Yumiko Ban,1,2,3) Seika Den,2) Jun Shimazaki,2,3) 　Morphologic Evaluation of Meibomian Glands Using Noncontact Infrared Meibography 　　Yumiko Ban,1,2,3) Seika Den,2) Jun Shimazaki,2,3) Department of Ophthalmology, Hino Municipal Hospital, 　　Tokyo, Japan 2) Department of Ophthalmology, Tokyo Dental College, School of Dental Medicine, Chiba, Japan 3) Department of Ophthalmology, School of Medicine, Keio University, Tokyo, Japan Authors have no financial interest. World Cornea Congress Ⅵ Boston, Massachusetts, April 7-9, 2010

Background ・ Recently, noncontact infrared meibography (NIM) has been developed1-3, which allows easy observation of the meibomian glands (MG) structure over a wide area encompassing both the upper and lower eyelids. ・　 To date, only semi-quantitative criteria of gland destruction (gland drop-out) have been used to evaluate the MG. ・ To evaluate the morphologic assessment of the MG using NIM and investigate the quantitative evaluation ・ To investigate the relationship between MG morphology and the condition of the tear film and ocular surface epithelia Purpose 1, Arita R, et al. Noncontact infrared meibography to document age-related changes of the meibomian glands in a normal population.　Ophthalmology. 2008 ;115:911-5 2, Arita R, et al. Contact lens wear is associated with decrease of meibomian glands. Ophthalmology. 2009 ;116:379-84. 3, Arita R, et al. Proposed diagnostic criteria for obstructive meibomian gland dysfunction. Ophthalmology. 2009 ;116:2058-63

Study Design Subjects recruited in this study ・ 37 eyes of 37 subjects (The data used in this study were obtained from the right eye in each subject.) ・ males: 23 cases, females: 14 cases ・ Mean age 46.5 ±15.4 years (range 19～75 years） Exclusion criteria ・ Obvious eyelid or ocular surface disorders, contact lens wear, history of ocular surgery, and dry eye according to the 2007 International Dry Eye Workshop Report

Methods Meibography The meibography apparatus comprised a slit lamp (RO 5000, Rodenstock) with a magnifying power of 12 and an infrared charge-coupled device video camera (XC-EI50, Sony). The digital images obtained by meibography were recorded and analyzed using image J (free software). Morphometric indices which we conducted morphologic assessment of the MG ・ Length of MG duct ・ Percent area of MG acini ・ Number of gland drop-outs Tear function Schirmer test Ⅰ Break-up time of tear film (BUT) Tear film lipid layer interferometry (TFLLI) (Yokoi’s grading system) 4 Evaluation of ocular surface Fluorescein staining score (FS) Expression of meibum (Shimazaki’s grading system) 5 4, Yokoi N , et al. Correlation of tear lipid layer interference patterns with the diagnosis and severity of dry eye. Am J Ophthalmol. 1996 ;122:818-24 5, Shimazaki J, et al. Meibomian gland dysfunction in patients with Sjögren syndrome Ophthalmology. 1998 ;105:1485-8

We measured and calculated the mean value for the length of the 5 selected central MG ducts. The white lesion was considered to be the lipid of MG. It seemed to be the MG acini. We defined a rectangle measuring 5x4 mm in the central upper eyelid. We measured the percent area of MG acini contained within the selected rectangle. ( In the lower eyelid, a square measuring 4x4 mm along the central lid margin was defined.) The number of gland drop-outs contained in the image was counted. Upper eyelid 10mm 13mm 4mm 5mm The white lesion was reversed to the black lesion. We calculated the black area, and found the percent area of MG acini. Statistical analysis ・ The unpaired t test was used to compare the upper and lower eyelid. ・ The Pearson and Spearman rank sum tests were performed to determine correlations between MG morphologic values and tear film or ocular surface.

Success rate for evaluation and morphometric values of MG in upper and lower eyelids Upper eyelid Lower eyelid Length of MG ducts (mm) 5.53 ± 1.27 * 2.97 ± 0.90 Number of eyes with successful 35 (94.6%) 36 (97.3%) evaluation (%) Percent area of MG acini (%) 41.6 ± 12.4 41.0 ± 15.1 20 (54.1%) 31 (83.8%) Number of gland drop-outs 27 22 1 2 4 3≥ 6 9 Uncountable * = p < 0.05

Data on tear function/ocular surface Schirmer (mm) BUT (seconds) FS (points) TFLLI (grade) Meibum 11.4±9.21 6.00±2.87 0.41±0.76 2.16±1.26 1.14±1.03 BUT = Break-up time of tear film FS = Fluorescein staining score TFLLI = Tear film lipid layer interferometry

Correlation between morphometric values of MG and tear film or ocular surface epithelia age Schirmer BUT FS TFLLI Meibum Length of MG Upper -0.485* 0.087 0.246 -0.223 -0.116 -0.345# duct Lower -0.533** -0.080 0.211 -0.438# -0.241 -0.312 Percent area of -0.600** 0.048 0.549* -0.367 -0.601# -0.641# MG acini -0.357* -0.352 0.208 -0.069 -0.032 -0.207 Number of 0.518# -0.254 -0.432# 0.212 0.457# 0.404# gland drop-outs 0.399# -0.018 -0.199 0.253 0.250 0.189 The number in the table represents the r value. *p < 0.05, **p < 0.001, Pearson r #p < 0.05, Spearman r BUT = Break-up time of tear film FS = Fluorescein staining score TFLLI = Tear film lipid layer interferometry

Summary of the Results Success rate for evaluation of MG ・ The length of the MG ducts could be evaluated in almost all cases in both the upper and lower eyelids, but the percent area of MG acini in the upper eyelid could be evaluated only in approximately half of the eyes. Morphometric values of MG ・　 The length of the upper MG ducts was significantly longer than that of the lower MG ducts.

Summary of the Results Aging ・ Both the length of the MG ducts and percent area of MG acini in the upper and lower eyelids showed a negative correlation with age. ・ The number of gland drop-outs in the upper and lower eyelids showed a positive correlation with age. Correlation between meibomian gland morphology and ocular surface The groups which showed a positive correlation ・ Percent area of MG acini (upper) and BUT ・ Number of gland drop-outs (upper) and TFLLI ・ Number of gland drop-outs (upper) and meibum The groups which showed a negative correlation ・ Length of MG ducts (upper) and meibum ・ Length of MG ducts (lower) and FS ・ Percent area of MG acini (upper) and TFLLI ・ Percent area of MG acini (upper) and meibum ・ Number of gland drop-outs (upper) and BUT

Discussion ・ We could conduct a morphologic assessment of the MG using new indices including the length of the MG ducts and the percent area of MG acini. ・ Improvement of the camera and video system may increase the number of eyes with successful evaluation. ・ Age showed a strong correlation with the MG morphology. Similar to the previous report,1,6,7 the structure of the MG increased changes with aging. ・ The morphological values of the MG in the upper eyelid had a stronger correlation with the condition of the tear film or ocular surface epithelia than that in the lower eyelid. The result suggests that it is important to observe the MG in the upper eyelid. 6, Den S, et al. Association between meibomian gland changes and aging, sex, or tear function. Cornea. 2006 ;25:651-5. 7, Obata H. Anatomy and histopathology of human meibomian gland. Cornea. 2002 ;21::S70-4

Conclusions ・　Noncontact infrared meibography offers a useful tool for obtaining a morphological analysis of the MG in ocular surface evaluation. ・ MG morphology is related to aging and various ocular surface conditions.