March Pulse Article (part 9/12, common diseases of the posterior segment)

March 28, 2019

Hypertensive Retinopathy

The retinal dysplasias (RDs) represent a group of inherited retinal diseases, associated with the abnormal differentiation & proliferation of one of more retinal layers. The RDs may involve;

  • Multifocal linear folds of tissue (notably affecting the Labrador Retriever, American Cocker Spaniel, Beagle, Rottweiler & Yorkshire Terrier)
  • Large irregular or “geographic” areas of tissue (notably affecting the Labrador Retriever, Golden Retriever, English Springer Spaniel & Cavalier King Charles Spaniel)
  • Complete dysplasia with or without retinal detachment (notably affecting the Labrador Retriever, Australian Shepherd, Samoyed, Doberman Pincher, Akita & Chow Chow)

Genetic testing is also available for multiple breed-related retinal dysplasias (www.optigen.com). No medical therapy is likely to be beneficial. Surgical management of retinal detachments may be indicated in selected cases.

The retinal atrophies (RAs) represent a group of inherited retinal diseases, which result in photoreceptor dysfunction and death, leading to visual impairment/blindness. Various forms have been described as affecting a large (and increasing) number of dog breeds as well as some cat breeds. The classification of the retinal atrophies is complex, however may be simplified into;

  • early and late onset progressive retinal atrophy (PRA)
  • congenital stationary night blindness (CSNB)
  • cone degeneration (“day blindness”)
  • the feline RAs

Genetic testing is also available for multiple breed-related RAs (www.optigen.com). Accurate gene-based testing facilitates breeding programs designed to help reduce the incidence of disease within a breed.

Sudden acquired retinal degeneration syndrome/immune-mediated retinitis (SARDs/IMR) describes a spectrum of disease resulting in acute onset blindness, which is generally irreversible. The mechanism of photoreceptor death in SARDs/IMR appears to be antibody-mediated retinopathy. Ophthalmic examination (including funduscopic assessment) is initially unremarkable (although signs of generalized neuroretinal degeneration including tapetal hyper reflectivity and vascular attenuation become evident in the ensuing months). Affected animals are commonly middle-aged, female, small-breed dogs, which may additionally be overweight and/or exhibit symptoms of polyuria/polydipsia/polyphagia. Intermittent associations have been made with paraneoplastic syndromes, hyperadrenocorticism &/or sex hormone imbalances. The diagnosis if SARDs/IMR supported by electroretinographic testing. Attempted treatment of fully extinguished photoreceptor function is fruitless. In rare cases of peracute IMR (associated with a degree of residual visual and/or electroretinographic function), experimental treatment using immunomodulating therapy comprising systemic doxycycline, corticosteroids and/or immunoglobulin therapy has been described.

Ocular changes are often the presenting symptom of systemic hypertension. Blood-ocular barrier breakdown results in variable combinations of sub-retinal fluid leakage, retinal hemorrhage &/or detachment, hyphema or visual deficits. Systemic hypertension may be primary or may occur secondary to systemic disease (including renal or cardiovascular dysfunction), endocrinopathy (including hyperthyroidism, hyperadrenocorticism, diabetes mellitus) or neoplasia (including lymphoma, multiple myeloma & phaeochromocytoma). Treatment comprises addressing underlying disease where present. Blood pressure may be directly regulated, typically using amlodipine, and/or an ACE-inhibitor where indicated. Retinal hemorrhage will typically resolve, and retinal detachment may spontaneously re-attach (notably in cats), depending on the chronicity & severity of the pre-exiting detachment.  Surgical re-attachment may also be considered in select cases, once underlying pathology has been addressed.

Clinical symptoms potentially associated with chorioretinitis (posterior uveitis) may include: chorioretinal edema, exudation, hemorrhage and/or retinal detachment, visual impairment and/or blindness. Potential etiologies include trauma, systemic disease, exposure to infectious organisms, the presence of (local or systemic) neoplasia and/or hereditary factors. Treatment encompasses addressing underlying systemic, infectious or neoplastic disease. Additionally, topical and/or systemic anti-inflammatory therapy is typically warranted.

Primary bullous retinal detachment represents a separation of the neurosensory retina from the underlying pigment epithelium due to sub-retinal fluid accumulation. This process is suspected to be immune-mediated in etiology. Clinical symptoms typically comprise bilaterally dilated poorly, or non-responsive pupils in association with acute onset blindness. Commonly affected breeds include the German Shepherd, Australian Shepherd and Labrador Retriever. Bullous detachments are typically promptly responsive to anti-inflammatory therapy

Rhegmatogenous retinal detachment, represents a separation of the neurosensory retina from the underlying retinal pigment epithelium stemming from a break in the retinal tissue.

Rhegmatogenous detachments may be;

  • primary –  frequently in association with vitreoretinal degeneration
  • secondary – arising as a result of inflammation and/or trauma  

Clinical symptoms may include dilated, poorly responsive pupil(s), vitreous degeneration, herniation, and/or hemorrhage visual deficits and/or blindness. Funduscopically retinal tears may visualized. Frequently affected breeds include the Shi Tzu & Bichon Frise’. Medical therapy is unlikely to result in resolution of rhegmatogenous retinal detachment. Where pathology is relatively recent (1-3 weeks) & significant secondary complications have not developed, surgical repair may be indicated.

Dr Esson is a board-certified veterinary ophthalmologist with more than twenty years of clinical experience and multiple areas of interest & expertise. His clinic Veterinary Ophthalmic Consulting (www.veterinaryophthalmicconsulting.com) is family owned & operated and he takes great pride & pleasure in working closely with his friends and colleagues in the greater Southern California veterinary community.

February Pulse Article Available (part 8 of 12, Common Small Animal Lens Disorders)

February 20, 2019

In this month’s installment we briefly review some of the more frequently encountered disorders associated with the lens.

Persistent hyperplastic tunica vasculosa lentis (PHTVL) represents a failure of the vascular supply to the developing lens to regress, typically leading to cataract formation and visual impairment. Commonly affected breeds include the Doberman Pincher & Greyhound. Where indicated, the lens & associated vascular tissue may be surgically removed and patent vessels cauterized.

Nuclear sclerosis describes the progressive thickening of the lens due to ongoing lens-fiber deposition and resultant compression of the lenticular nucleus. Clinically, this process imparts a grey-blue appearance to the nucleus, typically becoming apparent after 7-8 years of age. Unlike cataracts, the presence of nuclear sclerosis not does impede the normal fundic view or reflex. Although a degree of refractive error may be associated with ageing changes, significant visual impairment is not generally noted clinically and neither medical nor surgical treatment is typically warranted.

A cataract describes any opacity of the normally transparent & avascular lens. Cataractogenesis occurs most commonly as a result of hereditary factors, however may also result from systemic disease (notably diabetes mellitus), lenticular trauma/inflammation, dietary deficiencies (notably associated with the use of milk-replacers), exposure to pharmacologic agents (notably ketoconazole), as a sequela to the retinal atrophies (RAs) & following exposure to therapeutic radiation. Changes may be unilateral or bilateral, symmetrical or asymmetrical and may develop over varying timeframes. Most breeds (& mixed breeds) may be affected by hereditary cataracts and multiple breed-related features including age of onset and rate of progression have been described. Lens-associated uveitis, if present, should be treated with topical anti-inflammatory agents in order to minimize the risk of subsequent glaucoma. Phacoclastic uveitis describes severe, acute intraocular inflammation as a result of the sudden exposure to lens-associated proteins following lens capsule lacteration or rupture. If significant visual impairment is present, cataract surgery & lens-replacment may be indicated (pending the results of pre-surgical diagnostic testing including electro-retinal function).

The canine or feline lens may become luxated from their normal position within the patellar fossa posterior to the iris. This may be result of hereditary factors (predominantly abnormalities of the suspensory lens zonules and/or vitreous body), chronic intraocular inflammation, vitreous syneresis, glaucoma and/or trauma. Anterior lens luxation may be partial (termed “subluxation”) or complete such that the lens becomes displaced into the anterior chamber. Associated changes may include corneal edema, uveitis, varying degrees of cataract formation, the presence of degenerate vitreous material within the pupillary opening and/or anterior chamber and decreased or elevated IOP. Changes may be chronic or acute. Commonly affected breeds include multiple terrier breeds (Sealyham, Jack Russell Wire Haired Fox & miniature bull Terrier) & the Australian Cattle Dog. Subluxated lenses may be managed either medically or, more commonly, by surgical removal. The long term use of a miotic agent in the contralateral eye may be indicated in an effort to prevent similar pathology from developing. Complete anterior lens luxation is most appropriately addressed via surgical intracapsular lens extraction (ICLE) and limited automated vitrectomy.

Feline Post-Traumatic Ocular Sarcoma (FPTOS) represents a malignant intraocular neoplasm, which may develop following severe inflammation and/or traumatic injury to the ocular structures (particularly the lens).  Neoplastic changes typically take several years to develop. FPTOS encompasses several morphological variants, all of which are associated with the significant potential for extraocular extension and/or distant metastasis. Clinically, changes are typically unilateral and may include corneal edema, keratitis, corneal ulceration, uveitis, iridal thickening and/or dyscoria, the presence of an intraocular mass, hyphema, retinal detachment, glaucoma and/or exophthalmos. The diagnosis of FPTOS is made based on clinical findings in conjunction with history. Soft tissue imaging modalities including B-mode ultrasonography, computed tomography (CT) and/or magnetic resonance imaging (MRI) may contribute to the clinical diagnosis, which is confirmed histologically either by biopsy or following enucleation/exenteration. As a result of the potential or the development of FPTOS, chemical ciliary body ablation (CBA), in order to manage glaucoma, is generally discouraged in cats.

Dr Esson is a board-certified veterinary ophthalmologist with more than twenty years of clinical experience and multiple areas of interest & expertise. His clinic Veterinary Ophthalmic Consulting (www.veterinaryophthalmicconsulting.com) is family owned & operated and he takes great pride & pleasure in working closely with his friends and colleagues in the greater Southern California veterinary community.


‘For owl I know, work was a hoot’

February 6, 2019

Two successful Great Horned Owl surgeries at VOC today! Thank you to Dr Weldy & Dr Pokard (Serrano Animal and Bird Hospital) and Dr Palazzolo & Dr Wood (Long Beach Animal Hospital) and the future veterinary students for assisting Dr Esson during these owl eye surgeries. 🦉❤️🦉

Topic of the Day – Canine Glaucoma

February 1, 2019

What is glaucoma? In the video, Dr Esson describes canine glaucoma and different strategies for managing the disease.

First of all, the glaucomas represent a group of diseases which are generally associated with increased pressure inside the eye and the loss of vision due to nerve cell damage.

Just like people, dogs may be affected by many different forms of glaucoma, including…
-Congenital = present at the time of birth.
-Primary = generally in association with a hereditary predisposition for the development of elevated eye pressure. Although these changes typically take years to develop, the attack of the disease may occur acutely, sometimes within just a few hours.
-Secondary = generally in association with changes and/or inflammation inside the eye such as luxation of the lens, chronic uveitis, retinal detachment, trauma and/or various types of cancer related diseases.

To add, there are different strategies for managing the glaucoma’s by accurately assessing the changes present, topical and/or systemic medical therapy or surgical intervention. Surgery typically encompasses either maximizing fluid drainage from the eye with some form of implantable drainage device OR reducing fluid production and inflammation in the eye using laser energy to destroy ciliary tissue.

Overall, the decisions regarding the type and timing of therapy and/or intervention vary from patient to patient. These decisions are most ideally made by experienced & qualified board-certified veterinary ophthalmologists.

For more information, visit www.acvo.org!

January Pulse Article Available (part 7 of 12, Common Small Animal Uveal Diseases)

January 30, 2019

In January’s Pulse article, Dr Esson discusses common uveal diseases in small animals. The uveal tract is composed of anterior and posterior tissues. These tissue’s contain components of “blood ocular barrier” which regulates the passage of protein into the aqueous humor. Some very common clinical presentations are infectious, inflammatory, metabolic, and neoplastic disease. To read more, click on the Pulse article link:

The uveal tract is composed of anterior (iris & ciliary body) and posterior (choroidal) tissues. These tissues contain components of the “blood-ocular barrier” which regulates the passage of protein into the aqueous humor. Relatively common clinical presentations associated with uveal tissues encompass infectious, inflammatory, metabolic & neoplastic disease.

Uveal cysts (“iris cysts”) may arise from the posterior iridal or ciliary body epithelium, commonly affecting the Labrador Retriever, Golden Retriever, Boston Terrier, Great Dane & American Bulldog.  Most uveal cysts are benign and do not require treatment. Additionally, the presence of uveal cysts has been associated with elevated intraocular pressure in some breeds including the American Bulldog & Great Dane. Surgical intervention may be indicated in cases where cystic proliferation results in visual impairment and/or compromised aqueous outflow.

The term uveitis describes inflammation of any of the uveal tissues and is typically associated with variable breakdown of the blood-ocular barrier. Bilateral uveitis should prompt concern for the presence of systemic disease. Potential etiologies include hereditary factors, lens-associated inflammation trauma, systemic disease, exposure to infectious organisms and/or the presence of (local or systemic) neoplasia. Infectious etiologies which may be associated with the development of anterior uveitis in cats include; viral (FelV, FIV, FIP, FHV), protozoal (Toxoplasma gondii), bacterial (notably Bartonealla spp) and fungal (crytococcus, cocciodiomycosis, aspergillus, blastomyces & histoplasmosis) organisms. Infectious etiologies which may be associated with the development of anterior uveitis in dogs include; viral (canine adenovirus-1 & canine parvovirus), protozoal (Toxoplasma gondii), bacterial (notably Erlichia canis, Rickettsia rickettsia, Leptospira spp & Borellia spp) and fungal (cocciodiomycosis, aspergiullus, blastomyces & histoplasmosis) organisms. Frustratingly, the etiology of uveitis remains unclear in a significant proportion of cases. Treatment encompasses addressing underlying systemic, infectious or neoplastic disease, as well as the administration of topical and/or systemic anti-inflammatory therapy. Long-term treatment may be indicated in order to minimize the risk of secondary glaucoma.

A syndrome comprising slowly progressive intraocular changes, typically culminating in secondary glaucoma, is well recognized within the Golden Retriever breed (already briefly described in a previous review of conditions affecting the uveal tract). This syndrome has been variably described as “Pigmentary Uveitis”, “Golden Retriever Uveitis” and “Pigmentary & Cystic Glaucoma of Golden Retrievers”. Initial symptoms (comprising ocular redness, anterior pigment dispersion, cataract formation and/or IOP elevation) are frequently noted around middle age and are usually bilateral, although not necessarily symmetrical. Treatment is generally empirical, frequently comprising topical and/or systemic anti-inflammatory immune-modulating as well as IOP-lowering agents, however secondary glaucoma is frequently the end-point of this disease.

Canine uveodermatologic syndrome represents an immune-mediated disease affecting melanocytic tissue and exhibits similarities to Vogt-Koyanagi-Harada (VKH) disease in humans.  Ocular symptoms include anterior uveitis, chorioretinitis or panuveitis. Additional symptoms may include any combination of periocular, mucocutaneous oral and/or nasal viteligo (loss of pigment), poliosis (whitening of hair) and/or ulcerative dermatitis. Typically these symptoms are relatively bilaterally symmetrical in appearance. Commonly affected breeds include the Akita, Siberian Husky, Samoyed & Chow Chow. Treatment usually comprises aggressive, longterm anti-inflammatory and/or immune-modulating therapy, with successful management typically achievable.

Aqueous lipidosis describes a condition in which elevated levels of lipoproteins move into the anterior chamber. Changes may occur spontaneously as a result of primary hyperlipoproteinemia, following significant dietry indiscretion, in association with underlying metabolic disease and/or as a result of anterior uveitis.  Addressing underlying metabolic and/or dietary imbalances as well as concurrent uveitis, if present, typically results in rapid resolution of symptoms. In selected cases, treatment using fibrates (such as gemfibrozil) and/or statins (such as atorvastatin) may be indicated, however the use of these products in canine patients has not been approved.

Feline diffuse iris melanosis (FIDM) comprises the accumulation of pigmented melanocytes within the anterior iridal tissue. With time, some cases display deeper iris invasion and may additionally develop histologic characteristics of malignancy, representing true iris melanomas. The management of iris melanosis (& its differentiation from iridis melanoma) represents a challenge to the practitioner.  Options include;

  • clinical monitoring only (particularly relevant in cases displaying only minimally progressive focal nevi which are not elevated above the level of the iris)
  • laser photoablation of affected tissues (particularly relevant in cases showing relatively rapid progression or beginning to invade ICA structures)
  • enucleation (particularly relevant in cases displaying changes suggestive of outright uveal neoplastic progression and/or secondary glaucoma). Clinical changes suggestive of neoplastic proliferation may include the development of “velvety” appearance to focal areas of pigmentation, followed by obvious elevation of pigmented tissue above the iridal surface and resultant pupillary dyscoria

Other relatively commonly encountered neoplastic processes which may affect the uveal tract include lymphoma, melanoma & adenocarcinoma. These may be managed via chemotherapeutic intervention where indicated, surgical resection where possible or enucleation if necessary.

Dr Esson is a board-certified veterinary ophthalmologist with more than twenty years of clinical experience and multiple areas of interest & expertise. His clinic Veterinary Ophthalmic Consulting (www.veterinaryophthalmicconsulting.com) is family owned & operated and he takes great pride & pleasure in working closely with his friends and colleagues in the greater Southern California veterinary community.

SCVMA Lecture – Review of Ocular Neoplasia

January 10, 2019

Southern California Veterinary Medical Association and Veterinary Ophthalmic Consulting lectured at The Citrus Café on Thursday, Jan 10th about ocular neoplasia. Many great referring veterinarians and RVT’s joined us for dinner and an interactive discussion about identifying and managing common eye related tumors.

VOC – A Special Kind of Patient Care

January 10, 2019

The VOC technicians pride themselves in the care they provide to our surgical patients. Team members are compassionate, qualified & experienced, treating every pet that comes into VOC as though it was their own. Making the our patients feel loved and cared for, especially after having eye surgery, is an essential part of the recovery process.

December Pulse Article Available (part 6 of 12, Common Small Animal Scleral Abnormalities)

December 28, 2018

A dermoid (or “choristoma”) represents an area of normal haired skin in an abnormal location on the eye or adnexal tissue. Lesions may affect the tissues of the cornea, episclera and/or eyelids. Changes are congenital so are typically noted soon after the eyes open at 2 weeks of age. Commonly affected breeds include the German Shepherd, the Dachshund & the St Bernard.

The treatment of choice is surgical excision of the abnormal tissue. Once excised these lesions do not recur.

Primary scleritis describes a primary inflammatory disorder of the canine scleral and/or episcleral tissues, which is thought to be immune-mediated in origin. Clinically this condition presents as an inflammatory infiltrate around part or all of the corneoscleral limbus, affecting one or both eyes. Adjacent structures including the uveal tract may be involved & demonstrate clinical inflammation, extending in rare cases to necrotic scleral lesions, uveitis, retinal detachment and/or glaucoma. Commonly affected breeds include the Cocker Spaniel & Boston Terrier. Systemic screening for immune-mediated disorders may be indicated in some cases.

Treatment comprises topical and/or systemic immune-modulatory therapy using corticosteroids and or adjunctive agents such as azathioprine, chlorambucil & cyclosporine. Scleritis can typically be managed, however in most cases, ongoing therapy is required in order to maintain the patient in a disease-free state.

Nodular granulomatous episcleritis (NGE) describes a proliferative inflammatory disorder of the canine scleral and/or episcleral tissues, which is thought be immune-mediated in origin.

Multiple terms have been used to describe this condition, including; nodular fasciitis, fibrous histiocytoma, pseudotumor & collie-granuloma. Clinically, affected patients display one or more smooth, firm, mass(es) affecting the corneoscleral limbus of one or both eyes, arising most commonly in the superior-temporal region. Commonly affected breeds include the Collie-breeds, Spaniel-breeds & Terrier-breeds. The diagnosis of NGE may be confirmed where indicated by tissue biopsy & histopathology, which typically reveals a proliferation of fibroslasts and a significant infiltration of lymphocytes, plasma cells & histiocytes. Treatment comprises topical and/or systemic immune-modulatory therapy using corticosteroids and or adjunctive agents such as azathioprine, chlorambucil & cyclosporine. In severe cases, lesions may initially be managed by the injection of repository corticosteroids, surgical resection, cryotherapy &/or the application of B-irradiation. NGE can typically be managed, however in most cases, ongoing therapy is required in order to maintain the patient in a disease-free state.

Multiple neoplastic processes may affect the scleral & episcleral tissues, notably melanocytoma/melanoma, haemangioma/haemangiosarcoma, lymphoma and squamous cell carcinoma.  

Limbal (“epibulbar”) melanocytomasare the mostfrequently encountered and may affect dogs or cats.  In rare instances, these lesions may display malignant characteristics including significant anaplasia and/or metastasis. Lesions typically present as well defined, raised and pigmented masses with a smooth surface. Progressive enlargement typically results in corneoscleral and/or intraocular invasion and may ultimately lead to glaucoma and/or retinal detachment. Limbal melanocytomas should be differentiated from extension of more malignant uveal melanomas. Commonly affected breeds include the Labrador Retriever, Golden Retriever and German Shepherd. The diagnosis of melanocytoma is made based on clinical findings, supported by histopathology, following incisional or excisional biopsy. These lesions are typically relatively benign and frequently appear to be localized to ocular tissues only. Nevertheless, the evaluation of systemic health and/or involvement via local lymph node aspiration, three-view radiography and CBC/chemistry analysis, is prudent. Treatment typically encompasses surgical resection where possible (with or without adjunctive tectonic grafting procedures). Pigment-rich melanocytomas are also relatively susceptible to the application of cryotherapy.  The prognosis for successful management of most cases is good.

Dr Esson is a board-certified veterinary ophthalmologist with more than twenty years of clinical experience and multiple areas of interest & expertise. His clinic Veterinary Ophthalmic Consulting (www.veterinaryophthalmicconsulting.com) is family owned & operated and he takes great pride & pleasure in working closely with his friends and colleagues in the greater Southern California veterinary community.

Click on the Pulse article link: 112818 PULSE, December 2018_final 32112818 PULSE, December 2018_final 33