Histologic Basis of Ocular Disease in Animals

Foreword

Acknowledgements

1 Fixation and processing of ocular tissues

Fixatives

Fixation and sectioning artifacts

Fixation techniques

Electron microscopy

References

2 General pathology of the eye

Adaptations characterized by changes in cell size, number, or appearance

Neoplasia

Nomenclature

Distinguishing benign from malignant

Prognostication

Unsuccessful adaptation: cellular degeneration, necrosis, and apoptosis

Calcification, pigmentation, and cystic change

Ocular inflammation

Ocular manifestations of acute inflammation

Chronic inflammation

Ocular manifestations of chronic inflammation

Immune privilege

Lymphocytic–plasmacytic endophthalmitis

The sequelae of intraocular inflammation and other injuries

Limited regenerative ability

Susceptibility to scarring

Further reading

3 Congenital anomalies

Introduction

Defective organogenesis

Defective early organogenesis

Anophthalmos and cystic globe

Anophthalmos and microphthalmos

Cyclopia and synophthalmos

Congenital anomalies of lens

Congenital retinal nonattachment

Aniridia – iridal hypoplasia or aplasia

Coloboma

Defective later organogenesis

Neurectodermal defects

Multifocal retinopathies

Multiple ocular anomalies (MOA) in Rocky Mountain horses

Anomalies of surface ectodermal origin that develop during later organogenesis

Congenital adnexal cysts

Dermoids

Defects of neural crest migration and mesenchymal differentiation that develop in later organogenesis

Congenital corneal disease

Congenital disorders of neurocrest and mesenchymal tissues that manifest in the uvea during later organogenesis

Persistent pupillary membranes (PPMs)

Congenital glaucoma

Uveal hypoplasia

Collie eye anomaly (CEA) and related defects

Persistence of embryonic vasculature

References

4 Histopathology of ocular trauma

Perforating and penetrating wounds of the globe and ocular tissues

Perforating wounds of the globe

Traumatic intraocular hemorrhage

Expulsive subchoroidal hemorrhage

Sequelae of intraocular hemorrhage

Posttraumatic inflammation

Phacoclastic endophthalmitis and traumatic cataract

Infectious endophthalmitis

Trauma to individual ocular tissues

Orbit and optic nerve

Cornea/sclera

Uvea

Lens

Vitreous and retina

Globe as a whole

Reaction to foreign materials

Complications of ocular surgery

Chemical and thermal burns

Effects of radiant energy

References

5 Diseases of the eyelid, conjunctiva, lacrimal, and nasolacrimal systems

Eyelids

Structural disorders

Dermoids

Hamartomas

Subconjunctival fat prolapse

Entropion, ectropion, and medial canthal pocket syndrome

Distichiasis, districhiasis, and ectopic cilia

Inflammatory disease

Pyogranulomatous (granulomatous) blepharitis

Juvenile sterile granulomatous dermatitis and lymphadenitis (juvenile cellulitis)

Chalazion

Medial canthal erosion syndrome

Proliferative pox virus blepharitis in birds

Parasitic eyelid disorders

Demodicosis

Cnemidocoptes pilae (scaly beak) infestation of avian species

Eyelid tumors and neoplasms

Cystic apocrine hyperplasia (hidrocystomas, sudoriferous cysts, and apocrine cysts)

Granular cell tumor

Meibomian (tarsal gland) adenoma

Melanocytoma and melanoma

Histiocytoma

Mast cell tumor

Peripheral nerve sheath tumors

Equine sarcoid

Squamous cell carcinoma

Diseases of the conjunctiva

General pathology of the conjunctiva

Congenital conjunctival abnormalities

Infectious conjunctivitis

Herpesvirus

Chlamydophila (chlamydia)

Rickettsia rickettsi

Moraxella bovis

Parasitic conjunctivitis

Noninfectious inflammatory disease

Episclerokerataconjunctivitis

Lipogranulomatous conjunctivitis of cats

Eosinophilic conjunctivitis

Miscellaneous conjunctival disorders

Conjunctival overgrowth in rabbits (pseudopterygium)

Membranous (ligneous) conjunctivitis

Conjunctival neoplasms

Conjunctival lymphoma

Conjunctival mast cell tumors

Conjunctival melanoma and melanocytoma

Viral papillomas

Conjunctiva squamous papilloma

Conjunctival squamous cell carcinoma

Conjunctival vascular neoplasia

Miscellaneous neoplasms of the third eyelid

Lacrimal and nasolacrimal disorders

Neoplasms of the gland of the third eyelid

Prolapsed gland of the third eyelid

Keratoconjunctivitis sicca (KCS)

Dacryops and canaliculops

References

6 Diseases of the cornea

Corneal wound healing

Epithelial wound healing

Stromal wound healing

Endothelial wound healing

Epithelial and fibrous ingrowth

Healing of corneal grafts

Nonspecific corneal responses to insult

Corneal vascularization

Corneal pigmentation

Corneal edema

Keratitis

Epithelial alterations of keratitis

Stromal alterations of keratitis

Endothelialitis

Specific inflammatory corneal disease

Immune‐mediated nonulcerative keratitis

Immune‐mediated ulcerative keratitis

Superficial punctate keratitis (punctate erosive corneal dystrophy)

Chronic superficial keratitis (pannus)

Eosinophilic keratitis

Miscellaneous corneal disorders: corneal sequestrum, indolent corneal ulceration, corneal dystrophy, corneal lipid infiltrates, and corneal degeneration

Corneal sequestrum

Indolent ulceration (boxer ulcer, spontaneous corneal epithelial defects)

Corneal dystrophies, corneal lipid infiltrates, and corneal calcific/lipid degeneration

Miscellaneous corneal disease

Corneal neoplasia

References

7 Diseases of the episclera and sclera

Primary episcleral and scleral inflammatory disorders: a brief introduction

Secondary scleritis

Scleral neoplasia

Limbal melanocytoma

Episcleritis (episclerokeratitis, episclerokeratoconjunctivitis)

Scleritis and necrotizing scleritis a continuum or separate conditions?

Non‐necrotizing scleritis

Necrotizing scleritis

Parasitic episcleral disease (onchocerca vulpis/lienalis)

References

8 Histologic manifestations of disorders of the uvea

Normal aging changes

Degenerative diseases of the uvea

Uveal atrophy

Uveal cysts

Cystoid degeneration of the pars plana ciliary epithelium

Pre‐iridal fibrovascular membranes (PIFMs)

Heterotopic bony metaplasia of the ciliary body in guinea pigs

Uveitis

The nomenclature of uveitis

The intraocular events of uveitis

The etiologic implications of inflammatory exudates

Immune privilege

Consequences of uveitis

Histologic basis of the common infectious, idiopathic, and immune‐mediated uveitis syndromes in domestic animals

Lens‐induced uveitis

Phacolytic uveitis

Phacoclastic uveitis

Equine recurrent uveitis

Feline lymphocytic–plasmacytic uveitis

Pigmentary uveitis/pigmentary glaucoma of dogs

Equine heterochromic iridocyclitis with secondary keratitis

Vogt–Koyanagi–Harada‐like or uveodermatologic syndrome in dogs

Uveal xanthogranuloma in miniature schnauzers

Uveitis associated with specific infectious agents

Viruses

Feline infectious peritonitis

Canine adenovirus‐associated uveitis

Canine distemper virus‐associated uveitis

Bovine malignant catarrhal fever (MCF)‐associated uveitis

Bovine viral diarrhea mucosal disease‐associated uveitis

Ovine bluetongue

Equine viral arteritis (EVA)‐associated uveitis

West Nile‐associated avian uveitis

Hog cholera

Bacteria

Fungi

Other infectious causes for endophthalmitis

Algal endophthalmitis

Protozoan endophthalmitis

Metazoan parasitic uveitis

References

9 Histologic basis of glaucoma

Introduction

The gross, subgross, and histologic lesions of elevated IOP

Retinal changes

Optic nerve changes

Classification of canine glaucoma and introduction to open and closed angles

Congenital glaucoma

Primary glaucoma

Open angle glaucoma of beagle dogs

Primary (congenital) glaucoma in New Zealand white rabbit

Secondary glaucoma

Pre‐iridal Fibrovascular Membrane

Posterior Synechia with Pupillary Block

Vitreous degeneration, syneresis, and anterior chamber prolapse

Trabecular obstruction by tumor

Other causes of secondary glaucoma in dogs

Glaucoma in cats

Glaucoma in horses

References

10 Histologic manifestations of acquired and inherited diseases of the lens

Embryology and anatomy of the lens

Physiology of the lens

Pathology of the lens

Aging changes

Cataract

The classification of cataracts

The histopathology of cataract

The pathogenesis of cataracts

Etiologies of cataract

Lens luxation

Inherited lens zonular dysplasia

References

11 Acquired diseases of the vitreous

Primary disorders of the vitreous

Vitreous degeneration

Asteroid hyalosis

Posterior vitreous detachment

Synchisis scintillans

Uveal and neuroectodermal pigment and cysts within the vitreous and incidental parasitic encounters

Neovascularization

Conditions with secondary vitreous involvement

Vitritis

Vitreous hemorrhage

References

12 Histologic manifestations of retinal disease

Introduction

Retinal diseases by histologic pattern

Retinal atrophy

Inner retinal atrophies

The pathogenesis of retinal degeneration secondary to glaucoma

Retinal atrophy secondary to non‐glaucomatous optic nerve injury and vascular disease

Optic nerve hypoplasia/aplasia

Outer retinal (photoreceptor) atrophies

Inherited photoreceptor dysplasias and degenerations

Retinal detachment

Toxic and nutritional retinopathies

Fluoroquinolone‐induced retinal degeneration

Vitamin A deficiency

Vitamin E deficiency

Taurine deficiency

Light‐induced retinal degeneration

Sudden acquired retinal degeneration (SARD) and immune mediated retinopathy (IMR) of dogs

Diseases targeting the retinal pigment epithelium

Retinal pigment epithelial dystrophy (central progressive retinal atrophy)

Hereditary retinal pigment epithelial disorders (congenital stationary night blindness of briard dogs, multifocal retinopathies)

Canine multifocal retinopathy

Retinal pigment epithelial dysplasia in the royal college of surgeons rat

Localized chorioretinal atrophy in rats

Retinitis

Bystander retinitis

Retinitis as a manifestation of neurologic disease

Histophilus somni (formerly Hemophilus somnus) infection in cattle

Canine distemper

Retinal lesions reflecting noninfectious systemic disease

Retinal lesions of systemic hypertension

Retinal lesions resulting from inborn errors in the intermediary metabolism (lysosomal storage diseases and others)

Retinal injury from thermal energy

Retinal neoplasms

Medullopitheliomas

Retinoblastoma

References

13 Acquired diseases of the optic nerve

Intraocular disorders with associated optic neuropathy

Glaucomatous optic neuropathy

Endophthalmitis and ascending optic neuritis

Canine distemper optic neuritis

Orbital disorders that affect the optic nerve

Proptotic optic neuropathy

Orbital cellulitis/abscess with optic nerve sepsis

CNS conditions that affect the optic nerve

Optic nerve disorders

Granulomatous meningoencephalitis

Unilateral granulomatous optic neuritis

Optic neuropathy in horses

Feline optic neuropathies

Other causes of optic neuritis

Toxic optic neuropathy

Vitamin A deficiency

Primary optic nerve neoplasms

Meningioma

Optic nerve gliomas

Peripapillary medulloepitheliomas

Lymphosarcoma and other metastatic neoplasms

References

14 Acquired diseases of the orbit

Introduction

Inflammatory disease

Extraocular myositis

Lacrimal adenitis

Orbital trauma/hematoma

Zygomatic sialocoele

Orbital cysts and post‐enucleation orbital mucocoeles

Parasitic orbital disease

Orbital neoplasia

Multilobular tumor of bone (multilobular osteochondroma)

Primary orbital osteoma and osteosarcoma

Lacrimal adenoma and adenocarcinoma

Harderian gland adenomas and adenocarcinomas

Rhabdomyosarcoma

Orbital myofibroblastic sarcoma

Vascular anomalies

References

15 Intraocular neoplasia

Non‐neoplastic hyperpigmented lesions

Benign melanocytic neoplasia

Uveal melanocytoma

Uveal melanocytosis (melanosis)

Malignant uveal melanomas

Canine and feline uveal malignant melanoma

Diffuse iris melanoma of cats

Iris and ciliary epithelial neoplasia

Medulloepithelioma and retinoblastoma (primitive neuroectodermal tumors)

Primary ocular sarcomas of cats and rabbits

Schwannomas of blue eyed dogs

Osteosarcoma and chondrosarcoma

Miscellaneous primary intraocular tumors

Metastatic uveal neoplasia

Lymphosarcoma

Secondary intraocular neoplastic extension from primary nasal and orbital and adnexal neoplasms

References

Index