The eyelids develop from the surface ectoderm and mesenchyme. They protect the eye from injury and excessive light and help distribute tears over the eye surface. The eyelids have an anterior and posterior lamella. The anterior lamella contains skin, muscle and connective tissue. The posterior lamella contains the tarsal plates and conjunctiva. The eyelids receive innervation from facial and sympathetic nerves and contain structures like the orbicularis oculi muscle, tarsal plates, meibomian glands and conjunctiva. Common eyelid disorders include infections, chalazion, entropion/ectropion, blepharitis and ptosis.

2. Embryology
- eyelids develop as folds of surface ectoderm above and below the
developing cornea
- the mesenchymal core of the lids forms the connective tissue and tarsal
plates
- orbicularis oculi muscle is formed from the mesenchyme of second
pharyngeal arch
- eyelashes develop as epithelial buds from the surface ectoderm
- ciliary glands of Moll and Zeis grow out from ciliary follicles
- tarsal glands develop as columns of ectodermal cells from the lid
margins

3. Function
- protects the eye from injury and excessive light
- distribution of tears over the anterior surface of eyeball and their
exit into drainage system at medial angle of eye

4. General arrangement

7. Eyelashes
- short, thick, curved present on
margins of eyelid
- arranged in 2-3 rows
- 150 in upper eyelid
- 75 in lower eyelid
- sebaceous gland of Zeis open into
each follicle

8. Structure
- divided into anterior and posterior lamella
Anterior lamella - skin & orbicularis muscle
Posterior lamella - tarsal plate and conjunctiva
From superficial to deep
1. Skin
2. Subcutaneous tissue
3.Striated muscle fibers of orbicularis oculi
4. Orbital septum and tarsal plates
5. Smooth muscle
6. Conjunctiva

9. Skin
- very thin and easily folds
- has many small hairs with sebaceous
glands and small sweat glands
- keratinized stratified squamous
epithelium
Subcutaneous tissue
- very loose and rich in elastic fibers

10. Orbicularis oculi
- flat, elliptical, striated muscle
that surrounds the orbital margin
- main protractor of eyelids
- orbital portion extending to
temporal and cheek
- palpebral portion divided into
preseptal and pretarsal parts
- lacrimal portion behind the
lacrimal sac.

11. Lateral canthal tendon
- pretarsal muscles join laterally and insert by
a common tendon into WHITNALL'S TUBERCLE
- preseptal muscles join laterally to form a
lateral raphe which is connected to
underlying tendon
- orbital septum joins the lateral ends of tarsal
plates into whitnall's tubercle
- these structures together form lateral canthal tendon

12. Medial canthal tendon
- has fibrous and muscular component
- pretarsal muscle inserted medially by
superficial and deep head
- superficial head blends with fibrous
component to form anterior part of medial
canthal tendon
- deep head also known as pars lacrimalis
or horners muscle inserted into posterior lacrimal crest
- preseptal muscle also gets inserted by superficial and deep head

13. Nerve supply - zygomatic and temporal branches of facial nerve
Action- facial expression and closure of eyelids
Orbital part- voluntary
Palpebral part- voluntary & involuntary
Lacrimal part- dilates the lacrimal sac

14. Orbital septum
- membranous sheet which
forms the fibrous framework
of eyelid
-separates the eyelid from
contents of orbital cavity

15. Orbital septum pierced by
1. Lacrimal vessels & nerves
2. Supraorbital vessels & nerves
3. Supratrochlear nerve & artery
4. Infratrochlear nerve
5. Anastomosis b/w angular and ophthalmic vein
6. Superior and inferior palpebral arteries
7. Levator palpebrae superioris in upper & prolongation of inferior rectus
in lower lid.

16. Tarsal plates
- dense fibrous tissue
and gives the eyelid
firmness & shape
- tarsal glands are
embedded within

17. Tarsal glands
-20-25 in each lid
-seen as yellowish lines
on inner surface of everted lid
- secretes oily substance
- greyish line seen running along
the eyelid margin b/w eyelashes
and opening of tarsal glands

18. Smooth muscle
- forms the superior and inferior
tarsal muscles( Muller's)
- innervated by sympathetic
nerves from superior
cervical sympathetic ganglion

19. Conjunctiva
- thin mucous membrane lining
the eyelids
- nonkeratinized squamous
epithelium
- reddish/ pinkish due to rich
vascularity
- accessory lacrimal glands of
Wolfring & Krausse found b/w
upper tarsal border and fornices

20. Levator palpebrae superioris
- inserted into upper eyelid
- raises the upper eyelid
- striated part supplied by
superior branch of oculomotor
nerve
- smooth muscle supplied by
sympathetic fibers from
superior cervical sympathetic
ganglion

21. Fascial spaces

22. Arterial supply

23. Venous drainage

24. Lymphatic drainage

25. Nerve supply

26. Disorders of eyelashes
- Trichiasis
- Distichiasis

27. - eyelash ptosis
- trichomegaly
- madarosis
- poliosis

28. Meibomian gland dysfunction

29. Bacterial infections of eyelid
- External hordeolum (stye)
- Impetigo
- Erysipelas
- Necrotizing fascitis

30. Viral infections of eyelid

31. Chalazion

32. Ectropion and Entropion

33. Blepharitis

34. Ptosis
- neurogenic
- myogenic
- aponeurotic
- mechanical

35. Congenital malformations
Epicanthus Telecanthus

36. Coloboma

37. Cryptophthalmos

38. Euryplebharon

39. Microblepharon with anophthalmos

40. Ablepharon

41. Ankyloblepharon filiforme adnatum

42. Thank you!