eyes

Question 1

UVItis

Question 2

conjunctivitis

Answer 3

1. The wall of the eye has three layers: sclera, choroid, and retina. The retina contains millions of
   baroreceptors known as rods and cones that receive light through the lens and then convey
   signals to the optic nerve and subsequently to the visual cortex of the brain.

g.

Answer 4

2. The eye is filled with vitreous and aqueous humor which prevent it from collapsing.

Answer 5

3. The major alterations in ocular movement include strabismus, nystagmus, and paralysis of specific
   extraocular muscles.

Answer 6

4. Structural eye changes caused by aging result in decreased visual acuity.

Answer 7

5. Alterations in visual acuity can be caused by amblyopia, scotoma, cataracts, papilledema,
   glaucoma, and macular degeneration.

Answer 8

6. A cataract is a cloudy or opaque area in the ocular lens and leads to visual loss when located on
   the visual axis.
   7

Answer 9

9. Alterations in accommodation develop with increased intraocular pressure, inflammation, and
   disease of the oculomotor nerve. Presbyopia is loss of accommodation caused by loss of elasticity
   of the lens with agin

Answer 10

8. Age-related macular degeneration is irreversible loss of vision with dry or wet forms.

Answer 11

. Glaucomas are characterized by intraocular pressures greater than 12 to 20 mm Hg with death of
retinal ganglion cells and their axons.

Answer 12

10. Alterations in refraction, including myopia, hyperopia, and astigmatism, are the most common
    visual disorders.

Answer 13

11. Alterations in colour vision can be related to yellowing of the lens with aging and colour
    blindness, an inherited trait.

Answer 14

13. Trauma or disease of the optic nerve pathways, or optic radiations, can cause blindness in the
    visual fields.

Answer 15

12. The eyelids, conjunctivae, and lacrimal apparatus protect the eye. Infections are the most common
    conditions affecting the supporting structures of the eyes; they include blepharitis, conjunctivitis,
    chalazion, and hordeolum.

Answer 16

16. Keratitis is a bacterial or viral infection of the cornea that can lead to corneal ulceration.
    Photophobia, pain, and tearing are common symptoms.

Answer 17

14. Blepharitis is an inflammation of the eyelid; a hordeolum (stye) is an infection of the eyelid’s
    sebaceous gland; and a chalazion is an infection of the eyelid’s meibomian gland.

Answer 18

15. Conjunctivitis can be acute or chronic, bacterial, viral, or allergic. Redness, edema, pain, and
    lacrimation are common symptoms. Chlamydial conjunctivitis is the leading cause of blindness in
    the world and is associated with poor sanitary conditions.

Question 19

Blepharitis: I

Answer 19

Blepharitis: Inflammation of the eyelids.
Epidemiology: inflammation is caused by bacterial invasion of the eyelid. Typically caused by staphylococcus species that are normally present on the skin. Seborrheic dermatitis can be a condition that causes breaks in the skin, facilitating infection. Can also be caused by demodex mite species that live on the eyelashes.
Pathophysiology: skin barrier breakdown through mechanical damage or other illness (e.g. seborrheic dermatitis) leads to invasion of epithelial tissue by microorganisms. Adaptive and innate immune reactions ensue, leading to inflamed, painful, crusted eyelid margins.
Time course: acute infection that can be treated with symptoms relief and antibiotic ointment.

Question 20

Uveitis:

Answer 20

Uveitis: Inflammation of the vascular, middle layer of the eye (Uvea). The uvea is composed of the iris, choroid, and ciliary body.
Epidemiology: Can arise spontaneously but is more common in people with autoimmune disease or systemic infections. Associated with ankylosing spondylitis and Crohn’s disease.
Pathophysiology: Inflammation of the middle layer of the eye by a causative agent or through autoimmune reactions. Can be caused by infection with mycobacterium tuberculosis, syphilis, HSV and varicella zoster, or parasitic infection. Adaptive and innate immune reactions lead to inflammation and cellular responses in the uvea. Inflammation of the middle layer of the eye can have significant complications, including increased intraocular pressure, which can cause vision loss through retinal hypoxia.

Question 21

blepharitis

Answer 21

bacterial infection of eye lids
staph
sebborrtic dermatitis

Question 22

Uveitis

Answer 22

inflam of middle layer of eye.
Uvea: iris chorid, ciliari body

Question 23

Hordeolum

Answer 23

Acute inflammation of the glands of Moll or Zeis (external hordeolum) or the meibomian glands (internal hordeolum)
Risk factors are rosacea, seborrheic dermatitis, use of eye make up
Often caused by bacteria such as staphylococcus aureus

Question 24

Chalazion

Answer 24

Sterile lipogranuloma caused by obstruction of meibomian gland
Risk factors are rosacea and posterior blepharitis