Systemic Disease PDF

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Summary

notes on different systemic disease that affects the eye...

Description

Systemic Disease Diabetic retinopathy Ocular manifestations of diabetes Diabetic retinopathy Retinal micro-haemorrhage Exudates Cotton wool spots Diabetic maculopathy Macular oedema Exudates Ischaemia Extra ocular muscle palsy Isolated 3rd, 4th or 6th cranial nerve palsy Retinal vascular occlusions Cataract Posterior subcapsular cataract

Classification

Moderate nonproliferative

Intra-retinal haemorrhages or microaneurysms Cotton wool spots Venous beading Intra-retinal microvasculature anomalies

Severe non-

Intra-retinal haemorrhages or microaneurysms in 4 quadrants Or venous beading in 2 quadrants Or intra-retinal microvasculature anomalies in 1

proliferative

quadrant

Very severe non-

At least 2 of the criteria for severe

proliferative Non-high risk proliferative

New vessels on disc or new vessels elsewhere But not criteria for high risk

High risk proliferative Advanced proliferative

At least 1 ofNew vessels at disc 1/3-disc areaNew vessels at disc and vitreous or pre-retinal haemorrhage New vessels elsewhere 1/2-disc area plus pre-retinal or vitreous haemorrhage Tractional retinal detachment

Preventing complications Early detection Monitoring Good diabetic control Modification of risk factors Effective treatment Sight loss can occur from Macular oedema Macular ischaemia Vitreous haemorrhage Tractional retinal detachment Visual field loss from laser treatment Aetiology Hyperglycemia Is the main cause of micro vascular complications Clinical signs are caused by small blood vessel occlusion, increased vascular permeability and changes in blood vessel walls from loss of supporting pericytes Proliferative diabetic retinopathy occurs in response to VEGF form ischemic retina Retinal Signs

Micro-aneurysms Dot haemorrhages Blot haemorrhages Exudates Cotton wool spots Retinal oedema Venous changes Neovascularization Ocular Signs Extraocular muscle palsies Iris rubeosis (new blood vessel forming) cataract Screening Patients who are not attending an eye clinic should have dilated fundus photography at least once a year in dedicated screening service Management Control of hyperglycemia Good hypertensive control Smoking cessation Refer if Severe non-proliferative retinopathy Proliferative retinopathy Maculopathy Laser treatment may be needed to: 1st line: Reduce macular oedema (focal macular laser) Treat new vessel formation (pan retinal photocoagulationPRP

Intravitreal anti-VEGF injections: For maculopathy Agents directed against vascular endothelial growth factor VEGF, such as ranibizumab, are used as an alternative or adjunct to macular laser. They reduce vascular leakage and macular oedema. Injections usually need to be repeated Vitrectomy surgery occasionally needed to: Remove vitreous haemorrhage Relieve tractional retinal detachment

Thyroid Eye disease Introduction Usually affects the extra ocular muscles and orbital connective tissues. It is characterized by active orbital inflammatory stage followed by inactive fibrotic stage Usually associated with hyperthyroidism but can occur in euthyroid and hypothyroid Can develop sight threatening optic neuropathy or exposure keratopathy Inferior rectus commonly affected NOSPECS No symptoms or signs Only lid retraction +/- lid lag Soft tissue involvement Proptosis Extraocular muscle involvement (diplopia) Corneal disease Sigh threatening optic neuropathy

Signs Conjunctival inflammation and chemosis Upper lid retraction Lid lag on down gaze Lagophthalmous (can’t close lids completely) Proptosis (bulging eyes) Restricted eye movements from extraocular muscle involvement Exposure keratopathy (drying of eyes) Optic neuropathy Symptoms Injection Redness, dryness, watering Photophobia Vision loss Diplopia Investigations Thyroid function test TSH CT scan of orbit

Management Refer to endocrinology Treat exposure keratopathy with artificial tears Elevate head at night if patient is developing eyelid oedema Some require systemic steroids Radiation can be used if steroids fail Patients treated with steroids must have their IOP monitored

Multiple sclerosis Can affect the eye in various ways Optic neuritis Visual field defect Cranial nerve palsies

Nystagmus Symptoms Optic nerve dysfunction developing over hours or days, usually one eye at a time Typical age 1845 Pain on eye movement Uhtoff’s sign- worsening of sign during exercise due to increase in body temperature Signs RAPD Color vision defect Visual field defect Swollen disc or the disc may appear normal if the inflammation is further back History Age Duration and nature of vision loss Previous episodes Pain on eye movements Other focal neurological symptoms eg. weakness, numbness or tingling

HIV Introduction Ocular involvement varies with the level of immunocompromise Determined by the level of HIV virus in the blood (viral load) and CD4 count CD4 count 50 cell/mL has a high risk of ocular infection especially by CMV

Examination Visual acuity Eyelids External eye Dilated fundoscopy including peripheral retina Signs Blephartitis Mollescum contagiosum Conjunctival Kaposi sarcoma Herpes zoster HIV retinopathy Uveitis CMV retinitis Toxoplasmosis of the retina

Hypertensive Retinopathy Signs Focal arteriolar narrowing Venous nipping at arteriovenous crossings Copper and silver wiring Cotton wool spots from small areas of retinal ischemia and swelling Lipid exudates are yellow white intra-retinal lipid collections from vascular leakage. At the macula they may resemble a star Flame hemorrhages in the retinal nerve fiber layer Macular oedema Macro aneurysms seen as well-defined red dots

Optic dis swelling caused by local ischaemia Symptoms Usually asymptomatic Can have vision loss

Classification Grade 0-normal Grade 1 arteriolar narrowing Grade 2 focal arteriolar narrowing and arteriovenous crossing changes Grade 3 haemorrhages, exudates & cotton wool spots Grade 4 grade 3 & disc swelling...