Chapters 19 and 20 Disorders of Special Sensory Function Flashcards
Cornea
Most exterior portion of the eye. Clear, protective.
Where is the aqueous humour located in the eye? Function of this liquid?
Behind the cornea in the anterior and posterior chambers. Keeps the eye lubricated.
Sclera
The white part of the eye
Where is the iris? What is its function?
This is the colored part of the eye. Located behind the cornea and the anterior chamber. Responsible for constriction and dilation of the pupil in response to light.
Where is the lens? Shape?
Located behind the iris. Concave shape to reflect light for sight.
What structures are located at the back of the eye?
Retina, macula, optic disc, blood vessels
What is the uvea?
- Iris
- Ciliary body
- Choroid
Ptosis
1. Cause?
Eyelid drooping
1. Caused by muscle weakness of the levator muscle or unopposed action of the orbicularis oculi.
Function of the orbicularis oculi? Weakness vs unopposed action?
The OO closes the eyelid.
1. Weakness of this muscle can result in eyelids remaining open.
2. Unopposed action can result in ptosis
Levator muscle
Controls the eyelids opening
Ectropion
Eversion of the lower lid margin (eyelid turns out). Dry eyes.
Entropion
Inversion of the eyelid (eyelid turns inward). Infection.
Blepharitis
1. Describe the forms
2.Treatments
Inflammation of the eyelid.
1. Seborrheic form - associated with yeast (dandruff) of the scalp and brows. Kinda looks like cradle cap. Can be treated with gentle mix of baby shampoo.
2. Staphylococcal blepharitis - caused by Staph infection, lesions are often ulcerative. Usually antibiotic ointment.
Hordeolum
AKA stye
Infection of the sebaceous gland of the eyelid. Internal or external.
Chalazion
A chronic form of an internal hordeolum.
Caused by chronic inflammation of the granuloma of meibomian glands.
Dry eyes
1. What is the normal function of the tear film?
2. What are some common causes of dry eyes?
3. How can dry eyes affect a person’s health?
4. Treatment
- The tears work to lubricate the eyes.
- Common causes include - advanced age, contacts, Sjogren syndrome, loss of reflex lamrim.
- Places the patient at increased risk for inflammatory eye conditions and infection.
- Artificial tears, ointments, procedure
What is the conjunctiva? Where is it?
A thin mucus membrane that surrounds the eyelid. It works to keep the eye moist.
Conjunctivitis
1. Types
2. Treatment
Inflammation of the conjunctiva - a thin mucous membrane that surrounds the eyelids internally.
1a. Infectious - yellow drainage. Can be bacterial, viral, chlamydial, or ophthalmia neonatorum.
1b. Allergic - clear drainage.
- Most of the treatment involves antibacterial ointment or eyedrop. In regard to the neonatorum - prenatal care prevention is the best treatment.
A patient presents to the clinic with eye redness. How to differentiate between conjunctivitis vs corneal lesions or glaucoma?
- Conjunctivitis typically causes itchiness and drainage. Pain is only mild if any.
- Corneal lesions and glaucoma are serious conditions where the patient may be experiencing severe pain. Send to hospital. Need referral care.
Keratitis
1. Types
Inflammation of the cornea
1. Bacterial, Herpes simplex, Acanthamoeba
Arcus senilis
Fatty deposits found on the edge of the cornea. Seen with high cholesterol and/or age.
What part of the nervous system controls the pupil?
The ANS controls pupillary constriction and dilation. Parasympathetic controls constriction - decreased vision. Sympathetic nervous system controls dilation - allows greater light to enter the eye allowing for greater vision during times of stress.