Question

Compose a short (1.5 – 2.5 page) essay explaining one common alteration in vision and one common alteration in hearing. You should briefly describe the pathophysiologic changes, prevalence, manifestations, and treatment for each. You should also explain the mechanism that the specific treatment uses to return a normal functioning state. You may select a disease process from the book, but will need to use additional resources to provide all the information required for the essay.

Answer 1

Alteration in vision :

Introduction : Crossed eyes or strabismus, is a condition in which both eyes do not look at the same place at the same time. It usually occurs in people who have poor eye muscle control or are very farsighted.

Types : Strabismus is classified by the direction in which the eye turns:

• Inward turning is called esotropia
• Outward turning is called exotropia
• Upward turning is called hypertropia
• Downward turning is called hypotropia.

Other classifications include:

• The frequency with which it occurs—either constant or intermittent
• Whether it always involves the same eye—unilateral
• If the turning eye is sometimes the right eye and other times the left eye—alternating.

Pathophysiological changes : Six muscles attach to each eye recieves signals fromt the brain and control its movement . Normally, the eyes work together so they both point at the same place. An eye may turn in, out, up or down when problem on eye movement develops. The eye turning may occur all the time or may appear only when the person is tired, ill, or has done a lot of reading or close work. In some cases, the same eye may turn each time. In other cases, the eyes may alternate turning.

Strabismus can be caused by problems with the eye muscles, the nerves that transmit information to the muscles, the control center in the brain that directs eye movement,sometimes due to other general health conditions or eye injuries.

Risk factors for developing strabismus include:

• Family history : People with parents or siblings who have strabismus are more likely to develop it.
• Refractive error : People who have a significant amount of uncorrected farsightedness (hyperopia) may develop strabismus because of the additional eye focusing they must do to keep objects clear.
• Medical conditions : People with conditions such as Down syndrome and cerebral palsy or who have suffered a stroke or head injury are at a higher risk for developing strabismus.

Prevalance and manifestation : Strabismus usually develops in infants and young children, mostly of the age of 3. But older children and adults can also develop the condition. Any child older than 4 months whose eyes do not appear to be straight all the time, should be taken to an opthalmologist (a doctor of optometry).

Pseudostrabismus : In some new born children, eyes may appear to be misaligned, but they are actually both aiming at the same object. This is a condition called pseudostrabismus or false strabismus. The appearance of crossed eyes may be due to extra skin that covers the inner corner of the eyes or a wide bridge of the nose. Usually, the appearance of crossed eyes will go away as the baby's face begins to grow.

Many types of strabismus can develop in children or adults, but the two most common forms are:

• Accommodative esotropia often occurs because of uncorrected farsightedness (hyperopia). The eye's focusing system is linked to the system that controls where the eyes point. People who are farsighted are focusing extra hard to keep images clear. Symptoms of accommodative esotropia may include eyes to turn inward, seeing double, closing or covering one eye when doing close work, and tilting or turning the head.
• Intermittent exotropia may develop when a person cannot coordinate both eyes together. The eyes may point beyond the object being viewed. People with intermittent exotropia may experience headaches, difficulty reading and eye strain and they often close one eye when viewing at distance or in bright sunlight.

Diagnosis : A doctor of optometry diagnoses strabismus through a comprehensive eye exam which includes emphasis on how the eye focuses and moves, patient history and family history and tests like visual acuity, refraction, alignment and focusing test and examination of eye health.

Treatment : People suffering from strabismus have many treatment options for improving eye alignment and coordination which include the following :

• Eyeglasses or contact lenses : This may be the only treatment needed for some patients.
• Prism lenses : These are special lenses as they are thicker on one side than the other. The prisms alter the light entering the eye and reduce how much turning the eye has to do to view objects. Sometimes the prisms can help eliminating the eye turning.
• Vision therapy : The doctor of optometry can prescribe a structured program of visual activities to improve eye coordination and eye focusing. Vision therapy trains the eyes and brain to work together more effectively. These eye exercises can help problems with eye movement, eye focusing and eye teaming and reinforce the eye-brain connection.
• Eye muscle surgery. Surgery can change the length or position of the muscles around the eyes so they appear straight. In most cases, people who have eye muscle surgery will also need vision therapy to improve eye coordination and to keep the eyes from becoming misaligned again.

Alteration in hearing :

Introduction : Conductive hearing loss is a type of hearing loss which occurs when the passage of sound (in the form of sound waves) is blocked in either the ear canal or in the middle ear.

Causes : The most common causes of conductive hearing loss are as follows :

• Accumulation of ear wax within the ear canal
• Many episodes of middle ear infection (otitis media) resulting in scarring of the ear canal
• Chronic infection
• A growth in the middle ear (cholesteatoma)
• An abnormal bone growth near the middle ear (otosclerosis)
• Swimmer's ear
• Growth of a benign tumor
• Fluid in the middle ear
• Perforated eardrum
• Barotrauma (unequal air pressures in the externl and middle ear)

Pathophysiology : As the name suggests, difficulty in conduction of the sound waves from the outer ear through the three bones of the middle ear (known as eas ossicles) to the inner ear causes conductive hearing loss.

Symptoms : People affected with conductive hearing loss will find soft sounds difficult to hear at all pitches, both low and high.  Conductive hearing loss developing during childhood is usually due to otitis media with effusion and may present with speech and language delay or difficulty hearing.

Diagnosis : It includes a detailed patient and family history, local examination of the ear, nose, throat and neck, and detailed hearing tests like Otoscopy, Weber test, Rinne test, Tympanometry, Audiometry and ComputerizedTopography (CT) Scan.

Treatment : Treatment are of three types namely surgical, pharmaceutical and supportive depending on the nature and location of the cause. Not all conductive hearing loss cases are permanent. The ones developed due to temporary inhibitors in the ear can resolve on it's own.

1. If the Corti organ in the cochlea functions normally, hearing aids can help transmit and amplify sound in in the outer or middle ear.

2. In cases of infection, antifungal or antibacterial medications are useful.

3. Sugical interventions are necessary in cases like middle ear fluid, cholesteatoma, otosclerosis and head trauma.