In vivo detection of clinically non-apparent ocular surface inflammation in patients with meibomian gland dysfunction-associated refractory dry eye symptoms: a pilot study.

PURPOSE: The utility of in vivo confocal microscopy (IVCM) in the investigation of palpebral conjunctival and corneal inflammation in patients with meibomian gland dysfunction (MGD)-associated refractory dry eye symptoms following gland expression, despite objective clinical improvement. METHODS: A retrospective, observational pilot study was conducted evaluating five patients with MGD-associated refractory dry eye symptoms and three control groups: symptomatic untreated MGD patients (n=3), treatment-responsive MGD patients with improved symptoms (n=3) and asymptomatic healthy normals (n=11). Ocular surface disease index (OSDI) scores, tear break-up time (TBUT), the number of meibomian glands yielding liquid secretion (MGYLS), palpebral conjunctival epithelial and substantia propria immune cell (EIC, SIC), and corneal dendritic cell (DC) densities were measured. RESULTS: Despite clinical improvement (TBUT: 6.4±1.2 s to 10.1±2.1 s, P=0.03; MGYLS: 3.5±0.8 glands to 7.0±1.1 glands, P=0.13) and a normal clinical examination post treatment, MGD patients remained symptomatic. IVCM revealed increased immune cells in the palpebral conjunctiva (refractory MGD EIC=592.6±110.1 cells/mm2 untreated MGD EIC=522.6±104.7 cells/mm2, P=0.69; responsive MGD EIC=194.9±119.4 cells/mm2, P<0.01; normals EIC=123.7±19.2 cells/mm2, P< 0.001), but not the cornea (refractory MGD DC=60.9±28.3 cells/mm2; normals DC=25.9±6.3 cells/mm2; P=0.43). EIC did not correlate with TBUT (Rs=-0.26, P=0.33). OSDI scores correlated with both EIC (Rs=0.76, P<0.001) and TBUT (Rs=-0.69, P<0.01) but not SIC. Intraglandular immune cells were also seen. CONCLUSION: MGD-associated refractory symptoms and the symptom-sign disparity may be explained by clinically non-apparent, active inflammation of the palpebral conjunctiva as detected by IVCM. These patients may benefit from anti-inflammatory therapy.

Treatment of contact lenses with papain. Increase in wearing time in keratoconic patients with papillary conjunctivitis.

In 15 Keratoconic patients with papillary conjunctivitis associated with wearing rigid polymethylmethacrylate contact lenses, the cleaning of the lenses with enzymatic contact lens cleaner (papain) increased lens wearing time in nine and diminished the symptoms of mucus and itching in 12. In 13 control, lens-wearing keratoconic subjects with papillary conjunctivitis, three had a decrease, four had an increase, and six had no change in lens wearing time and one had a diminution of symptoms. Use of the enzymatic contact lens cleaner did not, however, influence the biomicroscopic appearance of the papillary conjunctivitis. The inclusion of the enzymatic contact lens cleaner in the cleaning regimen offered an adequate improvement in wearing time and tolerance for three of four patients that previously suffered a reduction in wearing time that compromised or precluded their vocational responsibilities.

Surface deposits on worn hard contact lenses.

Giant papillary conjunctivitis (GPC) is associated with deposits on contact lenses. We used scanning electron microscopy to study the anterior surface of 30 hard contact lenses, both cleaned and not cleaned, worn by patients with GPC and with keratoconus and by asymptomatic subjects. Uncleaned lenses worn by asymptomatic subjects for one day had deposits on about 5% of the surface. In most cases, the deposits were removed completely by one cleaning. Uncleaned lenses worn by patients with GPC or keratoconus had deposits on about 90% of the surface. Most of these deposits were removed by one cleaning. However, residual deposits after cleaning were greater on lenses from patients with keratoconus than on those from patients with GPC. Lenses from asymptomatic subjects rarely had residual deposits after cleaning. We found that the types of deposits on worn soft and hard contact lenses are similar, that there are fewer deposits on hard lenses than on soft lenses, and that deposits on hard lenses, unlike those on soft lenses, generally can be removed by one cleaning.

Human ocular mucus. Scanning electron microscopic study.

Twenty biopsy specimens of the human conjunctival epithelial surface with its associated mucus from normal subjects and contact lens wearers with biomicroscopic evidence of excess mucus were studied by scanning electron microscopy. Mucus existed in strands, sheets, and granules; each morphologic type of mucus was observed in all samples. No qualitative difference in morphologic features of mucus was found between normal subjects and those with excess mucus. Mucous forms observed by scanning electron microscopy closely resembled structures previously shown by biomicroscopic and light microscopic techniques, providing evidence that careful scanning electron microscopic preparation of biopsy specimens containing mucus may not greatly alter in situ morphologic characteristics of mucus.

Mucus secretory vesicles in conjunctival epithelial cells of wearers of contact lenses.

Biopsy specimens from the upper tarsal conjunctivae of ten patients with clinically evident contact-lens-associated giant papillary conjunctivitis (GPC) and eight asymptomatic contact lens wearers without clinically evident conjunctival changes were compared by light and transmission electron microscopy to determine the contribution of nongoblet epithelial cells to increased mucus. A control group consisted of five subjects who had never worn contact lenses. The apical cytoplasm of superficial nongoblet epithelial cells in specimens from all groups showed single-membrane-limited vesicular inclusions that stained metachromatically with toluidine blue and were positive with PAS staining, which indicated muco-protein content. Some vesicles appeared to discharge their contents into the conjunctival sac. More vesicles were found in the GPC subjects and the asymptomatic contact lens wearers than in the normal subjects. These observations, coupled with the sign of increased or excessive mucus discharge in GPC subjects and in asymptomatic lens wearers, support the premise that the superficial layers of non-goblet conjunctival epithelial cells can contribute to an increase in mucus production.

Branching of microvilli in the human conjunctival epithelium.

Biopsy specimens were obtained from the upper tarsal and limbal conjunctivae of ten normal persons and from the upper tarsal conjunctivae of five asymptomatic contact lens wearers and five patients with giant papillary conjunctivitis (GPC) associated with contact lens wear. The microvillar surface of the conjunctival epithelium was studied by transmission and scanning electron microscopy. Branches often stemmed from the side of a straight tubular microvillus and formed an acute angle with the main process. Branches sprouted at various distances from the origin of the microvillus. The most common branching pattern was the bifurcated (bifid) form. Occasionally, both primary and secondary bifurcations were primary and secondary bifurcations were observed on the same microvillus. Some microvilli were branched in the normal conjunctivae, but the conjunctivae of asymptomatic contact lens wearers and patients with GPC had more branched microvilli and greater polymorphism, which correlated with the degree of alteration. This report demonstrates the presence of branched microvilli and describes the types seen in normal conjunctivae and compares the frequency with which branched microvilli are seen in altered conjunctival surfaces.

Conjunctiva in asymptomatic contact lens wearers.

Biopsy specimens of the upper tarsal conjunctiva from 11 asymptomatic, biomicroscopically normal contact lens wearers (five hard and six soft) were studied by scanning electron microscopy. The conjunctiva in lens wearers showed areas of normal epithelial cell surfaces interspersed among areas of altered cells. The altered cell surfaces were characterized by centralized clumped microvilli and baring of that portion of plasma membrane around the cell periphery. The degree of centralization of microvilli varied widely, from a mild tendency to centralize accompanied by slight reduction in cell diameter, to an exteme centralization and dramatic diameter reduction. In some cells, the centralized microvillar structure had a unique mucuslike covering. Numerous altered cells were present in all 11 specimens from asymptomatic contact lens wearers. The number of these cells found by conjunctival biopsy of the hard contact lens wearers and the number in the soft contact lens wearers apparently did not differ. The upper tarsal conjunctiva in these asymptomatic contact lens wearers has an altered epithelial surface, different from that observed in normal subjects without contact lens-wearing experience and from subjects with contact lens-associated giant papillary conjunctivitis.

Prevalence of conjunctival changes in wearers of hard contact lenses.

The prevalence of elevated papillae more than 0.3 mm in diameter was 10.5% in the conjunctivae of 200 subjects who had successfully worn polymethylmethacrylate hard contact lenses for eight hours or more daily for more than five years. Only three of 500 (0.6%) control subjects who had never worn contact lenses had these papillary changes. The prevalence of papillary changes for those with the so-called normal symptoms of mucus, itching, or both associated with wearing of hard contact lenses was 53% (16 of 21 subjects). The prevalence of these symptoms was 76% among subjects with polymethylmethacrylate contact lenses who had papillary changes and 8% among subjects with polymethylmethacrylate contact lenses who did not have papillary changes. We conclude that changes in the upper tarsal conjunctiva are associated with the wearing of hard contact lenses, occur in a significant percentage of patients wearing hard contact lenses for prolonged periods, and include a spectrum of papillary changes.

Giant papillary conjunctivitis in contact lens wearers.

A syndrome that occurred in both hard and soft contact lens wearers was characterized by increased mucus, itching, decreased lens tolerance, and giant papillae in the upper tarsal conjunctiva. It developed in as few as three weeks with soft lens wearers but also occurred after months or even years of successful wear. The histology was characterized by basophils, eosinophils, and mast cells in the epithelium, and these cells as well as increased numbers of lymphocytes, plasma cells, and polymorphonuclear leukocytes in the stroma. The syndrome may be immunologic in origin with deposits on the lenses as the antigen, and the syndrome may be a major cause of difficulty in wearing contact lenses once they have been successfully fit.

Meibomian glands and contact lens wear.

A study of a syndrome characterised by deficient or inadequate Meibomian gland secretions, minimal or transient symptoms suggestive of ocular dryness, fluorescein staining of the cornea (often detected only after delayed observation or sequential instillation of stain), and contact lens intolerance is described. Clinical and cytological studies indicate that the syndrome is due to obstruction of the Meibomian gland orifices by desquamated epithelial cells that tend to aggregate in keratotic clusters, which results in alteration of the Meibomian glands' contribution to the precorneal tear film. Further complication may result from bacterial proliferation in the desquamated keratotic cells and the release of the bacteria and their toxic products into the precorneal tear film from these reservoirs in the excretory pathways of the Meibomian glands.

Biomicroscopy of papillae associated with wearing of soft contact lenses.

We studied the topographical, macrostructural, and fluorescein staining characteristics of papillary changes of the upper tarsal conjunctiva associated with the wearing of hydrophilic (soft) contact lenses. Fifty soft contact lens wearers with elevated conjunctival papillae greater than 0.3 mm in diameter were studied. Topographic characteristics recorded were distribution and number of papillae; macrostructural characteristics recorded were diameter and morphology of papillae. The information collected included age of patient, duration of lens wear, average daily time of wearing lens, presence or absence of itching or mucus, refractive status, and atopic history. Papillae were found in most cases in the conjunctival zone adjacent to the tarsal fold and were never found in the zone adjacent to the eyelid margin without also occurring in the intervening zone. The diameter of the papillae ranged from greater than 0.3 mm to 2.0 mm. The number of papillae per eyelid ranged from 4 to over 100. The apices of the papillae were frequently flattened, and these flattened surfaces frequently stained with fluorescein. The vascular supply of individual papillae was observed to radiate from a vessel occupying the central core of each papilla.

Survey of preferred tests for diagnosis of the tear film and dry eye.

PURPOSE: To survey practitioners in the tear film/dry eye field for their preferred diagnostic methods for the evaluation of the tear film and dry eye syndrome. METHODS: A survey was given to 36 optometrists and 41 ophthalmologists with backgrounds in the area of tear film and dry eye syndrome to find their preferred test if only one diagnostic option was available for tear film evaluation. Second, third, and fourth choices were also recorded, as well as any additional comments. RESULTS: Sixty-eight practitioners completed the survey. No one single test was a dominant first choice of the majority of respondents in either profession. History and/or dry eye questionnaire was the most frequent response to the question addressing the use of only one test (28%). The second most frequently chosen test was fluorescein break-up time (FBUT) (19%), followed by fluorescein staining (13%), and rose bengal (10%). The Schirmer test was most frequently included as one of the four choices (62%), although it was the first choice of only 9%. CONCLUSION: The importance of multiple tests in the evaluation of tear film disorders is overwhelmingly acknowledged, with patient history/dry eye questionnaires, FBUT, ocular surface staining, and the Schirmer test being the preferred diagnostic tools.

Comparison of fluorescein break-up time measurement reproducibility using standard fluorescein strips versus the Dry Eye Test (DET) method.

PURPOSE: To compare the repeatability of fluorescein break-up time (FBUT) measurements determined with either a standard fluorescein strip or the Dry Eye Test (DET) modified fluorescein strip methods. METHODS: This was a prospective, randomized contralateral study of 100 patients, in which FBUT measurements were determined with a standard FUL-GLO fluorescein strip (Akorn, Inc., Buffalo Grove, IL, U.S.A.) in one eye and a DET strip (Akorn, Inc., Buffalo Grove, IL, U.S.A.) for the contralateral eye. Three consecutive measurements were made immediately after fluorescein instillation. The second eye was evaluated 1 minute after completion of the first eye. Data from patients with FBUT values less than 20 seconds were included in the data analysis, because measurements greater than 20 seconds are not diagnostically significant. RESULTS: Seventy-five patients met enrollment and FBUT measurement criteria. For three consecutive FBUT measurements, the DET values were within 3 seconds for 72 of the 75 patients (96%). Eighty percent of patients reported no sensation with the DET strip, 20% reported mild sensation, and no patient reported moderate sensation. With FUL-GLO strips, measurements were within 3 seconds for 53 of the 75 patients (71%) (p <0.005). The standard fluorescein strip method elicited reports of no sensation from 31% of patients, mild sensation from 60%, and moderate sensation from 9% (p <0.001). CONCLUSIONS: The DET strip provides a significant reduction in sensation upon application, improved single measurement reliability, and enhanced measurement precision, compared with a conventional fluorescein strip.

Effect of periocular humidity on the tear film lipid layer.

The purpose of this study was to determine the relationship between the tear film and humidity by examining whether alterations in periocular humidity influence the thickness of the tear film lipid layer. Thirteen dry eye subjects presenting with a baseline lipid layer thickness of < or = 60 nm were fitted with modified swim goggles in which the right eye (OD) was exposed to conditions of high humidity and the left eye (OS) remained exposed to ambient room conditions. The lipid layer was monitored over a 60-min time course with goggles on and for an additional 60 min following goggle removal. The OD lipid layer increased significantly in thickness within 5 min of exposure to conditions of high humidity (p < 0.0001), reaching a maximum increase of 66.4 nm after 15 min of goggle wear (p < 0.0001). This maximum increase to a lipid layer thickness of 120.5 nm was maintained at the 30- and 60-min goggle time points. No significant change was detected OS. Following goggle removal, OD values declined but remained significantly elevated over the OS lipid layer thickness throughout the 60-min postgoggle period. Moderate to total relief of dry eye symptoms was reported during goggle wear and generally persisted at a reduced level for 1-3 h following goggle removal. Increased periocular humidity results in an increase in tear film lipid layer thickness, possibly by providing an environment that is more conducive to the spreading of meibomian lipid and its incorporation into the tear film.

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.

Tear film lipid layer thickness as a function of blinking.

Alterations in the tear film lipid layer as a function of blinking were investigated using a custom-designed specular reflection monitoring system. The tear film lipid layer of 104 subjects under conditions of normal ("baseline") blinking and "forceful" blinking was quantitated on the basis of specific interference colors. Deliberate, forceful blinking was found to significantly increase the lipid layer thickness (LLT) of the tear film. The magnitude of increase was found to be correlated with the baseline LLT values; individuals with baseline LLT values of 75-150 nm demonstrated a mean increase in LLT of 33 nm following forceful blinking, whereas subjects with baseline LLT values < or = 60 nm experienced a mean increase of 19 nm. The difference in the magnitude of increase between the groups was highly significant (p = 0.0001). The data suggest that, in addition to playing a role in the spreading of lipid across the tear film, the blinking mechanism may be important in the maintenance of the lipid layer by augmenting the expression of lipids from the meibomian glands.

Meibomian gland phospholipids.

The content of the meibomian gland lipid exprimate is known, but little is known about the phospholipids that comprise the glandular cells. The purpose of the present study is to identify and quantitate the phospholipid complement of the meibomian gland cells that produce the lipid secretion of meibomian oil and which is vital to tear film stability. Eyelids (n = 50) were excised from rabbits, and after surgical removal of surrounding tissues, the tarsal plates with and without expressing meibomian oil were extracted and phospholipids of the plates quantified by 31P nuclear magnetic resonance (NMR). Seventeen phospholipids were quantified from tarsal plates expressed of oil and tarsal plates containing meibomian oil: alkylacylphosphatidylcholine (AAPC), dihydrosphingomyelin (DHSM), dimethylphosphatidylethanolamine, diphosphatidylglycerol (cardiolipin), ethanolamine plasmalogen (EPLAS), lysoethanolamine plasmalogen, lysophosphatidylcholine, lysophosphatidylethanolamine, lysophosphatidylserine, phosphatidic acid, phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylglycerol, phosphatidylinositol, phosphatidylserine, sphingomyelin (SM), sphingosylphosphorylcholine. The six zwitterionic and neutral phospholipids, DHSM, EPLAS, PE, SM, AAPC, and PC together comprise 79.5% of the total meibomian gland phospholipid profile (in meibomian oil this value is 84.2%). The zwitterionic and neutral phospholipids dominate meibomian gland phospholipid profiles. Since the meibomian gland cells undergo holocrine secretion and form the meibomian glad secretion, such a composition is consistent with the hypothesis that a chemically stable lamellar surfactant layer phospholipids bind non-polar meibomian oil to the aqueous layer of the tear film.

Tear film-contact lens interactions.

Contemporary contact lenses, when considered in perspective, are remarkably effective; the remaining primary challenge, however, appears to be the relationship of the contact lens to the tear film. The number of contact lens wearers in the United States is no longer increasing, perhaps the result of discomfort which may occur initially, preventing contact lens wear, or which may develop over a period of years, resulting in termination of wear. Contemporary lenses can usually provide comfort if tear film integrity can be maintained. The environmental humidity is a critical component in the formation and thickness of the lipid layer for both the preocular and the prelens tear films, thus influencing tear film stability and evaporation. A common clinical observation is the gradual development of discomfort over 10 or more years of contact lens wear by patients who initially are totally asymptomatic. This discomfort, probably the result of compromise to the tear film occurring with age, frequently leads to discontinuation of contact lens wear. Intermittent discontinuation of contact lens wear may also occur as the result of seasonal discomfort when the relative humidity is low, or when the nature of the visual demand, as in extended VDT operation, inhibits blinking. The fragile tear film and its relation to contact lenses is readily understood by two quotations: "The human tear film is rather unstable, but it is regenerated by frequent blinking", and "When a contact lens is placed in the eye, the lens alters the normal structure of the tear film and affects its rate of evaporation.(ABSTRACT TRUNCATED AT 250 WORDS)