Control of ocular inflammation

Although both topical and systemic anti-inflammatory agents have a place in veterinary ophthalmology, they play only a small role in overall patient management. They must be used appropriately to prevent ocular damage and loss of vision from inflammation and are not a replacement for a complete ophthalmic examination and specific treatment directed at the etiology of the problem. If used indiscriminately, they can result in local or systemic side effects or toxicities, many of which are worse than the initial problem for which they were selected. Just as topical corticosteroids are contraindicated with infectious keratitis, so are systemic corticosteroids contraindicated in patients with ocular inflammation resulting from a systemic infectious process. Anti-inflammatories must be used at the appropriate dosage and frequency. Use of corticosteroids that have low intraocular penetration for intraocular disease or corticosteroids with low potency is a waste of time and money. The most expensive medication is one that does not work. Avoid combination therapies when only a single medication is required. These do not save time or money and have the potential to result in the development of drug-related diseases. Diseases for which anti-inflammatory therapy has little or no indication include corneal scars, corneal edema, corneal pigmentation, corneal dystrophy, cataracts without inflammation, glaucoma, and retinal atrophy and degeneration. Last, remember that all commercially available ophthalmic medications are specifically formulated for use in the eye. Their pH, concentration, osmolality, and melting temperature all are designed to facilitate penetration. The use of dermal and otic preparations to treat ophthalmic problems is contraindicated.     

Corneal fungal disease in small animals

Corneal fungal diseases, including fungal keratitis and stromal abscess, are uncommon in small animals. Ocular infection secondary to systemic mycosis is reported far more frequently. Suspicion of a fungal corneal ulcer should be raised based on a history of underlying trauma, especially with plant material, geographic location, chronic use of topical antibiotics or corticosteroids, or an extremely prolonged course of disease despite appropriate treatment. Clinical signs observed with fungal keratitis may include blepharospasm, epiphora, miosis, corneal opacity, and vascularization. Unfortunately, none of these signs is specific to fungal infection. If fungal keratitis is suspected or confirmed, then aggressive medical therapy should be instituted. Medications used include topical antifungals, parasympatholytics, anticollagenases, and antibacterials as well as systemic anti-inflammatory drugs. Because there are very few fungicidal medications, the course of medical treatment for fungal corneal disease requires a prolonged duration with frequent re-examination and assessment. Surgical treatment is sometimes required to save the eye and vision. Surgeries to be considered include debridement, conjunctival graft placement, and corneal transplantation.     

Feline uveitis: diagnosis and treatment

Uveitis is the inflammation of any or all parts of the vascular tunic of the eye; the vascular tunic includes the iris, the ciliary body, and choroid. A good knowledge base, up-to-date reference materials, and good instruments will improve the diagnosis of uveitis. Feline uveitis can be caused by numerous infectious agents in addition to neoplasia and less likely trauma. The infectious causes most commonly associated with feline uveitis include feline leukemia virus, feline immunodeficiency virus, feline infectious peritonitis, systemic fungal infections, toxoplasmosis, and bartonellosis. Neoplastic causes of uveitis can be primary or secondary. Iris melanoma is the most common primary uveal neoplasia and trauma-associated sarcoma is the second most common primary uveal neoplasia. Treatment for the clinical signs of anterior uveitis include topical steroidal or non-steroidal anti-inflammatory agents, parasympatholytic agents for ciliary spasm, to keep the pupil dilated, and to prevent posterior synechia. Posterior uveitis should be treated with systemic medications that will address the underlying cause. Enucleation of blind, painful eyes not responsive to medications is a means to alleviate the animal's discomfort and to further diagnose the underlying cause.     

Nonsteroidal anti-inflammatory drugs in veterinary ophthalmology.

Uveitis is a common sequela to many ocular diseases. Primary treatment goals for uveitis should be to halt inflammation, prevent or control complications caused by inflammation, relieve pain, and preserve vision.Systemic and topical NSAIDs are essential components of the pharmaceutic armamentarium currently employed in the management of ocular inflammation by general practitioners and veterinary ophthalmologists worldwide. NSAIDs effectively prevent intraoperative miosis; control postoperative pain and inflammation after intraocular procedures, thus optimizing surgical outcome; control symptoms of allergic conjunctivitis;alleviate pain from various causes of uveitis; and circumvent some of the unwanted side effects that occur with corticosteroid treatment. Systemic NSAID therapy is necessary to treat posterior uveitis, because therapeutic concentrations cannot be attained in the retina and choroid with topical administration alone, and is warranted when diseases, such as diabetes mellitus or systemic infection, preclude the use of systemic corticosteroids.Risk factors have been identified with systemic and topical administration of NSAIDs. In general, ophthalmic NSAIDs may be used safely with other ophthalmic pharmaceutics; however, concurrent use of drugs known to affect the corneal epithelium adversely, such as gentamicin, may lead to increased corneal penetration of the NSAID. The concurrent use of NSAIDs with topical corticosteroids in the face of significant preexisting corneal inflammation has been identified as a risk factor in precipitating corneal erosions and melts in people and should be undertaken with caution[8]. Clinicians should remain vigilant in their screening of ophthalmic and systemic complications secondary to drug therapy and educate owners accordingly. If a sudden increase in patient ocular pain (as manifested by an increase in blepharospasm, photophobia, ocular discharge, or rubbing)is noted, owners should be instructed to contact their veterinarian promptly.     

Ophthalmic emergencies.

Ophthalmic emergencies are common presenting complaints in an emergency room. Most ophthalmic emergencies can be treated and stabilized until an ophthalmologist can be consulted. Most ocular emergencies involve loss of vision, compromised globe integrity, or severe ocular pain. Delay in treating true emergencies may result ina blind eye or loss of an eye. This article discusses the clinical signs,diagnosis, and treatment as well as the prognosis of some of the more common ophthalmic emergencies.     

Effect of topical 1% atropine sulfate on intraocular pressure in normal horses

OBJECTIVE: To determine the effect of topical 1% ophthalmic atropine sulfate on intraocular pressure (IOP) in ocular normotensive horses. Animals Studied Eleven clinically healthy horses. Procedures IOP was measured bilaterally twice daily, at 8 AM and 4 PM, for 5 days. No medication was applied for the first 2 days of the study. Thereafter, one eye of each horse was treated with 0.1 mL of topical 1% atropine sulfate ointment twice daily (7 AM and 7 PM) for 3 days. The contralateral eye served as a control. In eight of the horses, an additional IOP reading was taken 3 days following cessation of the atropine treatment. RESULTS: There was no significant difference in the IOP of control vs. treatment eyes in the pretreatment period, days 1 and 2 (P = 0.97 and 0.55, respectively). During the treatment period, treated eyes of 10 of the horses had significantly lower IOP than control eyes (P = 0.03). The mean IOP reduction in treated eyes, relative to untreated eyes, was 11.2%. One horse had a significant rise in IOP in the treated eye compared to the remaining study animals. The IOP of control eyes did not vary significantly over the observation period (P = 0.27). There was no significant variation in IOP between the 8 AM and 4 PM measurement (P = 0.9). CONCLUSIONS: Topical 1% atropine sulfate causes a small, but significant decline in IOP in most ocular normotensive horses. Because topical atropine may elevate IOP in some horses, it should be used with caution in the treatment of glaucoma in this species.     

Strategies for management of recurrent pyoderma in dogs

Staphylococcal skin infection (pyoderma) is a common clinical problem in dogs. The infection can be either superficial or deep. Most cases of staphylococcal pyoderma occur secondary to a definable underlying cause. Treatment consists of finding the underlying cause and correcting it, if possible, and treating the pyoderma with antibiotics. Antibacterial shampoos may be used as adjunct treatment, but corticosteroid drugs should not be used. When canine pyoderma recurs in the absence of an identifiable underlying cause, several treatment strategies can be effective in eliminating recurrence or limiting its severity. Frequent antibacterial shampoos are an easy and sometimes effective method. Immunomodulatory drugs are variably effective. Some commercially available bacterins are clearly helpful in treating recurrent pyoderma. As a last resort, the clinician may opt to keep the patient on long-term antibiotic therapy. Such therapy may promote development and dissemination of resistant strains of Staphylococcus and should be used only if absolutely necessary.     

Effect of topical atropine on intraocular pressure and pupil diameter in the normal horse eye

The objective was to determine whether topically administered 1% atropine would alter intraocular pressure. The animals studied were four healthy adult horses. Intraocular pressure and pupil diameter were measured prior to and during a 2-day period of treatment with 1% atropine sulfate. No significant changes in intraocular pressure occurred as a result of the treatment with atropine. Pupil diameter increased significantly after atropine was applied. Available information on the outflow of aqueous humor from the horse eye suggests that atropine might reduce intraocular pressure in the horse by increasing uveoscleral outflow. This could prove beneficial in the treatment of equine glaucoma. We could not confirm a significant pressure-lowering effect of atropine. It is possible, however, that a longer treatment period may be required or that atropine may have a more profound effect on glaucomatous globes.     

Phacoemulsification and intraocular lens implantation in a Canada lynx with phacoclastic uveitis

A 4-year-old male Canada lynx (Lynx canadensis) was referred to the ophthalmology service at the University of Saskatchewan with a 7-month history of cataract and chronic phacoclastic uveitis secondary to penetrating trauma from a lynx claw. Ophthalmic examination of the right eye revealed a corneal scar, marked aqueous flare, extensive fibrovascular membranes extending from the iris to the lens, anterior and posterior synechiae, immature cataract, and anterior vitritis; the fundus was not visible. Phacoemulsification surgery and intraocular lens implantation using a custom lens of D+46 and 14 mm (An-vision, West Jordan, Utah, USA) was performed. Post-operative medications included sub-conjunctival injections of atropine, cefazolin, and triamcinolone, and oral doxycycline and prednisolone. At the 5-month follow-up, the uveitis was controlled, and a normal fundus was visualized; at 21 mo, the eye remained comfortable and visual. This is the first case report to describe phacoemulsification in a wild felid as a treatment for a traumatic cataract and severe phacoclastic uveitis.Key clinical message:Despite chronic phacoclastic uveitis, phacoemulsification surgery can provide a positive outcome for mature wild felids with traumatic lens rupture, even when topical treatment cannot be administered.     

Feline ocular emergencies

Feline ocular emergencies include any ophthalmic condition that has rapidly developed or is the result of trauma to the eye or periocular structures. Common feline emergencies include proptosis, lid lacerations, corneal ulcers, and foreign bodies. Complete ophthalmic examination including procurement of the minimal ophthalmic database (Schirmer tear test, fluorescein stain, and intraocular pressure measurement) should be obtained whenever possible to ensure that the complete and correct diagnosis is made. Concern for the patient's vision and ocular comfort should guide the practioner's diagnostic and therapeutic plan. This article reviews some of the more common feline ocular emergencies, including conditions affecting the orbit and globe, adnexa, conjunctiva, and cornea. Feline uveitis, glaucoma, and lenticular diseases are covered more thoroughly elsewhere in this issue.     

USE OF THE RHOMBOID FLAP GRAFT IN RECONSTRUCTIVE LID SURGERY

Extensive destructive and erosive lesions of the eye lids may be the result of neoplasia, severe trauma, or inflammation. Surgical repair requires blepharoplastic procedures to restore the lid integrity and maintain a functionally sighted globe. The use of the rhomboid advancement flap is illustrated for the repair of lid defects involving destruction of 50% or more of the lid tissue.     

Granulomatous uveitis in an owl

Granulomatous lens-induced uveitis was diagnosed in a mature male barred owl. Initial ocular examination revealed a large white mass in the left eye. Differential diagnoses for the mass included intraocular granuloma, neoplasia, foreign body, bacterial or fungal enophthalmitis, and fibrotic hematoma. After enucleation of the left globe, histologic examination revealed the mass to be a granulomatous inflammatory reaction to a posteriorly luxated, traumatized lens. Lens-induced uveitis should be considered whenever a bird has suffered lenticular trauma.     

Nonulcerative keratouveitis as a manifestation of Leptospiral infection in a horse

A 2-year-old Thoroughbred filly presented with ocular pain and epiphora of the left eye. The pupil was miotic and the cornea edematous near the ventro-temporal limbus, but did not retain any fluorescein. The topical antibiotics and atropine and diclofenac, and systemic flunixin meglumine and antibiotic therapy did not resolve the condition. A pink and fleshy infiltrate developed near the limbus indicating nonulcerative keratouveitis. The anterior uveitis deteriorated as manifested by the presence of dyscoria, hypopyon, and organized fibrin in the anterior chamber. Ocular signs were improved by topical and subconjunctival corticosteroids, but repeatedly deteriorated as the frequency of medication was reduced. The horse was seropositive to three serovars of Leptospira interrogans. The animal was diagnosed as blind on day 91 by the absence of pupillary light and menace reflexes, and donated for histopathologic diagnosis. The corneal opacity was histologically fibrotic and infiltrated predominantly by lymphocytes with Descemet's membrane partially disrupted by macrophages. The choroid was infiltrated by lymphocytes, eosinophils and basophils, and was positive to IgG and C3. There were filamentous or spiral structures positive to Warthin-Starry stain in the renal cortex. There was also polymerase chain reaction amplification of the leptospiral gene in the kidney. From these findings nonulcerative keratouveitis was believed to be caused by systemic infection with Leptospira.     

Methicillin‐resistant Staphylococcus aureus keratitis in a dog

The purpose of this study is to report a case of methicillin‐resistant Staphylococcus aureus (MRSA) keratitis in a dog. A 7‐year‐old intact male American cocker spaniel that had undergone removal of a nictitating gland was referred for severe ulcerative keratitis. Slit‐lamp examination showed swelling of the eyelid, mucopurulent discharge, conjunctival injection and chemosis, diffuse corneal edema and opacity, and a deep ulcer in central cornea. Gram staining of discharge from the eye demonstrated Gram‐positive cocci. Despite topical ofloxacin, oxytetracycline and polymyxin B ophthalmic solution and intravenous cefazolin, there was no improvement. Cultures revealed MRSA that was sensitive only to chloramphenicol, vancomycin, lincomycin, and clindamycin. The antibiotic regimen was changed to topical and systemic chloramphenicol. After 9 days of treatment, although inflammation started to be resolved, the dog developed nonregenerative anemia. The antimicrobial regimen was changed again to topical and systemic vancomycin. Inflammation continued to improve over the next week. MRSA should be considered a potential organism in infectious keratitis, especially when general antibiotics are not effective. Although topical and systemic chloramphenicol and/or vancomycin are effective for treating MRSA keratitis, vancomycin should only be used when culture and susceptibility results indicate it is appropriate and no other options are available. To our knowledge, this is the first detailed case report of MRSA keratitis in a dog.     

Bilateral proliferative keratitis in a Domestic Long-haired cat

A 9-year-old, female spayed, Domestic Long-haired cat was presented with bilateral, progressive, pink-white corneal opacities. The referring veterinarian had diagnosed feline herpesvirus-1 (FHV-1) keratitis though diagnostics for FHV-1 had not been performed and treatment with antibiotics and antivirals did not improve the condition. Histopathology showed neutrophils, plasma cells and lymphocytes, but no eosinophils or mast cells. Routine diagnostics did not find an underlying cause, but Southern blot analysis for FHV-1 was positive. The cat responded to topical corticosteroids and cyclosporine when used consistently.     

Medical management of a corneal stromal abscess in a female Asian elephant (Elephas maximus).

A 47-yr-old female Asian elephant (Elephas maximus) developed a corneal stromal abscess in her right eye. The elephant was trained to open her eye for topical ophthalmic therapy, and was treated six times daily with antibiotics and an antifungal solution for almost 2 mo. Nonsteroidal anti-inflammatory drugs were used to control pain, and atropine was applied topically to dilate the pupil and provide additional comfort. Vascularization of the abscess began shortly after initiating therapy, and complete resolution was obtained by 7 wk.     

Intraocular findings in three dogs and one cat with chronic glaucoma

Intraocular neoplasia may cause secondary glaucoma. If an intraocular prosthesis is placed in an eye with glaucoma secondary to intraocular neoplasia, the neoplasm frequently regrows around the prosthetic ball, resulting in recurrence of buphthalmos and signs of pain. Histologic examination of eviscerated intraocular contents of 4 animals resulted in diagnosis of intraocular neoplasia in 2 glaucomatous eyes and ruled out neoplasia as the cause of glaucoma in 2 eyes.     

Diagnosis and medical treatment of otitis externa in dogs and cats

A review of otitis externa in dogs and cats is presented. Aetiology, includes primary causes: ectoparasitoses, allergic diseases, endocrine disorders, pyodermas, trauma and irritation, contact dermatitis, auto-immune skin diseases, drug eruption, keratoseborrhoeic skin disease, tumours and pseudoneoplastic lesions, as well as secondary causes: bacteria and yeasts. Clinical aspects are variable but a practical classification distinguishes two forms: erythematoceruminous otitis externa and suppurative otitis externa. Diagnosis is made in five steps which are clinical examination, direct examination of cerumen (erythematoceruminous otitis externa) or bacterial culture and sensitivity testing (suppurative otitis externa), direct impression smears, cleaning and otoscopy, and diagnosis of underlying skin disease. Medical therapy includes cleaning of the external ear canal and local therapy (acaricides, antifungal agents, antibiotics, corticosteroids, other topical agents, the appropriate selection of an optic preparation being essential). Treatment of underlying skin disease is always necessary. Otitis externa is in fact a dermatological disease complex (like pododermatitis). Although local secondary infections (bacterial and fungal) must be managed in every case, there are grounds for including otitis externa in a larger frame.     

Superficial stromal keratitis in the dog

Superficial stromal keratitis or pannus is a syndrome of corneal, conjunctival and third eyelid inflammation. Superficial stromal keratitis mainly presents as a subepithelial corneal infiltration of vascular connective tissue, and usually arises from the lateral (temporal) limbal area. In some dogs perilimbal hyperaemia and third eyelid blepharitis can be present without corneal involvement. The most commonly affected breed of dog is the German Shepherd. Most cases of superficial stromal keratitis can be controlled with topical corticosteroids, and only rarely is cryosurgery or superficial keratectomy required to remove excessive pigment and or granulation tissue. The precise aetiology of SSK is unknown, but is likely to be multifactorial, with sunlight being a significant factor. Corneal lipidosis and keratoconjunctivitis sicca can occur secondary to superficial stromal keratitis.     

Feline glaucomas

Cats are usually presented at a very late stage in the course of glaucoma when the eye is already blind. Secondary glaucoma because of another underlying ocular lesion is the most common form of glaucoma in the cat and is frequently associated with chronic anterior uveitis or intraocular neoplasia. Chronic stages of glaucoma in the cat are characterized by buphthalmus, anterior lens luxation, and exposure keratitis secondary to the enlarged globe. Ophthalmoscopic signs of glaucomatous retinal degeneration are only noticed in very advanced stages. Treatment of glaucoma in cats is usually aimed to keep the eye comfortable and within a normal intraocular pressure range. However, many antiglaucoma medications that are successfully used in humans and dogs are not very well tolerated by cats and, therefore, the selection of recommended drugs is limited in this species.