Lid Margin Microbiome in Stevens-Johnson Syndrome Patients With Lid Margin Keratinization and Severe Dry Eye Disease.

Purpose: The current study evaluated the lid margin microbiome of keratinized lid margins of patients with chronic Stevens-Johnson syndrome (SJS) and compared it with healthy controls and historically reported lid margin microbiome of patients with meibomian gland dysfunction (MGD). Methods: Eyelid margin swabs of 20 asymptomatic adults (mean age = 29 ± 12 years) and 10 patients with chronic SJS (mean age = 31.2 ± 14 years) with lid margin keratinization were sequenced using next generation of 16S rDNA V3 to V4 variable region. Within SJS, the keratinized lid margin microbiome was compared with adjacent eyelid skin. Results: All patients had obstructive MGD, and mean Schirmer I value was 2.8 ± 1.9 mm. The phyla were similar in two groups, whereas at the genera level, an increase in the relative abundance of Corynebacterium, Haemophilus, Azotobacter, and Afipia and a decrease of Acinetobacter was noted in SJS compared to healthy lid margins. SJS-associated microbiota displayed lesser diversity and more heterogeneity than healthy controls. The Principal Components Analysis (PCA) plot revealed wide separation in the SJS and the control groups. Correlational network analysis revealed Corynebacterium and Sphingomonas forming a major hub of negative interactions with other bacterial genera in the SJS group. Significant differences exist in the prevalent genera between keratinized lid margins and historically reported meibum microbiome of patients with MGD. In addition, the eyelid skin of patients with SJS had predominant Staphylococcus, whereas Corynebacterium and Pseudomonas were more in the keratinized lid margins compared to the eyelid skin microbiome. Conclusions: Lid margin microbiome is significantly altered in the keratinized lid margins of patients with SJS compared to the eyelid skin of patients with SJS, normal lid margins, and patients with MGD.

The Microbiome of Meibomian Gland Secretions from Patients with Internal Hordeolum Treated with Hypochlorous Acid Eyelid Wipes.

OBJECTIVE: The aims of our experiment were to compare the microorganisms in meibomian gland secretions from patients with internal hordeolum before and after treatment using hypochlorous acid eyelid wipes, to elucidate the mechanism underlying hypochlorous acid eyelid wipe treatment of internal hordeolum. METHODS: This was a prospective, matched-pair study. A total of eight patients with internal hordeolum who attended the ophthalmology clinic of our hospital from April to August 2020 were included. Meibomian gland secretions were collected from subjects before treatment (Group A) and from patients cured after eyelid cleaning with hypochlorous acid eyelid wipes for 7 days (Group B). Samples were submitted to 16S rRNA high-throughput sequencing, and the resulting data were analyzed to compare the differences in the structure and composition of meibomian gland secretion microbial flora before and after treatment of internal hordeolum. RESULTS: A total of 2127 operational taxonomic units were obtained from the two groups of samples, and there was no significant difference in alpha diversity before and after eyelid cleaning. At the phylum level, there was no significant difference between the two groups. The predominant phyla in Group A included the following: Firmicutes (32.78% ± 20.16%), Proteobacteria (26.73% ± 7.49%), Acidobacteria (10.58% ± 11.45%), Bacteroidetes (9.05% ± 6.63%), Actinobacteria (8.48% ±1.77%), and Chloroflexi (3.15% ± 3.12%), while those in Group B were the following: Proteobacteria (31.86% ± 9.69%), Firmicutes (29.07% ± 24.20%), Acidobacteria (11.33% ± 7.53%), Actinobacteria (7.10% ± 1.98%), Bacteroidetes (5.39% ± 5.17%), and Chloroflexi (3.89% ± 3.67%). Starting from the class level, significant differences in microbial communities were detected before and after eyelid cleaning (P < 0.05). Linear discriminant analysis effect size analysis showed the core flora in Group A microbiome comprising Actinobacteria, Staphylococcus, Staphylococcaceae, Staphylococcus aureus, Ruminococcacea UCg-014, Ruminococcacea-UCG-014, Halomonadaceae, Neisseria, Methylobacterium, Frankiales, and Neisseria sicca, while those in Group B microbial were Streptococcus sp., Blautia, Bifidobacterium pseudocatenulatum, Subdoligranulum, Subdoligranulum variabile, Faecalibacterium, and Faecalibacterium prausnitzii. CONCLUSION: Eyelid cleaning with hypochlorous acid eyelid wipes does not change the biodiversity in the meibomian gland secretions of patients with internal hordeolum. Hypochlorous acid eyelid wipes may affect the internal hordeolum through broad-spectrum antibacterial action to effectively reduce the relative abundance of symbiotic pathogens, such as Staphylococcus, Neisseria, Actinomycetes, and Ruminococcus and increase that of Faecalibacterium prausnitzii and other symbiotic probiotics with anti-inflammatory effects.

Evaluation of ocular involvement in patients with Hansen's disease.

Hansen's disease (HD) belongs to the group of neglected diseases and can cause physical deformities and disabilities, in addition to leading to social discrimination. Ocular involvement in HD is estimated at 70-75% worldwide. About 10-50% suffer from severe ocular symptoms and loss of vision occurs in approximately 5% of cases. Ocular changes may persist or worsen even after patients are considered cured and it is necessary to better understand these conditions in order to determine the need for additional public policies. The objective of this study was to identify the prevalence of ocular involvement in patients with HD at two specialist referral centers for treatment of the disease. A cross-sectional study was conducted with ophthalmological evaluations of patients with HD from June 2017 to June 2018. Diagnostic ocular findings, corrected visual acuity, and refractive error were described. Findings were correlated with patients' clinical and epidemiological variables. A total of 86 patients were evaluated, with a mean age of 50.1 years, predominantly males (59.3%), and with multibacillary HD (92%). The prevalence of ophthalmologic changes was 100% and the most common were dysfunction of the Meibomian glands (89.5%) and dry eye syndrome (81.4%). Cataracts were observed in 22 patients (25.6%), but best corrected visual acuity was normal or near normal in 84 patients (97.7%) and there were no cases of bilateral blindness. Patients with some degree of physical disability had more ophthalmological alterations, involving both the ocular adnexa (p = 0.03) and the ocular globe (p = 0.04). Ocular involvement is common in patients with Hansen's disease, reinforcing the importance of ophthalmologic examination in the evaluation and follow-up of these patients.

Cutibacterium modestum sp. nov., isolated from meibum of human meibomian glands, and emended descriptions of Cutibacterium granulosum and Cutibacterium namnetense.

An anaerobic and aerotolerant bacterium, strain M12T, was isolated from the meibum of inflamed human meibomian glands. Cells of the strain was Gram-stain-positive, non-spore-forming and non-motile rods. Growth on trypticase soy agar plates supplemented with 5 % sheep blood was fastest at 30-37 °C under anaerobic conditions. The 16S rRNA gene sequence of the strain revealed that it belongs to the genus Cutibacterium with a 98.0 % similarity value to the closest species, Cutibacterium acnes. Genome analysis of the strain with type strains of the other Cutibacterium species resulted in digital DNA-DNA hybridization values of 32.3-22.3% and average nucleotide identity (OrthoANI) values of 86.7-73.6 %. Biochemical and physiological analyses using API rapid ID 32A and API Coryne kits revealed relatively low reactivity of the strain compared with C. acnes and Cutibacterium namnetense. The most abundant major cellular fatty acid was iso-C15 : 0. Fermentation end-products from glucose were propionate, lactate, succinate and acetate. The diagnostic diamino acid of the peptidoglycan was meso-diaminopimelic acid. Major menaquinones were MK-9(H4), MK-9(H2) and MK-9. The major peaks of the MALDI-TOF mass spectrometry spectrum were at 3493, 3712, 6986 and 7424 Da. The DNA G+C content was 59.9 mol%. Based on these findings, we propose a novel species, Cutibacterium modestum. The type strain of C. modestum is M12T (=JCM 33380T=DSM 109769T). On the basis of further genomic analysis, we also provide emended descriptions of Cutibacterium granulosum (Prévot 1938) Scholz and Kilian 2016 and Cutibacterium namnetense (Aubin et al. 2016) Nouioui et al. 2018.

The Microbiome of the Meibum and Ocular Surface in Healthy Subjects.

Purpose: The purpose of this study was to investigate the microbiome in the meibum, conjunctival sac, and eyelid skin in young and elderly healthy subjects, and analyze the effect that age, sex, and region have on microbiome composition. Methods: This study involved 36 healthy subjects (young-age subjects: 9 men/9 women, age range: 20-35 years; elderly age subjects: 9 men/9 women, age range: 60-70 years). In all subjects, lower-eyelid meibum, lower conjunctival sac, and lower-eyelid skin specimens were collected from one eye, and then stored at -20°C. Taxonomic composition of the microbiome was obtained via 16S rRNA gene sequencing, and then analyzed. Results: The meibum microbiome showed a high α-diversity (within-community diversity), particularly in the young subjects. However, in approximately 30% of the elderly subjects, a low-diversity microbiome dominated by Corynebacterium sp. or Neisseriaceae was observed. In the young subjects, the microbiome of the meibum resembled that of the conjunctival-sac, yet in the elderly subjects, the microbiome of the conjunctival-sac became more similar to that of the eyelid skin. The eyelid-skin microbiome was relatively simple, and was typically dominated by Propionibacterium acnes in the young subjects, or by Corynebacterium sp. or Neisseriaceae in the elderly subjects. In both age groups, no significant difference was seen between the men and women in regard to the meibum, conjunctival-sac, and eyelid-skin microbiome. Conclusions: Our findings confirmed that the meibum of healthy adult-age subjects harbors highly diverse microbiota, and revealed that the meibum microbiome, especially the decrease of its diversity, alters with aging and may affect the homeostasis of the ocular surface.

Lysobacter oculi sp. nov., isolated from human Meibomian gland secretions.

A Gram-stain negative, rod-shaped bacterial, catalase and oxidase positive strain (83-4T) that formed yellow colonies was isolated from human Meibomian gland secretions. Strain 83-4T belongs to the genus Lysobacter according to phylogenetic analysis based on 16S rRNA gene sequences. The DNA G+C content was 67.1 mol%. The circular genome was 2.6 Mb, which contained 2431 protein-coding sequences, 75 pseudogenes, 46 tRNAs, 3 rRNAs and 4 ncRNAs. A bacteriocin cluster and aryl polyene cluster were also found in the genome. The average nucleotide identity value was 79.6% between isolate 83-4T and the closely related type strain Lysobacter tolerans UM1T. The estimated DNA-DNA hybridization value between strain 83-4T and L. tolerans UM1T was 41.6%. Diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylglycerol were the major polar lipids. Iso-C15:0, iso-C11:0 3-OH, iso-C11:0 and summed feature 9 (iso-C17:1ω9c) were the major fatty acids. Ubiquinone (Q-8) was the only respiratory quinone. Therefore, based on the data of phylogenetic analysis, chemotaxonomical and biochemical analyses, it is concluded that strain 83-4T represents a novel species of the genus Lysobacter with the name of Lysobacter oculi sp. nov. The type strain is 83-4T (= CGMCC 1.13464T = NRBC 113451T).

Effectiveness of meibomian gland massage combined with topical levofloxacin against ocular surface flora in patients before penetrating ocular surgery.

OBJECTIVE: To investigate the bacterial profile in the conjunctiva and meibomian glands in patients before penetrating ocular surgeries, and to compare the anti-bacterial efficacy of 0.5% levofloxacin and its combination with meibomian gland massage. DESIGN: Hospital-based, case-control study. PARTICIPANTS: Two hundred and twenty-six eyes from 226 patients with non-infective ocular diseases and scheduled for penetrating ocular surgeries. METHODS: Tested eyes were administered topical 0.5% levofloxacin (4 times daily) for 2 days. Among them, 91 eyes received meibomian gland massage before levofloxacin application. Samples from the conjunctival sac and meibomian glands were collected for aerobic and anaerobic cultures. MAIN OUTCOME MEASURES: Culture-positivity and bacterial strains. RESULTS: Before treatment, aerobes and anaerobes were cultured from 38.5% and 11.0% of the conjunctival samples respectively, compared with 38.5% and 8.8% in the meibomian secretions respectively. Staphylococcus epidermidis and Propionibacterium acnes were the commonest isolated aerobe and anaerobe. Two-day application of levofloxacin reduced aerobic growth to 29.6% in the conjunctiva and 19.3% in the meibomian glands. It had no effect on the anaerobes in these regions (13.3% in the conjunctiva and 10.4% in the meibomian glands). Combined levofloxacin with meibomian gland massage further reduced aerobic growth to 19.8% in the conjunctiva and 11.0% in the meibomian glands. It also drastically decreased anaerobic growth in the meibomian glands (1.1%). CONCLUSIONS: Meibomian glands carrying considerable bacteria should be considered as a potential source of contamination in ocular surgery. Meibomian gland massage shows additional anti-bacterial effects to topical levofloxacin and could be recommended as a complementary preoperative prophylaxis.

Ocular surface microbiome in meibomian gland dysfunction.

BACKGROUND: To investigate the ocular microbiome in meibomian gland dysfunction in Auckland, New Zealand. DESIGN: Prospective, cross-sectional, observational, university-based study. PARTICIPANTS: Participants resident in New Zealand for ≥2 years (n = 157) were classified as normal (n = 66), mild (n = 41) or moderate-to-severe meibomian gland dysfunction (n = 50). Contact lens wear and anterior blepharitis status were recorded, as well as symptoms and clinical features. METHODS: Bacteria collected from lid margin swabs, before and after gland expression, were isolated and identified by conventional microbiological culture techniques. Aerobic isolates were identified in all 157 participants, and both aerobic and anaerobic bacteria isolated in a subset of 87 subjects. MAIN OUTCOME MEASURES: Bacterial incidence according to meibomian gland dysfunction status RESULTS: Symptoms, bulbar hyperaemia, conjunctival staining, lipid layer grade and tear film stability, but not corneal staining, showed moderate association with meibomian gland dysfunction severity. Participants with and without meibomian gland dysfunction showed a similar microbiome, unaffected by gland expression. Anterior blepharitis, a common co-morbidity, was not an independent predictor of the microbiome. Sterile cultures were more common in contact lens wearers than non-wearers. The incidence of Staphylococcus aureus was higher than anticipated across all severity groups, and that of coagulase-negative Staphylococcus, Corynebacterium and streptococci was lower. CONCLUSIONS: Modest differences in relative proportions of bacteria compared with other studies support climatic variations in the ocular surface microbiome. Similarity in microbiome profile, irrespective of meibomian gland dysfunction severity, anterior blepharitis presence or contact lens wear, suggests potential for commonality in treatment.

Microwave decontamination of eyelid warming devices for the treatment of meibomian gland dysfunction.

PURPOSE: The role of bacteria in meibomian gland dysfunction is unclear, yet contamination of compresses used as treatment may exacerbate this condition. This study therefore determined the effect of heating on bacteria on two forms of compress. METHODS: Cotton flannels and MGDRx EyeBags (eyebags) were inoculated by adding experimental inoculum (Staphylococcus aureus, Streptococcus pyogenes, Pseudomonas aeruginosa; one species for each set of 3 eyebags and flannels). One of each were then randomised in to 3 groups: no heating (control); therapeutic (47.4±0.7°C); or sanitisation (68±1.1°C). After treatment, bacteria cell numbers were calculated. The experiment was repeated in triplicate. RESULTS: There was a statistically significant difference between each treatment with the eyebag for S. aureus (control=7.15±0.11logC/ml, therapeutic heating=5.24±0.59logC/ml, sanitisation heating=3.48±1.43logC/ml; P<0.001) and S. pyogenes (7.36±0.13, 5.73±0.26, 4.75±0.54; P<0.001). P. aeruginosa also showed a significant reduction (P<0.001) from control (6.39±0.34) to therapeutic (0.33±0.26) and sanitisation (0.33±0.21), but the latter were similar (P=1.000). For the flannels, there was significant difference between each treatment for S. aureus (6.89±0.46, 3.96±1.76, 0.42±0.90; P<0.001). For S. pyogenes, there was a significant reduction (P<0.001) from control (7.51±0.10) to therapeutic (5.91±0.62) and sanitisation (5.18±0.8), but the latter were similar (P=0.07). For P. aeruginosa, there was a significant difference (P<0.001) from control (7.15±0.36) to sanitisation (5.83±0.44); but not to therapeutic (6.84±0.31) temperatures (P=0.07). CONCLUSIONS: Therapeutic heating produces a significant reduction in bacteria on the eyebags, but only sanitisation heating appears effective for flannels. However, patients should be advised to heat the eyebag to sanitisation temperatures on initial use.

Oral azithromycin for treatment of posterior blepharitis.

PURPOSE: To evaluate the effects of oral azithromycin in patients with posterior blepharitis. METHODS: Twenty-six eyes of 13 patients with posterior blepharitis diagnosed by a qualified ophthalmologist were enrolled in this study. Patients were instructed to use oral azithromycin 500 mg per day for 3 days in 3 cycles with 7-day intervals. Subjective clinical outcomes were graded and scored 1 day before and 30 days after the end of the treatment (53 days after initiating the treatment) based on severity scores of: (1) eyelid debris; (2) eyelid telangiectasia; (3) swelling of the eyelid margin; (4) redness of the eyelid margin; and (5) ocular mucus secretion. For the assessment of global efficacy, patients were asked by the investigator to rate the subjective symptoms (eyelid itching, ocular itching, eyelid hyperemia, ocular hyperemia, ocular mucus secretion, photophobia, foreign body sensation, and dry eye sensation) on a scale of 0 (no symptoms) to 5 (severe symptoms). Break-up time, Schirmer I test, corneal fluorescein staining score, and rose bengal staining score were also performed in all patients. RESULTS: All clinical outcomes scoring showed statistically significant improvement after oral azithromycin, except for eyelid swelling. Average subjective symptom grading improved statistically after treatment with oral azithromycin, except for eyelid hyperemia, photophobia, and foreign body sensation. Average tear film break-up time values showed statistically significant improvement after the treatment with oral azithromycin. No statistically significant improvement was observed on average values of Schirmer I test, corneal fluorescein staining score, and rose bengal staining score. CONCLUSIONS: The combination of multiple clinical parameters shown in this study supports the clinical efficacy of pulsed oral azithromycin therapy for the management of posterior blepharitis.

Does orally administered doxycycline reach the tear film?

BACKGROUND/AIMS: Orally administered doxycycline, a broad-spectrum antibiotic, is an established treatment for ocular surface diseases, particularly rosacea, meibomian gland dysfunction and recurrent epithelial cell erosion. In recent times, its efficacy in treating these diseases has been ascribed to an ability to inhibit matrix metalloproteinase (MMP) activity and both MMP and interleukin-1 (IL-1) synthesis. Since these functions are concentration-dependent, the aim of this project was to determine whether sufficient doxycycline reached the tear film to fulfil these roles in vivo. METHODS: Doxycycline was extracted with 1-butanol from tear and blood plasma samples obtained from patients with ocular surface disease and healthy individuals and quantified spectrophotometrically. The MMPs present in the patients tear films before and during doxycycline treatment were analysed zymographically. RESULTS: The quantity of doxycycline detected in the blood plasma samples of patients undergoing treatment ranged from 1.83 to 13.18 microM. Although doxycycline was not detected in their tear samples, the treatment caused the disappearance of the MMPs symptomatic of disease progression. CONCLUSION: The inability to detect doxycycline in the tear film of patients undergoing treatment indicates that doxycycline does not directly inhibit MMP activity or the synthesis/secretion of these proteases and IL-1 from corneal epithelial cells.

Effect of antibacterial honey on the ocular flora in tear deficiency and meibomian gland disease.

PURPOSE: To assess for differences in the ocular flora of patients with dry eye caused by tear deficiency and/or meibomian gland disease and to assess the effect of antibacterial honey on the ocular flora in these forms of dry eye. METHODS: In this prospective, open-label pilot study, bacteria isolated from the eyelid margin and conjunctiva were identified and quantified before and at 1 and 3 months after initiation of treatment with topical application of antibacterial honey 3 times daily. Subjects had non-Sjogren tear deficiency (n = 20), Sjogren syndrome tear deficiency (n = 11), meibomian gland disease (n = 15), and non-Sjogren tear deficiency with meibomian gland disease (n = 20), and there were 18 non-dry eye subjects. RESULTS: The total colony-forming units (CFUs) isolated from each of the dry eye subgroups before antibacterial honey use was significantly greater than the total CFU isolated from the non-dry eye group. Antibacterial honey use significantly reduced total CFUs for the eyelids and the conjunctiva of dry eye subjects from baseline at month 1 (eyelids: P = 0.0177, conjunctiva: P = 0.0022) and month 3 (eyelids: P < 0.0001, conjunctiva: P < 0.0001). At month 3, there were reductions in total CFUs for all dry eye subgroups such that the CFUs were not significantly different from those of the non-dry eye group. CONCLUSION: From these results, there is sufficient preliminary data to warrant further study of the effects of antibacterial honey in chronic ocular surface diseases.

Short term oral minocycline treatment of meibomianitis.

AIM: To evaluate the clinical impact, aqueous tear parameters, and meibomian gland morphology in patients with primary meibomianitis before, during, and 3 months after a course of oral minocycline. METHODS: 16 patients were prospectively enrolled, 11 male and five female (mean age 69 years old). Each patient received routine clinical evaluations before, after 3 months therapy, and at 6 month study follow up visit. The clinical appearance, tear volume, flow and turnover, evaporation, Schirmer I test, meibomian gland dropout, lissamine green staining, and bacteriology wer evaluated. RESULTS: Improvement was observed in clinical signs of meibomianitis at the second and third visits. Microbial culture findings improved. Decreased aqueous tear volume and flow, and increased evaporation rate range at 35-45% relative humidity (RH) (p < 0.05) were also detected. Other related tear parameters did not change. Meibomian gland dropout showed no improvement. CONCLUSIONS: 3 months of oral minocycline resulted in clinical improvements in all meibomianitis signs that persisted for at least 3 months after discontinuation despite decreased aqueous tear volume and flow with increased evaporation (35-45% RH). However, there was improvement in the turbidity of secretions. Short term minocycline therapy probably has efficacy in the management of meibomianitis that extends beyond eradication of bacteria.

[Clinical investigation of chronic blepharitis and evaporative loss dry eye].

OBJECTIVE: To investigate the relationship between chronic blepharitis and evaporative loss dry eye. METHODS: Forty-one patients (82 eyes) were diagnosed as chronic blepharitis from November 2002 to April 2003 in Beijing Tongren Eye Center, of which 22 cases were male and 19 female. All patients' ocular surface was judged by Schirmer I test, tear film break up time (BUT) and Tearscope. Meibomian gland secretion was used for bacteria culture and antibiotic sensitivity test. Thirty patients (60 eyes) of glaucoma, cataract and LASIK before surgery were used as control, which included 16 male and 14 female. Microbiological results of meibomian gland secretion were compared and the statistical difference was evaluated by chi(2) test. RESULTS: Of the blepharitis group, ST value was less than 10 mm in 30 eyes (36.6%), BUT less than 10 s in 56 eyes (68.3%) and tear film tearscope evaluation more than 3 grade in 46 eyes (56.1%). The bacteria spectrum of meibomian secretion in both groups was similar, which included staphylococcus epidermidis, staphylococcus aureus and corynebacterium. However, the bacterium culture positive rate and antibiotic sensitivity showed significant difference (P < 0.05). CONCLUSION: The chronic blepharitis is one of important cause in evaporative loss dry eyes.

The role of tetracycline in chronic blepharitis. Inhibition of lipase production in staphylococci.

Tetracycline administered in low doses can be effective in the long-term management of patients with meibomian keratoconjunctivitis (MKC). However, the mechanism of action does not appear to be a reduction of bacteria. Seventy-five percent of the ocular staphylococci in such patients are resistant to tetracycline. An alternative mechanism of action could be the inhibition of production of extracellular enzymes by the ocular flora. Inhibition of lipase production could result in lowered levels of toxic hydrolysis products (free fatty acids), which may exacerbate the disease process. The authors tested this hypothesis by examining the differential effect of tetracycline on growth and lipase production in a tetracycline-resistant and tetracycline-sensitive strain of Staphylococcus epidermidis and S. aureus isolated from patients with MKC and Staphylococcal blepharitis. Tetracycline caused significant decreases in the production of lipase in the sensitive and resistant strains of S. epidermidis without concominant decreases in growth. In contrast, S. aureus strains showed parallel decreases in both lipase production and inhibition of growth. The authors propose that the sensitivity of lipase production to tetracycline, in tetracycline-resistant S. epidermidis, may partially explain the clinical improvement observed in MKC patients.

Bacterial lipases and chronic blepharitis.

Eyelids and conjunctivae of 36 normal individuals and 60 patients from six clinical groups of chronic blepharitis were cultured for aerobic and anaerobic bacteria. The most common species isolated were coagulase-negative staphylococci (C-NS) and Propionibacterium acnes. All strains of these species, and all Staphylococcus aureus strains isolated were tested for the ability to break down triglycerides, cholesterol esters, and fatty waxes. Each strain was incubated independently with appropriate substrates in nutrient media. Each medium was then extracted and assayed for the presence of substrate hydrolysis products by thin-layer chromatography. The percentage of strains capable of hydrolyzing a particular substrate was determined for each individual. S. aureus was a consistent and strong lipase producer, able to hydrolyze all three substrates. P. acnes was able to hydrolyze triolein and behenyl oleate but not cholesteryl oleate. No differences were observed among groups for P. acnes or S. aureus. C-NS showed a high degree of strain variability. Eighty-three percent of C-NS strains could hydrolyze triolein, 82% behenyl oleate, and 40% cholesteryl oleate. Significant group differences were seen in the percentage of lipase positive C-NS strains isolated per individual. Patients in the mixed staphylococcal/seborrheic, meibomian seborrheic, secondary meibomitis, and the meibomian keratoconjunctivitis (MKC) groups harbored significantly more C-NS strains capable of hydrolyzing cholesteryl oleate than did normal individuals. Patients in the meibomian seborrheic, secondary meibomitis, and MKC groups harbored significantly more C-NS strains capable of hydrolyzing behenyl oleate than did normals. No group differences were seen among groups with triolein hydrolyzing C-NS strains.

Meibomian gland dysfunction and contact lens intolerance.

A study of a syndrome characterized 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 cytologic 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.

Meibomian keratoconjunctivitis.

We evaluated, dermatologically and ophthalmologically, 26 patients who had chronic blepharitis (meibomitis); we also investigated 26 age- and sex-matched controls. All of the blepharitic patients had an abnormality of sebaceous gland function ranging from seborrhea sicca to seborrheic dermatitis or acne rosacea, suggesting a generalized sebaceous gland dysfunction that included the meibomian glands. Sebaceous gland abnormalities most frequently involved the cool areas of the face or scalp. Stagnation of the meibomian glands presumably caused a defect in the tear lipid layer; this resulted in an unstable tear film that produced superficial punctate keratopathy. The break-up time was much lower in these patients than in controls. The break-up time returned to normal or super-normal levels when fresh meibomian secretions were expressed into the tear film. The superficial punctate keratopathy had the characteristics of those seen in conditions with a known unstable tear film and not of those experimentally produced by staphylococcus toxin.