Color Atlas of Veterinary Ophthalmology

Table of Contents

Cover

Title Page

Preface

1 Ocular Anatomy

The Globe

The Adnexa

2 The Ophthalmic Examination and Diagnostics

External Examination

Nerve Blocks

Tear Film Assessment

Corneoconjunctival Culture

Corneoconjunctival Cytology

Ophthalmic Stains

Anterior Segment

Intraocular Pressure

Gonioscopy

Posterior Segment

3 Clinical Signs and Their Interpretations

Blepharospasm and Ophthalmic Pain

Ocular Discharge

Globe Position

Globe Size

Vascular Changes

Corneal Changes

Corneal Pigmentation

Corneal Cellular Infiltrate

Corneal Sequestration

Corneal Scarring

Corneal Dystrophy and Degenerations

Hemorrhage and the Eye

Opacity in the Anterior Chamber (Flare, Hypopyon, and Fibrin)

Changes in the Pupil

Iris Color Change

Inflammations of the Retina and/or Choroid

4 Canine Orbit

Congenital Orbital Anomalies

Acute and Chronic Orbital Cellulitis

Zygomatic Salivary Inflammations, Cysts & Mucoceles

Masticatory or Eosinophilic Myositis

Extraocular Polymyositis

Strabismus

Traumatic Proptosis

Orbital Trauma and Hemorrhage (Traumatic Exophthalmia/Incomplete Proptosis)

Craniomandibular Osteopathy

Orbital Neoplasia

Orbital Surgical Results

Phthisis Bulbus ‐ Sequelae of Intraocular Diseases

5 Canine Eyelids

Congenital and Developmental Disease

Breed‐Associated Eyelid Disorders

Distichiasis

Trichomegaly

Trichiasis

Eyelid Trauma

Diffuse and Focal Blepharitis

Inflammatory Lid Masses

Eyelid Neoplasia

6 Canine Tear and Nasolacrimal Systems

Diseases of the Tear Producing System

Quantitative Changes in Tears

Qualitative Changes in Tears

Diseases of the Nasolacrimal Drainage System

7 Canine Conjunctiva and Nictitating Membrane (Nictitans)

Congenital or Developmental Disease of the Nictitans

Cherry Eye (Inflammation and Prolapse of Nictitans Gland)

Protrusion of Nictitans

Plasmoma or Plasma Cell Infiltration of Nictitans

Nictitans Foreign Bodies

Neoplasia of Nictitans

Conjunctivitis

Subconjunctival Hemorrhage

Non‐neoplastic Conjunctival Inflammatory Masses

Neoplasms of the Canine Conjunctiva

8 Canine Cornea and Sclera

Developmental and Congenital Defects

Corneal Ulcerations and Inflammation

Corneal Trauma and Lacerations

Corneal Foreign Bodies

Corneal Dystrophies

Corneal Degenerations

Corneal Cysts

Limbal or Epibulbar Melanomas

Scleral Diseases

9 Canine Glaucomas

Optic Nerve Head Changes in the Glaucomas

Congenital Glaucoma

Primary Narrow/Closed Angle Glaucoma

Primary Open Angle Glaucoma

Comparisons of Human and Canine Glaucomas

Secondary Glaucomas

Surgical and Laser Treatment for Canine Glaucoma

10 Canine Anterior Uvea

Congential Variations and Disorders

Inflammations of the Anterior Uvea

Anterior Uveitis and the Mycoses

Iridal Degenerationsand Iridal Atrophy

Anterior Uveal Trauma

Hyphema

Anterior Uveal Tumors

11 Canine Lens and Cataract Formation

Congenital Abnormalities

Cataracts

Inherited Cataracts in the Dog

Secondary Cataracts

Cataract Resorption

Lens Luxation or Displacement

Pseudophakes

12 Canine Vitreous

Congenital Abnormalities

Vitreal Opacities

13 Canine Ocular Fundus and Optic Nerve

Normal Ocular Fundus and Variations

Congenital Diseases

Retinal Photoreceptor Dysplasia and Degeneration (Retinal Atrophy)

Retinal Pigment Epithelium Dystrophy

Retinitis, Chorioretinitis, and Retinochoroiditis

Sudden Acquired Retinal Degeneration

Vascular Diseases and Systemic Hypertension

Retinal Detachments

Granulomatous Meningoencephalitis

Neoplasms of the Ocular Fundus

Diseases of the Optic Nerve Head (Optic Disc or Optic Papilla)

Papilledema

14 Feline Ophthalmology

Diseases of the Orbit

Diseases of the Eyelids

Diseases of the Tear and Nasolacrimal System

Diseases of the Conjunctiva

Lipogranulomatous Conjunctivitis

Diseases of the Cornea

Diseases of the Iris and Ciliary Body

Ocular Neoplasia

Feline Glaucoma

Cataracts and Luxations

Diseases of the Ocular Fundus

Hypertensive Retinopathy

15 Equine Ophthalmology

Ophthalmic Diseases in Foals

Equine Ophthalmology in Adult Horses

16 Food and Fiber Animal Ophthalmology

Diseases of the Orbit

Diseases of the Eyelids

Diseases of the Conjunctiva and Cornea

Mycoplasma Infectious Keratoconjunctivitis

Diseases of the Anterior Uvea

Glaucomas

Diseases of the Lens

Diseases of the Ocular Fundus

Ophthalmic Diseases in New World Camelids

17 Ophthalmology in Exotic Pets

Diseases of the Snake Spectacle

Ophthalmic Disease in Raptors

Ophthalmic Disease in Rabbits

Ferrets

18 Systemic Diseases with Ophthalmic Manifestations

Ophthalmic Manifestations of Canine Systemic Diseases

Infectious Diseases

Ophthalmic Manifestations of Feline Systemic Diseases

Ophthalmic Manifestations of Equine Systemic Diseases

Ophthalmic Manifestations of Bovine Systemic Diseases

19 Neuro‐ophthalmic Syndromes

Horner’s Syndrome

Neurotropic Keratitis and Fifth Nerve Paralysis

Neurogenic Keratoconjunctivitis Sicca and Xeromycteria in the Dog (Ophthalmic Branch of the Trigeminal Nerve; Fifth Cranial Nerve)

Pupil Changes in the Cat

Strabismus

Ophthalmoplegia in the Dog

Appendix A: Glossary: Frequently Used Veterinary Ophthalmology Terms

Common Ophthalmic Roots

Appendix B: Eye Diseases in the Brachycephalic Breeds

Predisposed Eye Diseases and Therapy

Appendix C: Inherited Cataracts in the Dog

Part 1: Inherited Canine Cataracts

Part 2: Characteristics of Inherited Canine Cataracts

Index

End User License Agreement

List of Illustrations

Chapter 01

Figure 1.1 (A) The anterior eye showing the cornea, limbus, iris, ciliary body (pars plicata and pars plana), and the zonules that suspend the lens from the ciliary processes. The anterior chamber is the space between the interior cornea and the anterior lens and iris which is filled with aqueous humor. The bulbar conjunctiva covers the sclera which is the posterior continuation of the fibrous tunic (the cornea is the anterior portion). The pupil is the aperture in the center of the iris. (B) A normal horse eye. The iris in this animal is blue in color. There is a pigmented extension of the posterior pigmented epithelium of the iris along the dorsal pupil margin which is called the corpora nigrum or granula iridica. (C) A freshly enucleated canine globe from the front. (D) The globe from the side showing the cornea, limbus, anterior chamber, iridocorneal angle, posterior chamber, ciliary body (pars plicata, pars plana, and the ciliaris retinae), vitreal chamber, sclera, and optic nerve. The fundus is divided into tapetal and nontapetal sections. The tapetum is located within the dorsal choroid. The choroid, or the posterior aspect of the vascular tunic, lies interior to the sclera (the anterior extension of the vascular tunic is the ciliary body and the iris) and the retina lies interior to the choroid and adjacent to the vitreous body. (E) A normal horse eye in profile. (F) A freshly enucleated canine globe in profile. The optic nerve is observed extending from the posterior aspect of the globe. (G) Posterior aspect of a freshly enucleated canine globe. Running along the sclera anteriorly at the 3 and 9 o’clock positions are the long posterior ciliary arteries. These are important landmarks for surgical approaches to the eye. The insertions of the extraocular muscles (the muscles themselves have been removed) which move the globe are appreciable. (H) In this prosection, the cornea and a sector of the iris have been removed to reveal the lens equator and the ciliary body behind. (I) In this prosection, the cornea, and the anterior uvea have been removed revealing the lens sitting within the patellar fossa of the vitreous. (J) The lens has been removed from the globe and placed upon a page of type. Note the clarity and the magnification. (K) In this prosection, the anterior segment and lens have been removed, revealing the retina (artifactually detached in areas), the retinal vasculature, the tapetum in the dorsal choroid, the pigmented nontapetal fundus, and the optic disc. (L) Prosection of the posterior globe. In this example, the globe has been cut in order to flatten it.

Figure 1.2 (A) The eyelids. A. Haired skin. B. Orbicularis oculi (eyelid musculature responsible for closure of the palpebral fissure). C. Tarsal plate. D. Insertion of the levator palpebrae superioris (responsible for elevation of the upper eyelid). E. Meibomian glands. F. Palpebral conjunctiva. G. Cilia (eyelash). (B) The eyelid musculature showing the muscles of facial expression and eyelid movement. The levator palpebrae superioris and the Müller’s muscles, responsible for eyelid opening, are not shown. (C) The location of the lacrimal glands (orbital and gland of the third eyelid) and the meibomian glands lining the upper and lower eyelids along their margins. (D) The location of the lacrimal puncta of the nasolacrimal apparatus in the medial canthus and the subcutaneous pathway into the nasolacrimal duct. (E) A normal dog eye. Note the apposition of the eyelids to the globe, the smooth, regular margins of the lids and the third eyelid, and the normal appearance of the conjunctiva and the nictitans.

Chapter 02

Figure 2.1 (A) Essential equipment for ophthalmic examination. (B) An example of an examination form for recording findings.

Figure 2.2 (A) Pupillary light reflexes should be assessed with a bright light (here, a Finoff transilluminator is being used) in both bright and dim lighting conditions. (B) Retropulsion of the globes should be equal on each side and nonpainful to the patient. (C) Assessing the patient for asymmetry is an important part of the ophthalmic examination. In this case, a retrobulbar mass has resulted in relative exophthalmos and strabismus. Radiation therapy has resulted in cataract formation and whitening of the hair coat. (D) Characterization of any ocular discharge can help with diagnosis and staging of severity and chronicity of ocular conditions.

Figure 2.3 Landmarks for the auriculopalpebral motor block to facilitate a complete ophthalmic examination in a horse.

Figure 2.4 (A) Schirmer tear test 1 being performed in a dog. The notched end of the strip is inserted behind the eyelid margin along the lateral lower eyelid so that it comes into contact with the globe. (B) Nasolacrimal patency can be assessed indirectly with the application of topical fluorescing stain to the ocular surface. After several minutes, the dye should be seen exiting the nares (Jones’ test positive). Note the green colored nasal discharge from the left nare. (C) Cats may not have fluorescein exit from their nares. Some individuals drain tears into their oral pharynx, so assessment of nasolacrimal patency includes opening the mouth and observing the base of the tongue for fluorescein. (D) If the Jones’ test is negative, the next step in assessing patency of the nasolacrimal apparatus is to flush the nasolacrimal duct manually. After application of a topical anesthetic, a small cannula is introduced into one of the lacrimal puncta. Mild pressure is applied to force fluid through the duct. If it does not flow appropriately, dacryorhinocystography should be considered. (E) Flushing of the nasolacrimal duct in horses is usually performed retrograde from the nasal punctum.

Figure 2.5 (A) Equipment employed in sample acquisition for microbial culture and susceptibility testing. (B) Taking a sample for microbiologic culture and susceptibility testing.

Figure 2.6 (A) The basic equipment necessary to perform cytology. (B) Taking a corneal sample from a melting corneal ulcer with a cytology brush. (C) Taking a corneal sample with the dull side of a scalpel blade. (D) A stained example of corneal cytology from a case of fungal keratitis. There are numerous epithelial cells. The linear septate structures are hyphal elements.

Figure 2.7 (A) Topical ophthalmic stains can be applied to the ocular surface directly from the impregnated strip or applied to the eye after dilution with saline in a syringe. (B) Fluorescein delineating the margins of a superficial corneal ulcer. (C) Fluorescein employed in determining tear film break-up time. (D) Rose Bengal staining a qualitative dry eye. (E) Rose Bengal highlighting a dendritic ulcer in a cat with feline herpesvirus type 1 keratitis.

Figure 2.8 (A) Performing slit lamp biomicroscopy. (B) All corneal ulcers should be evaluated for depth or degree of stromal loss. Lesions or deposits in the cornea can be localized by depth as well. This infected corneal ulcer in a horse is approximately 40% depth in the center and the cellular infiltrate in the periphery is in the anterior stroma. (C) Evaluation of the anterior segment should include assessment of the anterior chamber depth. In this eye, the cataractous lens has moved anteriorly at its ventral aspect. Note the narrowing of the space between the cornea and the lens in the ventral anterior chamber. Aqueous flare is visible in this image as well. (D) Slit lamp biomicroscopy can help with cataract localization within the lens. In this dog there are two small cataracts, one in the anterior cortex and the other in the posterior aspect of the lens.

Figure 2.9 (A) Estimating intraocular pressure with a TonoVet rebound tonometer. (B) Estimating intraocular pressure with a TonoPen applanation tonometer.

Figure 2.10 (A) A variety of types of goniolenses are available for examination of the iridocorneal angle. (B) Performing gonioscopy with a Franklin goniolens. (C) The view of the normal iridocorneal angle of a dog as seen with gonioscopy.

Figure 2.11 (A) Performing direct ophthalmoscopy. (B) Performing monocular indirect ophthalmoscopy. (C) Performing binocular indirect ophthalmoscopy. (D) The view of the fundus of a dog as seen with indirect ophthalmoscopy. (E) The view of the fundus of a cat as seen with indirect ophthalmoscopy. (F) Performing ophthalmoscopy with the PanRetinal ophthalmoscope, which is a hybrid of direct and indirect ophthalmoscopy. (G) This canine patient has been appropriately dilated prior to ophthalmoscopy.

Chapter 03

Figure 3.1 (A) Pain/blepharospasm in a cat secondary to entropion. The eyelid outer margin and hair are directly contacting the conjunctival and corneal surfaces. (B) Pain/blepharospasm secondary to distichiasis and a corneal ulcer in a young Bichon Frise. (C) Blepharospasm in a horse with severe anterior uveitis and infected corneal ulcer and blepharitis. There is an abundance of mucoid ocular discharge. (D) Subtle pain in a horse may be demonstrated not by overt blepharospasm but instead by a downward deviation of the cilia (eyelashes).

Figure 3.2 (A) Epiphora can be the result of overproduction of tears, usually a reflex manifestation of pain, or because there is an obstruction of outflow of tears through the nasolacrimal apparatus. This horse has severe anterior uveitis and pain. (B) Mucopurulent discharge usually indicates chronicity or severity. It is common in keratoconjunctivitis sicca as a compensatory mechanism for the lack of aqueous tears.

Figure 3.3 (A) Exophthalmos is the anterior displacement of the globe. In this cat, a retrobulbar squamous cell carcinoma has pushed the globe forward. There is conjunctival hyperemia and chemosis and serosanguinous ocular discharge. (B) Same cat as in part A from a view looking down. If exophthalmos is subtle, the dorsal view can make the difference in globe position more appreciable. (C) When the globe is farther back into the orbit than usual, this is referred to as enophthalmos. This occurs as the result of pain, loss of orbital contents, or sympathetic denervation to the periocular structures. (D) Strabismus is the deviation of the globe from its normal directional axis. This dog has a dorsolateral strabismus of the right globe. (E) Dorsal strabismus in a Chihuahua following trauma.

Figure 3.4 (A) Microphthalmia is a congenitally small globe. (B) Phthisis bulbus is an acquired reduction in size of the globe, usually the result of chronic inflammation or chronically elevated intraocular pressure that damages the ciliary body over time and reduces its ability to produce aqueous humor in quantities sufficient to keep the globe turgid. (C) Buphthalmos is an enlargement of the globe resulting from elevation in intraocular pressure with glaucoma.

Figure 3.5 (A) Conjunctival hyperemia, especially of the ventral conjunctiva, in a dog, associated with conjunctivitis and ectropion. Note the enlarged lymphoid follicles which indicate some degree of chronicity. (B) Severe conjunctival hyperemia in a cat affecting the upper and lower palpebral conjunctiva and the conjunctiva of the nictitans. (C) Conjunctival hyperemia in an English Bulldog with keratoconjunctivitis sicca. (D) Chemosis is edema of the conjunctiva. It can be quite pronounced, especially in allergic conditions. (E) Conjunctival hyperemia in a horse secondary to an allergy.

Figure 3.6 Iridocyclitis and associated ciliary flush secondary to corneal ulceration and uveitis in a dog.

Figure 3.7 (A) Combination of episcleral venous congestion (associated with elevated intraocular pressure) and ciliary flush (associated with iridocyclitis) in a Shih Tzu with uveitis, secondary glaucoma, and a corneal ulcer. (B) Combination of episcleral venous congestion (associated with elevated intraocular pressure) and ciliary flush (associated with iridocyclitis) in a Beagle with lymphoma. (C) Episcleral injection in an American Cocker Spaniel with primary glaucoma and a subluxated lens. (D) Episcleral injection in a Bassett Hound with primary glaucoma and a subluxated lens. (E) Episcleral injection in a Golden Retriever with pigmentary uveitis and secondary glaucoma. Note the diffuse corneal edema and the fibrin clot in the pupil. There is posterior synechiae as well.

Figure 3.8 (A) Corneal edema accompanies glaucoma and iridocyclitis in a horse. (B) Generalized corneal edema can also occur when the endothelial pump is impaired, and fluid accumulates within the stroma as in endothelial dystrophy in this old dog. (C) Corneal edema accompanied by bullae (vesicle or blister) in a horse. This cornea has been chronically irritated and inflamed. Note the vascularization and pigmentation. (D) Diffuse severe corneal edema in a horse with multiple small bullae. There is also vascularization entering the cornea along its dorsal margin.

Figure 3.9 (A) Superficial corneal ulceration in a Boxer dog with edema and superficial blood vessels approaching the ulcer. These superficial corneal vessels invade the corneal stroma at the rate of about 0.6–1.0 mm/day and this rate can be influenced by the intensity of the insult and the effects of medications, such as nonsteroidal anti‐inflammatory drugs (NSAIDs). (B) Superficial corneal vascularization in a dog associated with chronic keratoconjunctivitis sicca and a ventral paraxial corneal ulcer. (C) Deep corneal vascularization associated with corneal stromal abscess (at the 2 o’clock position) and secondary iridocyclitis in a horse. The deep corneal vascularization is located primarily in the deep corneal stroma and signals disease of the iris and ciliary body. These vessels are very fine and shorter.

Figure 3.10 (A) Corneal pigmentation that is progressing in a Pekingese secondary to lagophthalmia. New pigmentation is developing in the more central cornea with corneal vascularization, and older pigmentation is in the peripheral cornea. Pigmentary keratitis signals low grade chronic irritation as with distichiasis, trichiasis, entropion, ectropion, ectopic cilia, and other insults. (B) Corneal pigmentation with invading vasculature in chronic superficial keratitis (pannus) in a German Shepherd dog.

Figure 3.11 (A) Cellular infiltrate within the cornea appears white to yellow in color in an infected corneal ulcer in a horse. (B) In this example of a stromal abscess in a horse, the infiltrate surrounds a fungal pathogen. Note the deep corneal vessels, the surrounding edema, and the miosis which signals concurrent uveitis. (C) Cellular infiltrate in a cat with stromal keratitis, an immune‐mediated form of corneal inflammation.

Figure 3.12 (A) The first suggestion of the development of a sequestrum in the cat is a very faint light brown lesion within the anterior stroma. (B) As the sequestrum increases in size and density, superficial corneal vascularization begins to surround the lesion, often with signs of superficial keratitis. The epithelium overlying the sequestrum is eroded. Fluorescein stain is not usually retained by the sequestrum but it may stain the edges of the sequestrum and the surrounding inflamed cornea. (C) This sequestrum extends to nearly Descemet’s membrane and has incited an intense keratitis. Surgical removal with some type of reconstructive graft (conjunctival flap or corneoconjunctival transposition) is indicated.

Figure 3.13 (A) Corneal scarring (fibrosis) occurs when inflammation, neoplasia, or other causes disrupt the normal organization of the corneal lamellae preventing light from penetrating the corneal tissue. New and active scars are usually vascularized but those completely healed usually have no obviously perfused blood vessels and are level or even slightly depressed from the surrounding corneal surface. (B) Corneal fibrosis following corneal transplantation to remove a deep stromal abscess in a horse. The dense linear foci of fibrosis adjacent and perpendicular to the limbus are scars from suture tracks. The paraxial area of fibrosis in the temporal cornea is the original site of the abscess and subsequently the donor corneal graft which has incorporated into the host tissue. (C) Deep corneal scarring and lipid degeneration in a puppy following a full‐thickness corneal and anterior lens capsular laceration secondary to a cat’s claw.

Figure 3.14 (A) Corneal lipidosis is associated with many inherited primary corneal stromal dystrophies in dogs as well as degenerations secondary to other corneal and intraocular diseases. The bilateral lipid deposits appear as discrete white opacities usually within the anterior corneal stroma. Vascularization may or may not be visible. (B) A severe case of corneal lipidosis in a dog. (C) Calcification of the cornea is much less frequent that lipidosis, and can occur simultaneously. Calcification appears as minute white to gray deposits within the corneal stroma. It can occur as the result of chronic inflammation or chronic medication administration. This horse has equine recurrent uveitis and the mineral is forming a band in the axial cornea where the palpebral fissure opens. Blood vessels are approaching the mineral deposits.

Figure 3.15 (A) Orbital hemorrhage secondary to trauma in a dog. The combination of blood in the orbit, subconjunctival tissues, and anterior chamber (hyphema) usually indicates considerable damage to the entire eye. (B) Subconjunctival hemorrhage can occur secondary to several blood clotting disorders, and simple trauma to the face in a dog. Hyphema is present concurrently. (C) Hyphema following laser photocoagulation for an iridal melanoma in a dog. (D) Hyphema associated with systemic lymphoma in a dog. (E) Iridal hemorrhages associated with systemic disease (Rocky Mountain spotted fever) in a dog. (F) Vitreal and intraretinal hemorrhages in systemic hypertension in an aged cat.

Figure 3.16 (A) A slit beam image demonstrating the Tyndall effect, which occurs when a light beam reflects from proteins and cells in the aqueous humor, resulting in a translucent to opaque media. (B) Feline infectious peritonitis is a good example of anterior chamber infiltration by large numbers of inflammatory cells including plasma cells, macrophages, and lymphocytes which clump together and adhere to the posterior cornea and anterior lens capsule. Sometimes red blood cells are also incorporated in these keratitic precipitates rendering them pink or red. (C) Hypopyon in the horse and an intense iridocyclitis secondary to a paraxial stromal abscess. (D) Fibrin in the anterior chamber of a horse with uveitis. Some hemorrhage is also present. (E) Fibrin in the anterior chamber of a horse with a corneal perforation.

Figure 3.17 (A) Pupil size is usually increased (mydriasis) in glaucoma when intraocular pressure is elevated. This Bassett Hound has primary glaucoma and lens subluxation. (B) Pupil size is B reduced (miosis) with anterior uveitis or iridocyclitis. This horse has anterior uveitis secondary to a corneal abscess (ventrolateral paralimbal cornea at 8 o’clock). Miosis is the hallmark sign of uveitis.

Figure 3.18 (A) Pupil shape can be very irregular with adhesions (posterior synechiae) between the posterior iris and anterior lens capsule as with chronic anterior uveitis in a horse. (B) The pupil margins of the iris can adhere together (annular posterior synechiae) and completely obstruct the pupillary flow of aqueous humor as in the cat with anterior uveitis. This condition is termed iris bombé. (C) In this cat with anterior uveitis, the dyscoria is the result of posterior synechiae. The cellular infiltrate in the ventral anterior chamber are neoplastic cells.

Figure 3.19 (A) Rubeosis irides is the term given to the proliferation of new vessels or neovascularization on the iris surface. In this Siberian Husky with uveitis, the normally blue iris has turned red because of new vessels and congestion of existing vessels. Corneal vessels are present in this example as well. (B) Uveitis can result in iris color change. In this horse with a normally blue iris, the stroma has turned yellow because of the leakage of proteins. Note, too, the new vessels on the iris surface and the fibrin clot in the anterior chamber which is obscuring visualization of the pupil. (C) Hyperpigmentation of the iris usually develops with chronic uveitis. In this dog, the iris is several shades darker brown than normal as the result of pigment proliferation during chronic uveitis. There is also diffuse corneal edema.

Figure 3.20 (A) Acute chorioretinal inflammations of the tapetal fundus appear as raised translucent to white opacities with irregular or fuzzy margins, often near retinal blood vessels as in this young dog with canine distemper. (B) Acute chorioretinal inflammation involving the nontapetal fundus is easier to detect, because of the dark brown to black underlying retinal pigment epithelium. The inflamed areas appear white raised areas with irregular margins as in this young bull with pneumonia.

Figure 3.21 (A) Chronic chorioretinal inflammation (retinopathy/chorioretinopathy/retinal–chorioretinal scars) of the tapetal fundus can involve partial to full‐thickness focal destruction of the retina and tapetal lucidum, and the resultant proliferation and migration of the retinal pigment epithelium. They appear as focal to diffuse hyperreflective areas with variable pigmentation, and sharp or smooth margins such as in this young dog with distemper. (B) Chronic chorioretinal inflammation of the nontapetal fundus appears as diffuse to focal gray to white areas with sharp margins, variable proliferation and migration of the retinal pigment epithelium, and changes in the retina blood vessels such as in this young dog with distemper.

Chapter 04

Figure 4.1 (A) Bilateral but not symmetrical microphthalmia in a homozygous blue merle Australian Shepherd puppy. (B) Close up of microphthalmia with multiple ocular defects including heterochromia, corectopia (off center pupil), and basal iridal coloboma (atypical equatorial coloboma). (C) Australian Shepherd litter of puppies with 3 normal eyed blue merles and 3 excessively white blue merles with colobomatous microphthalmia (merle ocular dysgenesis). (D) Bilateral microphthalmia in a mixed breed puppy.

Figure 4.2 (A) Acute orbital cellulitis in a Basset Hound of three days duration. (B) Resolution of the condition several days later after therapy with high levels of systemic antibiotics, and topical antibiotics and 1% atropine. (C) German Pointer with unilateral retrobulbar abscess. (D) Oral view on a dog revealing swelling and hyperemia of the palatal tissue posterior to the last maxillary molar. This is an access point for sample collection and drainage of a retrobulbar abscess.

Figure 4.3 (A) Zygomatic salivary mucocele in large dog. The condition had progressed over several weeks. (B) Zygomatic salivary mucocele in a small breed dog. Note the swelling ventral to the globe. The eye was mildly exophthalmic and resistant to retropulsion.

Figure 4.4 Acute masticatory myositis in a German Shepherd dog. The swelling of the temporal muscles cause the bilateral exophthalmia and protrusion of the nictitating membranes.

Figure 4.5 (A) Golden Retriever with bilateral polymyositis. The eyes are relatively fixed in position. (B) Same dog (A) after immunosuppressive corticosteroid therapy.

Figure 4.6 (A) Esotropia accompanied by microphthalmos in a young Samoyed. Often these eyes are not visual. (B) Lateral strabismus following rupture of the medial rectus resulting from traumatic proptosis. Note the hemorrhage at the insertion site. (C) Restrictive strabismus in a Shar Pei dog. The globe is rotated ventromedial and the cornea hidden totally and vision lost.

Figure 4.7 (A) Traumatic proptosis in a mixed breed dog after fighting with a larger dog. The globe became trapped beyond the palpebral fissure, causing immediate drying of the corneal surface. Replacement is recommended. (B) Severe traumatic proptosis in an American Cocker Spaniel after being hit by a car. Retrobulbar and subconjunctival hemorrhage can exacerbate the displacement. (C) Traumatic proptosis in an America Cocker Spaniel with the globe nearly totally exposed and tearing of several of the extraocular muscles. Enucleation is recommended. (D) Surgical therapy consists of a complete temporary tarsorrhaphy. Rubber band stents help distribute the suture pressure along the entire eyelid length, prevent necrosis when the sutures are very tight or the orbital swelling is excessive, and can be adjusted during the 10 to 20 days that the sutures are needed before a vigorous protective blink returns. (E) Exotropia in a Pug 3 weeks after traumatic proptosis and replacement of the globe. As the medial rectus m is the shortest of the extraocular muscles, it is the most susceptible to tearing and transection during proptosis.

Figure 4.8 (A) Moderate orbital trauma after a dog fight in a Maltese. Both subconjunctival and retrobulbar hemorrhage are present. The globe is fixed and cannot move. (B) A more severe case of orbital trauma in a Pug hit by a baseball. Bright red blood is present within the entire anterior chamber.

Figure 4.9 Craniomandibular osteopathy in a White West Highland Terrier puppy. The bony orbital abnormalities have displaced the eyes forward and lateral (exotropia).

Figure 4.10 (A) Orbital osteosarcoma in a mixed breed dog. The globe is exophthalmic and dorsally and laterally deviated. Note the significant disfigurement of the face. (B) Orbital lymphosarcoma in an Australian Shepherd. The tumor has produced unilateral exophthalmia and protrusion of the nictitating membrane. (C) Labrador mix had adenocarcinoma which resulted in exophthalmos and impingement of the optic nerve (note the mydriasis).

Figure 4.11 (A) Clients must be advised of the post‐operative appearance of the orbit after enucleation. In dogs with short‐hair coats the concave permanent complete tarsorrhaphy is more disfiguring. (B) In dogs with longer hair coats and less prominent eyes, the adverse effects of enucleation are less obvious. The enucleation procedure was performed in this dog five months earlier.

Figure 4.12 A: (A) Intraocular silicone prosthesis (ISP) can be used to treat painful eyes without removal of the eye as in this Beagle with end‐stage glaucoma. The globe size is maintained by the intraocular silicone sphere, and placement within the corneoscleral tunic avoids daily removal and cleaning. Corneal pigmentation and fibrosis almost always occur. (B) ISP one year after placement. Note the corneal edema, fibrosis and vascularization.

Figure 4.13 A. Phthisis bulbus in a Schnauzer mix after aphakic glaucoma of several months duration. Note the corneal edema (from very low intraocular pressure) and pigmentation.

Chapter 05

Figure 5.1 Ankyloblepharon and neonatal ophthalmia in a Shetland Sheepdog puppy. Note the marked swelling of the eyelids. Purulent exudate is escaping at an opening in the medial ankyloblepharon.

Figure 5.2 Agenesis of the lateral upper eyelid in a Miniature Poodle puppy. Lack of eyelid margin in the affected area has resulted in trichiasis and local keratoconjunctivitis.

Figure 5.3 (A) Dermoid of the palpebral conjunctiva and lower eyelids in a Cairn Terrier. Note the long and coarse hairs which cause considerable discomfort. (B) Dermoid of the upper eyelid in a young Golden Retriever.

Figure 5.4 Blepharophimosis or a reduced palpebral fissure in a Chow Chow puppy. The shortened eyelids usually develop entropion and require surgical correction (lateral canthoplasty). The entropion has resulted in corneal and conjunctival irritation and a mucopurulent discharge.

Figure 5.5 (A) Pekingese dog has euryblepharon or an enlarged palpebral fissure which results when the eyelids are longer than normal. The result is greater exposure of the cornea (note the central scar from a previous ulcer) and conjunctiva (which is visible nearly 360° around the cornea). (B) Euryblepharon in a Shih Tzu. Note the dramatic amount of scleral show. This animal is at risk for proptosis.

Figure 5.6 Clumber Spaniel with very prominent V notch in the central lower eyelid.

Figure 5.7 (A) Entropion appears to be inherited in many breeds; in the Norwegian Elkhound the entropion is usually confined to the lateral and lower eyelid, and may self‐correct in young dogs. (B) Lateral canthal and lower entropion in a young Labrador Retriever. (C) Lateral lower eyelid entropion in a Shar Pei. Note the temporal keratitis. (D) Chinese Shar Pei puppy with nearly 360° entropion. At this age, maintaining the eyelids open using tacking sutures is recommended. (E) Entropion affecting upper and lower eyelids of a mature Chinese Shar Pei. Surgical correction may also include a face lift (removal of one or more of the facial skin folds).

Figure 5.8 (A) Severe bilateral ectropion in Bloodhound with chronic discomfort and secondary bacterial conjunctivitis. (B) Severe cicatricial ectropion in a Bracco Italiano following surgery to correct entropion.

Figure 5.9 (A) Combined entropion–ectropion in a young St. Bernard dog with elongated eyelids. Both corneal and conjunctival diseases result from the exposure as well as direct lid contact with the cornea. Lateral canthal entropion and instability often compound the surgical correction. (B) Combined entropion–ectropion in an English Bulldog. Note the central notches in both the upper and lower eyelids.

Figure 5.10 (A) Multiple distichia are emerging from the lateral lower eyelid margin in a mixed‐breed dog. Very fine distichia are frequently non‐irritating. (B) Cryotherapy is the most often performed procedure as it can be repeated and tends not to affect the eyelid margins (unlike many of the surgical procedures). Application of a cryoprobe to the palpebral conjunctiva near the eyelid margin targets the follicles of distichia. (C) Immediate appearance after cryotherapy. Over‐freezing can cause necrosis of the eyelid tissues and under‐freezing does not destroy the distichia follicles. Recurrence of cilia after these surgeries is in the range of 10–30%, so multiple treatments may be necessary.

Figure 5.11 An ectopic cilia is emerging from the central palpebral conjunctiva beyond the lid margin. Cilia such as this are very irritating and can contribute to ulceration of the cornea. There are several hairs visible beneath the palpebral conjunctiva in this individual which have not yet emerged.

Figure 5.12 Trichomegaly affecting both upper eyelids in an American Cocker Spaniel. These extremely long eye lashes do not produce eye disease and are usually periodically trimmed.

Figure 5.13 (A) Trichiasis secondary to nasal folds in a Pekingese dog. The hairs from the upper aspects of both nasal folds contact the medial corneas causing irritation and medial pigmentary keratitis. (B) Upper eyelid trichiasis in a Shih Tzu.

Figure 5.14 (A) Eyelid laceration affecting the lower lateral eyelid and canthus in a Labrador Retriever. The torn eyelid margin should be carefully apposed by sutures (rather than excised) to the remaining eyelid. (B) Previous eyelid laceration that was not corrected. Fibrosis of the wound edges often results in persistent irritation.

Figure 5.15 Puppy pyoderma blepharitis in a young Rottweiler puppy. Note the multiple focal abscesses affecting the skin about the mouth and eyelids.

Figure 5.16 (A) Sarcoptic mange in a young dog. The skin has hyperemia, alopecia, pruritus, and often the effects of self‐trauma. (B) Demodex in a young dog; the disease is often confined to the eyelids and face.

Figure 5.17 (A) Immune‐mediated blepharitis affecting the medial canthus in a dog. Note the localized lid inflammation. In the German Shepherd this condition is often coupled with chronic superficial keratitis (pannus). (B) Severe ulcerative immune‐mediated blepharitis in a German Shepherd Dog.

Figure 5.18 (A) Pyogranulomatous blepharitis affecting the upper and lower eyelid in a dog. Biopsy of the inflamed lids is recommended to confirm the diagnosis and exclude neoplasia. (B) Pyogranulomatous blepharitis in a chocolate Labrador Retriever affecting both the upper and lower eyelids. The condition was bilateral.

Figure 5.19 Uveodermatologic syndrome typically results in severe panuveitis, which can result in secondary glaucoma and cataract formation, in addition to depigmented or ulcerative lesions of the skin, particularly in highly pigmented areas.

Figure 5.20 (A) Acute meibomianitis affecting the lower eyelids in an American Cocker Spaniel. The blepharitis is localized to the palpebral surface of the lids. (B) Chronic meibomianitis with numerous impacted glands. These chronic cases are often quite stubborn to treat, and cause long‐term lid fibrosis and entropion. (C) Severe meibomianitis affecting both upper and lower eyelids in a Shih Tzu.

Figure 5.21 (A) Stye or hordeolum in a young dog. The inflamed glands are located on the eyelid margin, and can be quite irritating. (B) Large chalazion affecting the upper eyelid in a young Collie‐mix female. There is marked blepharitis and swelling of the upper palpebral aspects of the lid.

Figure 5.22 Proliferative keratoconjunctivitis in a young Rough Collie. Eyelids, conjunctiva, and cornea are affected. The condition was bilateral.

Figure 5.23 (A) Adenoma of the meibomian gland of the upper eyelid in an aged mixed‐breed dog. (B) The full extent and origin of these tumors can be appreciated by everting the upper lid and inspecting the lid margin and the palpebral conjunctiva overlying the base of the tumor.

Figure 5.24 Melanoma of the lower eyelid margin in a mixed‐breed dog. These tumors typically arise from and spread along the eyelid margin. Because the lid margin is infiltrated (usually in both directions), tumor excision is more difficult and some lid scarring can occur.

Figure 5.25 (A) Squamous cell carcinoma (SCC) of the eyelid in terrier‐Boxer mix. The history was one of persistent nonresponsive ulceration of both eyelids and the third eyelid. Histopathology confirmed SCC. Tumor was excised by surgery. (B) Mast cell tumors in a dog. These tumors present as firm raised pink masses with or without ulcerations, or can appear as roughened areas of alopecia and erythema.

Figure 5.26 Histiocytoma in a 1‐year‐old Afghan Hound. This mass rapidly developed over 2 months, and just as rapidly regressed spontaneously over the next 2 months. In young dogs, eyelid histiocytomas can expand rapidly only to regress spontaneously a few weeks later. This tumor type in older dogs, however, can be quite malignant and should be removed with wide margins. Biopsy of these masses guides therapy.

Figure 5.27 Oral papillomatosis in puppies and young dogs, a viral‐induced tumor, can also affect the eyelids. They also regress spontaneously in a few weeks, and removal is considered necessary only when corneal contact and ocular irritation develop.

Chapter 06

Figure 6.1 Acute keratoconjunctivitis sicca (KCS) in dogs. (A) Acute keratoconjunctivitis (KCS) in a puppy secondary to canine distemper. Often distemper‐associated KCS is bilateral and acute. (B) Acute KCS in a terrier‐mix dog. The eye has been stained with rose Bengal. Note the lack of corneal luster and diffuse stain retention by both the cornea and bulbar conjunctiva. (C) Acute KCS in a Shih Tzu. Note the superficial ulcerations of both corneas. Profound blepharospasm is often present with acute onset KCS. This patient has had a topical anesthetic applied to facilitate examination. (D) Acute KCS in a young dog with corneal ulceration and iris prolapse.

Figure 6.2 (A) Chronic KCS in a Chinese Crested Dog. Note the superficial corneal vascularization, pigmentation, and fibrosis. (B) Chronic KCS in a Shih Tzu of several months’ duration. Note the vascularization and pigmentation of the cornea. (C) Chronic KCS in an American Cocker Spaniel after several weeks of topical tacrolimus. The cornea has regained its most of its luster, but conjunctivitis, keratitis, and corneal pigmentation are still present. (D) Neurogenic KCS in a Miniature Schnauzer characterized by chronic KCS and a dry nostril on the same side. Note the blepharospasm and corneal opacity. This type of KCS is secondary to parasympathetic denervation of the lacrimal gland and will often respond to oral pilocarpine therapy. Lesions causing this disease are associated with otitis media or interna and petrositis of the petrous temporal bone.

Figure 6.3 (A) Postoperative appearance several months after bilateral parotid duct transposition in a Miniature Schnauzer female with chronic KCS that failed to resolve with medical therapy. (B) The most frequent short‐ and long‐term postoperative complication after parotid duct transposition is the onset of mineral deposits that irritate the corneal and conjunctival surfaces. These same deposits can cover the eyelids. (C) Note the mineral deposits on the eyelids in this postoperative parotid duct transposition patient. There is a conjunctival graft present on the cornea that was placed to address a previous descemetocele.

Figure 6.4 (A) Qualitative KCS in a Shih Tzu. This dog’s aqueous tear production was sufficient; however, the tear quality was impaired. Note the rose Bengal retention and the corneal vascularization. (B) Qualitative KCS in a mixed‐breed dog. Note the conjunctival hyperemia and the corneal vascularization and fibrosis.

Figure 6.5 Young dog with medial lower entropion that has collapsed the lower lacrimal punctum, and redirected tears onto the medial canthus. With constant moisture in this area, chronic dermatitis and tear staining result. Surgical correction is indicated but varies depending on the individual’s conformation. Options include medial canthoplasty or removal of a small triangular or oval section of skin immediately below the medial entropion, avoiding the eyelid margin, to evert the medial lower lid margin and open the lower lacrimal punctum.

Figure 6.6 Acute dacryocystitis in this dog is characterized by painful swelling of the medial canthus and obstruction of the lower lacrimal punctum by inflammatory exudate and, not infrequently, small foreign bodies.

Figure 6.7 (A) Longer term dacryocystitis often develops a ventromedial fistula (arrow) which provides a bypass for tears. (B) Nasolacrimal flush performed through upper lacrimal punctum produces the extrusion of inflammatory debris (and occasionally a foreign body, i.e., plant awn) through this bypass. Additional nasolacrimal flushes may be necessary to lavage the nasolacrimal sac of all exudate and debris and then to establish patency of the entire system to the nose. (C) Treatment of chronic nasolacrimal obstruction with catheterization with monofilament nylon suture or silicone tubing which is secured by