Ocular Pathology

Front 1

Keratomalacia

Back 1

Liquefactive necrosis of corneal stroma as a bystander effect of neutrophilic inflammation. Ordinarily, it is a sequel to bacterial or fungal contamination.

Front 2

Descemetocele

Back 2

Outward bulging of Descemet’s membrane through a defect created by corneal stromal necrosis of any pathogenesis

Front 3

Iris prolapse

Back 3

protrusion of iris through a full thickness in defect in corneal epithelium, stroma, and Descemet’s membrane. Occasionally seen as a sequel to a gradually deepening ulcer, it is more often encountered as in instant sequel to full thickness corneal perforation

Front 4

Persistent ulcer (recurrent erosion, Boxer ulcer)

Back 4

failure of proper epithelial: stromal adhesion leading to persistent or recurrent shallow ulceration. There is no apparent defect in epithelial proliferation, or in production of adhesion molecules. The defect probably lies in the superficial corneal stroma, which seems unable to properly anchor the hemidesmosomes.

Front 5

Corneal facet

Back 5

focal corneal epithelial thickening as a consequence of purely epithelial healing of a shallow corneal defect that included the superficial stroma

Front 6

Corneal sequestrum

Back 6

devitalization of the corneal stroma secondary to ulceration. Most commonly seen in cats, in which the dead stroma acquires a characteristic brown/black discoloration, the same histologic phenomenon occurs in dogs and in horses with persistent ulcers. The dead stroma becomes acellular and is usually surrounded by a thin zone of lytic neutrophils. The lesion is slowly extruded through the corneal surface, in step with gradual corneal stromal turnover.

Front 7

Corneal epithelial downgrowth

Back 7

the corneal epithelium will grow down the “cut edge” of the stromal scaffold. It may gain access to the anterior chamber and grow over the surface of iris, through the pupil, etc. Alternatively, the epithelium can be implanted into the stroma and grow as an epithelial inclusion cyst

Front 8

Feline eosinophilic keratitis

Back 8

idiopathic ulcerative and superficial stromal keratitis in which eosinophils predominate

Front 9

Equine mycotic keratitis

Back 9

in other species as opportunistic overgrowth within a devitalized superficial corneal stroma, deep stromal mycotic keratitis is almost exclusively of disease of horses. The disease is probably always secondary to chronic antibiotic and/or steroid administration for some otherwise-harmless traumatic corneal ulceration. The histologic lesion is distinctive: a deep stromal suppurative keratitis in which the neutrophils are always karyorrhectic. They are most numerous adjacent to Descemet’s membrane, and the fungi are also found in greatest numbers adjacent to, or within, Descemet’s membrane

Front 10

Pannus

Back 10

slowly progressive, often bilateral lesion affecting German Shepherd dogs and many other breeds, particularly those that are “shepherd-like” in body phenotype

interface plasmacytic keratitis with basal cell injury, pigmentary incontinence and superficial stromal scarring with vascularization.

Front 11

Corneal endothelialitis

Back 11

in concert with anterior uveitis

edema

cross-reaction between corneal endothelium and infectious disease antigen that makes the corneal endothelium an accidental target for immune attack

Front 12

Corneal cutaneous metaplasia

Back 12

epithelial hyperplasia and keratinization, epithelial or stromal melanin pigmentation, thickening of the basement membrane with development of rete ridges, superficial stromal fibrosis, and stromal vascularization

Front 13

Retrocorneal fibrous membrane

Back 13

endothelium proliferates as fibroblast-like cells. They are distinguished from true fibroblasts by the retention of PAS-positive basement membrane production. The cells may be restricted to this “fibrous” plaque lining the cornea, but the cells may also migrate across the filtration angle to grow on the anterior surface of iris, caused pupillary block, or enter the posterior chamber

Front 14

Lipid keratopathy

Back 14

the deposition of lipid, usually as cholesterol, within the corneal stroma is a relatively common observation in corneas with chronic inflammation. It also occurs without pre-existing inflammation as a consequence of abnormal dietary lipid profiles, in animals with metabolic lipid abnormalities, and as poorly-characterized primary corneal “lipid dystrophy”

Front 15

Corneal mineralization

Back 15

mineralization of basement membrane and subepithelial stroma occurs commonly in dogs

transient in puppies

Front 16

Bullous keratopathy

Back 16

secondary to profound corneal stromal edema, there is percolation of the edema fluid from the stroma outwardly into the corneal epithelium where it becomes temporarily trapped as bulla between adjacent epithelial cells

Front 17

Anterior uveitis

Back 17

iridocyclitis

Front 18

Panuveitis

Back 18

inflammation of iris, ciliary body, and choroid

Front 19

Endophthalmitis

Back 19

panuveitis plus inflammatory exudate within the anterior chamber, posterior chamber, and vitreous cavity (note: in histologic sections, almost all diseases that have been clinically characterized as anterior uveitis or some other type of uveitis are histologically classified as endophthalmitis).

Front 20

Panophthalmitis

Back 20

endophthalmitis that has progressed to involve the sclera. Almost all such cases are bacterial

Front 21

Hyalitis

Back 21

inflammation limited to the vitreous

Front 22

Infectious uveitis
1. Dog
2. Cat
3. Cow

Back 22

1. blastomycosis, cryptococcosis, erlichiosis and Rocky Mountain spotted fever, and coccidioidomycosis

2. FIP, cryptococcus, toxoplasma

3. MCF

Front 23

Lymphonodular anterior uveitis

Back 23

Perivascular accumulations of lymphocytes and plasma cells are found within iris and ciliary body, and occasionally within choroid. No infectious agent is seen. Immune-mediated

Front 24

VKH-like syndrome

Back 24

bilateral, granulomatous, destructive endophthalmitis that seems to target melanin-containing cells throughout the uveal tract. It is particularly destructive of the RPE, but will also affect the pigmented iridociliary epithelium. It has a predilection for the Akita and various “arctic” breeds. It has a presumed immunologic basis. Also has a skin form.

Front 25

Phacolytic uveitis

Back 25

mild lymphocytic anterior uveitis in response to the leakage of denatured lens protein from hypermature cataracts

Front 26

Phacoclastic uveitis

Back 26

severe destructive suppurative and granulomatous endophthalmitis that occurs as a delayed response to the rupture of a previously normal lens

Front 27

Cataractous lens changes

Back 27

hydropic swelling of lens fibers, liquefaction of cortical fibers, and the proliferative consequences of attempted lens repair. The degenerative changes include the formation of spherical globules of hypereosinophilic lens protein known as Morgagnian globules

Front 28

Hypertensive retinopathy

Back 28

>arterioles become thickened with edema and sometimes with fibrinoid change
>muscular hypertrophy
>perivascular hemorrhage or the accumulation of hemosiderin,
>ischemic degenerative changes within tissue
>Retinal detachment secondary to the leakage of fluid into the subretinal space

Front 29

Retinal dysplasia

Back 29

patchy gliosis, pigmentary migration, scarring, tubular/acinar accumulations of primitive photoreceptors

Front 30

Retinal detachment

Back 30

secondary to a retinal tear with subretinal seepage of liquefied vitreous, secondary to organization and traction of a vitreal inflammatory exudate, or by serous effusion secondary to choroidal inflammation or vascular hypertension