Gradual loss of vision including cataracts, POAG + ARMD Flashcards
name an inherited cause of gradual loss of vision
Retinitis pigmentosa
vitamin that can slow the progression of retinitis pigmentosa?
vitamin A
vision affected in retinitis pigmentosa? (3)
- peripheral vision
- decreased visual acuity
- night blindness
name 6 causes of gradual loss of vision
- Cataracts
- Diabetic maculopathy
- Retinitis pigmentosa
- Age related macular degeneration
- Primary open angle glaucoma
- Refractive errors
opacity of the lens
cataracts
most common cause of blindness worldwide
cataracts
risk factors for cataracts
- age
- smoking
- DM
- long term ocular corticosteroids
- drugs
3 drugs that are risk factors for developing cataracts
- steroids
- amiodarone
- phenothiazines
describe the typical presentation of a patient with cataracts
- Gradual reduced vision, difficulty recognising faces, reading and watching TV
- Glare: lights seem brighter than they are
- Halos around lights
what is the surgical and non surgical management of cataracts
surgical: removal and replacement with artificial lens
non surgical: stronger glasses, encourage use of brighter lights
Glaucoma is
a multifocal optic neuropathy, associated with raised intraocular pressure
what is the most common type of glaucoma
primary open angle glaucoma
pathophysiology of primary open angle glaucoma
the angle between the iris + cornea is open and the obstruction to the outflow of aqueous humor leading to blockage of the drainage system –> raising IOP –> pressure on optic nerve –> atrophy of the outer rim
risk factors for primary open angle glaucoma
- Africo-caribbean
- Fhx
- Myopia
- Hypertension
- DM
presentation of primary open angle glaucoma
progressive peripheral visual loss, progressing to affect the central vision
decreasing visual acuity
Fundoscopy findings in POAG? and why does this occur?
optic disc cupping + optic disc pallor
because the raised intraocular pressure causes compression on the optic nerve leading to loss of optic nerve fibres leading to enlargement of the optic disc (widening and deepening)
normal optic cup to disc ratio?
0.4 - 0.7
cup to disc ratio in POAG?
> 0.7
how is POAG diagnosed?
- referral to ophthalmologist
- applanation tonometry Golmann-Type (to measure IOP)
- goinoscopy
- corneal thickness measurement
1st line management of POAG?
- prostaglandin analogue
2nd line management of POAG?
- BB
- CAI
or - sympathomimetic
Management of more advanced POAG?
- surgery
- laser treatment
- name a prostaglandin analogue
- mechanism
- adverse effect
- LATANOPROST
- increases uveoscleral outflow
- brown pigmentation of iris
- name a BB used to treat POAG
- mechanism
- avoided in ___
- TIMOLOL
- reduced aqueous production
- asthmatics + patients with heart block
- name a CAI
- mechanism
- DORZALOMIDE
- decreases aqueous production
- name a sympathomimetic
- mechanism
- avoid if taking which other meds
- BRIMOMIDINE
- reduces aqueous production + increases outflow
- MAOI or TCA
what is the surgical management for more advanced POAG?
Trabeculoectomy
what is the most common cause of blindness in the UK
Age related macular degeneration
what is ARMD characterised by
- degeneration of retinal photoreceptors
- presence of drusen formation seen on fundoscopy
which form is 85% of all ARMD (dry or wet)
dry
risk factors for ARMD (7)
- female
- smoking history
- family history
- hypermetropia
- hypercholesterolaemia
- hypertension
- diabetes mellitus
describe the presentation of ARMD (what the patient may describe)
- difficulty reading near field content
- difficulties adjusting to darkness
- fluctuation in visual disturbance which may vary from day to day
- reading and lines may appear distorted
- flickering/flashing of lights
- glare around objects
how can distortion of line perception be tested for
amsler grid testing
fundoscopy findings in ARMD
- drusen, yellow areas of pigment deposition in the macular
Management of Wet ARMD?
anti-VEGF injections
name 2 anti-VEGF injections
- Ranibizumab
- Aflibercept
how does anti-VEGF work?
closing off the areas of choiroidal neovascularisation
what is the frequency of anti-VEGF injections?
following diagnosis: loading dose of 3 injections across 3 months initially, and then given variably depending on the response
what is VEGF and what does it do?
vascular endothelial growth factor
it drives increased vascular permeability in patients with wet AMRD
side effects of anti-VEGF injections?
- bleeding
- irritation and redness of eye
what therapy can be offered if a patient does not respond to anti-VEGF injections
- laser photocoagulation
- photodynamic therapy
- macular translocation
management of dry ARMD?
nutritional supplementation in the form of AERDS
includes: zinc, vitamin A, C + E
when must you inform the DVLA about your macular degeneration?
when the macular degeneration affects both your eyes
