Systemic Disease Flashcards
How does diabetes cause eye problems?
Chronic hyperglycaemia causes glycosylation of the basement membrane in the ocular capillaries which leads to loss of pericytes (make up the tight junctions), leading to out pouching and micro aneurysm
Name the two aspects of a micro-aneurysm
- leakage
- ischaemia
Other than micro aneurysms what else can lead to visual loss
Retinal scarring and retinal oedema (affecting the fovea)
How do micro aneurysms lead to vision loss?
Ischaemia leads to new vessels formation which are prone to haemorrhage
How does retinal oedema occur?
The increased accumulation of sorbitol (converted from glucose) creates a hyperosmotic effect that results in an infusion of fluid to countervail the osmotic gradient.
New vessels on which part of the eye cause most damage?
Disc or iris
How is retinopathy classified?
- None
- Non-proliferative (mild/moderate/severe)
- Proliferative
How is maculopathy classified?
None
Observable
Referable (thick)
Clinically significant (involving the fovea)
How is diabetic eye disease managed?
Control diabetes
Laser treatment - pan retinal photocoagulation or macular grid
Vitrectomy
Biologics
How does hypertension cause ocular manifestations?
Stress on the vessels causes the lumen to narrow and the walls to thicken.
What are the features of ocular manifestations of hypertension?
Attenuated blood vessels (copper/silver wing) Cotton wool spot Hard exudate (follows axon alignment) Haemorrhage Oedema
Name the infective causes of uveitis
TB, herpes, candida, toxoplasmosis, syphillus, lyme’s disease
Name the non-infective causes of uveitis
HLA B27, Bechet’s, Juvenile arthritis
What is giant cell arterities and what disease is it associated with?
Inflammation of middle sized arteries associated with polymyalgia rheumatica
What are the symptoms of GCA?
Headache, jaw claudication, malaise, blinding
What are the extra-ocular manifestations of thyroid eye disease?
Proptosis
Lid retraction, oedema, lag, pigmentation
Restrictive myopathy
What are the ocular manifestations of thyroid eye disease?
Anterior - chemosis, injection, glaucoma
Posterior - nerve swelling, choroidal folds
What is thyroid eye disease characterised by?
Swelling of extra ocular muscles and orbital fat due to autoimmune condition
How is thyroid eye disease treated?
Lubricants
Surgical decompression
What are the ocular manifestations of rheumatoid arthritis?
Dry eyes, scleritis, corneal melt
How does scleritis present?
Deeps dusky and painful inflammation
What are the ocular manifestations of sjogrens and why?
Dry eyes, xerostomia due to infiltration of lacrimal glands
Describe the ocular manifestations of marfans and explain why they occur
Disease of collagen, the zones ‘ping’ causing upwards lens dislocation
What dermatological condition can cause severe ocular problems?
Steven Johnson Syndrome
Describe steven johnson syndrome
Exfoliation of skin, in the eye leads to symblepharon, occlusion of lacrimal gland, corneal ulcers
What is symblepharon?
Eyelid attaches to the conjunctiva
