Meibography

meibomian gland

1. Meibography Rajeshwori Ngakhushi B Optometry

2. Meibomian gland Specialized sebaceous gland Which is approximately linear and 3–4 mm in length Traversing the posterior eyelid perpendicularly from the lid margin to the opposite edge of the tarsus

3. Contd … Demonstrates a tubulo-acinar architecture with saccular arrangements of acini A ductal system that communicates with orifices near the mucocutaneous junction of the eyelid

4. Contd … Glandular acini contain clusters of modified sebaceous cells called meibocytes Which synthesizes and secretes lipids ( meibum ) into the precorneal tear film

5. MEIBUM Lipid component of the tear film maintains stability and prevents the premature evaporation of the aqueous tear component Abnormalities in the lipid production lead to chronic irritation and damage to the ocular surface epithelium

6. Number of meibomian glands in the upper eyelid (approximately 30–40 ) Lower eyelid (approximately 20–30) (Driver and Lemp , 1996) Meibomian glands of the lower lid are significantly wider than of the upper lid

7. Examination techniques 1. Slit-lamp evaluation of meibomian gland orifices

8. 2. Meibometry - measure basal meibum levels at the eyelid margin - quantify the amount of lipid 3. Meibography

9. MEIBOGRAPHY

10. Infrared photography and imaging of meibomian glands For the purpose of observing the morphology of meibomian glands in vivo Provides photographic documentation of the meibomian gland under specialized illumination techniques

11. History First described by Tapie (1977 ) Used UV Woods light to fluorescene meibomian ducts on biomicroscopy and infrared light to illuminate the meibomian glands on Infra Red photography

12. Contd … Mathers et al (1991) was the first to refer to IR photography of meibomian glands as ‘‘ meibography ’’

13. Two principles in meibography

14. 1. Contact meibography : Traditional technique Developed in the late 1970’s Involve direct application of a light probe to the skin for eversion and transillumination of the eyelid followed by imaging with a specialized camera

15. 2. Non-contact meibography : Introduced in 2008 by Arita et al Uses a slit-lamp biomicroscope with IR filter and an IR charge-coupled device video camera to image a digitally everted eyelid Latest, faster, more patient friendly, and easier to use than contact techniques

16. Meibographic technologies 1. Infrared meibography 2. Laser confocal meibography : Ability to resolve and characterize the microenvironment and microscopic structures of the meibomian glands

17. 3. Optical coherence tomographic meibography : Capable of obtaining 2-D and 3-D tomograms of the meibomian glands  in vivo

18. When near infrared light coming from a transilluminator pass through the lipid, the light becomes scattered gives the meibomian glands a dark appearance compared with the rest of the tarsus

19. Procedures:- Acquiring meibography images Processing the examination Starting evaluation

20. 4. Tracing eye-lid bounds

21. 5. Tracing gland-points

22. 7. Zooming and tracing 8. Finalizing meibography examination

23. Interestingly, meibography showed the meibomian glands of the upper eyelid were thinner and longer as compared with the lower eyelids May facilitate evaluation of the impact of the surgery on the meibomian glands.

24. Meibomian gland dysfunction( MGD ) International Workshop on Meibomian Gland Dysfunction formally defined it as a chronic, diffuse abnormality of the meibomian glands , commonly characterized by terminal duct obstruction and/or qualitative/quantitative changes in the glandular secretion

25. Most prevalent in Asian populations (46.2–69.3%)

26. Types of MGDs

27. 1. Low delivery or obstructive-type MGD: Absence or hyposecretion of meibum Results in a lipid-deficient tear film and evaporative dry eye Histopathologic studies demonstrate squamous metaplasia and keratinized plugs at gland orifices, inspissation of lipids and cell debris within dilated ducts, gland hypertrophy, lysis of meibocyte cell junctions, and gland atrophy

28. 2. High delivery or seborrheic -type MGD: Hypersecretion of meibum into the tear film incites an inflammatory reaction at the ocular surface resulting in symptoms of eye irritation less common

29. Meibographic image analysis

30. Meiboscores method Inspect for the presence of partial or absent meibomian glands and assigned a numerical score proportional to the area of involved eyelid  

31. Meibograde method Comprises three distinct categories based on histopathologic changes in the meibomian glands: gland distortion, gland shortening, and gland dropout Assigning a score of 0 through 3 to each of the three categories and then sums the categories to obtain a meibograde from 0 through 9 per eyelid

32. Area of loss of MG is significantly correlated to lipid layer thickness, noninvasive break-up time and dry eye symptoms Loss of 16.9% of the upper lid MG and 28.7% of the lower lid was suggested to be the threshold of dry eye 

33. THANK YOU!