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 are the risk factors for cataracts?
Increasing age
Diabetes
Excessive exposure to sunlight
Smoking
Obesity
High blood pressure
Previous eye injury or inflammation
Previous eye surgery
Prolonged use of corticosteroid medications
Drinking excessive amounts of alcohol
Iris colour
What is conjunctivitis?
Inflammation of the conjunctiva - viral or bacterial
What type of conjunctivitis is not highly contagious?
Allergic conjunctivitis
What is the difference between viral and bacterial conjuntivitis?
Bacterial
-Purulent discharge
-Usually unilateral
-Eyes feel gritty and uncomfortable
-Usually presents with pre-auricular lymphoedema
-Corneal involvement (red flag)
Viral
-Assosciated with upper respiratory tract infections
-Presents bilaterally
-Watery discharge
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.
What is the difference between dry, wet and juvenile macular degeneragtion?
Dry
-85-90% of cases
-May progress to we.
-Characterised by the build up of drusen.
-Usually progresses slowly.
Wet
-10-15% of cases.
-Blood vessels grow into the macula and leak, causing destruction.
-Can be treated with intraoccular injections of anti-angiogenic drugs.
Juvenile
-Usually Stargardt disease
-Presents like wet macular degeneration
-Rare hereditary condition, recessive gene
-Usually presents ages 6-20
-Patients should avoid excessive amounts of vitamin A
What are the risk factors for macular degeneration?
Age >50s most at risk
Family history and genetics-Heritable disease, several genes are associated with macular degeneration
Race- Caucasians most at risk
Smoking
Obesity
Cardiovascular disease.
What are the risk factors for glaucoma?
Age
Family members with glaucoma
Long-term steroid use
Ethnicity
Eye trauma and other recognised causes of secondary glaucoma
What is glaucoma?
Damage to the optic nerve
What are the main types of glaucoma?
Open-angle
Acute angle-closure
Normal-tension
Pigmentary
Congenital
Juvenile (in children)
Secondary
What are the symptoms of glaucoma?
Open-angle glaucoma
-No symptoms in early stages
-Gradually, patchy blind spots in your side vision. Side vision also is known as peripheral vision
-In later stages, difficulty seeing things in your central vision
Acute angle-closure glaucoma
-Severe headache
-Severe eye pain
-Nausea or vomiting
-Blurred vision
-Halos or colored rings around lights
-Eye redness
Normal-tension glaucoma
-No symptoms in early stages
-Gradually, blurred vision
-In later stages, loss of side vision
Glaucoma in children
-A dull or cloudy eye (infants)
-Increased blinking (infants)
-Tears without crying (infants)
-Blurred vision
-Nearsightedness that gets worse
-Headache
Pigmentary glaucoma
-Halos around lights
-Blurred vision with exercise
-Gradual loss of side vision
