Ocular Manifestations of Systemic Diseases Dalman

Dysthyroid Orbitopathy autoimmune disorder usually associated with Graves' disease 10-25% euthyroid extra-ocular muscles are the target of the autoimmune attack  restrictive ophthalmoplegia and proptosis Cardinal Signs – upper eyelid retraction and lag, conjunctival injection and chemosis, and periorbital edema.

Dysthyroid Orbitopathy Pathophysiology – antibody-mediated reaction against the TSH receptor with orbital fibroblast modulation of T- cell lymphocytes

Dysthyroid Orbitopathy Pathophysiology T- cells Thyroid cells inflammation cytokinesmucopolysaccharides Orbital fibroblast EOM edema Hyperosmotic shift

Dysthyroid Orbitopathy Pathophysiology Preadipocyte fibroblasts adipocytes Inc. orbital volume Inc. fat proptosis edema Tissue damage and fibrosis lagophthalmos EO motility restriction

Dysthyroid Orbitopathy

Management – self-limited (over 1 year) – No immediate cure available

Dysthyroid Orbitopathy Management – Orbital radiation moderate-to-severe inflammatory symptoms, diplopia, and visual loss in patients with TAO – Optic nerve compression High-dose steroids (proceed to surgery if unresponsive) – Surgical Orbital decompression Strabismus surgery Lid lengthening Blepharoplasty

Occular Changes in Hypertension Damage to the retina caused by high blood pressure 3 manifestations – Hypertensive retinopathy – Hypertensive optic neuropathy – Hypertensive choroidopathy

Occular Changes in Hypertension Pathophysiology – Retinal microvasculature Inc BP Hyperoxic & hypercapneic stress Bifurcation angles and retinal arteriolar diameters show Dec vascular reactivity Disadvantageous branching geometry in retinal vasculature

Occular Changes in Hypertension Pathophysiology – Dynamics of ocular blood flow Inc BP Hypertensive arterial changes Breakdown of autoregulation Inc resistance to optic nerve head blood flow

Occular Changes in Hypertension Pathophysiology – Different manifestations because Acute HTN disrupts blood-retinal barriers Retinal and optic nerve head vascular beds have autoregulation (choroidal has none) Choroidal vessels has no blood-ocular barrier Retinal vessels (no autonomic nerve supply) Choroidal vessels (richly supplied by both sympathetic and parasympathetic nerves)

Hypertensive Retinopathy Represents target-organ damage

Grade II

Grade III

Grade IV

Hypertensive Retinopathy Clinical features – Vasoconstriction – Fundus focal and generalised arteriolar narrowing, microaneurysms, intraretinal hemorrhages, cotton- wool spots, hard exudates, optic disc swelling 2 o to arteriolosclerosis  arteriovenous nipping Flame-shaped hemorrhages (abnormal vascular permeability) Macular star (lipid deposition around the fovea) Disc swelling (minimal microvascular change)

Cotton-wool spots

Hypertensive Retinopathy Clinical features – Vasoconstriction – Fundus Untreated hypertension  hemorrhagic detachment of retina and vitreous hemorrhage

Hypertensive Retinopathy Clinical features – Vasoconstriction – Fundus – Secondary arteriosclerosis Bonnet’s sign - banking of the venule distal to the crossing Gunn’s sign - nipping of the blood column Salus’ sign - displacement of the venule at right angles to the arteriole

Hypertensive Retinopathy Gunn’s sign and Bonnet’s sign

Hypertensive Retinopathy Focal arterial narrowing of the retina

Hypertensive Optic Neuropathy Papilloedema or bilateral disc swelling – Grade IV hypertensive retinopathy – Poor prognostic sign – Other causes like space-occupying lesions and benign intracranial HTN should be excluded – Theories on the pathophysiology Ischemia and raised ICP as a part of hypertensive retinopathy/enchephalopathy

Hypertensive Optic Neuropathy Usually resolve following control of BP, but some might develop disc pallor Longstanding uncontrolled HTN  retinal nerve fiber loss

Hypertensive Choroidopathy Less well recognized than retinopathy Commonly described features: – Choroidal vascular sclerosis – Elschnig spots – focal areas of degenerative retinal pigment epithelium – Siegrist’s streaks – linear pigment epithelial changes poor prognosis

Hypertensive Choroidopathy Elschnig spots

Management Control hypertension Grade I and II – Non-urgent referral Grade III – More urgent referral to the GP Grade IV – Patient is in medical crisis. Patient needs immediate referral to a hospital eye casualty department