Monday, June 15, 2009

Abstract: Tears & MGs, bleph or no

Meibomian gland dropout, ick.

Tear and Meibomian Gland Function in Blepharitis and Normals.
Eye Contact Lens. 2009 Jun 9. [Epub ahead of print]

McCann LC, Tomlinson A, Pearce EI, Diaper C.
From the Department of Vision Sciences (L.C.M., A.T., E.I.P.), Glasgow Caledonian University; and Department of Ophthalmology (C.D.), Southern General Hospital, South Glasgow University Hospital Trust, Glasgow, United Kingdom.

PURPOSE: To determine the differential features of tear physiology and meibomian gland function in blepharitics for ascertaining the diagnostic potential of a number of clinical tests.

METHODS: Two groups of subjects, 15 with clinically diagnosed blepharitis (11 women and 5 men mol/L; age 60.9 +/- 12.5; range 41-79) and 15 age- and sex-matched controls (11 women and 5 men mol/L; age 60.7 +/- 12.6; range 40-78), were included in the study. Tear physiology was assessed by evaporimetry and interferometry and the meibomian glands by expression and meibography.

RESULTS: Tear evaporation rate was significantly higher (P<0.001) in blepharitics (46.3 +/- 22.9 g/m/hr) than that in normals (18.0 +/- 10.7 g/m/hr). The lipid pattern was found to be significantly less stable (P=0.001) in the blepharitic group compared with that in the normal group. By meibography, meibomian gland dropout was scored and found to be significantly greater (P=0.001) in blepharitics in both the upper eyelids (blepharitis 1.0 +/- 0.8; normal 0.1 +/- 0.3) and lower eyelids (blepharitis 2.1 +/- 8.3; normal 1.0 +/- 0.8). The dropout score was the same or greater for the lower lids than for the upper lids, in all cases. A significant difference (P=0.000) in meibomian gland expression was found between blepharitics and normals; meibum was significantly thicker and more opaque in blepharitics in both the upper (blepharitis 2.2 +/- 0.7; normal 1.0 +/- 0.2) and lower (blepharitis 2.6 +/- 0.7; normal 1.3 +/- 0.4) eyelids.

CONCLUSIONS: There are significant differences in tear physiology and meibomian gland function in patients with blepharitis when compared with those without. All the tests employed would be useful as single tests in the diagnosis of blepharitis, with meibomian gland dropout of the lower eyelid offering the greatest effectiveness as a single measure.

Abstract: Dry eye and systemic medications

Short and French, but it's nice to see systemic drugs mentioned more, including HRT.

J Fr Ophtalmol. 2009 Jan;32(1):64-70. Epub 2009 Feb 5.
[Ocular dryness related to systemic medications][Article in French]

Creuzot-Garcher C.
Service d'Ophtalmologie, hôpital général, CHU de Dijon, 3, rue du Faubourg Raines, BP 159, 21033 Dijon cedex, France.

Iatrogenic ocular dry eye disease remains a frequent associated cause of ocular dryness. Lachrymal secretion depends on hormonal and nervous factors. Anticholinergic agents play an important role in ocular dryness because of hyposecretion. Sexual hormones and particularly androgens greatly influence lachrymal and meibomian secretions leading to the main symptoms found during menopause or hormone replacement therapy. Rare causes such as graft-versus-host disease (GVHD) and Lyell disease must be identified and promptly managed to avoid severe complications. The treatment of iatrogenic ocular dryness is mainly based on lubricants while trying to decrease the use of desiccating systemic treatments.

Abstract: Performance of a new small-sample osmometer

Cornea. 2009 May 30. [Epub ahead of print]
Evaluation of a New Tear Osmometer for Repeatability and Accuracy, Using 0.5-muL (500-Nanoliter) Samples.

Yildiz EH, Fan VC, Banday H, Ramanathan LV, Bitra RK, Garry E, Asbell PA.
*Department of Ophthalmology; daggerThe Henry Dazian Department of Chemistry, Mount Sinai School of Medicine, New York, New York; and double daggerAdvanced Instruments, Inc., Norwood, Massachusetts.

PURPOSE:: To evaluate the repeatability and accuracy of a new tear osmometer that measures the osmolality of 0.5-muL (500-nanoliter) samples.

METHODS:: Four standardized solutions were tested with 0.5-muL (500-nanoliter) samples for repeatability of measurements and comparability to standardized technique. Two known standard salt solutions (290 mOsm/kg H2O, 304 mOsm/kg H2O), a normal artificial tear matrix sample (306 mOsm/kg H2O), and an abnormal artificial tear matrix sample (336 mOsm/kg H2O) were repeatedly tested (n = 20 each) for osmolality with use of the Advanced Instruments Model 3100 Tear Osmometer (0.5-muL [500-nanoliter] sample size) and the FDA-approved Advanced Instruments Model 3D2 Clinical Osmometer (250-muL sample size).

RESULTS:: Four standard solutions were used, with osmolality values of 290, 304, 306, and 336 mOsm/kg H2O. The respective precision data, including the mean and standard deviation, were: 291.8 +/- 4.4, 305.6 +/- 2.4, 305.1 +/- 2.3, and 336.4 +/- 2.2 mOsm/kg H2O. The percent recoveries for the 290 mOsm/kg H2O standard solution, the 304 mOsm/kg H2O reference solution, the normal value-assigned 306 mOsm/kg H2O sample, and the abnormal value-assigned 336 mOsm/kg H2O sample were 100.3, 100.2, 99.8, and 100.3 mOsm/kg H2O, respectively.

CONCLUSIONS:: The repeatability data are in accordance with data obtained on clinical osmometers with use of larger sample sizes. All 4 samples tested on the tear osmometer have osmolality values that correlate well to the clinical instrument method. The tear osmometer is a suitable instrument for testing the osmolality of microliter-sized samples, such as tears, and therefore may be useful in diagnosing, monitoring, and classifying tear abnormalities such as the severity of dry eye disease.

Abstract: Acidic um....

Couldn't bring myself to type the whole name into the title. Sounds like a rare disease, but I gather it's really an enzyme which seems to be showing up a lot in meibomian gland disease and also in Sjogrens.

Acidic Mammalian Chitinase in Dry Eye Conditions.
Cornea. 2009 May 30. [Epub ahead of print]
Musumeci M, Aragona P, Bellin M, Maugeri F, Rania L, Bucolo C, Musumeci S.
From the *Department of Hematology, Oncology and Molecular Medicine, Italian National Institute of Health, Rome, Italy; daggerDepartment of Surgical Specialities, Section of Ophthalmology, University of Messina, Messina, Italy; double daggerCRIBI Biotechnology Center, University of Padova, Padova, Italy; section signDepartment of Experimental and Clinical Pharmacology, University of Catania, Catania, Italy; and parallelDepartment of Neurosciences and of Mother and Child Sciences, University of Sassari and Institute of Biomolecular Chemistry, National Research Council, Li Punti, Italy.

PURPOSE:: An acidic mammalian chitinase (AMCase) seems to be implicated in allergic asthma and allergic ocular pathologies. The aim of this work was to investigate the role of AMCase during Sjögren's Syndrome (SS) and Meibomian Gland Dysfunction (MGD) dry eye diseases.

METHODS:: Six patients with MGD dry eye (20-58 years, median 40) and six patients with dry eye associated to SS (32-60 years, median 47) were enrolled in this study. AMCase activity was measured in tears and AMCase mRNA expression was evaluated by real-time polymerase chain reaction from RNA extracted from epithelial cells of the conjunctiva. Six healthy adult subjects of the same age (34-44 years, median 39) were also studied as the control group.

RESULTS:: AMCase activity was significantly increased in patients affected by MGD dry eye (18.54 +/- 1.5 nmol/ml/h) and SS dry eye (8.94 +/- 1.0 nmol/ml/h) respectively, compared to healthy controls (1.6 +/- 0.2 nmol/ml/h). AMCase activity was higher in the tears of subjects with MGD dry eye (P < 0.001). AMCase mRNA was detected in conjunctival epithelial cells and the expression was significantly higher in MGD dry eye than SS dry eye. A significant correlation between AMCase activity in the tears and mRNA in conjunctival epithelial cells was found.

CONCLUSION:: AMCase may be an important marker in the pathogenesis of dry eye, suggesting the potential role of AMCase as a therapeutic target in these frequent pathologies.

Plug news: FCI SnugPlug "new and improved"

...according to a massmail I received. Actually it's not the plug that's improved, it's the inserter, but that's important for doc and patient alike.

Docs, any comments?