Equine phacoclastic uveitis: the clinical manifestations, light microscopic findings, and therapy of 7 cases

This retrospective clinical study describes the clinical manifestations, light microscopic findings, and diagnosis and treatment of acute and chronic lens rupture in the horse. Rupture of the lens capsule in the horse usually results in a chronic, blinding inflammation (phacoclastic uveitis) unless prompt surgical and medical therapies are implemented. The clinical manifestations of acute lens capsule rupture included: cataract; intralenticular displacement of iridal pigment; lens cortical fragments attached to the perforated lens capsule, iris, and corneal endothelium; miosis; aqueous flare; and usually a corneal or scleral perforation with ulceration or focal full thickness corneal edema and scarring. The clinical signs of chronic phacoclastic uveitis include blindness, phthisis bulbi, and generalized corneal opacification related to scarring, vascularization, pigmentation, and edema. In one horse, acute phacoclastic uveitis was successfully treated with phacoemulsification to remove the ruptured lens and medical therapy to control the accompanying inflammation. The affected eyes of the horses with chronic phacoclastic uveitis were enucleated because of persistent clinical signs of nonulcerative keratitis and uveitis, despite long-term medical management. The clinical manifestations and lack of improvement with medical therapy are similar in the horse, dog, cat, and rabbit. However, the histologic findings in equine phacoclastic uveitis differ significantly from those in the dog, and rabbit.     

Lens-induced uveitis

Lens-induced uveitis has been described in humans and many animal species. Traumatic rupture of the lens capsule may result in vision-threatening intraocular inflammation that is poorly responsive to medical management. Phthisis bulbi, persistent uveitis or glaucoma often occurs in these eyes. Surgical removal of the lens material is generally indicated shortly after the injury in an effort to preserve vision. Leaking of lens proteins through an intact lens capsule may result in a lympho-plasmacytic anterior uveitis. This is most commonly associated with the presence of a hypermature cataract. The presence of lens-induced uveitis prior to cataract surgery significantly reduces the success rate of cataract surgery. Small amounts of circulating lens proteins maintain a normal T-cell tolerance for lens proteins. Lens-induced uveitis develops when a breakdown occurs of this normal T-cell tolerance. Immune complexes play an important role in the tissue damage associated with the ensuing inflammation. Other factors associated with the tissue damage include hydroxyl radicals, nitroxide radicals, and hydrogen peroxide and arachidonic acid metabolites. Treatment consists of topical and systemic anti-inflammatory medications, mydriatic agents, and glaucoma medications when indicated. Experimental pharmacological agents include dual cyclooxygenase/lipoxygenase inhibitors, interleukin-1 blockers, antioxidants and hydroxyl radical scavengers.     

Septic implantation syndrome in dogs and cats: a distinct pattern of endophthalmitis with lenticular abscess

Objective To summarize the clinical and pathologic findings in a group of dogs and cats with progressive clinical ocular disease, which were diagnosed with suppurative endophthalmitis and lens capsule rupture. Animals studied Twenty cats and forty‐six dogs that underwent unilateral enucleation or evisceration for intractable uveitis and/or glaucoma. Procedure Biopsy submission requests and microscopic case material were evaluated for clinical and histological features, including history of ocular trauma, duration of ocular disease, pattern of inflammation, and the presence of intralenticular microorganisms. Results The median duration for cats and dogs was 6 and 5 weeks, respectively. A history of trauma was reported for four (20%) cats and 18 (39%) dogs. All confirmed cases of trauma—three in cats and 14 in dogs—were caused by a cat scratch. Microscopically, all cases had suppurative endophthalmitis centered on the lens, lens capsule rupture, cataract, and lenticular abscess. Infectious organisms were identified by Gram stain within the lens of 14 (70%) cats and 30 (65%) dogs. Gram‐positive cocci were seen most commonly. Male cats were overrepresented as compared to females. There were no apparent gender, age or breed predilections in dogs. Conclusions A unique pattern of slowly progressive or delayed‐onset endophthalmitis with lens capsule rupture, lenticular abscess, and frequently intralenticular microorganisms is associated with traumatic penetration of the globe and lens capsule. The term Septic Implantation Syndrome (SIS) is favored in lieu of ‘phacoclastic uveitis’ to avoid confusion with phacolytic uveitis and to clearly implicate the role of intralenticular microorganisms in the pathogenesis.     

Clinical symptoms and diagnosis of encephalitozoonosis in pet rabbits

Infections with Encephalitozoon cuniculi in rabbits are observed at increasing frequency and are known as opportunistic infections in immunocompromised humans. 191 pet rabbits with suspected encephalitozoonosis, presented at the Animal Hospital of the Veterinary University of Vienna (Austria), were included in this study. Rabbits were serologically examined for antibodies against E. cuniculi (144 positive out of 184 rabbits with suspected encephalitozoonosis compared to 14 positive out of 40 clinically healthy rabbits tested as part of a standard health check) and Toxoplasma gondii (8 positive out of 157). Of the 144 seropositive rabbits with clinical signs, 75% showed neurological symptoms, 14.6% demonstrated phacoclastic uveitis and 3.5% suffered from renal failure. 6.9% of the animals had combined symptoms. Vestibular disease dominated within the rabbits that showed neurological symptoms. Polymerase chain reaction (PCR) could not detect parasite DNA in urine or cerebrospinal fluid (CSF), but did so in 4 out of 5 samples of liquefied lens material in cases with phacoclastic uveitis due to lens capsule rupture. Additionally further diagnostic procedures, such as inspection of the external ear canal (N=69), radiography of the tympanic bullae (N=65) were performed to rule out differential diagnosis. 54.2% of the patients exhibiting neurological symptoms recovered within a few days, while 87.5% of the rabbits suffering from renal failure died or had to be euthanized.     

Detection of Encephalitozoon cuniculi in the feline cataractous lens

Purpose Identification of Encephalitozoon cuniculi (E. cuniculi) as a possible causative agent for cataracts and uveitis in cats. Methods Within a 12‐month study period, cats that were presented with focal anterior cortical or mature cataract and secondary uveitis underwent a complete ophthalmic examination, complete blood count, serum biochemistry, serologic tests for E. cuniculi and tests for feline immunodeficiency virus (FIV), feline infectious peritonitis (FIP), feline leukemia virus (FeLV) and Toxoplasma gondii (T. gondii). PCR for DNA detection of E. cuniculi and T. gondii as well as cytologic examination of aqueous humor after paracentesis and phacoemulsified lens material were also performed. In addition histopathologic examination of the resected anterior lens capsule and attached lens epithelial cells was performed. Serologic testing for antibodies against E. cuniculi was also performed in 100 ophthalmologically healthy cats. Results Eleven (19 eyes) European shorthair cats with a median age of 3.5 years were included. Nine of 11 cats had bilateral cataracts, with 12/19 eyes having focal anterior cortical cataracts and 7/19 eyes having mature cataracts. In 14/19 eyes anterior uveitis was present. All cats had a positive antibody titer (1:80–1:10 000) for E. cuniculi. Encephalitozoon cuniculi DNA was detected by PCR and sequencing in 18/19 lenses and in 10/19 aqueous samples. Five tentative positive results were detected by cytologic examination. Spores were detected in 15/19 samples of lens material with histopathologic staining. Only 2/100 ophthalmologically healthy cats showed a positive antibody titer for E. cuniculi. Conclusion Encephalitozoon cuniculi is a cause of focal anterior cortical cataract and anterior uveitis in cats.     

Surgical management and histologic and immunohistochemical features of a cataract and retrolental plaque secondary to persistent hyperplastic tunica vasculosa lentis/persistent hyperplastic primary vitreous (PHTVL/PHPV) in a Bloodhound puppy

The objective of this study was to describe the clinical, histologic and immunohistochemical features, the surgical treatment, and outcome of a cataract secondary to persistent hyperplastic tunica vasculosa lentis/persistent hyperplastic primary vitreous (PHTVL/PHPV) in a dog. A 4-month-old male Bloodhound dog presented for evaluation of a cataract. A complete ophthalmic examination and ocular ultrasonography were performed. A resorbing cataract with intralenticular hemorrhage, lens induced uveitis, and PHTVL/PHPV were diagnosed. Extracapsular cataract extraction using phacoemulsification was performed. A primary posterior capsulectomy was performed to remove a retrolental plaque with the posterior capsule; the excised plaque was submitted for histopathology and immunohistochemical staining. A 41-Diopter intraocular lens (IOL) was implanted. Functional vision was maintained postoperatively during the 21-month follow-up period. Histologically, the posterior capsule was coiled and exhibited duplication. The retrolental plaque was comprised of dense fibrous connective tissue, blood vessels, free red blood cells, hemosiderin-laden macrophages, a pocket of neural tissue and numerous perivascular mast cells. With immunohistochemical staining, the neural elements were determined to be glial cells compatible with astrocytes. Cataract secondary to PHTVL/PHPV can be successfully treated using phacoemulsification and planned posterior capsulectomy. Posterior lens capsule duplication, mast cells and astrocytic glial cells may be normal components of the fibrovascular retrolental plaque associated with PHTVL/PHPV.     

A pathologic study on ocular disorders in calves in southern Kyushu, Japan

Of 822 calves, ranging in age between one day and six months necropsied between 1996 and 1998 at Miyazaki University, histological examination showed that 25 (3.0%) had ocular lesions. These ocular lesions consisted of suppurative inflammation (13 cases), cataract (seven cases), and retinal atrophy (five cases). Inflammatory changes were classified as suppurative keratitis (one case), keratitis and uveitis (ten cases), and uveitis and retinitis (two cases). Cataract was subclassified into three categories; cortical (three cases), nuclear (one case), and mature (three cases). These lesions were characterized by degenerative changes in the lens fibers and the appearance of eosinophilic globules known as Morganian globules. In the most severely affected case, there was capsular rupture of the lens, resulting in severe infiltration by eosinophils and histiocytes of the whole anterior chamber. Almost all the calves with retinal atrophy had been suffering from severe hydranencephaly and three had significantly raised levels of neutralization antibodies for the Akabane and/or Aino viruses. This study indicates that congenital arbovirus infections may predispose calves to ocular diseases, especially retinal atrophy.     

Lens-induced uveitis in dogs: 151 cases (1985-1990).

During a 5-year period, phacolytic uveitis was diagnosed in 202 eyes of 151 dogs admitted to the veterinary teaching hospital. The diagnosis of phacolytic uveitis was based on the finding of a cataractous lens and anterior uveitis, unassociated with other identifiable causes of uveal inflammation. The most commonly affected breeds were the Toy and Miniature Poodle (35%) and the American Cocker Spaniel (19%). The mean age was 7.0 years for all breeds, 5.1 years for the Cocker Spaniel, and 9.0 years for the Poodle breeds. Evidence of cataract resorption was visible in 72% of the eyes. Fifty-one dogs were affected bilaterally and 100 dogs unilaterally. The mean interval between recognition of the cataract and the onset of lens-induced uveitis (LIU) was 17 months; mean times of 25 and 11 months were seen in the Poodle breeds and American Cocker Spaniel, respectively. The mean age of dogs requiring greater than 1 revisit before the inflammation had subsided was 5.5 years. Complications, referable to the uveitis, were seen in 14% of eyes, the most important of which were glaucoma (16 eyes) and phthisis bulbi (9 eyes). Lens extraction surgery was done on 50 LIU-affected eyes, and on 35 normal eyes in LIU-affected animals. The 2- and 6-month success rates for LIU-affected eyes were 78 and 39%, respectively, and for normal eyes in LIU-affected animals were 85 and 71%, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)     

Intraocular sarcoma associated with lens capsule rupture and persistent hyperplastic primary vitreous in a dog

This case report describes the clinical findings and ocular pathology in an adult Golden Retriever diagnosed with an intraocular sarcoma. Nineteen s prior to diagnosis with a lens capsule rupture and intraocular sarcoma, the dog was diagnosed with persistent hyperplastic primary vitreous and uveitis based on clinical signs and the ultrasonographic appearance of the eye. Two years after enucleation, there was no evidence of metastatic spread of the sarcoma. The immunohistochemical characteristics of the tumor as well as the limitations and supportive evidence used in attempting to identify the histogenesis of the tumor are outlined.     

Evaluation of risk factors for development of secondary glaucoma in dogs: 156 cases (1999-2004)

OBJECTIVE: To determine the immediately antecedent cause of secondary glaucoma and the prevalence of secondary glaucoma with anterior uveitis or lens dislocation in dogs. DESIGN: Retrospective case series. ANIMALS: 156 dogs with secondary glaucoma. PROCEDURES: Cause of glaucoma was determined from records. Breed, age, sex, and neuter status of all dogs with secondary glaucoma were compared with the general hospital population. The prevalence of secondary glaucoma in dogs with a primary diagnosis of lens dislocation or anterior uveitis during the same period was determined. RESULTS: Secondary glaucoma was diagnosed in 156 of 2,257 (6.9%) dogs examined because of ophthalmic disease and was bilateral in 33 (21.2%) of those dogs. In 31 (94%) bilaterally affected dogs, the antecedent cause was the same in both eyes. Common causes of secondary glaucoma were non-surgical anterior uveitis (44.9%), anterior uveitis associated with prior phacoemulsification (15.8%), and lens dislocation (15.2%). Parson Russell Terriers, Poodles, Boston Terriers, Cocker Spaniels, Rhodesian Ridgebacks, and Australian Cattle Dogs had diagnoses of secondary glaucoma more often than expected, compared with the reference population. Age, sex, neuter status, and laterality were not associated with secondary glaucoma. The prevalence of secondary glaucoma in dogs with lens dislocation or uveitis was 15% or 17%, respectively. CONCLUSIONS AND CLINICAL RELEVANCE: Glaucoma develops secondary to many intraocular diseases, particularly uveitis and lens dislocation. Diagnosis of these diseases should prompt frequent monitoring of intraocular pressure, regardless of signalment.     

Effects of lipoxygenase inhibitors in a model of lens-induced uveitis in dogs

Uveitis was induced in dogs by intracameral injection of canine lens protein. The lipoxygenase inhibitors phenidone and norhydroguaiaretic acid, and dimethyl sulfoxide decreased fibrin production at 0.5 and 1 hour after induction of uveitis. Phenidone and norhydroguaiaretic acid also inhibited the initial increase in intraocular pressure early in the course of inflammation. Leukotriene B4 in the aqueous was measured by use of radioimmunoassay at 1 hour after inflammation. In control dogs, 230 to 1,700 pg of leukotriene B4/ml was measured; in dogs treated with phenidone, leukotriene B4 was not measured.     

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.     

Immunohistochemical identification of Encephalitozoon cuniculi in phacoclastic uveitis in four rabbits

PURPOSE: Encephalitozoon cuniculi is a microsporidium with a wide range of mammalian hosts. In rabbits it can be responsible for cataract and lens-induced uveitis (LIU). The aim of this study was to provide specific immunohistochemical demonstration and localization of E. cuniculi within the eye, in rabbits with LIU. MATERIAL AND METHODS: Four rabbits were presented with a white mass in the eye and iris discoloration. Complete ophthalmic examinations were performed and a presumptive diagnosis of LIU was made in all cases. Initial therapy with a topical steroid, atropine and systemic enrofloxacin was instituted while serologic (IFA or ICA tests) and cytologic lab results were pending. The final outcome in all cases was enucleation. Routine histology and immunohistochemistry (ABC method) with an antiserum anti-Encephalitozoon cuniculi were performed. RESULTS: Indirect immunofluorescence performed on one rabbit serum expressed a titer of 1 : 32; carbon immunoassay on the serum of the other three rabbits expressed a titer of 1 : 5120 in one, and a titer of 1 : 2560 in the other two cases. Histologically, an intraocular, locally extensive pyogranulomatous infiltration that partially filled the posterior chamber, encasing a wide anterior lens capsule break, was detected in all cases. Immunohistochemically, spores reacting with anti-Encephalitozoon cuniculi antiserum were present in all specimens, occasionally within macrophages and lens epithelial cells. CONCLUSION: Detection of E. cuniculi in rabbits with phacoclastic uveitis has been investigated in the past with different methods. Based on our results, we suggest that immunohistochemistry should be regarded as a useful tool both for specific demonstration of E. cuniculi and for its localization within tissues.     

Detection of feline herpesvirus-specific antibodies and DNA in aqueous humor from cats with or without uveitis.

OBJECTIVE: To determine whether uveitis in cats was associated with intraocular production of feline herpesvirus type 1 (FHV-1)-specific antibodies or with detection of FHV-1 DNA in aqueous humor (AH). ANIMALS: 44 cats with idiopathic uveitis, 29 cats with uveitis attributed to Toxoplasma gondii infection, 13 FHV-1 seropositive cats without uveitis, and 9 FHV-1 seronegative cats without uveitis. PROCEDURE: ELISA were used to detect FHV-1-specific antibodies and total IgG antibodies in serum and AH, and the Goldmann-Witmer coefficient (C-value) for intraocular antibody production was calculated. A polymerase chain reaction assay was used to detect FHV-1 DNA in AH. RESULTS: FHV-1 seroprevalence among cats with uveitis was not significantly different from seroprevalence among cats without uveitis. Intraocular FHV-1 antibodies were never detected in cats without uveitis. Significantly more cats with idiopathic uveitis (22/44) or with toxoplasmic uveitis (11/29) had evidence of intraocular antibody production (C-value > 1) than did cats without uveitis. Only cats with idiopathic uveitis had FHV-1 C-values > 8. Among cats with evidence of intraocular antibody production, cats with idiopathic uveitis had a significantly higher median FHV-1 C-value (9.61) than did cats with toxoplasmic uveitis (2.56). Overall, FHV-1 DNA was detected in AH from 12 cats, 11 of which had uveitis. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that FHV-1 can infect intraocular tissues of cats and that intraocular FHV-1 infection may be associated with uveal inflammation in some cats.     

Comparison of flunixin meglumine and flurbiprofen for control of ocular irritative response in dogs

Dogs were treated with the cyclo-oxygenase inhibitors flunixin meglumine IV or flurbiprofen topically. Acute inflammation was induced in the eyes by disruption of the anterior lens capsule, using a neodymium:yttrium aluminum garnet laser. Pupil diameter and intraocular pressure were measured before and after inducing ocular inflammation. Both drugs maintained mydriasis and increased intraocular pressure in the inflamed eyes, compared with untreated controls.     

The incidence of posterior capsule disruption during phacoemulsification and associated postoperative complication rates in dogs: 244 eyes (1995-2002)

OBJECTIVE: The objective of this retrospective study was to report the incidence of posterior capsule disruption during routine phacoemulsification and to document the postoperative outcomes and complications in eyes with posterior capsule disruption compared with eyes with intact posterior capsules. PROCEDURES: Records of 143 dogs (244 eyes) were reviewed. Data collected included whether the posterior capsule was disrupted, whether the disruption was planned or accidental, whether an intraocular lens was implanted, and visual outcome. Records were reviewed for postoperative complications. Intraocular lens implantation rates, complication rates, and visual outcomes were compared between intact and disrupted posterior capsule groups using Chi-square analyses. RESULTS: The posterior capsule was disrupted in 33/244 eyes (14%). Planned capsulotomies accounted for 36% of the disruptions. Intraocular lenses were implanted in 76% of eyes without a disruption of the posterior capsule and in 31% of eyes with a posterior capsule disruption. Intraocular lenses were more likely to be implanted in eyes with a planned disruption of the posterior capsule (7/12; 58%) than in eyes with an accidental disruption (3/20; 15%). There were no significant differences in postoperative complications or visual outcome between eyes with posterior capsule disruption and those without. CONCLUSIONS: The most significant complication of posterior capsule disruption during phacoemulsification is the inability to implant an intraocular lens. Intraocular lenses are more likely to be placed in eyes with intentional disruptions of the posterior capsule than those with accidental ruptures.     

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.     

Rabbits' eye globe sonographic biometry

Objective To measure intraocular structures in New Zealand White breed rabbits (Oryctolagus cuniculus Linnaeus, 1758) using A‐mode and B‐mode ultrasound with a 20 MHz transducer. Procedures In this study, the eyes of 15 rabbits were evaluated for determination of intraocular measurements using an ophthalmic ultrasound unit able to operate in both A and B‐modes. The distances from the cornea to the anterior capsule of the lens (D1), from the anterior capsule of the lens to the posterior capsule of the lens (D2), from the posterior capsule of the lens to the retina (D3) and the complete length of the eye, which corresponds to the distance from the cornea to the retina (D4) were taken. Results The mean values obtained were 2.70 mm (±0.22 mm) for D1, 7.32 mm (±0.40 mm) for D2, 7.10 mm (±0.45 mm) for D3 and 17.12 mm (±0.41 mm) for D4. Statistical analyses using the Student’s t‐test showed that there were no differences between the eyes. Conclusions The study was feasible without the need of pharmacological restraint and yielded normal mean values for ocular sonographic biometry in rabbits.     

Posterior lens luxation with associated glaucoma in a pony

Secondary lens luxation is an infrequent consequence of equine recurrent uveitis (ERU). This Case Report describes a pony with posterior lens luxation with associated glaucoma, thought to be secondary to ERU.     

Morphologic alterations in the anterior lens capsule of canine eyes with cataracts

OBJECTIVE: To examine the morphologic changes in the anterior lens capsule and lens epithelium of canine eyes with cataracts. SAMPLE POPULATION: Anterior lens capsules from the eyes of 25 dogs with cataracts and from an additional 10 canine globes with lenses subjectively assessed to be normal. PROCEDURE: Thickness of each anterior lens capsule was measured by use of a digital microscopic camera and imaging software. All 25 capsules from eyes with cataracts were submitted for light microscopy; 4 were also submitted for electron microscopy. RESULTS: Thickness of the anterior lens capsule increased with age for the normal lenses and the lenses with cataracts; the change with age was similar for both groups. Light microscopy revealed fibrous metaplasia of lens epithelial cells in 7 of 25 anterior lens capsules with focal thickenings of the posterior aspect of the capsule. Electron microscopy revealed deposition of collagen and basement membrane-like material by fibroblast-like cells. CONCLUSIONS: Results indicate that thickness of the anterior lens capsule in dogs increases with age and that this increase in thickness is not significantly different between normal lenses and lenses with cataracts. In addition, epithelial cells from lenses with cataracts may undergo metaplasia to form plaques composed of fibrous tissue and ectopic basement membrane produced by epithelial cells.