conjunctiva

1. Conjunctiva and
sclera

2. Outline
• Conjunctiva
• sclera

3. Conjunctiva
• Introduction
• Surface anatomy
• Conjunctival layers
• Blood supply and drainage and nerve
supply

5. What is conjunctiva?
• Vascularized mucous membrane that
covers the anterior surface of the globe
(bulbar and forniceal conjunctiva) and the
posterior surface of the upper and lower
eyelids (palpebral conjunctiva).

6. Combats infection
1. Highly vascular
2. The different cell types can initiate and
participate in defensive inflammatory
reaction
3. Immunocompetent cells that contribute a
rich supply of immunoglobulins
4. The surface anatomy (microvilli) and
biochemistry (enzymatic activity) enable that
tissue to engulf and neutralize foreign
particles, such as viruses

7. Surface anatomy
• The conjunctiva lines the posterior surface
of the upper and lower lids and the
anterior surface of the globe
• Forms superior fornix(8-10mm from
limbus) and inferior fornix(8 mm from
limbus)
• Caruncle and the plica semilunaris

8. Arrow pointing to the region of the superior fornix
Region of the inferior fornix (arrow)

9. Medical region of the eye showing the
caruncle (C) and plica semilunaris (P)
Region of the lateral fornix (arrow)
14 mm from the limbus

10. Palpebral conjunctiva

11. Palpebral conjunctiva
• Starts from posterior end of the eyelid
margin at the mucocutaneous junction
• Marked adherent to tarsal plate of lids
• Freely movable in fornices (forniceal
conjunctiva)

12. Follicular reaction
•identical to lymphoid follicles
•viral and chlamydial infections as
well as toxic conjunctivitis due to
application of certain topical
medications
Papillary reaction
•chronic inflammatory cells such as
lymphocytes and plasma cells
•presence of blood vessels at their center
•,Allergic conjunctivitis, Bacterial
conjunctivitis,Contact lens wears,Superior
limbic keratoconjunctivitis.

14. Bulbar conjunctiva

15. Bulbar conjunctiva
• limbus to the forniceal area.
• thin and translucent.
• loosely adherent to the sclera to allow the eye free
movement in all directions.
• Approximately 3 mm from the limbus, the bulbar
conjunctiva, Tenon's capsule, and sclera become
firmly attached, and the conjunctiva cannot be
easily picked up.
This attachment is routinely
encountered during the dissection
of a limbal-based conjunctival flap
in ocular surgery.

16. Conjunctival glands
42
6-8
2-5
2

17. Conjunctival layers
• The stratified epithelial layer
• The substantia propria layer

18. Conjunctival epithelium
• 2 to 4 layers-upper tarsal portion
• 6 to 8 layers-corneoscleral junction,
• 8 to 10 layers-conjunctival margins

19. Conjunctival epithelium
• Columnar in the fornix
• Cuboidal on the bulbar and tarsal
conjunctiva

20. Types of cells
• Type I cells are the goblet cells
• Type II cells are defined by the numerous
60- to 300-nm electron-dense granules
• Type III cells are recognizable by their well
developed Golgi complex
• type IV cells are characterized by rough
endoplasmic reticulum
• Type V cells are identified by the high
content of mitochondria

21. Goblet cells

22. Goblet cells
• middle and superficial layers of the
epithelium
• 25 by 25 μm
• 2.2 μL of mucus daily

23. Function of goblet cell mucus
• Preserve stability of tear film
• Local immunity
• Cleansing mechanism of the eye
• Traps cell debris, foreign bodies, and
bacteria
• inflammatory response

24. Substantia propria
• Connective tissue layer
• Anti-infectious potential
• Numerous mast cells (6000/mm3),
lymphocytes, plasma cells, and
neutrophils are normally present in this
layer.

25. Substantia propria
Superficial lymphoid layer
•Not present at birth
•Lymphocytes aggregrated into
nodules
Deeper fibrous layer
•thick, collagenous, elastic
tissue and contains the vessels
and nerves of the conjunctiva in
addition to Krause's glands
Senile elastotic degeneration

26. Blood supply
Internal carotid artery ophthalmic artery
The palpebral branches of the
nasal and lacrimal arteries of
the lid
Anterior ciliary artery.

27. Venous drainage
• numerous than the arteries
• tarsal conjunctiva and the bulbar
conjunctiva is directed to the palpebral
veins
• superior and inferior ophthalmic veins

28. Lymphatic drainage
• a superficial plexus and a deeper
plexus
• Ultimately as in the lids drains to the
pre auricular and sub-mandibular
lymph glands.

29. Nerve supply

30. Caruncle
• small, flesh-like body that lies to the medial
side of the plica semilunaris
• stratified squamous epithelium similar to
skin, but does not undergo keratinization
• Hair,sebaceous and sweat glands, goblet
cells and accessory lacrimal glands similar to
Krause's glands.
• Blood supply-superior palpebral arteries
• Nerve supply-infratrochlear nerve
• Lymphatic drainage-sub maxillary lymph
nodes

31. Plica semilunaris
• Fold of conjunctiva lying lateral to the
caruncle
• cul-de-sac of approximately 2 mm in depth
is formed when the globe is adducted
• nonexistent when the globe is abducted
• nictitating membrane in lower vertebrates

32. Sclera
• Introduction
• Development
• Gross anatomy
• Layers
• Blood supply,drainage and nerve supply

33. Sclera

34. Introduction
• dense connective tissue that accounts for five
sixths of the outer coat of the eyeball
• sklera mannix- hard membrane
1.protects intraocular components from trauma,
light, and mechanical displacement
2.withstands the considerable expansive force
generated by the intraocular pressure
maintaining the shape of the globe
3.provides attachment sites for the extraocular
muscles.

35. Prenatal development
• neural crest-mesodermal origin
• anterior to posterior and from inside to
outside
5th
week double-layered optic cup or
neuroectoderm
6th
week Differentiation into sclera
and choroid anterior to
equator
8th
week Backward to the equator
12th
week Posterior pole
4th
month Scleral spur
5th
month Lamina cibrosa

36. Postnatal development and age
related characterstics
• Postnatal- relatively thin, bluish,
distensible, small, and translucent
• Childhood and puberty-thicker, whiter, less
distensible, larger, and more opaque
• Adult- poorly distensible,opaque or
translucent depending on water content
• Elderly- less distensible,yellowish color
and senile scleral plaques.

37. Gross anatomy
five sixths of the eyeball with a
radius of curvature of 12 mm

38. Optic nerve
Equator=0.4-0.5mm
Behind insertions
Insertions=0.6mm
Thickness of sclera

39. Clinical applications
• The traumatic scleral rupture
• Strabismus surgery.

40. Tenons capsule
• fascial sheath of the eyeball
• extends anteriorly from the
limbus backward, envelopes the
globe and fuses with the optic
nerve dural sheath and with the
sclera around the exit of the
optic nerve
• supports the eyeball within the
orbit
• permits the eyeball movement
produced by the extraocular
muscles

41. Sclera foramina
• anterior for the cornea
• posterior for the optic nerve

42. Anterior scleral foramen
• Sclera merges with the cornea at the anterior
scleral foramen forming the corneoscleral
junction or limbus
Fig: longitudinal section through the region
of the corneoscleral junction showing the
peripheral cornea, the sclera, the
conjunctiva, and Tenon's capsule, canal of
Schlemm, the trabecular meshwork, and
the iris

43. Posterior scleral foramen
• The exit of the optic nerve
• Lamina cribrosa-After piercing the lamina cribrosa, the axons of the
optic nerve become myelinated. One of the small perforations is larger than the rest
and permits the passage of the central retinal artery and vein.

44. Layers of sclera
• Episclera
• Scleral stroma
• Lamina fusca

45. Episclera
• Superficial aspect of sclera
• bundles of collagen circumferentially
arranged
• rich blood supply anteriorly
• thickest anterior to the rectus muscle
insertions and becomes progressively
thinner toward the back of the eye.

46. Scleral stroma
• bundles of collagen intermingled with
fibroblasts, melanocytes, elastic fibers,
proteoglycans, and glycoproteins
• variability in collagen fiber diameter,
interlacing in bundles of collagen, and
relative deficiency in water-binding
substances accounts for the scleral dull-
white color.

47. Lamina fusca
• Brown color due to melanocytes
• grooves for the passage of ciliary vessels
and nerves (emissary canals)
• attached to the choroid by fine collagen
fibers

48. Melanosis oculi

49. Blood supply
• Episclera-anterior and posterior ciliary
arteries
• Scleral stroma-relatively avasculature
structure

51. Venous drainage
• Episcleral collecting veins
• Vortex veins
Anterior ciliary veins

52. Nerve supply
• Rich in nerve supply
• Anterior sclera- long posterior ciliary
nerves
• Posterior sclera- short posterior ciliary
nerves
• Pain- inflammation, stretching due to
oedema and movement of eye

53. Thank you

54. References
1. Fundamentals and principles of Ophthalmology,section
2,2014-2015, American Academy of Ophthalmology
2. External Disease and Cornea, Section 8, 2014-2015,
American Academy of Ophthalmology
3. Duane's Foundations of Clinical Ophthalmology, Foundation
volume 1
4. Jack J Kanski, Brad Bowling, Clinical Ophthalmology,
seventh edition 2011
5. M.J. Roper- Hall, Stallard’s Eye Surgery, Seventh Edition,
1989
6. Parsons’ Diseases of the Eye, Twentieth Edition 2007
7. Internet