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At least 127 records · Page 7Linked to original sources
PubMed2002

Combined surgery, cryotherapy, and mitomycin-C for recurrent ocular surface squamous neoplasia.

PURPOSE: To report the outcome of combined excision, cryotherapy, and antimetabolite treatment of recurrent ocular surface squamous neoplasia. METHODS: The patients with recurrent ocular surface squamous neoplasia were treated by excision of lesion, cryotherapy of limbus, and conjunctival margin followed by 0.02% Mitomycin C application at the time of surgery. Patients have been followed up for at least 1 year. RESULTS: A total of five eyes of five patients with recurrent ocular surface squamous neoplasia were treated by combined excision, cryotherapy, and Mitomycin C. Histopathologic diagnosis included invasive squamous cell carcinoma in four cases and squamous dysplasia in one case. No recurrences have been noted for a follow-up period of more than 1 year now. CONCLUSION: Combining excision with cryotherapy and Mitomycin C application at the time of surgery is a very effective therapy for recurrent ocular surface squamous neoplasia. It is relevant for cases in large, poor countries where patients present late and are less likely to come for follow-up care.

Adult↗
PubMed2004

Impression cytology of the ocular surface: a review.

PURPOSE: To historically review the technique of impression cytology as a minimally invasive diagnostic tool for ocular surface pathology. METHODS: A comprehensive review of published literature cited in PubMed since the first description of impression cytology in 1977 up to date has been undertaken. RESULTS: A wide range of processing methods have been adapted to the technique of impression cytology (from conjunctiva, cornea or limbus): regular light microscopy with different stainings, transmission and scanning electron microscopy, immunofluorescence, immunocytochemistry, polymerase chain reaction analysis, immunoblotting analyses, or flow cytometry. At present, it is widely used as a non-invasive alternative to the full-thickness biopsy for the obtention of epithelial cells from the ocular surface. CONCLUSIONS: Impression cytology represents a non- or minimally invasive biopsy of the ocular surface epithelium with no side effects or contraindications. It has demonstrated to be a useful diagnostic aid for a wide variety of processes involving the ocular surface. In addition, and mainly during the last decade, its use as a research tool has experienced an enormous growth and has greatly contributed to the understanding of ocular surface pathology.

Biopsy↗
PubMed2000

[A clinical study on fresh amniotic membrane transplantation for treatment of severe ocular surface disorders at acute inflammatory and cicatricial stage].

OBJECTIVE: To investigate the safety and evaluate the effect of fresh amniotic membrane transplantation to reconstruct the ocular surface with severe inflammation and scarring. METHOD: Amniotic membrane transplantation (38 cases, 46 eyes), or combined with either limbal transplantation (9 cases, 9 eyes) or lamellar keratoplasty (8 cases, 8 eyes) was performed on ocular surface burns (5 cases, 6 eyes), recurrent Mooren's ulcer (8 cases, 8 eyes) and severe symblepharon (38 cases, 46 eyes). All the patients were followed-up for 6 - 18 months (mean, 11 months). Impression cytology was examined in 21 eyes with normal tear secretion post-operatively. RESULTS: No acute rejection was observed after fresh amniotic membrane transplantation. No progressive melt and perforation were seen in five out of six eyes with burns in reconstructed ocular surfaces. Neovascularization, pseudopterygium and iris atrophy were not found during the follow-up. Visual acuity was improved in various degrees. Corneal ulceration was not noted in 8 cases (8 eyes) with frequently recurrent Mooren's ulcer. Ocular surface reconstruction was successful in 46 of 49 eyes with severe symblepharon. Symblepharon occurred in the remaining three eyes but much less than pre-transplantation in degree. Amniotic epithelia have been examined in about three months on the transplanted eyes with normal tear secretion. CONCLUSION: Fresh amniotic membrane can be used as a graft to reconstruct ocular surface. Such transplantation can effectively reduce neovascularization, fibrosis and inflammation. Our data indicated that complete removal of pathological tissues and perfect fixation of amniotic membrane graft are crucial steps in the reconstruction of ocular surface.

Acute Disease↗
PubMed2004

Ocular surface disorders and tear function changes in patients with chronic renal failure.

BACKGROUND: Ocular surface changes, mainly squamous metaplasia of the conjunctival epithelium and corneoconjunctival calcification of unknown etiology, may develop in patients with chronic renal failure undergoing hemodialysis. An association between squamous metaplasia and corneoconjunctival calcification has been suggested. The purpose of this study was to investigate the relation between ocular surface disorders and tear function changes in patients with chronic renal failure undergoing hemodialysis. METHODS: In this prospective case-control study, 42 patients with chronic renal failure and 20 age- and sex-matched control subjects underwent full ophthalmologic examination, tear function tests (including Schirmer's test, tear film break-up time [BUT] test and rose bengal staining) and impression cytology to determine the degree of conjunctival squamous metaplasia. They also responded to a questionnaire regarding subjective ocular complaints. Corneoconjunctival calcification was graded on a scale of 0 to 5 according to the system proposed by Porter and Crombie. Impression cytology samples were graded on scale of 0 to 3 according to the Nelson classification. The relation between ocular surface disorders and tear function changes was evaluated. RESULTS: Of the 42 patients, 12 (28%) had grade 0 calcification, 10 (24%) had grade 1, 14 (33%) had grade 2, and 6 (14%) had grade 3 or higher. Four patients (10%) had grade 0 squamous metaplasia, 22 (52%) had grade 1, 12 (28%) had grade 2, and 4 (10%) had grade 3. The difference between the patient and control subjects in squamous metaplasia grades and corneoconjunctival calcification grades was statistically significant (p < 0.001 and p = 0.022 respectively). Abnormal tear film BUT (p = 0.002) and abnormal rose bengal staining (p = 0.023) were significantly more frequent in the patient group than in the control group. The grade of conjunctival squamous metaplasia was correlated with abnormal rose bengal staining (tau = 0.79, p < 0.001) and with the existence of subjective ocular complaints (tau = 0.32, p = 0.026). There was no correlation between corneoconjunctival calcification and tear function changes. INTERPRETATION: Abnormal rose bengal staining and the presence of subjective ocular complaints may be used as follow-up criteria for ocular surface disorders in patients with chronic renal failure regularly undergoing hemodialysis.

Adult↗
PubMed1993

Eyelid opening induces expression of a glycocalyx glycoprotein of rat ocular surface epithelium.

PURPOSE: We previously characterized a monoclonal antibody against a glycoprotein of rat ocular surface glycocalyx (ROSG). This monoclonal antibody recognizes a carbohydrate epitope on a glycoprotein expressed in apical cells of the differentiated ocular surface epithelium. Our goal was to determine the developmental appearance of the ROSG glycoprotein. METHODS: We localized the antigen immunohistochemically and immunocytochemically in newborn (day 1) rats and in rats 2-5, 7, and 11-15 days after birth. RESULTS: Before eyelid opening (days 12-14), the ROSG antigen was localized in the palpebral conjunctiva near the lid margin. The binding extended to layers of the subapical flattened cells. However, the antigen was not found in the corneal epithelium while the eyelid remained closed. In contrast, at the first day of eyelid opening (days 12-15), the antigen was present contiguously in several cell layers from the eyelid margin along the entire ocular surface, including the corneal epithelium. Thus, the binding pattern seen upon eyelid opening was similar to that of adult rats. The phenomenon of appearance of the glycoprotein upon eyelid opening was further demonstrated in rats with asynchronous eyelid opening. Artificial, premature eyelid opening at days 8-11 also induced the expression of the antigen along the entire ocular surface epithelium, similar to the binding in naturally opened eyes. CONCLUSION: Eyelid opening may induce glycosylation or expression of a glycocalyx component that we hypothesize to be involved in mucin spread.

Animals↗
PubMed2002

[Application of impression cytology in diagnosis of ocular surface diseases]

OBJECTIVE: To evaluate the usefulness of impression cytology in diagnosing of ocular surface diseases. METHODS: Impression cytology was performed on 18 eyes with Sjgren's syndrome (dacryosialo-adenopathia atrophicans), 23 eyes with non-Sjgren's syndrome, 15 eyes after thermal or chemical burn at the scarred stage and 20 normal eyes. Conjunctival goblet cell density, conjunctival epithelial squamous metaplasia and corneal cytological features were evaluated respectively. RESULTS: In impression cytology, eyes of Sjgren's syndrome demonstrated a significantly higher grade of squamous metaplasia and lower goblet cell density (P<0.05) as compared with normal eyes and with eyes of non-Sj gren's syndrome in the bulbar conjunctiva, whereas no statistically significant difference of squamous metaplasia grade or goblet cell density was found in the palpebral conjunctiva (P>0.05) in these two groups. In thermal or chemical burned eyes at the scarred stage, the inferior, nasal and temporal bulbar conjunctiva showed higher conjunctival goblet cell density than in the normal eyes (P<0.01). Before surgery of ocular surface reconstruction, conjunctival goblet cells were detected on the corneal area in the 8 thermal or chemical burned eyes. However, the goblet cells in the corneal area of 7 burned eyes were completely resolved after successful ocular surface reconstruction. CONCLUSION The demonstrations of impression cytology in Sjgren's syndrome, thermal or chemical burn are distinctive. Impression cytology is a noninvasive,quick,easy and inexpensive technique, being a useful tool for diagnosis of ocular surface diseases.

Journal Article↗
PubMed1997

Histopathology of the ocular surface after eye rubbing.

PURPOSE: This study demonstrates the effects of eye rubbing on ocular surface tissue. METHODS: Rabbits (3-4 kg; n = 24) were killed at 0, 4-h, 8-h, and 12-h intervals after a 5-min period of eye rubbing. Ocular surface tissues were studied by light and scanning electron microscopy. Contralateral eyes served as controls. Eye rubbing was accomplished by using digital pressure over the closed eyelid with a force sufficient to appreciate by palpation the orbital rim. Biomicroscopic examination revealed marked vascular injection of the conjunctiva. Ocular surface tissues studied included the lid margins, the upper and lower tarsal conjunctivae, the bulbar conjunctiva, and the cornea. RESULTS: Changes in the ocular surface included dramatic alteration in the upper tarsal conjunctiva when compared with controls. The cornea and bulbar and lower tarsal conjunctiva were not altered when compared with control tissues, except for some increase in exfoliating cells in the cornea. The surface epithelial cells of the upper tarsal conjunctiva had a spheroidal structure and were markedly elevated, the microprojections were altered, and there was evidence of increased cellular exfoliation. These changes were most pronounced at the 0 and 4-h time points, less noticeable at 8 h, and no appreciable changes were observed when compared with control tissues at 12 h. CONCLUSION: This study demonstrates that eye rubbing causes surface alterations in the stratified cuboidal to columnar epithelial surface of the upper tarsal conjunctiva while sparing the stratified squamous epithelial surface of the distal lid margins and cornea.

Animals↗
PubMedDate not supplied

[Ocular surface analysis in patients affected with rheumatic diseases].

OBJECTIVE: The international criteria for primary Sjögren's Syndrome (SS I) diagnosis (Vitali et al. 2002) include the Schirmer test I and vital dye staining as tests for ocular surface involvement, but diagnosis can be reached also when the item for ocular signs is not satisfied. The purpose of our study was to evaluate the ocular surface in patients with Sjögren's Syndrome, non-Sjögren's autoimmune diseases and Sicca Syndrome, to understand whether the SS I diagnosis can be targeted also on other tests related to the ocular surface status. METHODS: Clinical and cytological data were collected from 122 patients: 40 patients had diagnosis of Primary Sjögren's Syndrome, 51 a non Sjögren's autoimmune disease and 31 had symptoms of dry eye. A validated questionnaire on symptoms was filled by each patient; clinical tests included: Schirmer test I, Jones test, Ferning test, Break Up Time, corneal aesthesiometry, tear clearance test, vital dye staining of the ocular surface, scraping and impression conjunctival cytology. Data were statistically evaluated by using SPSS software and Mann-Whitney analysis on unpaired data. RESULTS: Data show that the subjective symptoms score, tear production, tear turnover, corneal sensitivity and ocular surface integrity are affected in SS I patients, with a statistically significant difference when matched to the other two groups. CONCLUSIONS: Our results suggest to enlarge the spectrum of ocular surface analysis, to support and orient a differential diagnosis among the autoimmune diseases.

Arthritis, Rheumatoid↗
PubMed1998

The exposed ocular surface and its relationship to spontaneous eyeblink rate in elderly caucasians.

The purpose of this study was to assess spontaneous eyeblink activity in the primary eye position, and its relationship to the exposed ocular surface area in elderly individuals without significant ocular surface disease. Spontaneous eyeblink frequency (SEBF) was assessed for a group of Caucasians aged 61 to 81 years, by videography in silence over a 5 min period; inter-blink interval (IBI), the maximum inter-blink interval (mIBI) and the modal eyeblink frequency (mEBF) were derived from video recordings. The ocular surface area was calculated from video-planimetry using different formulae. The average palpebral aperture was 8.3 +/- 2.3 mm (n = 45, +/- S.D.), resulting in an average exposed area of 1.13-2.13 cm2 depending on the formula used; the preferred estimate was 1.25 cm2. A highly significant relationship (P < 0.001, r2 = 0.835) was found between time-averaged palpebral aperture (p) and exposed ocular surface (A = 0.244p-0.763). An average SEBF of 11.9 blinks min-1 was measured (range 0.8-43.6). No correlation (P > 0.35, r2 < or = 0.01) was found between SEBF, IBI, mIBI, or mEBF and the palpebral aperture or the exposed surface area, regardless of the formulae used. The exposed ocular surface area per se does not appear to be an important determinant of spontaneous eyeblink activity in elderly Caucasians.

Aged↗
PubMedDate not supplied

Effect of laser in situ keratomileusis for hyperopia on tear film and ocular surface.

PURPOSE: To examine the effects of laser in situ keratomileusis (LASIK) for hyperopia on the tear film and ocular surface. METHODS: A retrospective 12-month analysis of 88 eyes (88 participants) who had LASIK for hyperopia was performed. Participants were evaluated before and after (2 weeks, 1, 3, 6, and 12 months) surgery for dry eye symptoms (McMonnies Dry Eye Survey primary symptoms), tear film stability (fluorescein break-up time), tear volume (phenol red thread test), ocular surface staining (fluorescein), and conjunctival goblet cell density. RESULTS: Chronic dry eye was experienced by 32% of participants; symptoms were significantly associated with female gender, preoperative dry eye symptoms, lower tear film stability after surgery, greater ocular surface staining after surgery, lower tear volume before and after surgery, and lower goblet cell densities after surgery. Regression rate 12 months after surgery was 32% and significantly associated with female gender, chronic dry eye symptoms, lower tear film stability after surgery, greater ocular surface staining before and after surgery, and lower tear volume before and after surgery. CONCLUSIONS: Dry eye, particularly in females, is problematic after LASIK for hyperopia and is associated with refractive regression. Current methods for managing the tear film and ocular surface may not control LASIK-induced dry eye, particularly in some females during the first 6 months after surgery.

Adult↗
PubMed2001

The effects of six months of contact lens wear on the tear film, ocular surfaces, and symptoms of presbyopes.

PURPOSE: To assess the tear film, ocular surfaces, and symptoms of ocular discomfort in a presbyopic population before and after contact lens wear. METHODS: A total of 150 presbyopes (49% were previous soft contact lens wearers) participated in a clinical trial in which they wore either monovision (single vision Acuvue lenses) or Acuvue Bifocal contact lenses. Clinical measurements of tear film, biomicroscopy, and corneal sensitivity as well as subjective ratings using the Dry Eye Questionnaire were collected at the initial visit and repeated after 6 months. Comparisons were made between age groups (40 to 51 years and 52 to 71 years) and genders before and after contact lens wear. Associations between objective and subjective tests were sought. RESULTS: After 6 months of contact lens wear, clinical signs had worsened by less than one-half of a grade, and tear break up time (TBUT) worsened by 3 s. Only TBUT was lower for the older age group. Females had less bulbar hyperemia, more sensitive eyes, more lissamine green staining, and lower TBUT and phenol red thread measurements (all p < 0.04). Twenty-eight percent experienced dryness before contact lens wear, but this figure increased to 68% when wearing contact lenses. There were no age differences, but almost twice as many females as males reported dryness. Reporting symptoms of dryness was associated with gender, corneal sensitivity, and type of corneal staining. CONCLUSIONS: These results provide a representation of the ocular surface condition and symptoms of ocular discomfort in the middle-aged population and seem similar to reports of younger populations. Wearing contact lenses seems to influence dry eye symptoms more than age or gender. Therefore, presbyopes should not be excluded from consideration for contact lens fitting.

Adult↗
PubMed2006

Alterations of the ocular surface epithelial mucins 1, 2, 4 and the tear functions in patients with atopic keratoconjunctivitis.

BACKGROUND: An increased understanding of the ocular surface alterations at the cellular level in the conjunctiva and the cornea, may help explain the pathogenesis and the subsequent clinical appearance of atopic ocular allergies, which may be potentially blinding. PURPOSE: To investigate MUC 1, 2 and 4 alterations, tear function and the ocular surface disorder in patients with atopic keratoconjunctivitis. METHODS: Twenty-eight eyes of 14 atopic keratoconjunctivitis patients as well as 22 eyes of 11 age-and sex-matched normal subjects were studied. The subjects underwent corneal sensitivity measurements, Schirmer's test, tear film break-up time (BUT), fluorescein and Rose Bengal staining of the ocular surface, conjunctival impression cytology and brush cytology. Impression cytology samples underwent periodic acid-Schiff and immunohistochemical staining with MUC 1, 2 and 4 antibodies. Brush cytology specimens underwent evaluation for inflammatory cell numbers and quantitative real-time-PCR for MUC 1, 2 and 4 mRNA expression. Patient eyes with fluorescein and Rose Bengal scores greater than four points were regarded to have significant epithelial disease in this study. RESULTS: The mean corneal sensitivity and BUT values were significantly lower in atopic patients with significant epithelial disease, compared with patients with insignificant epithelial disease and controls (P < 0.01). Brush cytology specimens from patients with significant epithelial disease revealed significantly higher numbers of inflammatory cells (P < 0.01). Specimens from patient eyes showed positive staining for MUC 1, 2 and 4. MUC 1, 2 and 4 mRNA expressions were significantly higher in eyes with significant epithelial disease compared with eyes with insignificant epithelial disease and eyes of control subjects. CONCLUSION: Ocular surface inflammation, decline in corneal sensitivity, tear film instability, changes in conjunctival epithelial MUC 1, 2 and 4 mRNA expressions were thought to be important in the pathogenesis of atopic ocular surface disease.

Adolescent↗
PubMed2006

Complications of mitomycin C therapy in 100 eyes with ocular surface neoplasia.

AIM: To determine the complications associated with mitomycin C (MMC) in the treatment of ocular surface neoplasia. METHODS: A retrospective and consecutive study of 100 eyes in 91 patients with ocular surface neoplasia treated with MMC in a single centre between November 1998 and January 2005. Outcome measures included complications of MMC and the treatment required for these complications. RESULTS: One to three 7 day cycles of topical MMC 0.04% four times a day were given to 59 eyes with localised corneal-conjunctival intraepithelial neoplasia (CIN), 19 eyes with diffuse CIN, six eyes with recurrent CIN, one eye with ocular surface squamous cell carcinoma, three eyes with primary acquired melanosis (PAM) with atypia, nine eyes with conjunctival malignant melanoma (MM), two eyes with sebaceous carcinoma with pagetoid spread, and one eye with recurrent atypical fibroxanthoma. Nine patients had bilateral CIN. 31 (34%) cases developed an allergic reaction to MMC and 14 (14%) eyes had epiphora secondary to punctal stenosis at a mean follow up period of 26.5 months. CONCLUSION: In the largest study looking at complications of topical MMC in the treatment of ocular surface neoplasia, allergic reaction and punctal stenosis are relatively common. Serious complications were not observed suggesting the safe use of MMC in mid-term follow up.

Adenocarcinoma, Sebaceous↗
PubMed2002

Ocular surface problems following topical medication.

BACKGROUND: Adverse effects following topical medication account for a significant ocular morbidity. Toxic and allergic reactions are second in frequency among all external eye diseases (after keratokonjunctivitis sicca). Knowledge on the clinical background that predisposes to such reactions is scarce. This study aims to identify the factors that render commonly used topical medications to powerful ocular irritants. PATIENTS AND METHODS: 168 consecutive tertiary referrals with external eye disease problems were studied. The adverse effects on the ocular surface were analysed using a modified Wilson's classification (1983). RESULTS: At least 39 out of 168 (24 %) patients had problems related to topical medication. Factors that predisposed to adverse reactions included a compromised ocular surface in 17 patients (43 %), long-term drug exposure in 8 (21 %), intensified treatment in 8 (21 %), concomitant acute disorders in 4 (10 %), and additive drug toxicity (> 3 medications) in 2 patients (5 %). Toxic papillary keratokonjunctivitis was the most common adverse reaction (n = 31; 80 %) and was associated in 13 patients with epithelial defects, in 2 with keratinisation of the ocular surface and in one with conjunctival scarring. Aminoglycoside antibiotics were the drugs that were most frequently involved in adverse ocular surface reactions. CONCLUSION: Toxic reactions are far more common than allergic ones. They are frequent in eyes with compromised surface, and after long-term or intensified therapy.

Comorbidity↗
PubMed1997

Efficacy of a training programme designed to teach cervical smear screeners to identify ocular surface squamous neoplasia using conjunctival impression cytology.

Ocular surface squamous neoplasia (OSSN) is a recently proposed term introduced to encompass both intraepithelial neoplasia and invasive squamous cell carcinoma of the conjunctiva and cornea. A teaching programme incorporating a manual, slide sets, and an evaluation test was developed. The aim was to teach experienced cervical smear screeners to evaluate ocular surface specimens collected by conjunctival impression cytology, with a minimum of individual tuition. The use of the manual was well accepted and half of the original six candidates were able to master the new skill adequately within 8 h. It was considered that the differences between the cytology of OSSN and the equivalent lesions of the uterine cervix are sufficient to prevent some experienced screeners acquiring these skills rapidly.

Carcinoma, Squamous Cell↗
PubMed1988

Application of immunologic technology to the diagnosis of viral infections of the ocular surface.

Recent advances in immunologic technology are making the rapid diagnosis of viral infections of the ocular surface possible. The prompt use of these diagnostic techniques can directly influence therapeutic decision making, such as the use of antiviral drugs and steroids. In this article, existing methods of sampling the ocular surface are discussed, and the yield of infectious virus and viral antigens from various sites on the ocular surface is reviewed. The immunologic principles underlying radio-immunoassays, enzyme immunoassays, and a variety of immunocytologic methods are outlined, along with the advantages and disadvantages of each immunologic technique. In addition to reviewing the methods for detecting viral antigens on the ocular surface, the value of assessing antiviral antibodies in the tear film, as well as prospects for future diagnostic techniques, are discussed.

Avidin↗
PubMed2003

[Dry eye disease as a complex dysregulation of the functional anatomy of the ocular surface. New concepts for understanding dry eye disease].

INTRODUCTION: Dry eye disease is a disorder of the tear film that results in epithelial damage and in a disruption of the normal homeostasis at the ocular surface. It is widespread and causes symptoms ranging from discomfort to blindness. METHODS: A review of the existing literature was used to compare different past and recent concepts for the understanding of dry eye disease with a focus on aspects of the integrating functional anatomy of the ocular surface. RESULTS: The understanding of the pathogenesis of dry eye disease has proceeded from the mere recognition of a lack of tears to a consideration of their quality and to the concept of wetting of the ocular surface. However, several other aspects as epithelial differentiation, innervation, hormonal status or immune protection contribute to the intact functional anatomy of the ocular surface. Recently it has been recognized that immunologically regulated mechanisms of inflammation represent a primary or secondary pathogenetic factor for dry eye disease. This is conceivably regulated by the cells of the physiological mucosal immune defence system, the eye-associated lymphoid tissue (EALT). Androgens represent an important trophic factor for the ocular surface and their deficiency predisposes to inflammation. CONCLUSION: Dry eye disease represents a complex dysregulation of the functional anatomy of the ocular surface that can start from different alterations (e.g. insufficient secretion, defects in wetting or innervation). Immune-based inflammation is able to interconnect and negatively reinforce these different pathomechanisms, resulting in a vicious circle.

Conjunctiva↗
PubMed2005

CFTR-regulated chloride transport at the ocular surface in living mice measured by potential differences.

PURPOSE: To define the role of the cystic fibrosis transmembrane conductance regulator (CFTR) in Cl(-) secretion at the mouse ocular surface in vivo. METHODS: Open-circuit potential differences (PDs) across the fluid-bathed ocular surface were measured in anesthetized wild-type and cystic fibrosis (CF) mice in response to Cl(-) ion substitution and transport agonists and inhibitors. RESULTS: Basal ocular surface PD was -23 +/- 1 mV (SE; 20 wild-type mice), depolarizing to -16 +/- 2 mV after amiloride, then hyperpolarizing to -34 +/- 3 mV after low Cl(-). CFTR activation by forskolin or a selective activator caused further sustained hyperpolarization to -50 to -60 mV. UTP produced a comparable but transient hyperpolarization. The CFTR inhibitors CFTR(inh)-172 and GlyH-101 largely reversed agonist- but not low Cl(-)-induced hyperpolarizations. PD in CF mice hyperpolarized by 2.1 mV after low Cl(-) and was insensitive to CFTR activators or inhibitors. CONCLUSIONS: CFTR provides a major pathway for mouse ocular surface Cl(-) secretion, suggesting the application of CFTR activators as therapy for dry eye. Amiloride-sensitive Na(+) transporters facilitate Na(+) absorption. PD measurements provide a robust and reproducible means of assessing ocular surface ion transporting mechanisms.

Amiloride↗