2.3 Ocular adnexa 1

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2.3 Ocular adnexa 1
2015-05-24 10:48:51
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  1. What are the ocular adnexa? (6)
    • muscles of the eyelids and adjacent facial muscles
    • eyelids
    • conjunctiva
    • lacrimal apparatus
    • orbit and contents - EOM, orbital fat, nerves, vessels
    • innervation and vascular supply
  2. Orbicularis oculi is divided into 3 parts. What are they?
    • orbital part
    • palpebral part
    • ciliary part
  3. What is the role of the orbital part of the OO?
    forced closure
  4. What is the role of the palpebral part of the OO?
    soft closure e.g. sleeping, blinking
  5. What muscle and nerve is involved in lid closure?
    • OO
    • CN7
  6. What muscles and nerves are involved in lid opening?
    • levator - CN3
    • Muller's muscle - sympathetic innervaion
  7. What are the branches of the LPS and what do they give rise to?
    • levator palpebrae superioris
    • superior - anterior and posterior layers of aponeurosis
    • inferior - muller's muscle
  8. The bulbar conjunctiva merges with the __________ at the ___________
    • corneal epithelium
    • limbus
  9. The palpebral/tarsal conjunctiva adheres tightly to the ________  and ________ to the inferior lid
    • tarsus of the superior lid
    • less tightly
  10. Normally there are more lashes in the:
    a. upper lid
    b. lower lid
    a. upper lid
  11. What are the fornices and what do they contain?
    • loosely attached conj
    • accessory lacrimal glands of Kraus (and Wolfring)
    • high conc of goblet cwwla, lymphocytes (CALT)
  12. Where are eyelashes located?
    At the anterior tarsal surface between orbicularis oculi and muscle of Riolan
  13. Where do the lashes exit?
    At the anterior lid margin and curves away from the globe
  14. What eyelid glands are there?
    Meibomian, Zeis, Moll, Krause, Wolfring
  15. What are meibomian glands?
    Modified sebaceous glands
  16. What are Zeis glands?
    Modified sebaceous glands at base of eyelash follicle
  17. What are Moll glands?
    Modified sweat glands
  18. What are Krause and Wolfring glands?
    Accessory lacrimal glands
  19. What is trichiasis?
    Abnormal misdirected growth of lashes
  20. What is the cause of trichiasis?
    Trichiasis is commonly acquired
  21. Trichiasis is often secondary to? (4)
    • chronic bleph
    • tarsal plate or conj scarring (e.g. trachoma, Stevens-Johnson syndrome
    • ageing changes (entropion)
    • trauma
  22. How is pain from trichiasis relieved?
    Pull the lid away from the eye
  23. Signs and symptoms of trichiasis (8)
    • check history
    • posterior misdirection of normal lashes
    • most frequently lower lid
    • corneal epithelial defects
    • red eye
    • discomfort
    • tearing
    • FB sensation
  24. Complications associated with trichiasis? (3)
    • corneal irritation
    • abrasions
    • worse with blinking
  25. Worst case scenario associated with trichiasis? (3)
    • infection
    • ulceration
    • pannus (if long term)
  26. Management of trichiasis? (3)
    • treat underlying cause
    • treat infection
    • remove aberrant eyelashes
  27. How can aberrant eyelashes be removed? (5)
    • expilation
    • electrolysis
    • cryotherapy
    • laser¬†
    • surgery
  28. What is trachoma?
    A bacterial infection
  29. Epidemiology of trachoma (5)
    • ~84mil ppl in 51 endemic countries have active trachoma
    • WHO estimates ~6mil cases of blindness due to trachoma occur yearly
    • 3% of global blindness
    • 7 previously endemic countries (Gambia, Ghana, Iran, Morocco, Myanmar, Oman and Vietnam)
    • elimination of blinding trachoma as a public health problem
  30. Cause of trachoma (2)
    • Infectious agent: Chlamydia trachomatis
    • a gram negative bacteria
  31. Serotypes of C. Trachomatis
    • Serotypes A, B, Ba, C: classic trachoma (poor hygeine)
    • Serotypes D to K: adult inclusion conjunctivitis (sexually transmitted), neonatal conjunctivitis (Chlamydia most common infectious cause)
    • Serotypes L1 to L3: lymphogranuloma venerem (a STD)
  32. What are the two phases of trachoma
    • active
    • scarring/cicatrical
  33. Signs during active phase of trachoma (5)
    • usually seen in children
    • conj inflammation (follicles and papillae)
    • limbal follicles
    • irritating and watery discharge
    • keratitis
  34. Signs during cicatrical phase of trachoma (4)
    • tarsal conj scarring(esp upper) - linear/stellate then confluent
    • distortion of eyelid and trichiasis
    • secondary trichiasis/entropion and associated corneal scarring leading to blindness
    • resolved limbal follicles result in gaps in corneal pannus (Herbit's Pits)
  35. Trachoma Grading Scale
    • TF: Trachamatous inflammation - follicular
    • TI: Trachomatous inflammation - intense
    • TS: Trachomatous scarring
    • TT: Trachomatous trachiasis
    • CO: Corneal opacity
  36. What is distichiasis? (3)
    • rare
    • extra row of lashes arising from meibomian gland orifices
    • associated with trichiasis
  37. Causes of congenital distihiasis
    • differentiation of complete pilosebaceous glands (hair follicles) cf normal sebaceous (meibomian glands)
    • meibomian glands may be abnormal
  38. Cause of acquired distichiasis (metaplastic lashes)
    • transformation from normal meibomian glands to hair follicles (pilosebaceous units)
    • related to conjunctival scarring
    • e.g. chemical burns, ocular pemphigoid, Stevens-Johnsons Syndrome
  39. Treatment for distichiasis (3)
    • surgical excision
    • cryotherapy
    • laser
  40. Lid-splitting procedure
    • division into anterior and posterior lamellae
    • cryotherapy to posterior lamella
    • reapposition of lamellae
  41. What is madarosis
    Loss of eyelashes/eyebrows partial or complete
  42. Cause of madarosis (6)
    • local disease
    • systemic disorders
    • infectious
    • skin-related
    • eyelash removal
    • trauma