic subjects with vernal conjunctivitis. Cytological evaluation of tear fluid was performed before and after the treatment. In the lodoxamide-treated group, but not in the placebo-treated group, the number of neutrophils (P = 0.051) and eosinophils (P = 0.020) in the tears significantly decreased at the end of 4 weeks when compared with baseline (Wilcoxon-signed rank test). It was concluded that lodoxamide treatment was significantly more effective than the placebo in terms of reducing inflammatory cells in the tear fluid in vernal conjunctivitis. This objective inhibition of inflammatory cells may be associated with clinical relief.

Differences in central and peripheral responses to oxotremorine in young and aged rats

Few studies have investigated the pharmacological response of agents that act on the cholinergic system from the point of view of age. The present article investigated central responses (tremor) and peripheral responses (chromodacryorrhea) subsequent to the administration of oxotremorine to young (3-6 months of age) and aged rats (24-30 months of age). The aged rats presented greater duration and intensity of tremor in three doses utilized (0.25, 0.5, and 1.0 mg/kg) compared to young rats. These two groups of animals did differ in latency for the onset of the tremor. The aged rats presented more intense chromodacryorrhea than the young rats in all utilized doses. These data are indicative that both responses--central and peripheral--are affected by aging, possibly as a result of pharmacokinetic alterations and/or alterations in functionality of the cholinergic system in aged rats.

Size and number of epithelial cells washed from the cornea after contact lens wear

Using the technique of Fullard and Wilson, tear samples were collected atraumatically from the corneas of 14 rigid gas permeable (RGP) contact lens wearers, 14 soft contact lens (SCL) wearers, and 22 controls who did not wear contact lenses. Samples were analyzed for the number, size, and contiguity of the cellular contents. Both RGP and SCL groups had, on average, significantly fewer cells per sample than controls (median values were 11 and 12 cells vs. 44). The difference remained significant even after a correction of three cells was applied to account for cells adherent to the lenses. Approximately 80% of epithelial cells from both lens wear and control eyes were found in isolation, whereas 20% were contiguous with 1 or 2 other cells. This result is compatible with the majority of epithelial cells having exfoliated from the surface of the cornea after detaching from their neighbors, rather than detaching in sheets of cells. The cell length and cell area were analyzed. RGP wearers had significantly smaller cells than controls, whereas SCL wearers had slightly (but significantly) larger cells. These results may reflect changes in the exfoliation mechanism of the corneal epithelium in contact lens wear.

[Imaging the tear film and in vivo cornea. Initial results with a modified confocal laser scanning ophthalmoscope]

BACKGROUND

As the slit-lamp technique is an restrictive method for the in-vivo examination and documentation of the multi-layer structure and the dynamics of the tear film and the cornea, e.g. during wound-healing processes, our aim was to find out whether it is possible to change the confocal laser scanning ophthalmoscope (CLSO; Zeiss) into a high-resolution confocal laser scanning microscope (CLSM) for the visualization of the anterior segments of the eye and the tear film by adapting a special objective system. In order to gain information concerning the function of such a cornea microscope we examined selected patients with erosion or pterygium before and after operation and subsequent phototherapeutic keratectomy (PTK), as well as some in-vitro corneal surfaces after photorefractive keratectomy (PRK).

MATERIAL AND METHODS

We developed an objective adapter for the CLSO in order to focus the laser beam onto anterior segments of the eye to visualize the tear film and the layer structure of the cornea. By combining the long-distance objective or a contract objective with different zoom-optic lenses it was possible to alter the scan field size and so the magnification of the CLSM by a factor of up to 1000.

RESULTS

The CLSM provides a new method for the in-vivo examination of the tear film and its dynamics as well as the thin layers of the cornea in real-time imaging technique with high contrast and resolution in non-contact or contact procedures.

CONCLUSION

This system is a unique took for evaluating and monitoring the effect of excimer laser ablation after PTK and PRK on the corneal surface and the dynamics of the tear film. The application of this method causes no pain for the patient.

Polymorphonuclear leukocyte cells and elastase in tears

PURPOSE

To characterize the effects that mode of sampling and overnight eye closure have on the nature of caseinolytic activity recovered in tear fluid.

METHODS

Reflex, open and closed (R, O and C) eye tear fluids were collected by microcapillary tubes or from the inferior formix by Schirmer strip. Microcapillary collected samples were centrifuged and recovered cells cytochemically characterized and probed by immunofluorescence microscopy, or alternatively extracted in acidic PBS. Tear supernatants, pellets and Schirmer strip extracts were subjected to casein zymography or SDS-PAGE and immunoprobed for plasmin/plasminogen. To identify caseinolytic activity, samples were immunoprecipitated with antibodies to plasmin/plasminogen or to elastase, and the immunoprecipitated materials were subjected to zymographic analysis.

RESULTS

Immunoblot assays revealed R and O samples contained low levels of plasminogen (approximately 1.1 micrograms/ml) and only trace levels of plasmin (< 0.1 ng/ml). Insufficient levels of caseinolytic activity were present to allow zymographic detection. Cytochemical analysis revealed that R and O pellets consisted almost exclusively of desquamated epithelium. Immunoblot analysis revealed that C fluid was associated with an increase in plasminogen and its partial conversion to plasmin (approximately 3.2 ng/ microliter), high molecular weight covalent complexes and degradative products. Zymographic analysis disclosed much greater caseinolytic activity than could be attributed to plasmin or its cleavage products. This consisted primarily of three bands (30-26 kDa) which were identified as polymorphonuclear leukocyte (PMN) cell elastase based on size and antigenicity. This is derived from PMNs recovered from the C pellet. Elastase could also be recovered from Schirmer strips from 90% of donors, provided that the strips were extracted in sample loading buffer. The activity was restricted to the portion of the strip that had been in contact with the ocular tissue.

CONCLUSIONS

The main source of caseinolytic activity in C fluid is elastase. This arises from PMNs that undergo recruitment, activation and degranulation in the C environment. In contrast, the elastase recovered in Schirmer strip extracts is derived from intact PMNs that adhere to the strip during sample collection. This would suggest that PMN cells undergo a low level of recruitment into the open eye environment.

Efficacy of lodoxamide eye drops on mast cells and eosinophils after allergen challenge in allergic conjunctivitis

PURPOSE

The purpose of the study is to evaluate in a double-blind, randomized study the efficacy of lodoxamide tromethamine 0.1% versus placebo.

METHODS

Signs and symptoms, tear tryptase, and tear fluid cytology were evaluated in 20 asymptomatic subjects with allergic conjunctivitis. The study included three allergen challenges in skin test-positive patients. At the first visit, a threshold dose of allergen was established. At the second visit, a bilateral ocular challenge was performed without pretreatment. At the third visit, either lodoxamide or placebo eye drops were used for 1 week before ocular challenge.

RESULTS

Lodoxamide significantly reduced tryptase levels (P < 0.01), neutrophils (P < 0.04), and eosinophils (P < 0.01) in the tear fluid and significantly inhibited ocular itching (P < 0.02) when compared with that of placebo.

CONCLUSIONS

Lodoxamide is effective in reducing tryptase levels and the recruitment of inflammatory cells in the tear fluid after allergen challenge.

Flow cytometry tear analysis in patients with chronic allergic conjunctivitis

Tears from patients with chronic allergic conjunctivitis were analyzed with flow cytometry to determine the function of the T lymphocyte-related immunological reactions in the disease pathogenesis. Twenty-eight patients and 22 normal volunteers were studied; tears were obtained with capillary tubes. T helper/T suppressor ratios and the percentages of HLA DR+, CD23+, and CD3+ cells were significantly higher in patients than in controls. This study provides support for the hypothesis that chronic allergic conjunctivitis results from T lymphocyte-related immunological reactions.

Assessment of the tear film with tandem scanning confocal microscopy

PURPOSE

To evaluate the confocal microscopic appearance of the tear film by correlating the interference pattern created by the lipid surface with physiologic measurements of tear function and with clinic diagnosis.

METHODS

A series of 53 patients was examined with a battery of tests to evaluate the tear film and with confocal microscopy to evaluate the interference pattern created by the lipid surface of the tear film. Assessment of the tear-film appearance involved five nonparametric scales: degree of debris in the tear film, variability of the interference pattern over time, linearity of the interference pattern, number of dry spots seen, and relative thickness of the lipid layer. For 10 other subjects, the confocal appearance of the tear film and evaporation from the ocular surface was tested for before and after meibomian gland expression.

RESULTS

The confocal appearance correlated with multiple physiologic variables and clinical diagnosis. Patients with seborrheic meiboman gland dysfunction had a thicker lipid layer, greater variability, and more debris than did patients with obstructive meibomiam gland dysfunction. After meibomian gland expression, lipid thickness and linearity increased, whereas pattern variability and evaporation decreased significantly. The mean reduction in evaporation was 48%.

CONCLUSIONS

Confocal microscopy can be used to examine the tear film, and its appearance correlates significantly with physiologic variables in normal-individuals and in disease states. The confocal appearance of the lipid interference patterns and evaporation from the ocular surface are altered after lipid expression from meibomian glands.

[Exfoliative conjunctival cytology in Sjögren's syndrome]

The study has been performed in order to give a contribution to the knowledge of the conjunctival cytology in Sjögren's syndrome. Exfoliated cells were obtained by a tampon from the inferior conjunctival sac of 11 patients affected by primary or secondary Sjögren's syndrome; the material was placed onto a microscope slide and it was stained with May-Grumwald-Giemsa, after the ferning test had been performed. Tear production had been previously assessed in all patients by Schirmer's I test and basic secretion test that showed an evident tear fluid hyposecretion. Cytoanalysis of tear fluid showed, in all patients, a marked lymphocytosis, presence of epithelial cells (sometimes cell-adhesion) and a number of "snake-cells", with a nucleus-cytoplasm ratio in favour of cytoplasm. Some of those cells have a thicker cytoplasmic membrane and/or a spindle-shaped peripheral nucleus, characteristic finding of keratoconjunctivitis sicca. In all cases we found mucus and fibrin (sometimes with included cells), organic debris and big crystals, some of which aggregated.

[Ultrastructural study on rat precorneal tear film by quick freezing-freeze substitution method]

The ultrastructure of rat precorneal tear film was visualized by the quick freezing-freeze substitution (QF-FS) method and the conventional fixative method under the scanning electron microscope (SEM). In the QF-FS method, the eyeballs of rats were quickly frozen with an isopentane-propane mixture cooled by liquid nitrogen applied directly to the eyes. After enucleating the eyes and fracturing the frozen corneas, the corneas were prepared for SEM observation. In contrast to the conventional fixative method, by which the microvilli of the surface epithelial cells could be visualized clearly, a very thin membrane-like structure was observed to cover the corneal surface in the eyes prepared by the QF-Fs method. Between the membrane-like structure and corneal surface, a homogeneous and fine network-like structure was observed. The results suggest that the structure of the tear film might be different from the one we have believed to consist of three layers until now. The QF-FS method is considered to be useful for the morphological study of the precorneal tear film.

Oxidative reactions in the tear fluid of patients suffering from dry eyes

PURPOSE

To evaluate whether products of oxidative and inflammatory reactions are detectable in the tear fluid of patients suffering from dry eyes.

METHODS

The tear fluid of 217 patients (397 eyes) was sampled. Criteria for grouping of the patients were (1) basic secretion test ("sicca 1": BST = 0-5 mm, n = 78 eyes; "sicca 2": BST = 6-10 mm, n = 109 eyes) and (2) subjective symptoms (normal BST, burning, foreign body sensations, tearing, dryness of the eyes: n = 78 eyes). One group of healthy patients (normal BST, n = 132 eyes) served as controls. Lipid peroxide levels and myeloperoxidase activity, as parameters for oxidative tissue damage and inflammatory activity, were determined in the tear fluid. Those patients whose consent could be obtained were subjected to the rose bengal test (sicca 1: 56 eyes; sicca 2: 97 eyes; subjective symptoms: 44 eyes; controls: 49 eyes). The correlation between BST and rose bengal test results was calculated.

RESULTS

Lipid peroxides were significantly (P < 0.05) higher in the groups sicca 1 and subjective symptoms than in healthy controls, as was the inflammatory activity in groups sicca 1, sicca 2 and subjective symptoms. Additionally, the inflammatory activity in the group sicca 1 was significantly (P < 0.05) higher than in the groups sicca 2 and subjective symptoms. No evidence of a significant correlation between BST and rose bengal test results was observed.

CONCLUSIONS

Both oxidative tissue damage and polymorphonuclear leukocytes indicating an oxidative potential occur in the tear film of patients suffering from dry eyes. These reactions lead to severe damage of the involved tissue. Free radicals and inflammation may be involved in the pathogenesis or in the self-propagation of the disease.

Eosinophil cationic protein in tears of normal subjects and patients affected by vernal keratoconjunctivitis

The objectives of this study were to determine: 1) levels of tear eosinophil cationic protein (ECP) in patients with vernal keratoconjunctivitis (VKC); 2) the effect of pharmacologic therapy on ECP release; and 3) the correlation of this mediator with the severity of the disease. Tears were collected from 10 controls and 20 VKC patients before and after therapy for cytologic analysis and ECP measurement by radioimmunoassay. Ocular signs and symptoms were evaluated before tear collection. Mean ECP levels in controls were 7.5 +/- 0.4 microgram/l, and in VKC patients, 988.3 +/- 128 micrograms/l before therapy (P < 0.001) and 566.3 +/- 121 micrograms/l after therapy (P < 0.005). In dexamethasone (Dex) 0.1% or cyclosporin A (CsA) 2% patients (five per group), tear ECP decreased significantly after 7-14 days of treatment. Disodium cromoglycate (DSCG) 4% (five patients) for 14 days did not significantly affect ECP levels. ECP levels were significantly correlated with allergic signs (P < 0.001), symptoms (P < 0.001), and the number of eosinophils in tears (P < 0.005). The results of this study suggest that tear ECP levels accurately reflect the clinical status of VKC patients. The measurement of ECP may prove useful not only in the diagnosis and monitoring of allergic disease, but also as an objective parameter for the evaluation of new antiallergic therapies.

[Effect of prostaglandin inhibitors on leukocyte infiltration and on leukocytes in tears after experimental injury of the corneal epithelium]

The effect of drug inhibiting prostaglandin biosynthesis on permeation of leucocytes to tears and cornea after experimental removal of the epithelium was observed. It was shown that 1% indomethacin solution and 0.5% ibuprofen solution considerably decreased the number of leucocytes in tears and their infiltration to the proper substance and negatively affected regeneration of corneal epithelium. The investigations have shown that prostaglandin inhibitors inhibit leucocyte infiltration and may, in effect, decrease the number of proteolytic enzymes that are secreted by these cells.

Effects of nitrous acid exposure on human mucous membranes

Nitrous acid (HONO) is formed both indirectly from the reaction of nitrogen dioxide (NO2) with water on indoor surfaces, and directly during combustion. This gaseous pollutant may be a previously unrecognized causal factor in assessments of nitrogen oxide exposure effects. The present study is the first attempt to evaluate exposure effects of HONO on the human airways and the mucous membranes of the eyes and nose. Fifteen healthy adult nonsmokers were exposed for 3.5 h in a double-blind, balanced protocol to clean air, 77, and 395 ppb HONO. Each exposure was preceded by a 1-h baseline measurement period, and exposures were separated by 1 wk. There was a 10-min exercise period during exposure. Effects measurements included assessment of bronchial reactivity, measurement of specific airway conductance, spirometry, acoustic rhinometry, nasal lavage, tear-fluid cytology, a CO2 eye-provocation test, evaluation of eye redness, and subjective sensations. Effects of HONO exposure on the eyes were found as exposure-related changes in tear-fluid cytology. In particular, the number of squamous cells increased by 20, 67, and 80% following exposure to clean air, 77, and 395 ppb HONO, respectively (p = 0.004). Possible indications of exposure effects on sensitivity to CO2 eye provocation and on specific airway conductance were also measured. For specific airway conductance there was an approximate 10% decrease in conductance following exercise in association with HONO exposure, compared with a 2% decrease with clean air (p = 0.038).

Vernal keratoconjunctivitis: a model of 5q cytokine gene cluster disease

Clinical studies of vernal keratoconjunctivitis (VKC) patients show that total IgE serum levels are increased even in the absence of IgE antibodies to common allergens. Activated eosinophils are also a constant feature of VKC at both the circulation (cytofluorimetry) and tissue (tear cytology and conjunctival scrapings) levels. Moreover, allergen challenge induces a prolonged inflammatory reaction with a prevalent participation of eosinophils, lymphocytes and possibly basophils. Immunohistochemical studies of VKC biopsies show a multicellular inflammatory infiltrate with prevalence of activated eosinophils, mast cells and CD4 lymphocytes in both epithelium and subepithelium. Mediator studies indicate that eosinophil products (eosinophil peroxidase, eosinophinal cationic protein and eosinophil-derived neurotoxin/eosinophil protein X) are increased in both serum and tears, where tryptase and interleukin (IL)-5 are also detectable in higher amounts than in controls. On the basis of these findings, we postulate that VKC can represent a phenotypic model of up-regulation of the cytokine gene cluster on chromosome 5q which through its products (IL-3, IL-4, IL-5 and granulocyte/macrophage-colony-stimulating factor) regulates Th2 prevalence, IgE production as well as mast cell and eosinophil growth and function in VKC.

Tear Fluid Cellular Fibronectin Levels After Photorefractive Keratectomy

BACKGROUND

Fibronectin is supposed to have an important role in wound healing. The extradomain A-containing cellular fibronectin (EDAcFn) refers to fibronectin, which instead of being a hepatocyte derived component of blood plasma or body fluids, is produced locally. The present study was undertaken to clarify the possible changes in excretion of EDAcFn in tears following excimer laser photorefractive keratectomy (PRK).

METHODS

An immunoassay was used to determine EDAcFn concentrations in human tear fluid samples of 11 eyes after PRK. Tear fluids were collected with scaled microcapillaries preoperatively as well as 1, 2, and 7 days after PRK. The time used to collect a known volume of tears was registered. This was done to estimate the dilution effect related to the hypersecretion of tears after PRK.

RESULTS

The mean preoperative tear fluid EDAcFn concentration was 0.28 +/- 0.07 ng/microliter with a wide range (0.05 to 0.63). The tear fluid flow-corrected excretion of EDAcFn was 1.36 +/- 0.35 ng/min (range, 0.145 to 3.50). There was a significant increase in both postoperative tear fluid flow and excretion of EDAcFn on days 1 and 2. The elevation of the mean EDAcFn concentration did not decrease in spite of reflex tearing. The mean excretion of EDAcFn in tears was 28-fold on the first and 17-fold on the second postoperative day. Normal level was reached by day 7.

CONCLUSION

There is a rapid increase in excretion of EDAcFn in tears following PRK. This seems to last only as long as an epithelial defect persists. The epithelium of all eyes healed in 3 to 4 days in spite of wide interindividual variations in both tear fluid flow and EDAcFn excretion.

Effects of rigid lens extended wear on lactate dehydrogenase activity and isozymes in rabbit tears

Effects of and recovery from continuous wear of four rigid gas permeable (RGP) contact lenses was assessed by noninvasive measurement of lactate dehydrogenase (LDH) activity and isozyme pattern in rabbit tears. Oxygen transmissibility (Dk/L) of lenses used was 27, 44, 84, and 97 x 10(-9) (cm/s)(ml O2/ml mm Hg); lens thickness (0.15 mm) and diameter (14.0 mm) were standardized. Lenses were worn continuously for 90 days; recovery was assessed 30 days after cessation of lens wear. LDH activity was measured by UV rate assay; isozyme subtypes were determined by agarose gel electrophoresis. Light and scanning electron microscopy (LM, SEM) were used with the determination of total protein as additional measures of lens effects. LDH levels were inversely correlated with lens Dk/L values; low Dk/L values increased the anaerobic (LDH4,5)/aerobic (LDH1,2,3) subtypen ratio indicating in vivo metabolic shift. SEM observations were consistent with these results. There was no significant difference in the total cell content of tears or total tear protein levels between control and RGP test-wear groups. Measurement of tear LDH activity and isozyme ratios appears to provide a sensitive, noninvasive assessment of the effects of RGP lens-induced hypoxia over time on the corneal surface. A level of Dk/L of > or = 84 appears best for maintaining corneal physiology during extended wear. Recovery from chronic lens-induced hypoxia is characterized by a return to normal tear LDH levels and isozyme subtypes.

Sampling methods for tear stix tests

Four different methods for transferring conjunctival fluid to stix test pads were studied. One hundred and twenty eyes from 120 cataract-extracted patients (35 in the operated eye 0-5 days post-operatively and 85 in the contralateral eye) were included in the study. Transfer of fluid by a glass rod from the lateral part of the inferior fornix was demonstrated to be the most suitable method, showing the highest sensitivity to leucocyte-esterase (83%, N = 120, p < 0.05) and with a specificity equal to that of the other methods tested (cotton, spongostan, Schirmer paper strip). The glass rod method is suitable for detecting blood, nitrite, albumin, pH, and glucose, and is a both quick and unintrusive procedure. All four transferring methods may, however, cause an increased desquamation of epithelial cells and an increased amount of mucus.

Effectiveness of nedocromil sodium 2% eyedrops on clinical symptoms and tear fluid cytology of patients with vernal conjunctivitis

A double-masked, randomised, placebo-controlled study was conducted to evaluate the effectiveness of nedocromil 2% eyedrops, a mast cell stabilizer, in 20 symptomatic patients with vernal conjunctivitis. A 1-week baseline period was followed by 6 weeks of treatment. Clinical examination and cytological evaluation of tear fluid were performed weekly, and the patients recorded their subjective assessment on a daily diary card. The nedocromil group showed significantly less hyperaemia in the course of treatment than did the placebo group, and significantly less itching at all visits compared with baseline itching. In the nedocromil-treated group, but not in the placebo group, the number of neutrophils, eosinophils and lymphocytes in tears decreased significantly during some treatment weeks when compared with baseline. The overall assessment of treatment efficacy by both clinician and patient was significantly in favour of nedocromil treatment over placebo.

Ocular surface alteration after long-term treatment with an antiglaucomatous drug

BACKGROUND

This study was undertaken to see whether long-term locally applied ocular medications produced any alterations in the ocular surface, and, in particular, whether it caused damage to the mucus layer of the tear film.

METHODS

The authors studied the ocular surface of 40 control subjects (group 1), 21 patients (group 2) chronically treated with a commercial preparation of 0.5% timolol maleate, and 20 previously untreated glaucomatous patients (group 3) in need of treatment with the same drug. Parameters studied were Schirmer's test, lacrimal meniscus height, break-up time, fluorescein and rose Bengal stains, conjunctival impression cytology, mucus staining, and the ferning test.

RESULTS

Patients in groups 2 and 3 showed a significant decrease (P less than 0.001) in the number of normal Schirmer's and break-up time tests. All had positive vital stains. Results showed a significant decrease (P less than 0.001) in goblet-cell density, mucus granules, and reticular sheets, and an increase (P less than 0.001) in pathologic crystallization patterns.

CONCLUSION

These results demonstrate that chronic application of a commercial preparation of timolol maleate damaged the ocular surface, especially the mucus layer of the tear film.

Immunologically induced purulent anterior segment inflammation of the guinea pig eye

A single conjunctival application of ovalbumin to inbred guinea pigs (IMM/S 209) immunized with the same antigen in Freund's complete adjuvant provoked an acute purulent inflammation of the anterior segment of the eyes with a duration of up to 1 week. Intense conjunctival injection and chemosis were followed by a purulent discharge. A corneal haze was observed regularly, and a considerable proportion of the animals developed a pronounced pannus and corneal ulcers. Tear fluid cytology revealed a rapid increase in cell concentration, from the normal level (less than 10(8)/l) to greater than 10(11)/l. Seventy to 95% of the cells were polymorphonuclear leukocytes. Histological examination revealed an acute inflammatory reaction which radiated from the conjunctival fornices to the entire anterior segments of the eyes. The process was characterized by an intense oedema, vasodilation and perivascular aggregations of polymorphonuclear leukocytes, and to a lesser extent eosinophilic granulocytes which characteristically infiltrated and penetrated the epithelial layers. Neovascularization could be observed early after challenge in the stroma of all parts of the outer eye. Ulcerations of the conjunctival and corneal epithelia were observed frequently. After a number of reiterations of the antigenic challenge, a marked infiltration with lymphocytes and basophils/mast cells was observed, and significant scarring of the conjunctival mucosa developed. In several animals, a slight, but significant co-reaction of the contra-lateral, non-challenged eye was observed.

Clinical and cytologic aspects of ocular late-phase reaction in the guinea pig

Conjunctival tissue of 12 guinea pigs (6 experimental animals, 6 controls) was sensitized with IgG1 (PCA titer 1:2,000) antisera to dinitrophenol carrier and challenged topically with hapten. Periorbital swelling, conjunctival edema and conjunctival redness were evaluated clinically at 0.5 h and hourly for 12 h, and again at 24 and 48 h. Tears were collected at each time point for cytology. Results showed an early-phase reaction (EPR) peaking at 0.5 h and a late-phase reaction (LPR) peaking at 5-7 h. Periorbital swelling was minimal 4 h after appearance of the EPR. Conjunctival edema and redness increased in both the early and late phases, but without two distinct peaks. However, individual animals in both groups did show biphasic reactions. Tear cytology showed an abnormal increase in neutrophils and eosinophils in the later time periods and was a significant way to detect ocular anaphylaxis. In conclusion, if the presence of two significant peaks of clinical inflammation after one antigen challenge is taken as the narrowest definition of a late phase in anaphylaxis, our results show an ocular LPR occurring in our animal model.

[Effect of drugs inhibiting prostaglandin activity on the appearance of leukocytes in the tears after experimental injury to the corneal epithelium]

The investigations were carried out on 3 groups of rabbits in which the corneal epithelium was removed and into the conjunctival sac were instilled drugs inhibiting the activity of prostaglandins such as indomethacin solution or a 0.5 p.c. solution of ibuprofen. It was demonstrated that these drugs lead in the period of the first 8 hours to reduction of the number of leucocytes in tears from 2 to 20 times in comparison with the control group. The presented observation show that prostaglandin inhibitors may be a successful mean leading to decrease of number of leucocytes in tears after corneal injury.

Quantitative tear meniscus cytology versus quantitative conjunctival fluid cytology

A technique for quantitative cytology of tear fluid collected by a micropipette from the tear meniscus is presented. This technique has been compared with that using the standardized Norn-pipette collecting fluid from the lateral part of the inferior fornix. The two methods show the same magnitude of sensitivity and specificity, the same coefficient of variation, as regards neutrophilic leucocytes and erythrocytes (200 samples). The normal tear meniscus contains less than 40 leucocytes or erythrocytes per microliter. The tear cell concentration is about 200 times lower in the meniscus than in the fornix inferior in normal eyes. This observation supports the compartment-theory of a rapid flow in the tear meniscus and a slow flow with insignificant admixture in the conjunctival fluid in the fornices. The tear meniscus cytology is of use in association with testing of other parameters in the tears, for instance. The conjunctival fluid cytology is quicker and more convenient for the patient. In addition, it is necessary in connection with observation for pathological epithelial desquamation, because the tear meniscus cytology brings about an artificial increase of the epithelial cell concentration.