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.     

Ocular complications of persistent hyperplastic primary vitreous in three dogs

Persistent hyperplastic primary vitreous (PHPV) syndrome associated with either severe ocular complications or multiple ocular lesions was diagnosed in three young dogs, a Samoyed, a Spanish Pachon, and a mixed breed dog. Due to opacification of the anterior ocular structures, B-mode and color-flow Doppler ultrasonography were performed to aid diagnosis. The Samoyed presented with unilateral hyphema; the Spanish Pachon presented with unilateral secondary glaucoma associated with uveitis and hyphema OD and leucocoria OU; and the mixed breed presented with bilateral leucocoria. B-mode ultrasonography of the Samoyed revealed a subcapsular cataract and a hyperechoic tubular structure attached from the optic disk to the posterior lens capsule. In the Spanish Pachon B-mode ultrasonography of the right eye indicated microphakia, cataract formation, and a retrolental mass with a thin hyperechoic strand stretching from the optic disk to the posterior lens; and for the right eye cataract formation, PHPV, retinal detachment, and vitreous hemorrhage. In the mixed breed dog, B-mode ultrasonography of both eyes indicated microphthalmia, retrolental mass, and hyperechoic lenses. By color-flow Doppler imaging, blood flow was present in the retrolental mass of the right eye suggesting a persistent hyaloid artery.     

Effects of topical administration of an aldose reductase inhibitor on cataract formation in dogs fed a diet high in galactose

OBJECTIVE: To determine effects of a topical formulation of an aldose reductase inhibitor (ARI) on the development of sugar cataracts in dogs fed a diet high in galactose. Animals-Ten 6-month old Beagles. PROCEDURES: Dogs were fed a diet containing 30% galactose, and after 16 weeks, 6 dogs were treated topically with a proprietary ARI formulation and 4 dogs were treated with a placebo. Cataract formation was monitored by means of slit-lamp biomicroscopy and fundus photography. Dogs were euthanized after 10 weeks of treatment, and lenses were evaluated for degree of opacity, myo-inositol and galactitol concentrations, and concentration of the ARI. RESULTS: All dogs developed bilateral cortical opacities dense enough to result in a decrease in the tapetal reflex after being fed the galactose-containing diet for 16 weeks. Administration of the ARI arrested further development of cataract formation. In contrast, cataracts in the vehicle-treated dogs progressed over the 10-week period to the mature stage. Evaluation of the isolated lenses after 26 weeks of galactose feeding indicated that lenses from treated dogs were significantly less optically dense than lenses from control dogs. Lenticular myo-inositol concentration was significantly higher in the treated than in the control dogs. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that topical application of a proprietary ARI formulation may arrest or reverse the development of sugar cataracts in dogs fed a diet high in galactose. This suggests that this ARI formulation may be beneficial in maintaining or improving functional vision in diabetic dogs with early lens opacities.     

Lens morphometry determined by B-mode ultrasonography of the normal and cataractous canine lens

Purpose To determine axial lens thickness, anterior chamber depth and axial globe length in canine eyes with normal lenses and in eyes with immature, mature, congenital, posterior polar and diabetic cataract. Methods B‐mode ultrasonography was performed in 50 normal dogs and, as a prephacoemulsification screening procedure, in 100 dogs with cataract. Axial B‐mode ultrasonograms were used to determine lens thickness, anterior chamber depth and globe diameter. Statistical comparisons between groups were made by analysis of variance and multivariate analysis, with a significance level of P < 0.05. Results Axial globe lengths were not statistically significantly different between groups apart from the smaller globes in younger dogs with congenital cataract. Axial lens thickness in diabetics (8.4 ± 0.9 mm) was statistically significantly different from the lens thickness in normal eyes (6.7 ± 1.0 mm), eyes with immature cataract (6.4 ± 0.8 mm) and eyes with mature cataract (7.4 ± 0.9 mm) although these groups, while varying in thickness, were not statistically significantly different from each other. Anterior chamber depth was statistically significantly reduced in eyes with diabetic cataract (2.9 ± 0.1 mm) from that in normal eyes (3.8 ± 0.1 mm), eyes with immature cataract (3.5 ± 0.1 mm) and eyes with mature cataract (3.2 ± 0.6 mm) although these groups, while varying in chamber depth, were not statistically significantly different from each other. Conclusions Lenses with diabetic cataracts were significantly increased in axial thickness compared to lenses in other eyes, although lenses with mature cataracts showed a trend towards increased axial thickness and immature cataracts demonstrated a trend towards reduced thickness. While previous studies on cataract pathobiology have suggested a reduction in lens thickness in immature cataract through lens protein loss and an increase in thickness in mature cataracts through intumescence, this study is the first to document these changes in the canine lens.     

Ehlers-Danlos syndrome in a dog: ocular, cutaneous and articular abnormalities

Ehlers-Danlos syndrome (EDS) is an hereditary connective tissue disease in man in which the skin is easily torn. A similar condition has been described in dogs and other animals. This case report records a case in the United Kingdom in which the whole syndrome was exhibited: skin fragility, joint laxity and ocular signs of bilateral lens luxation, cataract and corneal oedema. It is the first report of ocular signs in EDS in the dog and joint laxity has been reported only rarely.     

Familial cataracts and concurrent ocular anomalies in chow chows.

A closely inbred line of Chow Chows affected with congenital cataracts was studied. Sixteen dogs were examined including 1 adult male, 2 adult females, and 13 pups. Twelve of the pups were from 6 different litters, out of 6 different bitches, all sired by 1 adult male. The exact relationship of the thirteenth pup was undetermined. Clinical evaluation included slit-lamp biomicroscopy, biomicroscopic photography, and indirect ophthalmoscopy. Clinical appearance of the cataracts was variable, ranging from incipient nuclear or capsular lesions to advanced cortical opacity. The lens nucleus was most consistently affected, with variable involvement of the lens cortex. Concurrent ocular anomalies of some eyes included wandering nystagmus, entropion, microphthalmia, persistent pupillary membrane remnants, and multifocal retinal folds. A correlation was not apparent between the character or severity of the cataracts and the finding of the other anomalies. Histologic examination of 12 lenses revealed posterior displacement of the lens nucleus, retained lens epithelial cell nuclei in the nuclear and cortical lens, anterior capsular irregularity and duplication, anterior lens epithelial duplication, and posterior subcapsular migration of epithelium. The high incidence of cataract in this family of Chow Chows suggested an inherited defect, although the inheritance pattern was undetermined.     

Feline retinal degeneration: clinical experience and new findings (1994-1997)

A retrospective case series of 26 cats with diffuse retinal degeneration is presented. The most common presenting complaints included bumping into objects, dilated pupils, and reluctance to jump. Ophthalmic examination findings were consistent with those reported in dogs with progressive retinal atrophy. Breed predilection of the Siamese cat was observed. Cats with primary retinal degeneration presented late in the clinical course of their disease, when vision loss was severe. Early symptoms such as night blindness and secondary ocular complications (i.e., cataract and retinal detachment), reported in dogs with progressive retinal degeneration, were not observed in this study. All cats showed excellent adaptive capabilities to blindness.     

Convergent strabismus in a white Bengal tiger

A white Bengal tiger was noted to have a convergent strabismus with poor vision since a cub. The tiger and a littermate with normal colouring and apparently normal eyes were anaesthetised for comparative ocular examination. A fundus typical of colour-dilute cats and dogs was noted in the white tiger. Except for strabismus, no abnormalities were observed. Electroretinography showed similar retinal function in both tigers. Possible causes of strabismus considered were an adaptation to genetically determined abnormal visual pathways related to lack of pigment, abnormalities of the abducent nerves and mechanical restricting conditions of the medial rectus muscles.     

Posterior lenticonus with congenital cataract in a Shih Tzu dog

A seven-month-old, male Shih Tzu dog weighing 3.7 kg had an immature cataract in its left eye. A biomicroscopic examination revealed numerous vacuolations in the posterior cortices with nucleus cataracts, covered by an intact anterior lens capsule. The changes observed by ocular sonographic examination (OSG) of the left eye were hyperechoic, and a funnel-cone shape was observed posteriorly with cortex hyperechogenicity in the lens. The left eye was diagnosed as having a posterior lenticonus with congenital cataract. Phacoemulsification was performed on the left eye as diagnostic treatment of the posterior lenticonus and cataract. Postoperative OSG on the left eye revealed a V-shaped linear echo that was indicative of a posterior capsule of the lens. Moreover, it was confirmed that hyperechoic cataract material inside the lens had disappeared.     

Persistent hyperplastic tunica vasculosa lentis and persistent hyperplastic primary vitreous (PHTVL/PHPV) in two cats

Two domestic shorthair cats (6 and 9 months old) were presented for examination of ocular opacities. One cat had bilateral persistent pupillary membranes, unilaterally accompanied by persistent hyperplastic tunica vasculosa lentis, persistent hyperplastic primary vitreous (PHTVL/PHPV), and cataract. The second cat had bilateral PHTVL/PHPV with dense white plaques in the posterior lens capsule and subcapsular cortex.     

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.     

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.     

Primary lens instability in ten related cats: clinical and genetic considerations

Objectives : To describe bilateral lens instability in 10 related domestic shorthair cats over three generations. Methods : Complete ophthalmic examinations were performed. Lentectomies were carried out. Sections of affected lenses focused on the equatorial area were examined by transmission electron microscopy. The potential involvement of several candidate genes (ADAMTS17, ADAMTSL4, ADAMTS10 and FBN1) known to be associated with lens luxation in other species was investigated. Results : The group of animals included 10 related cats, nine of them being affected by lens instability over three generations. Transmission electron microscopy showed the presence of zonular material at the lens equator. Signs of lens instability were not associated with other ocular disease. Analysis of the pedigree suggests a dominantly inherited condition. A mutation in ADAMTS17 was excluded, but a possible association between the condition and a microsatellite flanking FBN1 indicates this gene should be considered a strong candidate responsible for primary lens luxation in this pedigree. Clinical Significance : These observations suggest an inherent zonular defect unrelated to extraneous factors. The family relationship is compatible with a possible genetic basis, and the pedigree suggests that the condition could be dominant. Data also suggest the mutation in the FBN1 gene could be responsible for primary lens luxation in this pedigree of cats.     

Aldose reductase activity and glucose-related opacities in incubated lenses from dogs and cats

OBJECTIVE: To determine responses of canine and feline lenses to incubation in a medium with a high glucose concentration. SAMPLE POPULATION: Lenses from 35 dogs and 26 cats. PROCEDURE: Glucose concentrations were measured in paired lenses from 25 dogs and 17 cats after incubation for 14 days in high-glucose (30 mmol of glucose/L) or control (6 mmol of glucose/L) medium. Aldose reductase activity was measured spectrophotometrically in the incubated lenses and in freshly frozen lenses from 10 dogs and 9 cats. Two lenses of each group were studied histologically. RESULTS: Canine and feline lenses in high-glucose medium developed glucose-specific opacities of variable localization and extent. Canine lenses developed equatorial vacuoles, but severity of the lesions was not associated with the age of the dog. Lenses from young cats (< or = 4 years old) developed extensive posterior cortical opacities, whereas those from older cats (> 4 years old) did not. Glucose concentrations were similar in all lenses incubated in high-glucose medium; however aldose reductase activity was significantly lower in lenses from older cats, compared with lenses from young cats and from dogs. CONCLUSIONS AND CLINICAL RELEVANCE: High aldose reductase activity and glucose-related opacities suggest a central role for this enzyme in the pathogenesis of diabetic cataracts in dogs and cats. Because onset of diabetes mellitus usually occurs in cats > 7 years of age, low activity of aldose reductase in lenses of older cats may explain why diabetic cataracts are rare in this species despite hyperglycemia.     

Canine cataracts, diabetes mellitus and spontaneous lens capsule rupture: a retrospective study of 18 dogs

OBJECTIVE: To describe the clinical presentation and surgical outcome of diabetic canine patients with cataracts and preoperative spontaneous lens capsule rupture. ANIMALS STUDIED: A total of 20 dogs and 40 eyes were included in the retrospective evaluation. The patients' ages ranged from 5 to 14 years (mean 8.5 years). RESULTS: All dogs had clinical diabetes mellitus, with the duration since diagnosis ranging from 30 to 240 days (mean 123 days). Cataracts were bilateral and noted to have been present for 14-112 days (mean 39 days). Of the 40 eyes affected with cataracts, 30 had a spontaneous rupture of the lens capsule prior to surgery. The capsular rupture was diagnosed on clinical examination in 28/30 eyes and was noted intraoperatively in 2/30. The location of the capsular rupture was equatorial in 29/30 and posterior in 1/30 eyes. Surgery was performed in 38/40 eyes, with one case lost to follow-up without surgical intervention. Prior to surgery, routine diagnostic ophthalmic examination, ocular ultrasound, electroretinography, and systemic evaluation were performed in all dogs. Surgical procedures included phacoemulsification in 28/40 eyes, with IOL placement performed in 20/28 eyes. Intrascleral prosthesis placement or enucleation was performed in 8/40 and 2/40 eyes, respectively, due to a significantly reduced ERG or secondary glaucoma. CONCLUSIONS: The duration of clinical follow-up (19/20 dogs) ranged from 1 to 36 months (mean 12.9 months). All eyes that had cataract surgery with or without IOL placement were sighted at the time of the last follow-up examination. Spontaneous lens capsule rupture associated with diabetes mellitus, cataract and rapid lens intumescence occurs in the dog. Early surgical intervention, prior to secondary complications of glaucoma and loss of retinal function, is associated with a favorable outcome.     

Prevalence of feline cataract: results of a cross-sectional study of 2000 normal animals, 50 cats with diabetes and one hundred cats following dehydrational crises

Objective In this study 2000 normal cats, 50 cats with diabetes and 100 cats with a history of dehydrational crises were examined ophthalmoscopically to determine presence of cataract. Materials and methods The cats examined were predominantly from veterinary hospital populations but also from re‐homing facilities and breeding catteries. Prevalence of cataract was determined for different age groups (year cohorts). The age at which prevalence of cataract was 50% (C₅₀) was determined indirectly from a fitted prevalence curve as previously described. C₅₀ was determined for animals of different genders and different breeds as well as for those with diabetes and histories of dehydrational episodes related to chronic renal failure, chronic vomiting or chronic diarrhea. Results The mean ± standard deviation of C₅₀ for all normal cats in the study was 12.7 ± 3.4 years. All cats over 17.5 years were affected by some degree of lens opacity. C₅₀ for cats with diabetes was 5.6 ± 1.9 years (significantly different from normal cats at P < 0.0001). For cats with a history of dehydrational crises C₅₀ was 9.9 ± 2.5 (difference from normal cats nearing statistical significance at P = 0.06). Conclusion The study yields novel findings regarding the prevalence of age‐related cataract in normal cats together with cats with diabetes and history of previous dehydrational episodes in which prevalence of cataract is increased.     

Diabetic cataracts: different incidence between dogs and cats

Diabetes mellitus is one of the most common endocrinopathies in the dog and cat. Diabetic cataract primarily affects the canine species and is rarely observed in the cat. It has been proposed that the incidence of cataracts in diabetic dogs is high because many of these patients have significant hyperglycemia despite insulin therapy. Age, gender, levels of serum glucose (before and during insulin therapy) and cataract formation were evaluated, retrospectively, in 23 dogs and 22 cats with diabetes mellitus. In the canine population, the groups with the highest frequency of presentation were females and sexually intact animals. In contrast, males and neutered animals were the most prevalent groups in the feline diabetic population. Over 80% of diabetic cats and dogs were older than 7 years. Our results confirm the almost total lack of cataracts in diabetic cats, while they were present in more than half of the dogs. A relation between the incidence of cataracts and the correspondent level of hyperglycemia in the canine and feline species could not be established. The estimation of the relative risk for the development of cataracts in diabetic dogs shows that some population groups have a higher probability for suffering from this ocular alteration. A relation between relative risk and the correspondent level of hyperglycemia in the various groups was not found. This fact indicates that other factors are involved in the unequal appearance of diabetic cataracts in dogs and cats.     

Ocular manifestation of lymphoma in newly diagnosed cats

Ocular manifestations of lymphoma are described in humans and dogs but rarely in cats. In this prospective study, cats with newly diagnosed and treatment‐naïve lymphoma were evaluated concerning clinical stage and ophthalmologic findings. Twenty‐six cats were included. In 12 cats (48%), ocular changes were documented. Uveitis anterior and posterior were predominant findings, being present in 58% of affected individuals. Other findings included exophthalmos, corneal surface lesions and chemosis. Eight cats received chemotherapy, two of which had ocular involvement. In these two cats, a complete remission of an anterior and a partial remission of a posterior uveitis were documented. Due to the detection of ocular involvement, a stage migration from stage IV to V occurred in four patients. In the light of these findings, an opthalmological examination may be considered as an important part of staging in feline lymphoma as well as of follow‐up examination in affected cats.     

Evaluation of acoustic wave propagation velocities in the ocular lens and vitreous tissues of pigs, dogs, and rabbits

OBJECTIVE: To evaluate propagation velocity of acoustic waves through the lens and vitreous body of pigs, dogs, and rabbits and determine whether there were associations between acoustic wave speed and age, temperature, and time after enucleation. SAMPLE POPULATION: 9 pig, 40 dog, and 20 rabbit lenses and 16 pig, 17 dog, and 23 rabbit vitreous bodies. PROCEDURE: Acoustic wave velocities through the ocular structures were measured by use of the substitution technique. RESULTS: Mean sound wave velocities in lenses of pigs, dogs, and rabbits were 1,681, 1,707, and 1,731 m/s, respectively, at 36 degrees C. Mean sound wave velocities in the vitreous body of pigs, dogs, and rabbits were 1,535, 1,535, and 1,534 m/s, respectively, at 38 degrees C. The sound wave speed through the vitreous humor, but not the lens, increased linearly with temperature. An association between wave speed and age was observed in the rabbit tissues. Time after enucleation did not affect the velocity of sound in the lens or vitreous body. The sound wave speed conversion factors for lenses, calculated with respect to human ocular tissue at 36 degrees C, were 1.024, 1.040, and 1.055 for pig, dog, and rabbit lenses, respectively. CONCLUSIONS AND CLINICAL RELEVANCE: Conversion factors for the speed of sound through lens tissues are needed to avoid underestimation of the thickness of the lens and axial length of the eye in dogs during comparative A-mode ultrasound examinations. These findings are important for accurate calculation of intraocular lens power required to achieve emmetropia in veterinary patients after surgical lens extraction.