SEARCH · PubMed Health

Results for “ocular surface disease”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 235 records · Page 13Linked to original sources

PubMed2000

Correlation between tear IgE levels and HLA-DR expression by conjunctival cells in allergic and nonallergic chronic conjunctivitis.

BACKGROUND: Chronic conjunctival inflammatory diseases may depend upon various mechanisms. Discriminating allergy from nonspecific inflammation has become of striking importance for diagnosis and treatment. We investigated conjunctival inflammatory response by comparing two objective biological tools, tear IgE and HLA-DR expression by conjunctival epithelium, as indirect indicators of activation of the Th2 and Th1 subsets, respectively. METHODS: Eighty-two patients with chronic conjunctivitis underwent tear IgE measurement by an ELISA technique and quantitation of HLA-DR expression in impression cytology specimens. Forty-two had direct or indirect clinical indications of allergic mechanisms, 26 had chronic conjunctivitis without any sign of allergy, and 14 suffered from isolated nonallergic dry eyes. RESULTS: Patients clinically considered as allergic only showed positive IgE in 47 of 84 eyes (56%), whereas 21% and 25% of eyes with nonspecific conjunctivitis and dry eyes respectively were also positive. IgE levels were significantly higher in the allergic group than in the other two groups. HLA-DR positivity in epithelial cells was found in 28.5%, 48% and 50% of eyes, respectively. HLA-DR expression by epithelial cells was negatively correlated with tear IgE, as most specimens positive to one criterion were negative to the other one (49 eyes DR+, IgE-; 47 eyes DR-, IgE+; only 9 eyes positive to both criteria; chi-square: P = 0.0001). CONCLUSION: As IgE synthesis and HLA-DR induction may represent indirect indicators of the activation of the Th2 and Th1 subsets, association of these two simple tests could be interesting for the routine assessment of the mechanisms of inflammatory ocular surface diseases.

Adolescent↗

PubMed2002

Management of vitreoretinal complications in eyes with permanent keratoprosthesis.

OBJECTIVES: To evaluate the spectrum and treatment of posterior segment complications in eyes that had undergone successful keratoprosthesis (KPro) placement and to determine whether transeyelid vitrectomy techniques could be effectively used in eyes otherwise vulnerable to surface exposure. DESIGN: In the last 10 years, 110 patients received a Dohlman-Doane KPro at the Massachusetts Eye and Ear Infirmary, Boston. We evaluated 22 eyes in 18 patients that required subsequent vitreoretinal surgery to treat posterior segment complications. One surgeon using modified vitreoretinal techniques, as described below, performed all vitreoretinal procedures. RESULTS: The posterior segment complications included 6 cases of retro-KPro membranes, 13 cases of retinal detachments, and 5 cases of isolated vitreous opacity. All 6 retro-KPro membranes were effectively removed by vitrectomy without significant complication and 3 of these patients enjoyed improvement of visual acuity of at least 5 Snellen lines. Of 13 cases of retinal detachment, 6 patients had some improvement in visual acuity, 5 showed no appreciable change, and 2 had some decline in the final visual acuity. In all 5 cases of isolated vitreous opacity, the media was effectively cleared with pars plana vitrectomy. Three patients enjoyed improvement of visual acuity of at least 3 Snellen lines. Four cases of transeyelid vitrectomy were attempted and anatomical success was achieved in all 4 and vision improved in 3 of these patients. No special surgical complications were encountered in any of the 22 eyes as a result of these modified surgical techniques. MAIN OUTCOME MEASURES: Best preoperative and postoperative visual acuity and anatomical success were evaluated in relation to the preoperative posterior segment complication. CONCLUSIONS: Modified vitreoretinal surgical techniques can be effectively and safely used to treat posterior segment complications in patients with KPro devices. Retro-KPro membranes and other vitreous opacities were the most amenable to treatment. Retinal complications posed a special challenge. However, all of these cases highlight that modified vitrectomy techniques can be used in eyes with permanent KPro devices. These techniques can be performed without additional risk to the eye. Additionally, we demonstrated that transeyelid vitrectomy techniques could be used effectively to manage complications in eyes with severe ocular surface disease without undue exposure of vulnerable tissues.

Adult↗

PubMed2003

Interpolated conjunctival pedicle flaps for the treatment of exposed glaucoma drainage devices.

OBJECTIVE: To describe an alternative method to repair exposed glaucoma drainage devices (GDDs) when conventional attempts have failed. METHODS: Four eyes, from 3 patients, with severe ocular surface disease were included in the study. All eyes had previously received a Baerveldt GDD for uncontrollable intraocular pressure and postoperatively had exposed GDDs. The conjunctival defects were unrepairable with a scleral patch or pericardium, conjunctival advancement, or a conjunctival patch graft. Two eyes had chemical burns, one eye had extensive scarring from multiple surgical procedures, and one patient had rheumatoid arthritis. Each patient provided informed consent, and was given the option of removing the GDD and undergoing diode cyclophotocoagulation or attempting to save the GDD by a conjunctival pedicle flap. An interpolated conjunctival pedicle flap was taken from the cul-de-sac (fornix). The conjunctiva and Tenon capsule were incised radially to the tube, rotated from the fornix at a 90 degrees angle, and sutured to the remaining healthy conjunctiva to cover the exposed tube. RESULTS: Postoperatively, all eyes had vascularized flaps that showed viable tissue. All eyes retained the GDDs, and the intraocular pressure has been under control during follow-up (7, 13, 25, and 27 months). CONCLUSION: Interpolated conjunctival pedicle flaps seem to be a viable alternative to repairing exposed GDDs when other methods are impractical or impossible.

Aged↗

PubMed2003

Risk factors for various causes of failure in initial corneal grafts.

OBJECTIVE: To determine the risk factors for specific causes of initial corneal graft failure. METHODS: This study analyzed corneal graft survival rates in a longitudinal noncomparative case series of 3992 consecutive penetrating keratoplasties performed at a single large referral center. Regrafts (n = 352) were excluded from the analysis of risk factors for initial graft failure. Data were collected retrospectively from August 1, 1982, through December 31, 1986, and prospectively from January 1, 1987, through August 31, 1996. Patients were examined preoperatively, at 1, 3, 6, 9, 12, 18, and 24 months posttransplantation, and annually thereafter. Potential risk factors were evaluated individually by Kaplan-Meier survival analysis. Cox proportional hazards regression modeling was then used to investigate the impact of each independent variable, adjusted for the confounding influence of the other independent variables. RESULTS: The use of topical glaucoma medications was a significant risk factor for corneal graft failure by 3 major causes: rejection, endothelial decompensation without a documented immunologic reaction, and ocular surface disease. Deep stromal vascularization was an independent risk factor for rejection failure. Diabetes mellitus, peripheral anterior synechiae, recipient race, and small trephination size were significant risk factors for endothelial failure. CONCLUSION: Independent risk factors differentially impact specific causes of corneal graft failure.

Adolescent↗

PubMed2006

Chemokine receptor CCR5 expression in conjunctival epithelium of patients with dry eye syndrome.

OBJECTIVE: To characterize chemokine receptor CCR5 expression on the conjunctival epithelium in dry eye syndromes. METHODS: Conjunctival impression cytology samples were obtained from normal subjects (n = 15) and patients with dry eye syndrome (n = 45). Cells were harvested from impression cytology samples, and flow cytometry was performed to quantitatively analyze the cell surface expression of chemokine receptor CCR5. Characterization of CCR5-positive cells was done by 2-color flow cytometry using fluorescein-conjugated anti-CCR5 and phycoerythrin-conjugated anti-CD45 antibodies (where CD45 is a marker for bone marrow-derived cells). To study CCR5 messenger RNA transcripts, real-time polymerase chain reaction was done on RNA isolated from the impression cytology samples of normal subjects (n = 5) and patients with dry eye syndrome (n = 14). RESULTS: We found significant up-regulation in cell surface expression of CCR5 in patients with both aqueous tear-deficient and evaporative forms of dry eye syndrome (P<.001). The real-time polymerase chain reaction results (for messenger RNA) corroborated the flow cytometry data (for protein). The majority of the cells expressing CCR5 were non-bone marrow-derived resident epithelial cells of the conjunctiva. CONCLUSION: Our findings suggest that CCR5 up-regulation is significantly associated with dry eye syndrome-associated ocular surface disease. Clinical Relevance Chemokine receptor CCR5 or its ligands may serve as useful targets for modulation of tissue immunoinflammatory responses in dry eye syndromes.

Adult↗

PubMed1987

Goblet cell density in thermal and chemical injuries.

Abnormality of the conjunctival epithelium was evaluated in ten patients with severe thermal and chemical injuries at the scarred stage, eight patients with Stevens-Johnson syndrome, five with cicatricial ocular pemphigoid, and 13 normal subjects, based on goblet cell densities obtained using impression cytologic examination. The average and SDs of goblet cell densities were 197.4 +/- 264.4/mm2 in thermal and chemical injuries, 3.0 +/- 5.6/mm2 in Stevens-Johnson syndrome, 0.6 +/- 0.8/mm2 in cicatricial ocular pemphigoid, and 38.7 +/- 25.8/mm2 in normal subjects. There were statistically significant differences in goblet cell densities between thermal and chemical injuries and both Stevens-Johnson syndrome and cicatricial ocular pemphigoid. Moreover, conjunctival specimens from both eyes in six unilateral cases of thermal and chemical injuries revealed higher goblet cell densities in the injured than in the normal fellow eyes in all cases. These findings imply that ocular surface diseases with similar clinical manifestations may have different cell-biologic abnormalities in the conjunctival epithelium.

Burns, Chemical↗

PubMed2001

Two-dimensional analysis of tear protein patterns of diabetic patients.

In diabetic patients, dry eye and other ocular surface diseases occur more often than in healthy subjects. The aim of this study was to analyze the tear protein patterns of patients suffering from diabetes mellitus type II (dia) and to compare them to the patterns of healthy volunteers (ctrl). Tear proteins of nonstimulated tears of 20 patients (ctrl n=10, dia n=10) were separated using two-dimensional electrophoretic techniques. The protein patterns of each group were analyzed by a multivariate analysis of discriminance. Furthermore, for all spots of each gel, a 50 x 50 variables pH/Mr (molecular weight) array was generated and subsequently analyzed by a multivariate analysis of discriminance. Additionally, an artificial neural network was trained using the matrix data as input and a sensitivity analysis was performed to figure out, which spots were the most important to differentiate between the tear protein patterns. In both groups a complex staining pattern could be obtained. In diabetic patients significantly more spots were detected compared to the control group (P<0.02). The analysis of discriminance found a highly significant difference between dia and ctrl (P<0.00001). Using the matrix data, the analysis of discriminance showed a significant difference between the two groups, too (P<0.0001). The sensitivity analysis by means of the artificial neural network revealed several spots that were more expressed or more frequently present in the diabetic group. Our findings reveal that the composition of tear proteins of diabetic patients is different from that of healthy subjects. The use of the two-dimensional electrophoretic technique could give more insight into the diabetic-related changes in the tear film composition.

Adult↗

PubMed1998

Alterations of ocular surface gene expression in Sjögren's syndrome.

We have demonstrated that conjunctival epithelium of SS patients displays increased numbers of S-phase cells compared with non-dry eye controls. Moreover, in SS patients, these S-phase cells are distributed throughout all strata of the epithelium. The expression of MUC-1, a cell surface marker indicative of terminally differentiated epithelium, is localized to the conjunctival epithelial surface in SS and control patients. However, MUC-1 surface immunoreactivity appears to be reduced in SS epithelium, suggesting disruption of normal epithelial differentiation. A MUC-1 epitope exposed by pretreatment with neuraminidase is expressed in the basal and suprabasal layers of both patient populations. This antigen likely represents nascent, partially processed MUC-1(6) and may serve as a marker of the preterminally differentiated epithelial phenotype. Messenger RNA encoding several different inflammatory cytokines, including TNF-alpha, IL-1 alpha and beta, IL-6, IL-8, IL-10, and TGF-beta 1, is expressed at elevated levels within the conjunctival epithelium of SS patients compared with non-dry eye controls. Based on these observations, we have formulated a model to explain the ocular surface pathology of Sjögren's syndrome. We hypothesize that mechanical abrasion secondary to aqueous tear deficiency creates an inflammatory environment where conjunctival epithelial cells and lymphocytes are stimulated to produce and secrete various cytokines (i.e., IL-1, TNF-alpha, IL-6, IL-8, etc.) into the tear film. Elevated cytokine levels within the tear film, perhaps combined with reduced concentrations of essential lacrimal gland-derived factors (i.e., EGF, retinol), create an environment in which terminal differentiation of the ocular surface epithelium is impaired. As a consequence, the epithelium becomes hyperplastic, displaying increased mitotic activity, and loses the ability to express mature protective surface molecules including the membrane-bound mucin, MUC-1. This would imply that anti-inflammatory medications (i.e., corticosteroids or cyclosporine) that suppress the inflammatory component of this cascade may ameliorate the ocular surface disease and discomfort experienced by SS patients.

Cell Cycle↗

PubMed2005

[Gas permeable scleral lenses as a conservative treatment option for extreme corneal ectasias and severe dry eye].

PURPOSE: Due to their exclusive scleral contact zone, non-ventilated gas permeable scleral contact lenses can be used to correct extreme keratectasia, even if corneal fitted contact lenses failed previously. As the gap between the scleral lens and the cornea is filled with fluid substitutes, they also can be used for patients with severe aqueous-deficient dry eyes. PATIENTS, MATERIAL AND METHOD: Scleral lens fitting was attempted in 13 eyes (9 patients, group I) of patients with extreme corneal ectasia and 9 eyes (5 patients, group II) with severe ocular surface disease. Best corrected visual acuity, keratometry, Schirmer's test, foreign body sensation, and total daily lens wearing time were recorded prior to and after scleral lens fitting. RESULTS: Scleral lenses were successfully fitted and used on a long-term basis in 6 of 13 eyes (4 patients) of group I and 4 of 9 eyes of group II. In 9 eyes visual acuity increased by at least 2 lines, but long-term lens wear was not possible due to severe foreign body sensation or fornix shortening. CONCLUSIONS: Modern gas permeable scleral lenses can successfully be used for nonsurgical rehabilitation of severe corneal ectasia and dry eyes.

Adult↗

PubMed2004

An assessment of the pattern of spontaneous eyeblink activity under the influence of topical ocular anaesthesia.

PURPOSE: To determine whether there is a change in the pattern of human eyeblink events under topical ocular anaesthesia. METHODS: Forty male subjects, aged between 19 and 52 years and with no significant ocular surface disease, were recruited. Their spontaneous eyeblink activity, in primary eye gaze position and in silence, was recorded for 5-min periods, before and after instillation of benoxinate 0.4% eyedrops. The surface anaesthesia was confirmed by aesthesiometry. RESULTS: The spontaneous eyeblink rate (SEBR) decreased from 9.1+/-4.0 blinks/min to an average of 5.7+/-3.3 blinks/min, with 37 subjects showing a decreased eyeblink rate under anaesthesia. Three blink patterns were observed before anaesthesia (symmetrical, J-type and I-type) and these were essentially unchanged under anaesthesia. CONCLUSIONS: These studies confirm that the SEBR is usually reduced under surface anaesthesia (so is sensitive to exogenous control) but the pattern of the eyeblink activity is unchanged (so is less sensitive to exogenous control). The removal of exogenous stimuli by anaesthesia does not shift the eyeblink pattern to a single type, so indicates endogenous control.

Adult↗

PubMed1998

Limbal cell autograft transplantation for severe ocular surface disorders.

BACKGROUND: Limbal cell transplantation may improve the visual outcome after chemical trauma and ocular surface diseases. METHODS: Nine eyes of nine consecutive patients (eight males and one female, age 9-60 years), underwent limbal autograft transplantation (LAUT). In five cases LAUT was done for severe chemical burns in the acute stage (group 1). In four patients with old chemical trauma LAUT was performed years after the trauma (group 2). Penetrating keratoplasty (PKP) was carried out within 6 months after LAUT in three patients of group 2. Preoperatively, the visual acuity in all the patients except one was counting fingers. Postoperatively, patients were treated with topical antibiotics, topical corticosteroids and oral steroids. Oral cyclosporin was used after penetrating keratoplasty. RESULTS: No complications were observed during the surgical procedure. Postoperatively, the epithelialization was complete between days 7 and 12. The inflammatory response subsided within 3 months and the stromal neovascularization decreased. Visual acuity improved in all the nine cases, ranging from 6/6 to 6/30. The decreased visual acuity was due to corneal haze, scars and vascularization. Following PKP, the three grafts remained clear with intact epithelium. No complications were observed during the follow-up period from 7 to 60 months. CONCLUSIONS: Limbal cell transplantation is an efficacious procedure for rehabilitation of visual acuity after severe chemical trauma.

Acids↗

PubMedDate not supplied

Expression of alpha- and beta-defensins in human ocular surface tissue.

PURPOSE: Defensins are antimicrobial peptides and are classified into three groups, alpha-, beta- and theta-defensins. We investigated the localization of human neutrophil peptides (HNP) 1-3, which are members of the alpha-defensin subfamily, and the expression of human beta-defensin 1 (hBD-1) and hBD-2 in the ocular surface tissues. METHODS: Corneal or conjunctival tissues were obtained from 17 patients undergoing surgery. The reasons for surgery were thermal burns (two patients), acid burn (one patient), corneal perforation (one patient), corneal abscess (one patient), and pterygium (two patients). As a control, tissue samples were collected from ten patients undergoing cataract surgery. The samples were examined for HNP 1-3 by immunohistochemical analysis, and for hBD-1 and hBD-2 by the reverse transcriptase-polymerase chain reaction (RT-PCR) method. RESULTS: Results of staining for HNP 1-3 were positive in all of the six tested samples. The RT-PCR method detected hBD-1 mRNA in all samples. However, hBD-2 was detected in only 7 of the 17 samples. In eight of the ten normal conjunctiva samples and in the two samples from conjunctiva with thermal burn or pterygium, hBD-2 mRNA was not detected. CONCLUSIONS: We concluded that HNP 1-3 and hBD-1 are constitutively expressed in the ocular surface. However, hBD-2 may or may not be expressed, depending on the stage of ocular surface diseases.

Adult↗

PubMed2005

A device to facilitate limbal stem cell procurement from eye bank donor tissue for keratolimbal allograft procedures.

PURPOSE: To develop a device that facilitates the procurement of corneal limbal stem cell grafts for keratolimbal allograft procedures used in the treatment of ocular surface disease associated with stem cell deficiency. DESIGN: Description of device design and technique for use. METHODS: The device is composed of a pedestal with a convex surface mounted to a flat platform. A corneoscleral button placed endothelial side down and centrally upon the convexity is secured by suction conveyed through a hollowed core in the pedestal that connects to fenestrated openings on the convex surface. A donut-shaped stainless steel ring placed on tension by springs braces the peripheral tissue. A circular corneal incision is created of a desired thickness by a suction trephine, and a crescent blade is utilized to peripherally dissect a donut-shaped keratolimbal allograft. RESULTS: This device facilitated the harvesting of the keratolimbal allograft tissue from four eye bank donor practice corneoscleral buttons and was then used to successfully procure grafts from six corneoscleral buttons used in three keratolimbal allograft procedures in three patients, one each with aniridia, alkali burn, and drug-induced limbal stem cell deficiency. CONCLUSIONS: The described device effectively facilitates procurement of corneoscleral buttons for keratolimbal allograft procedures. It appears to offer advantages over freehanded techniques and previously described devices used for the same purpose.

Cell Separation↗

PubMed2005

Experimental study of an automated system for the delivery of eyedrops using a microinfusion pump.

PURPOSE: To determine the feasibility of using a commercially available microinfusion pump for the continuous delivery of eye drops using a rabbit model. DESIGN: Laboratory investigation. METHODS: Tear secretion was measured after attaching a microinfusion pump to the superior fornix of a rabbit. The pump was set to deliver artificial tears continuously. A rabbit eye was first chemically burned with 1N NaOH, the pump was then set to deliver 0.1% fluorometholone continuously. Results were compared with those obtained using 0.1% fluorometholone. RESULTS: Schirmer tests indicated that an average of 22.3 mm in eyes supported by a pump and an average of 10.3 mm in eyes without pump. Moreover, eyes treated with corticosteroid delivered by pump recovered faster than those treated with topical corticosteroid. CONCLUSIONS: The continuous delivery of eye drops by a microinfusion pump could be applicable to patients with severe dry eyes or ocular surface diseases. Further study should be needed.

Animals↗

PubMed2006

Marx line: fluorescein staining line on the inner lid as indicator of meibomian gland function.

PURPOSE: To determine whether the location of a fluorescein-stained line, the Marx line (ML), which runs along the inner eyelid, is correlated with meibomian gland function. DESIGN: Prospective observational case series. METHODS: After applying fluorescein dye solution to the eye, the ML score was calculated for the outer, middle, and inner thirds of the lower eyelid margin. ML scoring was as follows: 0, entirely on the conjunctival side of the meibomian orifices (MOs); 1, part of the ML touches the MOs; 2, ML runs through all of the MOs; and 3, ML runs on the eyelid-margin side of the MOs. Correlations were calculated between the total ML score and age for 251 randomly recruited subjects without acute ocular surface diseases, and between age and the ML score for the three regions of the lower eyelid. Correlations between the regional ML score and the meibographic score, and the meibomian gland secretion score were also determined. The total ML scores of 15 subjects without meibomian gland dysfunction (MGD) were compared with 15 age-matched patients with MGD. RESULTS: The three regions of the lower eyelid had significantly different ML scores. Strong correlations were found between the ML score and age, the meibographic score, and the meibomian gland secretion score. The total ML score of MGD group was significantly higher than that of the non-MGD group. CONCLUSIONS: The strong correlation between the ML score and the meibomian gland scores indicates that the ML score can be used as a simple and rapid screening score for meibomian gland function.

Adult↗

PubMed2026

Corneal Epithelial Alterations Associated With Cyclin-Dependent Kinase 4/6 Inhibitor Therapy in Hormone Receptor-Positive Breast Cancer.

IMPORTANCE: Cyclin-dependent kinase 4/6 (CDK4/6) inhibitors are standard therapy for hormone receptor-positive (HR+), HER2-negative breast cancer. By blocking the G1/S cell-cycle transition, these agents may impair renewal of the corneal epithelium. No controlled study has systematically evaluated corneal epithelial changes in patients receiving CDK4/6 inhibitors. OBJECTIVE: To determine whether CDK4/6 inhibitor-based therapy is associated with cornealepithelial alterations independent of aromatase inhibitor exposure and tear film dysfunction. DESIGN, SETTING, AND PARTICIPANTS: Retrospective comparative cross-sectional study at a tertiary ophthalmology center. A total of 132 women were enrolled: 45 receiving a CDK4/6 inhibitor plus an aromatase inhibitor (CDKAI group), 44 receiving aromatase inhibitor monotherapy (AI group), and 43 age-matched postmenopausal controls without systemic oncologic therapy. EXPOSURES: CDK4/6 inhibitor (ribociclib, palbociclib, or abemaciclib) combined with an aromatase inhibitor; aromatase inhibitor alone; or no systemic oncologic therapy. MAIN OUTCOMES AND MEASURES: Prevalence and severity of punctate epitheliopathy and vortex keratopathy, assessed by a masked ophthalmologist. Secondary outcomes included Schirmer I test, tear film break-up time, and Ocular Surface Disease Index (OSDI). RESULTS: PE was present in 44.4% of eyes in the CDKAI group vs 4.7% in the AI group and 2.3% in controls (χ² = 34.31; P < .001). All moderate (13.3%) and severe/complicated (8.9%) PE cases occurred exclusively in the CDKAI group. Vortex keratopathy was observed in 13.3% of CDKAI patients and in none of the other groups (P = .025). Schirmer values, tear film break-up time, and OSDI scores did not differ among groups (all P > .05). Within the CDKAI group, PE was not associated with treatment duration (P = .963) or tear film parameters. CONCLUSIONS AND RELEVANCE: In this comparative study, CDK4/6 inhibitor-based therapy was associated with significantly higher prevalence and severity of PE and vortex keratopathy, independent of aromatase inhibitor exposure and in the absence of measurable tear film dysfunction. These findings suggest a direct cytostatic effect on the corneal epithelium. Symptom scores were low, although OSDI interpretation was limited by incomplete responses. Proactive corneal surface evaluation with fluorescein staining may be warranted during CDK4/6 inhibitor treatment.

Humans↗

PubMed2006

Laboratory findings in tear fluid analysis.

The tear film, composed of the lipid, aqueous and mucin layers, has many functions including defending the ocular surface. The tear film covering the ocular surface presents a mechanical and antimicrobial barrier and ensures an optical refractive surface. The lipid component originates from the meibomian glands of the tarsus and forms the superficial layer of the tear film. The aqueous component contains electrolytes, water, and a large variety of proteins, peptides and glycoproteins, and is primarily secreted by the lacrimal gland. Mucins are glycoproteins expressed by epithelial tissues of mucous surfaces. They protect tissues by functioning as antioxidants, providing lubrication, and inhibiting bacterial adherence. Quantitatively and qualitatively, its composition must be maintained within the fairly narrow limits to maintain a healthy and functional visual system. Abnormalities of the tear film, affecting the constituents or the volume, can rapidly result in serious dysfunction of the eyelids and conjunctiva and ultimately affect the transparency of the cornea. Many ocular surface tests have been developed for the clinical diagnosis of dry eye syndromes. This paper provides an overview on laboratory methods for the analysis of the tear film. Understanding the components of the tear film will aid in the treatment of dry eye syndromes and the ocular surface diseases.

Animals↗

PubMed2006

Alteration pattern of tear cytokines during the course of a day: diurnal rhythm analyzed by multicytokine assay.

Our aim was to study the alteration pattern and interaction of inflammatory tear cytokines during the course of a day. Using a prospective, experimental design, tears were collected from 28 healthy volunteers with normal eyes during the period from April 2004 to March 2005. Tears (10 microl) were collected by capillary outflow from each eye at 9:00, 12:00, 16:00, 21:00, and 24:00 h. The concentrations of inflammatory cytokines, IL-1beta, IL-6, IL-8, IL-10, IL-12p70, and TNF-alpha were measured using cytometric bead arrays. Although the concentration of tear cytokines varied widely among eyes, the amount of cytokine had a specific alteration pattern in each eye during the course of a day. IL-1beta, IL-6, IL-10, IL-12p70, and TNF-alpha showed slight increases in the morning and the late evening. IL-8 remained low throughout the day. The alteration pattern of IL-8 was significantly different from those of TNF-alpha and IL-12p70 (P<0.01). The ratio of each pro-inflammatory cytokine to anti-inflammatory cytokine IL-10 did not significantly change throughout the day. The amount of tear cytokines changed during daytime with a specific pattern. This diurnal rhythm may influence symptoms of ocular surface diseases during the course of a day.

Adult↗