Interpalpebral hyperaemia involving superficial episcleral vessels (large tortuous and radially orientated) and deep episcleral vessels (smaller and interlacing).

Normal vascular architecture even after multiple attacks.

Tenon capsule is separated from the sclera by oedema.

Involvement may be generalised ( Fig. 4.1 ) or sectoral ( Fig. 4.2 ).

Swollen eyelids and tender globe.

Intense hyperaemia and distortion of the deep episcleral vessels ( Fig. 4.3 ).

Variable involvement of the superficial episcleral and conjunctival vessels.

The inflamed sclera has a violaceous hue when viewed in daylight.

Involvement may be sectoral or generalised.

Tender interpalpebral nodule ( Fig. 4.4 ) over which the conjunctiva can be moved, and the nodule itself can be moved slightly over the sclera.

Dilatation of the conjunctival and superficial episcleral vessels which will blanch on instillation of 10% phenylephrine.

A thin slit-lamp section shows that the deep beam is not displaced indicating that the scleral surface is flat ( Fig. 4.5 ).

Tender nodule which cannot be moved over the sclera ( Fig. 4.6A ).

Dilatation of the conjunctival vessels, and the superficial and deep episcleral vasculature.

Instillation of 10% phenylephrine constricts the conjunctival and superficial episcleral vessels but not the deep vessels ( Fig. 4.6B ).

A thin slit-lamp section shows that the nodule displaces the entire beam because the scleral surface is elevated ( Fig. 4.7 ).

Vascular distortion and occlusion of the deep episcleral vessels.

Painful avascular patches and necrotic areas ( Fig. 4.8 ).

Exposure of underlying uvea through thinned and necrotic sclera ( Fig. 4.9 ).

An asymptomatic condition that is seen exclusively in patients with long-standing rheumatoid arthritis.

Diffuse progressive scleral necrosis without inflammation resulting in exposure of large areas of underlying uvea ( Fig. 4.10 ).