Acquired Macular Diseases Flashcards
name 7 acquired macular diseases
-age related macular degeneration
-central serous retinopathy
-drug related retinopathies
-idiopathic macular hole
-epiretinal membrane
-cystoid macular oedema
-myopic maculopathy
what is AMD?
a progressive disease of the retina occurring in people over 55 years old causing damage to the macula resulting in loss of central vision while peripheral vision is usually spared
what kind of complaints do AMD patients report?
-reduced reading ability
-reduced ability to recognise people’s faces
-difficulty making out what people are saying
-initially starts out as distortion which turns into blur as central vision loss
what is the difference between prevalence and incidence?
Prevalence is number of cases overall and incidence is the number of cases per year
What are general stats on AMD?
-most common cause of blindness certification in people over 65 in the UK
-up to 30 million worldwide have AMD
-incidence of AMD in US is up to 200,00 people per year are diagnosed
what stats indicate AMD is increasing in prevelance?
-US and UK studies suggest that 20 –30 % of patients over the age of 65 are affected with AMD
-n UK 16 % of the population is currently over the
age of 65 and therefore at significant risk of
developing AMD
-The current demographic projections indicate that
the segment of the UK population over the age of
65 will increase by 29 % in the next 20 years
name the risk factors of AMD and state which is most common
– ageing
– smoking = most common
– family history AMD
– fair skin, light iris colour
– hypertension
– arteriosclerosis
– prolonged exposure to sunlight
pathogenesis of AMD
-drusen forms between bruchs membrane and the retinal pigment epithelium in dry AMD
-abnormal blood vessels grow under the rpe through retinal layers in wer AMD
-this is affected by genes, choroidal blood flow and inflammation
which form of amd is most common?
dry amd - 85-90% have dry amd and 10-15% have wet
what is the difference between dry and wet AMD?
dry is based on the absence of abnormal growth of blood vessels under the retina whereas wet is based on the presence of abnormal growth of blood vessels under the retina so in wet amd you would see blood leakages and drusen whereas in dry you would see just drusen
why does wet AMD cause more rapid and severe vision loss than dry AMD?
as in wet amd, the growth of abnormal blood vessels can cause leakage, bleeding and scarring
what are the signs if dry amd?
-non exudative
-drusen usually bilateral
-rpe hyperpigmentation
-geographic atrophy (later stage): round/ oval and well demarcated atrophy patches in the parafoveal/ foveal region
What are the three types of drusen?
-hard
-soft
-diffuse
-calcified
what does hard drusen look like?
Nodular, appear as
small discrete
yellowish-white spots
what does soft drusen look like?
– indistinct edges
– larger than hard drusen
– frequently become
confluent
describe diffuse drusen
– Represent a
widespread
abnormality of the
RPE
what’s different between the symptoms of dry and wet amd?
wet amd onsent of symptoms is sudden whereas in dry its gradual
what are the investigations for suspected amd in primary care?
-best corrected distance and near vas
-amsler grid
-fundoscopy
-oct
what is the neovascularisation in wet amd called?
-subretinal neovascular membrane (SRNVM) or choroidal neovascularisation (CNV)
what are the signs of wet AMD?
-pigment epithelial detachment
-retinal thickening and elevation
-subretinal fluid pinkinsh/ grey in colour
-blood
-exudate
-fibrosis
what amd investigation are done at secondary/ tertiary referral?
Further OCT, OCTa
why may you not advise a patient with AMD to get surgery?
May not be realistic as it is a complex surgery which may not have a positive outcome for majority of patients
what can high speed video
angiography be useful for when investigating amd?
it can help show feeder vessels in choroidal neovascularisation of wet amd
what referrals should you give for the two types of amd
wet - URGENT
dry - non urgent
what are the treatment options for geographic atrophy of amd?
none proven but
-give advice on lifestyle, diet,
smoking, hypertension,
sunlight
-encourage patient to self monitor weekly with amsler grid and to come back if there are any changes or they think their vision gets worse
-use of low vision aids (LVAs)
-visual rehab by teaching extra foveal fixation and reading startegies
what is the main treatment for cnv in AMD? How does it work? What are the most common drugs?
-anti-VEGF injections
-anti-VEGF will bind to the VEGF molecules in the retina, thus blocking their ability to cause abnormal blood vessel growth beneath the retina, which leads to “wet” AMD
-most common used drugs are lucentis and avastin
what were the historical treatments for CNV in AMD?
- Argon laser for extra and juxta-foveal lesions
- PDT for sub-foveal classic or predominantly classic lesions
what is the treatment plan with anti-VEGF for amd?
- Intra-vitreal injection
dosage schedule - Initially monthly
- Monitor with OCT
- 3 monthly review
what are the three types of surgery options being researched for amd treatment?
– submacular surgery
– macular translocation
– retinal implants
what future therapies are being researched for amd treatment?
– based on genetic knowledge- gene therapy
– Stem cell therapy- eg RPE sheets
name the surgery for wet amd and how it works
Submacular surgery to remove CNV
1. the eye wall is shortened and the macula is moved
away from the abnormal blood vessel under it.
2. Then laser surgery can be performed to destroy the
abnormal blood vessels without harming the macula.
3. initial results show that significant improvement in
vision is possible with this procedure.
who does central serous retinopathy usually affect?
young-middle aged men
what are some associations with central serous retinopathy?
– steroid usage, stress,
hypertension, headache
-those with immune diseases like psoriasis and eczema
– Rarely: pregnancy,
SLE, hemodialysis,
Cushings syndrome
what is central serous retinopathy?
localised shallow detachment of the sensory retina
what are 2 features of central serous retinopathy CSR
idiopathic and usually unilateral
what are the symptoms of CSR?
- Blurred vision
- Distortion
- Micropsia
- Positive scotoma
what can you see on an oct of someone with csr?
subretinal fluid
what are the signs of csr?
-variable VA
-amsler central distortion
-localised fluid in the fundus, bulls eye maculopathy as it looks like a bulls eye
what is pathogenisis of csr linked to?
increased permeability in choriocaplilaris, otherwise its unclear what causes it
what is treatment and prognosis of csr?
- Expectant: avoid steroids
- 90% recovery, usually 6 weeks
- Wait at least 4 months if have to treat:
– Laser may speed recovery but not alter outcome - Argon laser photocoagulation
- Recurrence 30-50%
- Mostly within 1 year
why may people with breastcancer develop retinal problems?
as Tamoxifen is used as an oestrogen drug used to treat breast cancer but can cause tamoxifen retinopathy.
what is a sign of tamoxifen retinopathy and what should you do if you see it?
idiopathic macular hole which should be referred but it is not an emergency as the px probably had it for months before you saw it as it does not necessarily come with symptoms
what is the management plan for tamoxifen retinopathy
usually doesnt get treated in early stages as it doesnt get worse, if necessary a vitrectomy can be done
name 2 drug related retinopathies
-hydroxychloroquine retinopathy
-tamoxifen retinopathy
what is the current guidance if someone is at risk of drug related retinopathy?
that patients should be offered an annual fundus examination with widefield fundus autofluorescence (FAF) after they’ve been taking the medication for a certain period of time:
-SD OCT rather than TD as resolution on TD is too poor
-if there is abnormality suggestive of toxicity, Px should get 20-2 or 20-3 humphrey visual field testing
what is the most common sign of hydroxychloroquine retinopathy?
bulls eye maculopathy
what is the main symptom of hydroxychloroquine retinopathy?
central vision loss
in routine screening for patients at risk of drug related maculopathies, when may the patients be considered for multifocal electroretinography?
Patients with persistent and significant visual field defects consistent with hydroxychloroquine retinopathy, but without evidence of structural defects on SD-OCT or FAF