Canine and feline uveitis

Evaluation of 0.1% and 1% atropine eyedrops in cats: A comparative study of tolerance, stability, and efficacy

OBJECTIVE

Investigate the tolerance, stability, and efficacy of topical 0.1% and 1% atropine in cats.

PROCEDURES

Six cats underwent two trials separated by a 2-week washout period. One drop of artificial tears was placed in one randomly selected eye (control), and one drop of either 0.1% atropine (Trial I) or 1% atropine (Trial II) was placed in the other eye. Immediate adverse effects were recorded for severity (0-3) and duration (seconds). Horizontal pupil diameter (HPD), pupillary light reflexes (PLRs), intraocular pressure (IOP), Schirmer tear test-1 (STT-1), and heart rate (HR) were monitored at baseline then 8 h post-administration. PLRs were assessed for a total of 72 h. Stability was assessed weekly for 1 month in room temperature and refrigerated conditions, evaluating solution clarity, pH, and drug concentrations.

RESULTS

Adverse effects had a significantly lower severity score and shorter duration with 0.1% versus 1% atropine (severity 1.2 ± 0.4 vs. 2.5 ± 0.5, p = .010; duration 107.5 ± 53.3 vs. 293.3 ± 106.5 s, p = .009). HPD was significantly greater than baseline measurements as early as 40 min for both atropine formulations. Pupils were non-responsive for a significantly shorter duration with 0.1% versus 1% atropine (median 7 h vs. 47.5 h, p = .031). Compared with control eyes, IOP was significantly elevated by 1% atropine (p = .021) but not 0.1% atropine (p = .502). No significant differences were noted in STT-1 and HR measurements. Both solutions were stable in room temperature and refrigerated conditions for 1 month.

CONCLUSIONS

Diluted 0.1% atropine was stable and better tolerated by cats, offering a potential alternative to feline patients that experience adverse effects from topical 1% atropine.

Ultrasound biomicroscopy analysis of ciliary muscle dynamics and its relation to intra-ocular pressure after phacoemulsification in dogs

Introduction

This study investigates the relationship between ciliary muscle dynamics, thickness, and the regulation of intraocular pressure (IOP), focusing on the progression of cataracts and changes post-phacoemulsification. It explores how these factors impact canine ocular health, particularly in the context of cataract development and subsequent surgical intervention.

Materials and methods

Data was collected using Ultrasound Biomicroscopy (UBM) from dogs at the Veterinary Medical Teaching Hospital of Chungbuk National University, Korea. The study involved 57 eyes from 35 dogs, categorized into five groups: 13 normal eyes, 14 with incipient cataracts, 12 with immature cataracts, 6 with mature cataracts, and 12 post-phacoemulsification. UBM measurements assessed various ciliary muscle parameters including ciliary body axial length (CBAXL), ciliary process-sclera angle (CPSA), longitudinal fibers of ciliary muscle thickness (Lf-CMT), and longitudinal and radial fibers of ciliary muscle thickness (LRf-CMT).

Results

Findings indicated a decrease in CBAXL and an increase in Lf-CMT as cataracts progressed in severity. Post-phacoemulsification, there was a notable increase in CBAXL and a decrease in CPSA, Lf-CMT, and LRf-CMT, compared to both cataractous and normal eyes. Regression analysis revealed a significant positive association between CBAXL and IOP, alongside a negative association between Lf-CMT and IOP. These findings suggest that variations in ciliary muscle dynamics and thickness, as influenced by cataract progression and phacoemulsification, have distinct impacts on intraocular pressure.

Discussion

The study proposes that phacoemulsification leads to ciliary muscle contraction, causing an inward and anterior movement of the ciliary muscle. This movement results in the narrowing of the ciliary cleft and constriction of the unconventional outflow pathway, potentially causing an increased risk of glaucoma post-surgery. Our research contributes to understanding the anatomical and physiological changes in the canine eye following cataract surgery and underscores the importance of monitoring IOP and ciliary muscle dynamics in these patients.

Sterile granulomatous panuveitis in dogs in the United Kingdom: A review of 33 cases

PURPOSE

To describe the clinical and histopathological features of a sterile granulomatous panuveitis syndrome in 33 dogs that underwent enucleation and ocular histopathology.

METHODS

Retrospective review of the medical records and ocular histopathology reports of 33 cases. Inclusion criteria were enucleation in conjunction with characteristic clinical and histopathological features.

RESULTS

Thirteen breeds were represented (including crossbreeds). Panuveitis was acute and fulminating, and secondary glaucoma was common (n = 27). Interval from initial presentation to enucleation was 99 days (median 33 days, range 5-605 days). The mean age at enucleation was 6.7 years. Ocular signs were initially unilateral (n = 18) or bilateral (n = 15). The disease became bilateral in 18/25 cases that initially underwent unilateral enucleation, resulting in enucleation or euthanasia in 9/18 (mean interval of 168 days). Seven out of 59 eyes had a good outcome following topical anti-inflammatory and systemic immunosuppressive therapy. None of the dogs had travel history nor relevant systemic signs from presentation to follow-up (mean 619 days, range 16-3012 days). Histopathology revealed histiocytic and lymphoplasmacytic panuveitis with pigment dispersion, and no infectious agents were identified on light microscopy.

CONCLUSION

To the authors' knowledge, this is the first report of a sterile granulomatous panuveitis syndrome in dogs in the UK. The clinical signs are severe, with rapid progression, and can result in bilateral enucleation or euthanasia in affected dogs. There does not appear to be an age or breed predisposition, however further research is necessary in this regard. Early and aggressive intervention, with both topical and systemic immunosuppressive therapy, is recommended to reduce the risk of blindness, enucleation, and euthanasia.

Oral 5-aminolevulinic acid combined with sodium ferrous citrate prevents blood-aqueous barrier breakdown after anterior chamber paracentesis in healthy beagle dogs

This study investigated the preventive effect of 5-aminolevulinic acid combined with sodium ferrous citrate (5-ALA/SFC) on blood-aqueous barrier (BAB) breakdown induced after anterior chamber paracentesis (ACP) in beagles. 5-ALA/SFC (1/0.64 mg/kg or 3/1.92 mg/kg) or carprofen (4.0 mg/kg) was orally administered daily for 7 days prior to ACP. Then, a sample of the aqueous humor (AH) was collected from one eye via ACP (first sample) and again 60 min later (second sample). The protein and prostaglandin E2 (PGE2) concentrations in both samples were measured. Compared with the control group, high-dose 5-ALA/SFC and carprofen significantly reduced the AH protein and PGE2 concentrations in the second sample. Our findings suggest that 5-ALA/SFC suppresses BAB breakdown in dogs.

Histological evaluation of the distribution of systemic AA-amyloidosis in nine domestic shorthair cats

Amyloidosis is a group of protein-misfolding disorders characterized by the accumulation of amyloid in organs, both in humans and animals. AA-amyloidosis is considered a reactive type of amyloidosis and in humans is characterized by the deposition of AA-amyloid fibrils in one or more organs. In domestic shorthair cats, AA-amyloidosis was recently reported to be frequent in shelters. To better characterize this pathology, we report the distribution of amyloid deposits and associated histological lesions in the organs of shelter cats with systemic AA-amyloidosis. AA-amyloid deposits were identified with Congo Red staining and immunofluorescence. AA-amyloid deposits were then described and scored, and associated histological lesions were reported. Based on Congo Red staining and immunofluorescence nine shelter cats presented systemic AA-amyloidosis. The kidney (9/9), the spleen (8/8), the adrenal glands (8/8), the small intestine (7/7) and the liver (8/9) were the organs most involved by amyloid deposits, with multifocal to diffuse and from moderate to severe deposits, both in the organ parenchyma and/or in the vascular compartment. The lung (2/9) and the skin (1/8) were the least frequently involved organs and deposits were mainly focal to multifocal, mild, vascular and perivascular. Interestingly, among the organs with fibril deposition, the stomach (7/9), the gallbladder (6/6), the urinary bladder (3/9), and the heart (6/7) were reported for the first time in cats. All eye, brain and skeletal muscle samples had no amyloid deposits. An inflammatory condition was identified in 8/9 cats, with chronic enteritis and chronic nephritis being the most common. Except for secondary cell compression, other lesions were not associated to amyloid deposits. To conclude, this study gives new insights into the distribution of AA-amyloid deposits in cats. A concurrent chronic inflammation was present in almost all cases, possibly suggesting a relationship with AA-amyloidosis.

Monoclonal Antibodies: A Therapeutic Option for the Treatment of Ophthalmic Diseases of the Eye Posterior Segment

The eye is an organ that allows us to observe the outside world. Pathologies of the eye's posterior segment, such as glaucoma, macular degeneration, diabetic retinopathy, uveitis, and retinoblastoma, cause vision loss. Traditional treatments consist of applying topical medications that do not penetrate properly or using high doses that generate adverse effects. Different laser surgeries stop the pathology's progression but do not allow visual improvement. So, an alternative is to use monoclonal antibodies, proteins produced by different processes that selectively bind to metabolites associated with diseases, reducing the adverse effects of traditional treatments and improving the application of the drug in the area. The two main molecular targets are TNF (adalimumab, infliximab, and certolizumab pegol) and VEGF (bevacizumab and ranibizumab); other possibilities are under investigation.

Pro-inflammatory cytokines in aqueous humor from dogs with anterior uveitis and post-operative ocular hypertension following phacoemulsification, primary glaucoma, and normal healthy eyes

Background

The aim of this study was to evaluate the levels of pro-inflammatory cytokines in aqueous humor (AH) from dogs with anterior uveitis and post-operative ocular hypertension (POH) following phacoemulsification, in AH from dogs with primary glaucoma, and in normal healthy eyes with no signs of anterior uveitis or other ocular diseases.

Methods

An exploratory study including 21 samples of AH collected from 15 dogs; post-phacoemulsification with anterior uveitis and POH (‘POH group’, n = 10 samples), primary glaucoma (‘glaucoma group’, n = 6 samples), and normal (‘normal group’, n = 5 samples). Target mass spectrometry via multiple reaction monitoring (MRM-MS) with the Canine Cytokine SpikeMix™ as internal standard was used to measure the pro-inflammatory cytokine levels.

Results

The MRM-MS method measured 15 pro-inflammatory cytokines. Tumor-necrosis-factor-alpha (TNFα) and interleukin-18 (IL-18) levels in AH were different between all three groups (glaucoma>POH>normal) (p = .05, p = .02, respectively). Additionally, IL-6 was higher in the ‘POH group’ compared to the ‘glaucoma group’ (p = .04) and IL-4 was higher in the ‘POH group’ compared to the ‘normal group’ (p = .04). Intraocular pressure (IOP) was positively associated with increased AH levels of IL-18 (Spearman correlation = .64, p = .03).

Conclusions

MRM-MS using the Canine Cytokine SpikeMix™ as an internal standard was established as a method to detect pro-inflammatory cytokine levels in canine AH. The study demonstrated increased levels of IL-4, IL-6, IL-18, and TNFα in AH from canines with POH following phacoemulsification. Primary glaucomatous eyes had the highest levels of IL-18 and TNFα which may indicate that inflammation plays a role in the pathogenesis of primary glaucoma in dogs.

A review of investigated risk factors for developing equine recurrent uveitis

Equine recurrent uveitis (ERU) is an ocular inflammatory disease that can be difficult to manage clinically. As such, it is the leading cause of bilateral blindness for horses. ERU is suspected to have a complex autoimmune etiology with both environmental and genetic risk factors contributing to onset and disease progression in some or all cases. Work in recent years has aimed at unraveling the primary triggers, such as infectious agents and inherited breed-specific risk factors, for disease onset, persistence, and progression. This review has aimed at encompassing those factors that have been associated, implicated, or substantiated as contributors to ERU, as well as identifying areas for which additional knowledge is needed to better understand risk for disease onset and progression. A greater understanding of the risk factors for ERU will enable earlier detection and better prognosis through prevention and new therapeutics.

The feasibility of clinical evaluation for anterior uveitis through spectral-domain optical coherence tomography in dogs

OBJECTIVE

To evaluate the clinical application of spectral-domain optical coherence tomography (SD-OCT) for anterior uveitis in dogs.

ANIMALS AND PROCEDURES

Client-owned dogs presenting with anterior uveitis and clinically healthy dogs were enrolled in this study. Included eyes were divided into 5 groups by flare grade and 3 groups by cell grade through slit-lamp biomicroscopy. Each eye was examined using SD-OCT following slit-lamp biomicroscopy. The ratio of aqueous signal intensity to air signal intensity, which is called the aqueous-to-air relative intensity (ARI) index, was used to evaluate the flare grade. Cell number, central corneal thickness (CCT), and the presence of keratic precipitates (KPs) were analyzed on SD-OCT. The OCT parameters, including ARI index, cell number, and CCT, were compared to the slit-lamp clinical flare and cell grade.

RESULTS

Thirty-six eyes with anterior uveitis and 27 healthy eyes were enrolled. The ARI index showed a significant correlation with clinical flare grade (r_s  = 0.811, p < .001). In multiple regression analysis, the ARI index and CCT showed a significant negative correlation (r = -0.258, p = .044). The number of cells on SD-OCT significantly increased with cell grade on slit-lamp biomicroscopy (r_s  = 0.653, p < .001). The clinical flare grade and CCT were significantly correlated in the partial correlation analysis after controlling for age (partial correlation coefficient = 0.471, p = .002). KPs were observed in 61% of the eyes with flare using SD-OCT (22/36 eyes).

CONCLUSIONS

Spectral-domain optical coherence tomography could provide quantitative information, including the ARI index, cell counts, and CCT in dogs. SD-OCT is an auxiliary modality for slit-lamp biomicroscopy when evaluating anterior uveitis in dogs.

Diagnosis and successful treatment of an Austrian dog infected with Trypanosoma congolense forest type

Canine African Trypanosomosis (CAT) is a rarely described disease with frequently lethal outcome. A 5-year-old female mongrel dog weighing 22 kg was presented in Austria due to unilateral uveitis, pancytopenia, and anorexia 4 months after return from a trip through Western Africa. Trypanosoma spp. flagellates were detected in a blood smear and identified as Trypanosoma congolense forest type by PCR. Initial treatment with imidocarb and miltefosine led to clinical improvement but only isometamidium chloride hydrochloride applied intramuscularly led to complete eradication of the pathogen from the dog's blood 4 months later.

Comparison of topically administered 0.05% difluprednate and 1% prednisolone acetate for inhibition of aqueocentesis-induced breakdown of the blood-aqueous barrier in healthy dogs

OBJECTIVE

To compare the efficacy of 0.05% difluprednate ophthalmic emulsion and 1% prednisolone acetate ophthalmic suspension for controlling aqueocentesis-induced breakdown of the blood-aqueous barrier in healthy dogs.

ANIMALS

34 healthy dogs.

PROCEDURES

Dogs were allocated to 5 groups (6 to 8 dogs/group) to receive 0.05% difluprednate, 1% prednisolone acetate, or saline (0.9% NaCl) solution (control treatment) in both eyes 2 or 4 times daily. Eye drops were administered topically for 5 consecutive days. Anterior chamber paracentesis (aqueocentesis) was performed in 1 eye on the third day. Automated fluorophotometry was performed immediately before and 20 minutes and 24 and 48 hours after aqueocentesis. Relative fluorescence (RF), defined as fluorescence of the eye that had undergone aqueocentesis divided by fluorescence of the contralateral eye, was calculated to help control for variation among dogs.

RESULTS

Mean RF was significantly lower at 24 hours after aqueocentesis in dogs treated twice daily with 0.05% difluprednate or 4 times daily with 1% prednisolone acetate than in dogs receiving the control treatment. At 48 hours after aqueocentesis, mean RF was significantly lower in dogs treated 4 times daily with 1% prednisolone acetate than in control dogs. Mean RF differed over time in dogs treated 4 times daily with 0.05% difluprednate but did not differ over time for any of the other treatments.

CONCLUSIONS AND CLINICAL RELEVANCE

All 4 treatments were effective for reducing aqueocentesis-induced anterior uveitis in healthy dogs regardless of the drug or frequency of administration. Topical ophthalmic administration of 0.05% difluprednate may be a viable treatment option for dogs with anterior uveitis and warrants further study.

Validation and comparison of four handheld tonometers in normal ex vivo canine eyes

OBJECTIVES

To determine the accuracy and precision of the Icare^® TONOVET Plus rebound tonometer and the Tono-Pen AVIA Vet™ applanation tonometer for intraocular pressure (IOP) measurement in normal ex vivo canine eyes and comparison to earlier models of these tonometers.

ANIMALS & PROCEDURES

The anterior chambers of six normal dog eyes were cannulated ex vivo. IOP was measured with the TONOVET (TV01), TONOVET Plus, Tono-Pen Vet™, and Tono-Pen AVIA Vet™ at manometric IOPs ranging from 5 to 70 mm Hg. Data were analyzed by linear regression, ANOVA and Bland-Altman plots. A P value ≤ .05 was considered significant.

RESULTS

Intraocular pressure values obtained using the TONOVET Plus and TV01 were significantly more accurate than with the Tono-Pen VET and Tono-Pen AVIA Vet, particularly at higher IOPs (30-70 mm Hg). Accuracy was not significantly different between any of the devices in the low to normal physiologic IOP range (5-25 mm Hg). Level of precision was high for all devices, though the TONOVET Plus was more precise than the Tono-Pen Vet in the 5-25 mmHg range and the TV01 was more precise than the Tono-Pen AVIA Vet over the whole IOP range.

CONCLUSIONS

All devices underestimated IOP, particularly at higher pressures. Rebound tonometers were more accurate over the full range of IOP tested and in the high IOP range; however, there were no significant differences in accuracy among devices in the physiologic IOP range. All tonometers can provide clinically useful IOP readings in dogs, but rebound and applanation tonometers should not be used interchangeably.

Prevalence of antibody seroconversion to Toxoplasma gondii in uveitis and non-uveitis dogs

Objectives

To evaluate the prevalence of seroconversion to Toxoplasma gondii in dogs with uveitis and dogs without uveitis.

Methods

In total, 135 dogs were evaluated: 51 dogs were diagnosed with uveitis, and 84 dogs were without uveitis. Latex agglutination tests were performed on all sera, and the results were evaluated.

Results

Overall, 7.8 and 6.0 per cent of sera were positive for the presence of anti-T gondii antibodies (dilution ≥1:64) in the groups with uveitis and non-uveitis dogs, respectively. The frequency distribution of variables (positive and negative results in the uveitis and the non-uveitis group of dogs) was tested with Fisher’s exact test. There was no statistically significant difference between groups (P=0.73).

Clinical significance

These findings suggest that evidence of exposure to T gondii was not significantly different between uveitis and non-uveitis groups of dogs and that the possible association between exposure to T gondii and canine uveitis requires further investigation. This study is the first to report the seroprevalence of anti-T gondii antibodies in dogs in the UK population and the first to report the seroprevalence of anti-T gondii antibodies in dogs with uveitis.

Early postoperative results of Descemet's stripping endothelial keratoplasty in six dogs with corneal endothelial dystrophy

OBJECTIVE

To describe and assess the clinical outcome and intraoperative and postoperative complications of Descemet's stripping endothelial keratoplasty (DSEK) in the treatment of canine corneal endothelial dystrophy.

ANIMALS STUDIED

Six dogs (six eyes) diagnosed with progressive corneal edema resulting from abnormal dystrophic endothelial cells underwent Descemet's stripping endothelial keratoplasty.

PROCEDURES

Six patients underwent Descemet's stripping endothelial keratoplasty (DSEK). The patients were examined preoperatively and postoperatively at 24 hours, 7 days, 1, 2, and 3 months after surgery. Corneal edema and ultrasonic pachymetry were evaluated preoperatively and postoperatively. The positions of DSEK grafts were evaluated 3 months after surgery using optical coherence tomography. Intraoperative and postoperative complications were noted.

RESULTS

The degree of corneal edema and corneal thickness improved postoperatively in all the patients (n = 6). Fibrin was encountered intraoperatively in one out of the six eyes (1/6) and postoperatively in two out of the six eyes (2/6). One out of the six DSEK grafts was partially scrolled (1/6). Secondary ocular hypertension was observed in one out of the six eyes (1/6). Corneal vascularization was encountered in four out of six patients (4/6).

CONCLUSIONS

Descemet's stripping endothelial keratoplasty is an effective surgical treatment option for corneal endothelial dystrophy in dogs. Corneal edema resolved and corneal thickness reduced significantly. The early postoperative results are encouraging. Further investigation is warranted to document any long-term complications and to study the longevity of the transplanted grafts.

Avaliação proteica do humor aquoso de equinos

RESUMO A avaliação proteica do humor aquoso (HA) pode ser utilizada como método diagnóstico nas uveítes. Entretanto, estudos sobre as proteínas nesse fluido, em equinos hígidos, são escassos e apresentam variações conforme a metodologia empregada. Dessa forma, objetivou-se realizar a análise proteica e citológica do HA nessa espécie, bem como verificar sua correlação com as proteínas plasmáticas. Foram avaliados 13 equinos adultos (26 olhos), sem raça definida, machos ou fêmeas. Mediante aqueocentese, foi coletado 0,5 mL de humor aquoso de cada olho. Cada amostra foi encaminhada para quantificação proteica pelo método de Bradford modificado e pela eletroforese em gel de poliacrilamida - dodecil sulfato de sódio (SDS-PAGE), bem como para avaliação citológica. Por meio de venopunção, coletou-se sangue para determinação da concentração de proteínas séricas. Treze olhos (50% das amostras) apresentaram valor proteico médio de 40,3 mg/dL±6,45 e a eletroforese demonstrou presença de proteínas de massas mais elevadas que 43 KDa. Houve ausência de células em 96,15% das amostras (25 olhos). Equinos hígidos apresentaram baixa concentração de proteínas no HA. Já a correlação entre proteína no humor aquoso/proteína plasmática total foi de 0,56%.

Aspergillus spp. panophthalmitis with intralenticular invasion in dogs: report of two cases

This case series describes the ocular, clinical and histologic manifestations of disseminated Aspergillosis in two dogs. Two dogs presented for severe unilateral panophthalmitis and secondary glaucoma with positive Aspergillus spp. titers. Case 1 showed no clinicopathologic systemic symptoms of fungal dissemination, however, case 2 was affected with acute renal failure. The affected eye of case 1 did not respond to medical therapy and was enucleated for comfort. The affected eye of case 2 responded to aggressive topical and systemic medical therapies, however, the patient was euthanized for acute renal failure. Globes were collected for histologic evaluation at the time of death. Histology of both revealed panophthalmitis with presence of significant intraocular hemorrhage, multifocal fungal granulomas, retinal and optic nerve changes consistent with secondary glaucoma, rupture of the anterior lens capsule, and fungal invasion and colonization of the intralenticular space. These cases represent a unique and devastating ocular manifestation of disseminated Aspergillosis. Cases presenting with uveitis and secondary glaucoma of unknown origin, especially with confirmed or suspected lens capsular rupture, should have serologic testing for this infectious agent.

Pyogranulomatous panophthalmitis with systemic coronavirus disease in a domestic ferret (Mustela putorius furo)

A 15-month-old spayed female ferret (Mustela putorius furo) presented for lethargy and weight loss of 2 weeks duration. Upon physical examination, a 2-mm-diameter focal area of opacity was noted in the left cornea. In addition, the ferret was quiet, in poor body condition, and dehydrated. A complete blood count and plasma biochemistry revealed a severe nonregenerative anemia, azotemia, hyperproteinemia, hypoalbuminemia, and mild hyperphosphatemia and hyperchloremia. Urinalysis revealed hyposthenuria. Whole body radiographs showed multifocal thoracic nodular disease, splenomegaly, and renomegaly. Abdominal ultrasonography confirmed bilaterally enlarged kidneys, hypoechoic liver and spleen, and a caudal abdominal hypoechoic mobile nodule. The ferret was humanely euthanized, and a postmortem examination with subsequent histopathology showed multifocal necrotizing pyogranulomas in the lung, spleen, kidneys, mesenteric lymph nodes, and serosa of the duodenum. Pyogranulomatous panophthalmitis was diagnosed in the left eye. The multisystemic granulomatous lesions were suggestive of ferret systemic coronavirus (FRSCV). The presence of coronavirus in the left eye was confirmed by positive immunohistochemistry. Reverse transcriptase polymerase chain reaction (RT-PCR) on formalin fixed paraffin embedded tissue from the lung, spleen, and kidney was negative for FRSCV and positive for ferret enteric coronavirus (FRECV). Systemic coronavirus disease in ferrets closely resembles feline infectious peritonitis (FIP) in domestic cats, which can manifest with anterior uveitis, chorioretinitis, optic neuritis, and retinal detachment. To the authors' knowledge, this is the first report of ocular lesions in a ferret with systemic coronavirus disease, suggesting that ferrets presented with similar ocular lesions should also be evaluated for evidence of coronavirus infection.

Causes of Feline Uveitis: A Retrospective Study of 96 Cases at the Faculty of Veterinary Medicine Bucharest, 2012-2015

Uveitis is a common cause of blindness in feline patients as incorrectly treated or its chronicization can lead to formation of pre-iridal fibrovascular membranes, pupillary block and secondary glaucoma. The objective of this study was to investigate the causes of uveitis in cats diagnosed at the Faculty of Veterinary Medicine, Bucharest between 2012 and 2015. Medical records were reviewed and cats were considered if complete diagnostic work-up, clinical examination and imaging studies were performed. All the feline cases were serologically tested for at least two of the common infectious causes: feline leukemia virus, feline immunodeficiency virus, feline coronavirus, Toxoplasma gondii, and Bartonella spp. Ninety-six cats with a mean age of 5.42 years, ranging from 1 month to 17 years old, with a male to female ratio of 1.33/1 were diagnosed with uveitis. The European domestic cat was overrepresented at 76% followed by Birman cat (6.3%), Persian cat (4.2%), Russian blue (4.2%), Norwegian cat (2%), British Short Hair (1%), Sphynx (1%) and Cornish Rex (1%). Infectious diseases were the cause of uveitis in 31 cases (32.3%), neoplasia was diagnosed in 22 cases (22.9%), uveitis secondary to septic keratitis in 8 cases (8.3%) and uveitis secondary to direct ocular trauma in 6 cases (6.3%). Twenty-nine cats (30.2%) with a mean age of 4.33 years old were diagnosed with idiopathic or immune-mediated uveitis, less than previously reported. Aqueous flare occurred in 91 cats and keratic precipitates were noted in 39 cats. The most common infectious cause of uveitis in this study was Toxoplasma gondii (n=18). Infectious diseases remain the most common cause of feline uveitis, therefore systemic evaluation and serological investigations should be performed in all cats with uveitis, cataract and glaucoma.

Causes of endogenous uveitis in cats presented to referral clinics in North Carolina

OBJECTIVE

To investigate the causes of endogenous uveitis in cats presenting to referral ophthalmology clinics in North Carolina.

PROCEDURE

Medical records of cats diagnosed with endogenous uveitis at North Carolina State University's College of Veterinary Medicine (NCSU-CVM) or Animal Eye Care Associates of Cary, NC between 2003 and 2015 were reviewed. Inclusion criteria were cats that had complete diagnostic workups, including clinical, clinicopathological, serological, and histopathological data, as well as imaging modalities. Serology was consistently completed for feline leukemia virus (FeLV), feline immunodeficiency virus (FIV), feline coronavirus (FCoV), Toxoplasma gondii, and Bartonella spp.

RESULTS

One hundred and twenty cats met the inclusion criteria. Seroprevalence of FeLV (2.7%), FIV (7.3%), FCoV (34.7%), T. gondii (23.7%), and Bartonella spp. (43.2%) was observed, with a combined seroprevalence of 59.2%. Nineteen cats (15.8%) were diagnosed with feline infectious peritonitis (FIP) based on clinical, hematological, serological, histopathological, and necropsy findings. The average age of all cases was 7.62 years, while the average age of cats diagnosed with FIP was 1.82 years. Neoplasia was diagnosed in six cats (5.0%). No underlying etiology was found in 49 cats (40.8%).

CONCLUSIONS

Both idiopathic and neoplastic causes of uveitis were less prevalent than previously reported in studies, while seropositivity was higher than previously reported for the study area. This may be due to improved diagnostic capabilities or that cats with infectious disease were more likely to be referred. Because of the high prevalence of FIP, young cats with uveitis should be evaluated for hyperglobulinemia and FCoV serology should be performed as minimal diagnostics.

Encephalitozoon cuniculi causes focal anterior cataract and uveitis in dogs

Three mongrel dogs, aged 10 months (case 1), 14 months (case 2) and 7.5 years (case 3), were presented because of ophthalmologic disorders of 4 months, 6 months and 7 years duration, respectively. All three dogs were offspring of stray dogs from Hungary and Serbia and had positive serum antibody titres against Encephalitozoon (E.) cuniculi. The two young dogs showed unilateral, the older dog bilateral chronic anterior uveitis with posterior synechia and focal anterior cortical cataract. The fundi that could be evaluated developed focal tapetal hyporeflective lesions in the course of the disease. Dogs 1 and 2 underwent removal of the lens via phacoemulsification. PCR of the lens material was positive for E. cuniculi strains IV and II, respectively. In dog 2 findings suggestive of microsporidia were detected underneath the anterior lens capsule by immunohistochemical staining. In all cases medical treatment consisted of systemic fenbendazole, prednisolone, and topical anti-inflammatory drugs, and additional brinzolamid/timolol for dog 3. For the time being all cases (follow up 23 months, 6 months and 3 months, respectively) are still on topical anti-inflammatory therapy. It is concluded that E. cuniculi infections can cause cataract and chorioretinal lesions in dogs.

Systemic absorption and adverse ocular and systemic effects after topical ophthalmic administration of 0.1% diclofenac to healthy cats

OBJECTIVE

To quantify plasma concentrations and determine adverse ocular, renal, or hepatic effects associated with repeated topical ophthalmic application of 0.1% diclofenac to healthy cats.

ANIMALS

8 healthy sexually intact male cats.

PROCEDURES

A randomized, placebo-controlled crossover study was conducted. A topical formulation of 0.1% diclofenac was administered 4 times/d for 7 days to 4 cats, and artificial tear (control) solution was administered to the other 4 cats. After a 12-day washout period, cats received the other treatment. Ophthalmic examinations were performed daily. Plasma samples were obtained on days 1 and 7 for pharmacokinetic analysis. A CBC, serum biochemical analysis, urinalysis, determination of urine protein-to-creatinine ratio, and determination of glomerular filtration rate were performed before the start of the study and after each 7-day treatment period.

RESULTS

Mild conjunctival hyperemia was the only adverse ocular effect detected. Maximal drug concentration and area under the curve were significantly higher on day 7 than on day 1. Diclofenac-treated cats had a significantly lower glomerular filtration rate than did control-treated cats after the second but not after the first treatment period, presumably associated with iatrogenic hypovolemia.

CONCLUSIONS AND CLINICAL RELEVANCE

Topical ophthalmic administration of 0.1% diclofenac was well tolerated in healthy cats, with only mild signs of ocular irritation. Detectable systemic concentrations of diclofenac were achieved with accumulation over 7 days. Systemic absorption of diclofenac may be associated with reduced glomerular filtration rate, particularly in volume-contracted animals. Topical ophthalmic 0.1% diclofenac should be used with caution in volume-contracted or systemically ill cats.

Intraocular pressure, specular microscopy, and prostaglandin E2 concentration in dogs with mature and hypermature cataract

This study aimed to evaluate and correlate intraocular pressure (IOP), endothelial cell density (CD), and hexagonality (HEX), and the aqueous humor prostaglandin E2 (PGE2 ) concentration in dogs with mature (MG, n = 8) and hypermature (HG, n = 8) cataracts. Eight laboratory beagles with no ocular abnormalities were included as a control group (CG). The IOP was measured using a digital applanation tonometer. Noncontact specular microscopy was used to evaluate CD and HEX. Samples of aqueous humor were used to determine prostaglandin E2 concentration using enzyme-linked immunoassay. Data were compared by anova and Bonferroni's multiple comparison test, and possible correlations among the PGE2 aqueous concentration and corneal endothelium cell parameters were assessed by Person's test (P < 0.05). Average values of IOP (P = 0.45) and CD (P = 0.39) were not significantly different between MG, HM, and CG. Average values of HEX were lower, and PGE2 concentration was increased in the MG and HG in comparison with CG (P < 0.05); however, such parameters did not change significantly between MG and HG (P > 0.05). PGE2 values did not correlate with IOP, CD, and HEX in any group (P > 0.05). Although there were a small number of dogs studied, our results demonstrated that cataract progression from mature to hypermature did not have a significant change in PGE2 aqueous concentration, IOP, corneal endothelial cell count, or morphology. In addition, PGE2 concentration was not correlated with parameters of the corneal endothelium or IOP in dogs with mature or hypermature cataracts.

Plasma and ocular prednisolone disposition after oral treatment in cats

Objective. To evaluate the plasma and aqueous humor disposition of prednisolone after oral administration in cats. Methods. Six cats were administered with a single oral dose of prednisolone (10 mg). Blood and aqueous humor samples were serially collected after drug administration. Prednisolone concentrations in plasma and aqueous humor were measured at 0.25, 0.5, 1.0, 1.5, 2.0, 3.0, 4.0, and 5.0 h after administration by a high-performance liquid chromatographic analytical method developed and validated for this purpose. Results. Mean ± standard error (SE) of maximum plasma prednisolone concentration (300.8 ± 67.3 ng/mL) was reached at 1 h after administration. Prednisolone was distributed to the aqueous humor reaching a mean peak concentration of 100.9 ± 25.5 ng/mL at 1.25 h after administration. The mean ± SE systemic and aqueous humor exposure (AUC) was 553.3 ± 120.0 ng∗h/mL and 378.8 ± 64.9 ng∗h/mL, respectively. A high AUC_{aqueous humor}/AUC_plasma ratio was observed (0.68 ± 0.13). The mean half-life time of elimination in plasma and aqueous humor was 0.87 ± 0.16 h and 2.25 ± 0.44 h, respectively. Clinical Significance. The observed high ratio between aqueous humor and plasma prednisolone concentrations indicates that extensive penetration of prednisolone to the anterior segment of the eye may occur. This is the first step that contributes to the optimization of the pharmacological therapeutics for the clinical treatment of uveitis.

Successful Treatment of Intracardiac and Intraocular Blastomycosis in a Dog with Combination Azole Therapy

A 4 yr old spayed female Labrador retriever with clinical signs of blindness, cutaneous lesions, coughing, inappetence, and lethargy was diagnosed with disseminated blastomycosis based on cytologic (skin and lymph node aspirates) and histopathologic (skin biopsy) examinations of tissue samples. The dog deteriorated clinically during hospitalization and developed sustained ventricular tachycardia. Echocardiography revealed pericardial effusion, a nodule associated with the left ventricular papillary muscle, and a right atrial mural lesion. Therapy for myocardial performance and glaucoma was initiated. A combination of itraconazole and fluconazole successfully treated the dog. The dog regained vision in the left eye (oculus sinister [OS]) and had no residual cardiac disease detectable by either electrocardiography or echocardiography. This report is unique in documenting survival from intracardiac blastomycosis and in the use of combination azole therapy for treating disseminated disease with intraocular involvement.

Therapeutic benefit of melatonin in experimental feline uveitis

Uveitis is a frequent ophthalmic disorder which constitutes one of the main causes of blindness in domestic cats. The aim of this report was to analyze the effect of melatonin on experimentally induced uveitis in cats. Bacterial lipopolysaccharide (LPS) was injected intravitreally into one eye from intact cats, while the contralateral eye was injected with vehicle. Melatonin was orally administered every 24 hr to a group of ten cats, from 24 hr before until 45 days after intravitreal injections. Eyes were evaluated by means of clinical evaluation, intraocular pressure (IOP), blood-ocular barrier integrity (via measurement of protein concentration and cell content in samples of aqueous humor [AH]), electroretinogram (ERG), and histological examination of the retinas. In LPS-treated eyes, several clinical signs were observed until day 45 postinjection. The treatment with melatonin significantly decreased clinical signs and prevented the reduction in IOP induced by LPS. In LPS-injected eyes, melatonin significantly preserved the blood-ocular barrier integrity, as shown by a decrease in the number of infiltrating cells and protein concentration in the AH. Mean amplitudes of scotopic ERG a- and b-waves were significantly reduced in eyes injected with LPS, whereas melatonin significantly prevented the effect of LPS. At 45 days after injection, LPS induced alterations in photoreceptors and at the middle portion of the retina, whereas melatonin preserved the retinal structure. These results indicate that melatonin prevented clinical, biochemical, functional, and histological alterations induced by LPS injection. Thus, melatonin might constitute a useful tool for the treatment of feline uveitis.