600 likes | 1.67k Views
Systemic Disease and the Eye. Dr Sancy Low. Background. Patients of all ages and medical history can present with eye problems Symptoms are often associated with systemic disease
E N D
Systemic Disease and the Eye Dr Sancy Low
Background • Patients of all ages and medical history can present with eye problems • Symptoms are often associated with systemic disease • Cardiovascular, endocrine, rheumatoid, connective tissue disease, inherited eye disease and HIV are prominent examples
Topics covered in this lecture • Diabetic Retinopathy • Hypertensive Retinopathy • Thyroid Eye Disease • Inherited Eye Disease • HIV and AIDS
Diabetic Retinopathy (DR) • Microvascular disease of the retinal microcirculation • Commonest cause of blindness under 65y • Symptom less until loss of vision : • Gradual = Central (macula) area of retina involved by oedema, exudates or haemorrhage (maculopathy) • Sudden = vitreous haemorrhage from new blood vessels (proliferative DR)
Pathophysiology Hyperglycaemia: • Glycosylation of proteins (capillary basement membranes) • Loss of endothelial supporting cells (pericytes) • Microaneurysms (hallmark of disease) = leakage • Capillary closure = ischaemia
Type 2 diabetes Leakage: Background diabetic retinopathy Maculopathy Type 1 diabetes Ischaemia: Background diabetic retinopathy Pre-proliferative diabetic retinopathy Proliferative Vitreous haemorhage Tractional retinal detachment
Background DR Features: • Microaneurysms / haemorrhages (‘dots and blots’) • Exudates Treatment:- Observe
Maculopathy Features: Background DR changes but in the macula area Treatment: • Argon Green laser (induces thermal burn) • Either focal or grid laser photocoagulation
Pre-proliferative DR Features: • Cotton wool spots • Extensive haemorrhages • Venous beading • Intraretinal microvascular abnormalities (IRMA)
Pre-proliferative DR Treatment: Close observation
Proliferative DR: new vessel formation Treatment: Argon laser panretinal photocoagulation (PRP)
Panretinal photocoagulation 3 days post treatment Old burns
End Stage Disease: fibrosis, retinal traction and eventual detachment
Prevention of DR • Progressive disease • Type I DM: 25% affected by 10y • Type II DM: 50% affected by 10y • Regular eye tests: Optician, GP, Diabetic team, Ophthalmologists • BM control (DCCT) • BP control (UKPDS) • Stop smoking
Hypertensive retinopathy • Has been graded 1 to 4 (but not satisfactory!) • Grade 1: arteriolar narrowing and vein concealment • Grade 2: severe arteriolar attenuation and venous deflections at crossings (AV nipping) • Grade 3: arteriolar copper wiring, haemorrhages, CWS and hard exudates • Grade 4: all of the above plus silver wiring and optic disc swelling
Causes • Systemic hypertension • Early signs difficult to tell from ageing changes • Malignant hypertension • Accelerated severe hypertension causing encephalopathy and papilloedema (sign of raised intracranial pressure)
Note black areas of non-perfusion on FFA (fundus fluorescein angiogram)
Malignant hypertension - papilloedema, ischaemia, infarction and macular star
Treatment • Treat the hypertension! • Watch out for other complications such as central retinal artery and central retinal vein occlusions (acute visual loss lecture)
Thyroid Eye Disease (aka Grave’s Ophthalmopathy) • Associated with thyrotoxicosis (but patient can be clinically and biochemically euthryoid) • Organ specific IgG mediated disease • Infiltration of muscles and fat surrounding eye • Unilateral or bilateral • Two stages: • Acute inflammatory (risk of sight loss); lasts approx 12-18 months • Chronic fibrotic
Conjunctival chemosis (oedema) Eyelid retraction (worse on downgaze) Diplopia (usually upgaze +/- lateral gaze) Proptosis Corneal exposure (corneal ulcers if severe) Compressive optic neuropathy: decreased V/A, RAPD, field loss, reduced colour vision Examination
TED symptoms • Nil • Grittiness • Redness • Eyelid swelling • Diplopia • Cosmetic appearance “bulgy eyes” • Visual loss
American Thyroid Association Classification • NOSPECS – 6 stages • (0) No signs or symptoms • (1) Only ocular irritation (dryness, FB) • (2) Soft tissue involvement (oedema) • (3) Proptosis • (4) EOM (extraocular muscle) involvement • (5) Corneal involvement • (6) Sight loss
Investigation: CT orbit Proptosis and EOM infiltration(medial & inferior rectus most commonly involved)
Treatment • Manage thyroid dysfunction • Ocular lubricants alone (in mild cases) • Acute optic nerve compression & corneal exposure • Systemic corticosteroids • Radiotherapy • Surgical orbital decompression • Chronic phase • Diplopia: Squint surgery, Prisms, Botulinum toxin • Cosmetic: Orbital decompression; lid surgery eg blepharoplasty, lid lowering etc
Inherited eye disease • Genetic eye disease accounts for 20% of blind registration in young adults • 40-50% of blindness in children is inherited • Retinitis Pigmentosa is the commonest inherited retinal dystrophy • Affects 1:5000 of the population • It is a heterogeneous condition which primarily affects the retinal rods and later retinal cones
Retinitis Pigmentosa • Bone-spicule pigmentation around blood vessels • Pale waxy appearance or the peri-papillary retina
Presentation • RP can be inherited in all forms: AR, XL, AD, and mitochondrial or simplex (where there is no other known family history) • Patients usually present with night blindness but can progress to tunnel vision and total blindness (as rods then cones are affected) • Syndromic forms of RP exist e.g. Usher syndrome = night blindness and deafness (usually recessive)
Photoreceptor loss • Progressive disease • Loss of rods first • Cone loss eventually • Night blindness first then peripheral field loss, tunnel vision and eventual blindness
Investigations • Symptoms are usually present before ophthalmoscopic signs • Electroretinography (ERG): contact lens probe and measurement of electrical potential of the photoreceptors • Visual field analysis • Good family history, examine relatives
Treatment/ Research • Currently no treatment for RP • Low visual aids and blind registration • Anti-oxidants (Vitamins A+E have been tried but majority or RP patients not responsive) • Genetic mapping and linkage studies • E.g. Peripherin gene – current research to find gene therapy
HIV and AIDS • AIDS is a multisystem disorder of opportunistic infections caused by HIV. • Ocular manifestations: • Keratitis sicca • Common infections: HSV/ HZO/ VZV/ CMV • Rarer: Candida choroiditis, Retinal toxoplasmosis • Neoplasms: Karposi’s sarcoma, Non-Hodgkin’s lymphoma
Herpes Zoster Ophthalmicus: Ophthalmic division of trigeminal nerve
CMV retinitis • Commonest – Occurs in 25% of AIDS patients • “Pizza fundus” with overlying vitritis • Related to high viral load or low CD4+ count • <50 cells/mm3 at greatest risk
Symptoms of CMV retinitis • May be minimal • Floaters and flashing lights • Visual field loss • Central visual loss (V/A) • Signs: progressive necrotising retinitis, retinal haemorrhage and intraretinal necrosis, hazy vitreous
CMV retinitis treatment • 14 day induction course: iv ganciclovir or foscarnet • May require lifelong treatment • 80-100% respond to initial therapy but 50% recur within 3 months • May require intravitreal injections or implants
Complications • Related to ocular disease or treatment • Blindness from retinal detachment • Optic nerve head involvement • Ganciclovir causes neutropenia • Foscarnet causes renal toxicity • Co-existence of other infections (low CD4)