Retina and Choroid Flashcards
What is retinal detachment
Detachment of the inner layer of the retina from retinal pigment epithelium
Types of causes of retinal detachment
Rhegmatogenous
Non-rhegmatogenous
What is the rhegmatogenous cause of retinal detachment
Caused by Retinal tear
Retinal tear -> vitreous humour pass through the tear to behind the retina and cause it to detach
What is the non-rhegmatogenous cause of retinal detachment
Detachment without any retinal tears
Tractional / exudative causes
What is tractional retinal detachment
Extensive growth of abnormal blood vessels in proliferative diabetic retinopathy
The blood vessels eventually becomes scar tissue
When the scar tissue contracts, it can pull the retina and cause it to detach
Tractional retinal detachment is most commonly seen in
Diabetic patients with proliferative diabetic retinopathy
What is the exudative cause of retinal detachment
Subretinal fluid accumulation without retinal tears
Which type of retinal detachment is more common
Rhegmatogenous
Risk factors of retinal detachment
Diabetes
Myopia
Increasing age
Previous surgery for cataracts
Eye trauma
Symptoms of retinal detachment
New onset floaters or flashes
Painless progressive visual loss
“curtain descending”
Central visual acuity can be reduced if macula is affected
RAPD
What are the fundoscope findings for retinal detachment
Retinal tear may be visible in rhegmatogenous
No retinal tear in non-rhegmatogenosu
Retinal folds may be pale / wrinkled/ opaque
management of retinal detachment
Urgent referral to ophthalmologist if new onset of floaters
Surgery to reattach retina
What is posterior vitreous detachment
Separation of vitreous membrane from the retina
Cause of posterior vitreous detachment
Increasing age -> degeneration of vitreous body
Highly myopic
Eye trauma
Why do myopic patients have higher risk of posterior vitreous detachment
Because myopic eye has longer axial length
What are the degenerative changes of vitreous fluid that causes posterior vitreous detachment
Vitreous fluid becomes less viscous hence does not hold its shape well
So pulls the membrane away from the retina
Symptoms of posterior vitreous detachment
New onset of floaters
Flashes of light in vision
Blurred vision
New onset of floaters + flashes are most commonly caused by
posterior vitreous detachment
If a patient with suspected posterior vitreous detachment describes a “curtain descending” what can this mean
This can mean that there is also retinal detachment
Sign of posterior vitreous detachment
Weiss ring on ophthalmoscopy - due to detachment of vitreous membrane around optic nerve to form a ring shaped floater
Management for posterior vitreous detachment
Urgent referral to ophthalmologist to examine
Most do not need treatment - resolves in 6 months
Complication of posterior vitreous detachment
Retinal detachment
What is vitreomacular traction
Incomplete posterior vitreous detachment with the persistent tractional pull on the macula
Symptom of vitreomacular traction
Metamorphopsia - dysfunction that causes straight lines to appear warped, distorted or bent
Visual loss
What is central serous chorioretinopathy
Dysfunction of retinal pigment epithelium causing fluid from choroid to leak into subretinal space
Central serous chorioretinopathy most commonly affect
Men 30-50 years old
Symptoms of central serous chorioretinopathy
Hyperopia
Metamorphopsia
Investigations for central serous chorioretinopathy
Fundoscopy
Fluorescein angiography
Fundoscope findings of central serous chorioretinopathy
Roundish detachment of central retina
What is the most common cause of blindness
Age related macular degeneration
Risk factors of age related macular degeneration
Females
Increasing age
Smoking
Family history
Hypertension
Diabetes
Dyslipidaemia
Age related macular degeneration more commonly affects females / males
Females
Types of ARMD
Dry macular degeneration
Wet macular degeneration
Which type of ARMD is the most common
Dry macular degeneration
What is dry ARMD
Deposition of drusen in Bruch’s membrane causing slow progressive atrophy of the RPE
What is drusen
accumulation of proteins, lipids, and inflammatory mediators - yellow round spots
Where is Bruch’s membrane
Between the RPE and choriocapillaries of choroid
What is wet macular degeneration
Neovascularisation in choroid due to VEGF causing leakage of fluid and blood -> vision loss
Symptom of wet ARMD
Rapid central visual loss
Metamorphopsis
Photopsia - Flashing lights
Deterioration in vision at night
fluctuations in visual disturbance vary from day to day
Symptoms of dry ARMD
Progressive central visual loss
Central vision missing - scotoma
Photopsia
fluctuations in visual disturbance vary from day to day
Deterioration in vision at night
Investigations for ARMD
Amsler grid testing
Fundoscopy
Slit lamp
Ocular coherence tomography (OCT)
What is amsler grid testing used to
To check for distortion of line perception
Fundoscope findings for dry ARMD
Drusen - yellow round spots
Areas of atrophy
Fundoscope findings for wet ARMD
well demarcated red patches - intraretinal/subretinal fluid leakage or haemorrhage
Why is OCT used for ARMD
visualise the retina in three dimensions because it can reveal areas of disease which aren’t visible using slit lamp microscopy
Management of wet ARMD
Anti-VEGF
Management of dry ARMD
No cure
Zinc with anti-oxidant vitamins A,C and E (for moderate and above dry ARMD)
Magnifier vision aids
