eye and ear ai from book

Anatomy of the Eye

• The eyes are protected by their placement in the skull's orbits
• Eyelids, eyelashes, and eyebrows shield the eyes from irritants
• The sclera is a hard outer layer that protects the eye
• The choroid, a layer within the sclera, nourishes the eye with blood vessels
• The iris regulates light entry by dilating and constricting the pupil
• The pupil is a hole in the iris
• The outer eye area is cleansed by tears
• The anterior chamber contains aqueous humor
• The cornea covers the iris, pupil, and anterior chamber and gets oxygen from tears
• The posterior chamber holds viscous vitreous humor
• Images are projected via the pupil and lens onto the retina's rods and cones
• The retina is light-sensitive tissue at the back of the eye
• Inverted images are sent to the brain via the optic nerve for interpretation

Eye Medications

• The eye is vulnerable to disorders, irritations, and infections, like glaucoma, conjunctivitis, macular degeneration, keratitis, chalazion, and cataracts
• Medications like atropine are used to facilitate eye exams
• Eye pressure is measured using a tonometer
• Increased pressure is usually caused by the incorrect outflow of aqueous humor
• Increased pressure is referred to as intraocular pressure (IOP)
• Pressure on the optic nerve can lead to blindness

Glaucoma Medications

• Glaucoma is a leading cause of blindness as increased eye pressure damages the optic nerve
• Primary open-angle glaucoma is the most common form and occurs when the Schlemm canal becomes obstructed, leading to a gradual increase in pressure
• It has no symptoms and can cause vision loss if undiagnosed
• Angle-closure glaucoma is rarer, eye pressure increases rapidly, and the iris can cover drainage canals, and must be surgically corrected
• Symptoms include headache, eye pain, nausea, seeing multicolored halos around lights, and blurred vision
• Normal-tension glaucoma is when the optic nerve is damaged despite normal eye pressure
• Congenital glaucoma occurs when infants are born with increased pressure from a hereditary malformation or abnormal fetal development
• Secondary glaucoma results from another disease, injury, or certain medications that increase eye pressure
• Glucocorticoids, antihypertensives, antihistamines, and antidepressants can decrease aqueous humor flow
• Pigmentary glaucoma is caused when pigment granules break off and lodge in the drainage system
• Miotic and prostaglandin medications treat glaucoma by increasing aqueous humor flow
• Miotics constrict the pupil while prostaglandins do not, but change iris pigmentation as a side effect
• Alpha and beta blockers, carbonic anhydrase inhibitors, and osmotic diuretics decrease IOP by reducing aqueous humor flow
• Glaucoma is more prevalent among patients with hypertension, diabetes, migraines, nearsightedness, farsightedness, and patients of advanced age

Medications for Eye Irritations and Infections

• Minor eye injuries can be treated with local anesthetics, antimicrobials, NSAIDs, and glucocorticoids
• Eye lubricants can be used for milder irritations and injuries, whereas keratitis needs medication to penetrate beyond the surface
• Ophthalmic glucocorticoids should not be used for long-term treatment because they can suppress the immune response
• Antiinfectives treat eye infections
• Conjunctivitis (pinkeye) is treated with antibiotics
• Styes are bacterial infections in the eyelid treated with topical or oral antibiotics
• Proper hand washing and hygiene is important to prevent spread

Medications for Eye Examinations

• Certain drugs help professionals examine the eyes
• Cycloplegic mydriatics relax ciliary muscles and dilate pupils
• Local ophthalmic anesthetic agents are used for removing foreign objects
• Staining agents are nontoxic dyes used to diagnose corneal defects, foreign bodies, or contact lenses

Miscellaneous Eye Medications

• Immunomodulators like Restasis treat chronic dry eye by increasing tear production, but the effect may take up to 6 months
• Macular degeneration progression may be slowed with ranibizumab or aflibercept

Anatomy of the Ear

• The ear consists of the outer, middle, and inner ear
• The outer ear includes the pinna and the external auditory canal
• The pinna protects the middle and inner ear and collects sound
• The external auditory canal contains cerumen-secreting glands
• The middle ear is separated from the outer ear by the tympanic membrane (eardrum)
• It includes the auditory ossicles, the middle ear cavity, and the eustachian tube
• The ossicles convert sound into mechanical vibrations, and the eustachian tube equalizes pressure
• The inner ear includes the oval window, round window, cochlea, and semicircular canals
• The oval window vibrates and sets fluid in motion, generating nerve impulses
• The round window serves as a pressure relief valve
• The cochlea helps with hearing
• The semicircular cells and vestibule maintain balance

Ear Medications

• Otic medications treat inflammation, wax buildup, or infections
• Common conditions are infections, cerumen impaction, and motion sickness

Medications for Ear Infections and Pain

• Swimmer’s ear (otitis externa) is an outer ear infection and can be treated with antibiotics
• Otitis media is a middle ear infection, sometimes needing systemic antibiotics
• Pain medications may be prescribed for trauma or infection

Medications for Cerumen and Motion Disorders

• Mineral oil, earwax softeners, and hydrogen peroxide decrease earwax buildup, which can cause decreased hearing, pain, and promote bacteria growth
• Motion sickness is caused by the ear’s inability to determine the body’s position relative to its motion
• It can be treated with tablets or transdermal patches
• Drugs like meclizine treat dizziness, or vertigo, and associated nausea

Gerontological Issues

• Good eye and ear health are important for preventing fall injuries in older adults

Medications and Ototoxicity

• Many drugs can cause ototoxicity (ear damage)
• Symptoms include tinnitus, hearing loss, headache, ataxia, and balance disturbances