Sense organs: The eye and the ear, Pathology Flashcards
Astigmatism
Defective curvature of the cornea or lens of the eye
-This causes light rays to be unevenly and not sharply focused on the retina, so that the image is distorted
Hyperopia (hypermetropia)
Farsightedness
myopia
Nearsightedness
Presbyopia
Impairment of vision as a result of old age
Cataract
Clouding of the lens, causing decreased vision
-degenerative eye disease (protein in the lens aggregates and clouds vision) and is often linked to old age but not always
Chalazion
Small, hard, cystic mass (granuloma) on the eyelid
-formed as a result of chronic inflammation of a sebaceous gland along the margin of the eyelid
Diabetic retinopathy
Disease of the retina caused by diabetes mellitus
- retinal effects include microaneurysms, hemorrhages, dilation of retinal veins, and neovascularization in the retina
- Macular edema: occurs as fluid leaks from blood vessels into the retina and vision is blurred
- Exudates (fluid leaking from the blood) appear in the retina as yellow-white spots
Glaucoma
Increased intraocular pressure results in damage to the retina and optic nerve with loss of vision
- Intraocular pressure is elevated because of the inability of aqueous humor to drain from the eye and enter the bloodstream. Normally, aqueous humor is formed by the ciliary body, flows into the anterior chamber, and leaves the eye at the angle where the cornea and the iris meet.
- diagnosed by means of Tonometry
- acute glaucoma: extreme ocular pain, blurred vision, redness of the eye, dilation of the pupil. if untreated can cause blindness
- Chronic glaucoma: may produce no symtoms intially. May experience a gradual loss of peripheral vision, with headaches, blurred vision, and halos around bright lights , or they may experience no symptoms at all
Blepharitis
inflammation of eyelid, causing redness, crusting, and swelling along lid margins
Chalazion
Granuloma formed around an inflamed sebaceous gland
Dacryocystitis
blockage, inflammation, and infection of a nasolacrimal duct and lacrimal sac, causing redness and swelling in the region between the nose and the lower lid
Ectropion
Outward sagging and eversion of the eyelid, leading to improper lacrimation and corneal drying and ulceration
Entropion
Inversion of the eyelid, causing the lashes to rub against the eye; corneal abrasion may result
Hordeolum (stye)
small, superficial white nodule along lid margin due to infection of sebaceous gland
Ptosis
Drooping of upper lid margin from neuromuscular problems or trauma
Xanthelasma
raised yellowish plaque on eyelid caused by lipid disorder
Hordeolum (stye)
Localized, purulent, inflammatory staphylococcal infection of a sebaceous oil producing gland in the eyelid
Macular degeneration
Progressive damage to the macula of the retina
- one of the leading causes of blindeness in the elderly
- severe loss of central vision
- Dry form: marked by atrophy and degeneration of retinal cells and deposits of clumps of extracellular debris, or drusen. No standard treatment
-Wet form: results from development of new (neovascular) and leaky (exudative) blood vessels close to the macula. Treatment.
Nystagmus
Repetitive rhythmic movements of 1 or both eyes
-brain tumors or diseases of the inner ear may cause this
Retinal Detatchment
2 layers of the retina separate from each other
- Trauma to the eye, head injuries, bleeding, scarring from infection, or shrinkage of the vitreous humor can produce holes or tears in the retina and result in the separation of layers. Patients often experiencephotopsia(bright flashes of light) and see floaters (black spots or filmy shapes), which are vitreous clumps that detach from the retina.
- Treatment to repair small retinal tears: Photocoagulation and cryotherapy
- Treatment for larger retinal detachments: scleral buckle
Strabismus
Abnormal deviation of the eye
- A failure of the eyes to look in the same direction bc of weakness of a muscle controlling the position of one eye
- diplopia (double vision) is common
Different forms:
- esotropia(one eye turns inward; “cross-eyed”),
- exotropia (one eye turns outward; “wall-eye”),
- hypertropia(upward deviation of one eye),
- hypotropia(downward deviation of one eye).
Fluorescein angiography
Intravenous injection of fluorescein (a dye) followed by serial photographs of the retina through dilated pupils
-this test provides diagnostic info about blood flow in the retina, detects vascular changes in diabetic and hypertensive retinopathy, and identifies lesions in the macular area of the retina
Ophthalmoscopy
Visual examination of the interior of the eye
Optical coherence tomography (OCT)
Non-invasive imaging technique using light waves to take cross-sectional pictures of the retina
-can be used to examine retina for glaucoma and other retinal diseases
slit lamp microscopy
Examination of anterior ocular structures under microscopic magnification
- provides magnified view of the conjunctiva, sclera, cornea, anterior chamber, iris, lens, and vitreous
- Tonometry: measures intraocular pressure to detect glaucoma
enucleation
removal of the entire eyeball
-This surgical procedure is necessary to treat tumors such as ocular melanoma (malignant tumor of pigmented cells in the choroid layer) or if an eye has become blind and painful from trauma or disease, such as glaucoma
keratoplasty
Surgical repair of the cornea
- also known as a corneal transplant
- replaces cornea with a donor cornea which is sutured into place
Laser photocoagulation
Intense, precisely focused light beam (argon laser) creates an inflammatory reaction that seals retinal tears and leaky retinal blood vessels
-Useful to treat retinal tears, diabetic retinopathy, and wet macular degeneration
LASIK
Use of an excimer laser to correct errors of refraction (myopia, hyperopia, and astigmatism)
Phacoemulsification
Cataract removal surgery in which ultrasonic vibrations break up the lens; the pieces are then aspirated through the ultrasonic probe
-Typical surgery for cataract removal
Scleral buckle
Suture of a silicone band to the sclera over a detached portion of the retina
- The band pushes the 2 parts of the retina against each other to bring tg the 2 layers of the detached retina
- Pneumatic retinopexy is an outpatient alternative
Vitrectomy
Removal of the vitreous humor
- Necessary when blood and scar tissue accumulate in the vitreous humor (a complication of diabetic retinopathy)
- also commonly used to provide better access to the retina
Acoustic Neuroma
Benign tumor arising from the acoustic vestibulocochlear nerve (8th cranial nerve) in the brain
-initially, this tumor causes ringing in the ears, vertigo, and decreased hearing
Cholesteatoma
Collection of skin cells and cholesterol in a sac within the middle ear
- cyst-like masses produce a foul smelling discharge and are most often the result of chronic otitis media
- associated with perforations of the tympanic membrane
Deafness
Loss of the ability to hear.
- Nerve deafness (sensorineural hearing loss) results from impairment of the cochlea or auditory (acoustic) nerve
- Conductive deafness results from the impairment of sound wave transmission from the external ear to the cochlea
Meniere disease
Disorder of the labyrinth of the inner ear; elevated endolymph pressure within the cochlea (cochlear hydrops) and semicircular canals (vestibular hydrops)
- signs and symptoms: tinnitus (ringing in the ears), heightened sensitivity to loud sounds, progressive loss of hearing, headache, nausea, and vertigo
- cause= unknown
Otitis Media
Inflammation of the middle ear.
-Acute otitis media: infection of the middle ear, often following an upper respiratory infection. Pain and fever with redness and loss of mobility of the tympanic membrane. As bacteria invade the middle ear, pus formation occurs (suppurative otitis media)
-Serous otitis media: noninfectious inflammation with accumulation of serous fluid. often results from a dysfunctional or obstructed auditory tube
Otosclerosis
Hardening of the bony tissue of the middle ear.
- hereditary
- bone forms around the oval window and causes fixation or ankylosis (stiffening) of the stapes bone. Conduction deafness occurs. Stapedectomy with replacement by a prosthesis is effective in restoring hearing. in order to do this, the oval window must be fenestrated (opened) using a laser
tinnitus
Sensation of noises in the ears without an external source.
-Caused by irritation of delicate hair cells in the inner ear, this disease symptom may be associated with presbycusis, Meniere disease, otosclerosis, chronic otitis, labyrinthitis, and other disorders.
Vertigo
Sensation of irregular or whirling motion either of oneself or of external objects
- can result from disease in the labyrinth of the inner ear or in the nerve that carries messages from the semicircular canals to the brain
- Benign paroxysmal positional vertigo (BPPV) a pateint experiences repeated, brief episodes of vertigo. occurs after movement changes in the position of the head
- It is a common a cause of vertigo that may result from calcium crystals (otoconia) moving around loose in the vestibule of the inner ear.
audiometry
Testing the sense of hearing
Cochlear implant procedure
Surgical insertion of a device that allows sensorineural hearing-impaired persons to understand speech.
Ear thermometry
Measurement of the temp of the tympanic membrane by detection of infrared radiation from the eardrum
Otoscopy
visual exam of the ear canal with an otoscope
tuning fork test
test of ear conduction using vibration source (tuning fork)\
- Rinne test:the examiner places the base of the vibrating fork against the patient’s mastoid bone (bone conduction) and in front of the auditory meatus (air conduction).
- Weber Test: the tuning fork is placed on the center of the forehead. The perceived loudness of sound is the same in both ears if hearing is normal.
