Gradual change in or loss of vision Flashcards
What is age-related macular degeneration (ARMD)?
ARMD is the most common cause of blindness in the UK, characterized by degeneration of the central retina (macula) and changes that are usually bilateral.
What are the key features of ARMD?
ARMD is characterized by degeneration of retinal photoreceptors resulting in the formation of drusen, visible on fundoscopy and retinal photography.
What is the greatest risk factor for ARMD?
Advancing age is the greatest risk factor for ARMD.
How does age affect the risk of ARMD?
The risk of ARMD increases threefold for patients older than 75 years compared to those aged 65-74.
What role does smoking play in ARMD risk?
Current smokers are twice as likely as non-smokers to have ARMD-related visual loss, and ex-smokers have a slightly increased risk (OR 1.13).
How does family history affect ARMD risk?
First-degree relatives of a sufferer of ARMD are thought to be four times more likely to inherit the condition.
What are other risk factors for ARMD?
Other risk factors include hypertension, dyslipidaemia, and diabetes mellitus.
What are the two traditional forms of macular degeneration?
The two forms are dry macular degeneration (90% of cases) and wet macular degeneration (10% of cases).
What characterizes dry macular degeneration?
Dry macular degeneration, also known as atrophic, is characterized by drusen, which are yellow round spots in Bruch’s membrane.
What characterizes wet macular degeneration?
Wet macular degeneration, also known as exudative or neovascular macular degeneration, is characterized by choroidal neovascularization and can lead to rapid vision loss.
What are the clinical features of ARMD?
Patients typically present with subacute onset of visual loss, difficulties in dark adaptation, fluctuations in visual disturbance, photopsia, glare, and possible visual hallucinations.
What signs may be noted in ARMD?
Signs include distortion of line perception on Amsler grid testing and the presence of drusen on fundoscopy.
What is the initial investigation of choice for ARMD?
Slit-lamp microscopy is the initial investigation of choice to identify changes affecting the retina.
What is the purpose of fluorescein angiography in ARMD?
Fluorescein angiography is used if neovascular ARMD is suspected, guiding intervention with anti-VEGF therapy.
What did the AREDS trial find regarding treatment for dry ARMD?
The AREDS trial found that a combination of zinc with vitamins A, C, and E reduced progression of dry ARMD by around one third.
What is the role of anti-VEGF agents in wet ARMD?
Anti-VEGF agents can limit progression of wet ARMD and stabilize or reverse visual loss, and should ideally be instituted within the first two months of diagnosis.
What are examples of anti-VEGF agents?
Examples of anti-VEGF agents include ranibizumab, bevacizumab, and pegaptanib.
What is the risk associated with laser photocoagulation in ARMD treatment?
Laser photocoagulation can slow progression of ARMD but carries a risk of acute visual loss, especially in patients with sub-foveal ARMD.
What is blurred vision?
Blurred vision may be defined as a loss of clarity or sharpness of vision.
What is the most common cause of blurred vision?
Refractive error is the most common cause of blurred vision.
What are some other causes of blurred vision?
Other causes include cataracts, retinal detachment, age-related macular degeneration, acute angle closure glaucoma, optic neuritis, and amaurosis fugax.
What assessments are used for blurred vision?
Assessments include visual acuity with a Snellen chart, pinhole occluders, visual fields, and fundoscopy.
How can pinhole occluders help in assessing blurred vision?
Pinhole occluders are useful to check if the blurred vision is due to a refractive error. If the blurring improves with a pinhole occluder, then the likely cause is a refractive error.
What is the management for blurred vision?
Management depends on the suspected underlying cause. If gradual onset is corrected by a pinhole occluder and there are no other associated symptoms, an optician review is the next step.
When should a patient with blurred vision be seen by ophthalmology?
Patients should be seen by ophthalmology if there are associated symptoms such as visual loss or pain; this should be urgent.
What is a cataract?
A cataract is a common eye condition where the lens of the eye gradually opacifies, becoming cloudy, which makes it difficult for light to reach the retina, causing reduced or blurred vision. Cataracts are the leading cause of curable blindness worldwide.
Who is more likely to develop cataracts?
Cataracts are more common in women than in men.
How does age affect the incidence of cataracts?
The incidence of cataracts increases with age. One study found that 30% of individuals aged 65 and over had a visually-impairing cataract in either one or both eyes.
What is the most common cause of cataracts?
The normal ageing process is the most common cause of cataracts.
What are other possible causes of cataracts?
Other possible causes include smoking, increased alcohol consumption, trauma, diabetes mellitus, long-term corticosteroids, radiation exposure, myotonic dystrophy, and metabolic disorders like hypocalcaemia.
What are typical symptoms of cataracts?
Patients typically present with a gradual onset of reduced vision, faded colour vision, glare, and halos around lights.
What is a sign of cataracts during examination?
A defect in the red reflex is a sign of cataracts, as cataracts prevent light from reaching the retina.
What investigations are used to diagnose cataracts?
Investigations include ophthalmoscopy (normal fundus and optic nerve findings) and slit-lamp examination (visible cataract).
What are the classifications of cataracts?
Cataracts can be classified as nuclear, polar, subcapsular, and dot opacities.
How are early-stage cataracts managed non-surgically?
In early stages, age-related cataracts can be managed conservatively with stronger glasses/contact lenses or brighter lighting to optimize vision.
What is the surgical treatment for cataracts?
Surgery involves removing the cloudy lens and replacing it with an artificial one. Referral for surgery depends on visual impairment, quality of life impact, and patient choice.
What should patients be advised about after cataract surgery?
Patients should be advised on the use of eye drops and eyewear, what to do if vision changes, and the management of other ocular problems.
What is the success rate of cataract surgery?
Cataract surgery has a high success rate, with 85-90% of patients achieving 6/12 corrected vision postoperatively.
What are common complications following cataract surgery?
Complications can include posterior capsule opacification, retinal detachment, posterior capsule rupture, and endophthalmitis.
What is optic atrophy?
Optic atrophy is seen as a pale, well demarcated disc on fundoscopy. It is usually bilateral and causes a gradual loss of vision.
Strictly speaking, optic atrophy is a descriptive term; it is the optic neuropathy that results in visual loss.
What are the acquired causes of optic atrophy?
Acquired causes include: multiple sclerosis, papilloedema (longstanding), raised intraocular pressure (e.g. glaucoma, tumour), retinal damage (e.g. choroiditis, retinitis pigmentosa), ischaemia, toxins (e.g. tobacco amblyopia, quinine, methanol, arsenic, lead), and nutritional deficiencies (e.g. vitamin B1, B2, B6, and B12 deficiency).
What are the congenital causes of optic atrophy?
Congenital causes include: Friedreich’s ataxia, mitochondrial disorders (e.g. Leber’s optic atrophy), and DIDMOAD syndrome (the association of cranial Diabetes Insipidus, Diabetes Mellitus, Optic Atrophy, and Deafness).
