Chapter 10. The Eye and Ear

Question 1

-In the front of the eyeball is a transparent opening. RATE LIMITING STEP FOR OPHTHALMIC DROPS.
-After light passes through the cornea, a portion of it passes through an opening known as the pupil.
-Pupil opening can be adjusted by the dilation of the iris.
Define ciliary muscles and gland

Answer 1

• Cornea
• Pupil
• Iris
• The lens is attached to the ciliary muscles.
• Ciliary gland secrete aqueous humor.

Question 2

• The inner surface of the eye
• Small central area of retina.
• The network of nerve cells is bundled together to form this on the very back of the eyeball

Answer 2

• Retina- images form here in the eye, in the region FOVEA
• Macula
• Optic nerve

Question 3

The nerve cells is bundled at very back of eyeball, explain the name.

Answer 3

Optic disk/Blind spot: rods and cones are NOT present on the optic disk

Question 4

• If the incoming light from a far away object focuses before it gets to the back of the eye, that eye’s refractive error is called?
• If incoming light from something far away has not focused by the time it reaches the back of the eye, that eye’s refractive error is?

Answer 4

• “myopia” nearsightedness- short-sightedness Eye disorder where light focuses in front of, instead of on the retina.
• “hyperopia” farsightedness

Question 5

The retina contains two types of photoreceptors
• More numerous, 120 million, more sensitive. However, they are not sensitive to color.
• These are 6 to 7 million provide the eye’s color sensitivity and they are much more concentrated in the central yellow spot known as?

Answer 5

-RODS Rhod”opsin” retinal
Rods are responsible for night vision, our most sensitive motion detection, and our peripheral vision.
-Cones: Macula
CONE Iod “opsin”

Question 6

Elaborate: Beta carotene to opsin

Answer 6

Beta carotene➡️ Retinol (vitamin A) ➡️11-Cis retinal ➡️ opsin
Rods: Light on the retina converts 11-cis retinal to all Trans retinal. The retinal is a vitamin A is essential for the regeneration of 11-cis retinal. Deficiency of vitamin A causes night blindness.

Question 7

Due to angle closure increasing intra ocular pressure (IOP) causes?
This is due to;
AH is secreted from?

Answer 7

Glaucoma
Increase aqueous humor production cause increase IOP.
Decrease aqueous humor secretion from shlemn canal.
-Celiary tissue (gland)

Question 8

Treatment of glaucoma

• Beta blockers (Timolol)- MOA
• Prostaglandin analogues :(“prost”)- MOA
• is diuretics. Decrease IOP by inhibiting enzyme that involved in formation of aqueous humor.
• Directly stimulate muscarinic receptors to contract ciliary muscle and increase trabecular outflow.

Answer 8

• Beta blockers (Timolol). They dec. IOP by inh. form. of AH
• Pg analogs- Lower IOP by inc. outflow of AH thru uvescleral pathway
• Topical CA inhibitors (Acetazolamide, Dorzolomide)
• Cholinergic agonist (Pilocarpine, carbachol)

Question 9

Age related macular disorder (AMD): It is due to gradual deterioration of macular in central vision. It is two types
-What test is useful for self monitoring by patients.

Answer 9

1) Dry- charac. by drusen (white to yellow spots in the central retina). May/not cause vision loss.
2) Wet- presence of choroidal neovascular membrane (CNM), =severe vision loss
- The Amsler grid

Question 10

When the eye lens becomes cloudy, decrease acuity, and no pain, and this obstruct the vision.
surgery postoperative care:

Answer 10

Cataract

Antibiotics, Dilators and anti-inflammatory drugs

Question 11

-Antibiotics: FQ and AG:

and how long drug tx.

Answer 11

• Fluroquinolones 7-10 d (basifloxacin, ciprofloxacin, gatifloxacin, moxifloxacin and ofloxacin)
• AG: 7-10 d. Gentamicin, neomycin, tobramycin

Question 12

-Keep iris away from implant during early healing period and improve comfort by dec. ciliary muscle spasm.
Cyclopentolate, phenylephrine, tropicamide and
-Anti-inflammatory:

Answer 12

• Dilators and cycloplegic

- 3-4wks: Dexamethasone, prednisolone, diclofenac, and ketorolac

Question 13

Drainage resulting from mild otitis externa may be self treated. When to refer to a physician?

Answer 13

Eczematous otitis externa

Ear pain assoc. w ear drainage, the pt should be referred to a physician

Question 14

Ear infx common in children, crying, irri. sleeplessness, pulling on ears, ear pain, HE, neck pain and feeling of pressure/fullness
-when is the patient be referred to a physician

Answer 14

• Otitis media

- with perforation of the tympanic membrane or drainage from the middle ear

Question 15

Ear pain, itch, redness and swelling in and around ear canal, feeling of pressure/fullness

Answer 15

Otitis externa

Question 16

Inner ear infection another term.

Answer 16

Meniere’s disease: vertigo, loss of hearing, tinnitus (ringing), aural fullness, loss of balance, HEs