Sensory organ disorders Flashcards
What are the symptoms of retinal detachment?
-Sudden appearance of many ‘floaters’ (tiny specks that seem to drift through your field of vision)
-Flashes of light in one or both eyes (photopsia)
-Blurred vision
-Gradually reduced side (peripheral) vision
-A curtain-like shadow over your field of vision
What is retinal detachment and why is it serious?
Retinal detachment describes an emergency situation in which a thin layer of tissue (the retina) at the back of the eye pulls away from its normal position.
Retinal detachment separates the retinal cells from the layer of blood vessels that provides oxygen and nourishment to the eye. The longer retinal detachment goes untreated, the greater your risk of permanent vision loss in the affected eye.
Medical emergency
What are the 3 types of retinal detachment?
Rhegmatogenous - caused by a hole or tear in the retina that allows fluid to pass through and collect underneath the retina. This fluid builds up and causes the retina to pull away from underlying tissues.
Tractional - scar tissue grows on the retina’s surface, causing the retina to pull away from the back of the eye.
Exudative - fluid accumulates beneath the retina, but there are no holes or tears.
What are the risk factors of retinal detachment?
-Aging (retinal detachment is more common in people over age 50)
-Previous retinal detachment in one eye
-Family history of retinal detachment
-Extreme nearsightedness (myopia)
-Previous eye surgery, such as cataract removal
-Previous severe eye injury
-Previous other eye disease or disorder, including retinoschisis, uveitis or thinning of the peripheral retina (lattice degeneration)
What is otitis media?
A middle ear infection
Otitis media is an infection of the middle ear that causes inflammation (redness and swelling) and a build-up of fluid behind the eardrum
Umbrella term for conditions including:
-Acute otitis media
-Otitis media with effusion
-Cholesteatoma
-Mastoiditis
What anatomical differences make children more susceptible to ear infections?
Their eustachian tubes are smaller and more horizontal, which makes it more difficult for fluid to drain out of the ear.
What are the symptoms of ear infections?
-Ear pain
-Fever
-Trouble hearing
-Drainage of fluid from ear
-Balance issues
-Feeling of ‘fullness’ in ear
-Headache
-Trouble sleeping
What are the possible complications of ear infections?
Ruptured tempanic membrane
Mastoiditis
Meningitis
What is the UK epidemiology of cataracts?
In the UK approx. 30% of >65s have at least one vision impairing cataract
10% of the UK population have already had at least one cataract operation by age 65
What are the symptoms of cataracts?
Clouded, blurred or dim vision
Increasing difficulty with vision at night
Sensitivity to light and glare
Need for brighter light for reading and other activities
Seeing “halos” around lights
Frequent changes in eyeglass or contact lens prescription
Fading or yellowing of colours
Double vision in a single eye
What are the 3 types of cataracts?
Nuclear sclerotic
Posterior subcapsular
Cortical
What are nuclear sclerotic cataracts?
Hardening and yellowing of the lens over time.
“Nuclear” refers to the gradual clouding of the central portion of the lens, called thenucleus
“Sclerotic” refers to the hardening, orsclerosis, of the lens nucleus.
As this type of cataract progresses, it changes the eye’s ability to focus, and close-up vision (for readingor other types of close work) may temporarily improve. This symptom is referred to as “second sight,” but the vision improvement it produces is not permanent.
A nuclear sclerotic cataract progresses slowly and may require many years of gradual development before it begins to affect vision.
What are cortical cataracts?
“Cortical” refers to white opacities, or cloudy areas, that develop in the lenscortex, which is the peripheral (outside) edge of the lens.
Changes in the water content of the lens fibers create clefts, or fissures, that look like the spokes of a wheel pointing from the outside edge of the lens in toward the center.
These fissures can cause the light that enters the eye to scatter, creating problems with blurred vision,glare, contrast, and depth perception.
People withdiabetesare at risk for developing cortical cataracts.
What are posterior subcapsular cataracts?
This type of cataract begins as a small opaque or cloudy area on the “posterior,” orback surfaceof the lens. It is called “subcapsular” because it formsbeneath the lens capsule, which is a small “sac,” or membrane, that encloses the lens and holds it in place.
Subcapsular cataracts can interfere with reading and create “halo” effects andglarearound lights.
People who use steroids, or havediabetes, extremenearsightedness, and/orretinitis pigmentosamay develop this type of cataract.
Subcapsular cataracts can develop rapidly and symptoms can become noticeable within months.
What are congenital cataracts?
Cataracts you’re born with. Some people are born with cataracts or develop them during childhood.
These cataracts may be genetic, or associated with an intrauterine infection or trauma.
These cataracts also may be due to certain conditions, such as myotonic dystrophy, galactosemia, neurofibromatosis type 2 or rubella.
Congenital cataracts don’t always affect vision, but if they do they’re usually removed soon after detection.
What is macular degeneration?
A degenerative condition affecting the central part of the retina (the macula) and resulting in distortion or loss of central vision.
