MT M4.9 Special Senses Conditions

Question 1

Disorders

Answer 1

Disorders of the special senses can either be acquired or genetic. Physical examination of the special senses utilizes several specialized tests used to assess the health of the organ and the surrounding structures.

Question 2

Visual acuity

Answer 2

Visual acuity is the sharpness of vision.

Question 3

Snellen eye chart

Answer 3

Visual acuity is the sharpness of vision. It is tested with a Snellen eye chart where a patient reads letters of various sizes from a distance of 20 feet.

Question 4

Colored vision

Snellen eye chart

Answer 4

Colored vision is tested with multicolored charts to assess the patient’s ability to recognize different colors. Figure 4.16 shows a multicolored chart used to test colored vision.

Question 5

tonometry

Answer 5

Interocular pressure is measured with tonometry. Figure 4.17 shows a tonometer measuring the pressure inside the eye.

Question 6

tuning fork tests

Answer 6

The tuning fork tests are used in the office to test for hearing loss. These tests can help distinguish between perceptive hearing loss and conductive hearing loss.

Question 7

Rinne test

tuning fork tests

Answer 7

A specific tuning fork test is the Rinne test where a tuning fork is struck and then held on the mastoid process until the patient is unable to hear sound. The tuning fork is then held outside the ear. A patient with healthy hearing will be able to hear a sound again as air conduction of sound is faster than bone conduction of sound. Figure 4.18 shows a tuning fork.

Question 8

hearing loss

Answer 8

There are two main types of hearing loss: conductive and sensorineural

Question 9

Conductive hearing loss

hearing loss

Answer 9

Conductive hearing loss occurs when there is external or middle ear dysfunction, and the sound cannot travel to the inner ear. This can be caused by obstruction by cerumen or a mass, fluid in the middle ear, **otosclerosis **(stiffness of the ossicles), or separation of the ossicles in the middle ear.

Question 10

otosclerosis

hearing loss

Answer 10

This can be caused by obstruction by cerumen or a mass, fluid in the middle ear, otosclerosis (stiffness of the ossicles), or separation of the ossicles in the middle ear.

Question 11

Sensorineural hearing loss

hearing loss

Answer 11

Sensorineural hearing loss occurs when there is deterioration of the cochlea. This is most common in older adults as a result of aging (called presbycusis) but also can occur with persistent exposure to loud noise, head trauma, or other systemic diseases.

Question 12

audiologist

Answer 12

Patients who complain of hearing loss or are found to have indications of hearing loss during office testing should be referred to an audiologist for formal hearing testing and assessment.

Question 13

Patients with hearing loss

Answer 13

Patients with hearing loss that cannot be corrected medically can be treated with hearing amplification tools, such as hearing aids. Figure 4.19 shows a patient with a hearing aid.

Question 14

Cochlear implants

Answer 14

Another hearing amplification tool that is useful for patients with hearing loss is a cochlear implant. Cochlear implants are small electronic devices that are surgically implanted to stimulate the cochlea with sounds detected on a receiver. Figure 4.20 shows a cochlear implant in an ear. These devices do not restore hearing; however, they do enhance transmission of environmental sounds and speech to improve a patient’s understanding of their environment.

Question 15

Acute otitis media

Answer 15

Acute otitis media is a bacterial infection of the middle ear. The middle ear is connected to the throat via the eustachian tube, which is shown in both Figures 4.13 and 4.15. When this tube is obstructed, most commonly during a viral upper respiratory infection, fluid and mucus can build up in the middle ear and then become infected with bacteria.

Question 16

otalgia

Answer 16

Patients will present with otalgia, increased pressure in the ear, decreased hearing, and fever. Upon physical examination with an otoscope, the tympanic membrane will appear erythematous and will have decreased mobility. Figure 4.21 shows a severe otitis media infection with a bulging tympanic membrane. If left untreated, the tympanic membrane can rupture, and chronic otitis media may develop. Treatment with oral antibiotics and nasal decongestants is the first-line therapy for acute otitis media. **Tympanocentesis **may be necessary for persistent infections to obtain a sample of the fluid in the ear for a bacterial culture and to relieve pressure behind the tympanic membrane. Severe and/or persistent otitis media cases may also require surgical drainage of the fluid in the middle ear via a myringotomy.

Question 17

Vertigo

Answer 17

Vertigo is a sensation of movement when there is no motion or an exaggerated sense of movement in response to motion. Patients report feeling like they are spinning or that the world around them is spinning. This is commonly due to a disturbance in the inner ear from injury, infection, inflammation, or positioning.

Question 18

Ménière’s syndrome

Answer 18

Ménière’s syndrome is a condition where patients experience episodic vertigo, hearing loss, tinnitus, and pressure in one ear.

Question 19

labyrinthitis

Answer 19

Vertigo can also be caused by labyrinthitis or inflammation of the inner ear.

Question 20

Benign paroxysmal positioning vertigo (BPPV)

Answer 20

Benign paroxysmal positioning vertigo (BPPV) is a condition of vertigo that is associated with changes in the position of the head.

Question 21

Cataracts

Answer 21

ataracts are opacities of the lens of the eye. Figure 4.22 shows a cataract in the right eye. They are the leading cause of blindness in the world and develop as patients age. Cataracts can also be genetic or a result of a systemic disease, such as diabetes mellitus. They are painless but cause progressive blurry vision. Cataracts are treated with surgical removal of the lens and placement of an intraocular lens implant. Figure 4.23 shows the cataract extraction and the new lens implant in the eye. Cataracts can also be treated with phacolysis or phacoemulsification, where the cataract is dissolved with ultrasound and then removed, and a lens implant put in place.

Question 22

Conjunctivitis

Answer 22

Conjunctivitis is inflammation of the conjunctiva, also known as pinkeye. It is most commonly caused by a bacterial or viral infection but also can be caused by allergens, chemical irritants, and/or trauma. Conjunctivitis symptoms include redness of the eye, increased tearing, thick discharge from the eye that crusts while sleeping, and itchy and burning eyes. Patients may have blurry vision or an increased sensitivity to light. The discharge from the eye in a viral infection tends to be watery, while bacterial infections cause purulent drainage. Viral conjunctivitis is self-limiting and will resolve within 14 days. Bacterial conjunctivitis will require antibiotic eyedrops and also resolves within 10-14 days.

Question 23

Glaucoma

Answer 23

Glaucoma is a condition where there is increased intraocular pressure secondary to a backup of fluid in the eye. This increased pressure can damage the optic nerve and the cells of the retina, resulting in decreased vision or blindness.

Question 24

Aqueous humor

Answer 24

Aqueous humor is fluid that fills the anterior chamber of the eye. It is produced in the posterior chamber and passes through the pupil into the anterior chamber. It leaves the anterior chamber through the trabecular meshwork and the Canal of Schlemn into the vascular system. When that flow of aqueous humor is either slowed or blocked completely, the intraocular pressure increases. This is demonstrated in Figure 4.24. Figure 4.24A shows the slow flow of the aqueous humor, which leads to increased pressure in the eye. Figure 4.24B shows a complete blockage of the flow of aqueous humor, while Figure 4.24C shows the narrowing of the visual field experienced by the patient as the retinal cells are damaged.

Question 25

acute angle-closure glaucoma

two common types of glaucoma

Answer 25

Acute angle-closure glaucoma occurs when the acute angle of the anterior chamber is blocked completely, and the aqueous humor cannot flow out of the eye. It is a medical emergency, and patients complain of severe eye pain and blurry vision.

Question 26

chronic glaucoma

two common types of glaucoma

Answer 26

Chronic glaucoma occurs when the flow of aqueous humor in the eye is slowed through the trabecular meshwork. It is typically discovered on a routine eye examination as elevated intraocular pressure.

Question 27

Treatment for both types of glaucoma

Answer 27

Treatment for both types of glaucoma involves reducing the intraocular pressure. Acute angle-closure glaucoma is treated with IV and topical medications that reduce the pressure in the eye. This can be followed by a surgical or laser iridectomy to prevent another closure of this space in the eye. Chronic glaucoma is treated with topical medication to decrease the pressure in the eye and a laser procedure called a trabeculoplasty.