The sclera, episclera and limbus

image of The sclera, episclera and limbus
Online Access: £ 25.00 + VAT
BSAVA Library Pass Buy a pass


The chapter looks at the sclera, episclera and limbus, their anatomy and physiology; investigation of disease; canine and feline conditions.

Preview this chapter:
Loading full text...

Full text loading...



Image of 13.2
13.2 Glaucoma secondary to chronic cataractous lens luxation. There is a circumlimbal brush-border of blood vessels (A). The congested episcleral blood vessels (B) are very prominent. Conjunctival blood vessels (C) are much narrower.
Image of 13.3
13.3 Corneoscleral limbus in a cat. A = major arterial circle of the iris; B = pigmented limbus; C = conjunctival blood vessels; D = deep scleral vessels.
Image of 13.4
13.4 Conjunctiva extending over the limbus on to the cornea (‘conjunctivalization’ of the cornea) following a corneal/limbal injury in a 3-year-old Domestic Shorthaired cat. (Courtesy of D Gould)
Image of 13.5
13.5 Jaundiced (icteric) sclera and conjunctivitis in a dog with leptospirosis.
Image of 13.6
13.6 Wide-field fundus image showing a large peripheral region of scleral ectasia (equatorial staphyloma) in an Australian Shepherd with merle ocular dysgenesis. (Courtesy of NC Buyukmihci)
Image of 13.7
13.7 Subgross photomicrograph showing a large area of scleral outpouching (*) in a dog with merle ocular dysgenesis. (Reproduced from with permission from the publisher)
Image of 13.8
13.8 T2-weighted MR image of a cat that suffered blunt trauma showing interruption of the sclera nasally along with vitreal dislocation of the lens.
Image of 13.9
13.9 Epibulbar dermoid arising from the temporal limbus and affecting the temporal cornea in a 6-month-old crossbred collie.
Image of 13.10
13.10 Sclerocornea in a 5-month-old English Cocker Spaniel with multiple ocular defects, including microphthalmia and persistent pupillary membrane. Note that the sclera has replaced the inferotemporal cornea.
Image of 13.11
13.11 Diffuse episcleral hyperaemia associated with peripheral corneal oedema, stromal lipid deposition and neovascularization in a 5-year-old crossbred collie with generalized episcleritis.
Image of 13.12
13.12 Focal thickening of the nasal episclera with extension into the adjacent cornea in a 2-year-old Cavalier King Charles Spaniel with regional episcleritis.
Image of 13.13
13.13 A focal nodular hyperaemic thickened region of episclera adjacent to the temporal limbus in a 4-year-old Border Collie with nodular granulomatous episcleritis.
Image of 13.14
13.14 Gross pathology of an English Springer Spaniel with scleritis. There is tumour-like thickening of the episclera and sclera, extending from the limbus to the optic nerve. Note also the uveal thickening. (Courtesy of J Mould)
Image of 13.15
13.15 Left and right eye of a Labrador Retriever following a road traffic accident. (a) Note the blepharoedema, conjunctivitis, extensive corneal oedema and protrusion of the uvea through a large inferior scleral rupture at the limbus. (b) Note the blepharoedema, chemosis, conjunctivitis and pan-corneal oedema. Ultrasonography revealed rupture of the globe at the posterior pole.
Image of 13.16
13.16 Laceration of the nasal cornea crossing the limbus to involve the adjacent sclera, resulting in protrusion of the underlying uvea, conjunctivitis and corneal oedema.
Image of 13.17
13.17 Gross enlargement of the right eye due to hydrophthalmos in a 12-week-old dog. Glaucoma occurred as a result of blunt trauma to the eye, and this led to exposure keratitis due to the inability to blink over such a large globe.
Image of 13.18
13.18 Raised dark focal area adjacent to the superior limbus, consistent with an epibulbar melanoma.
Image of 13.19
13.19 Multiple patches of dark pigment are visible within the sclera underlying the conjunctiva, along with episcleral congestion, corneal oedema and a dilated pupil in a Cairn Terrier with glaucoma secondary to ocular melanosis.
Image of 13.20
13.20 Protrusion of uveal tissue through a cat scratch laceration at the superior limbus. Note the fibrin and blood visible in the anterior chamber.
Image of 13.21
13.21 Gross pathology of a feline eye in which the sclera and lens were penetrated during a dental procedure. Features consistent with this form of penetrating trauma include the obvious scleral entry site (arrowed), dense infiltrate of inflammatory cells and protein exudation filling the anterior and posterior chambers and the vitreous cavity. Lens rupture was confirmed histologically. (Courtesy of J Mould)
Image of 13.22
13.22 Gross pathology of a feline eye with a limbal (scleral shelf) melanoma. Note the outward extension of the pigmented mass and extension just into the iris base and angle. (Courtesy of J Mould)
This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error