Clinical and pathological findings in five dogs with nodular histiocytic iritis in the United Kingdom: A case series.

PURPOSE: The aim of this study was to describe the clinical presentation, histopathology, management, and outcome of nodular histiocytic iritis, an intraocular variant of nodular granulomatous episcleritis (NGE). METHODS: A retrospective review of the medical records of five dogs with intraocular NGE-type inflammation as diagnosed by histopathology. RESULTS: Four Border Collies and one crossbreed dog, aged 1.5-3.4 years (mean age 2.38 years). The clinical presentation was an extensive, raised, pale iris lesion of variable location. All cases were unilateral. The physical examination was normal. Complete blood count/serum biochemistry (n = 1) and thoracic radiography (n = 1) were normal. Ocular ultrasound (n = 2) was normal apart from increased iris thickness. Enucleation (n = 4) or excisional biopsy (iridectomy, n = 1) was performed because of suspected neoplasia. Following enucleation, the remaining, contralateral eye did not develop additional lesions (9 days-3.7 years follow-up). There was no recurrence following sector iridectomy with 5 months topical 1% prednisolone acetate (3.9 years follow-up). The histopathologic findings in all five cases indicated a focal histiocytic and lymphoplasmacytic anterior uveitis (iritis), similar to that seen in cases of NGE. CONCLUSION: Nodular histiocytic iritis presents as unilateral iris thickening in isolation and young Collies appear to be predisposed. The histopathological findings are similar to NGE. Although the clinical presentation resembles intraocular neoplasia, an inflammatory process should be considered, which may be amenable to medical management. Definitive diagnosis may be obtained by iris sampling.

Atypical free-floating iridociliary pigmented epithelial cysts and secondary glaucoma in a caiman (Caiman latirostris).

We describe a case of chronic ocular trauma that resulted in fixed and free-floating, pigmented epithelial iridociliary cysts, inflammation, and secondary glaucoma in a caiman (Caiman latirostris). A 20- to 25-year-old male caiman was presented with phthisis bulbi in the right eye, and congested episcleral vessels, corneal leukoma, disorganized anterior chamber, multifocal anterior synechia, and elevated intraocular pressure in the left eye. Ocular ultrasound of the left eye revealed round structures dispersed in the anterior and posterior chambers and vitreous cavity. Bilateral enucleation was performed, and gross pathology of the left eye revealed multiple pigmented cysts attached to the iris and posterior corneal surface causing marked distortion of the anterior uvea, and free-floating in the vitreous cavity. Histopathology demonstrated heavily pigmented cystic structures of iridociliary epithelium origin carpeting the anterior segment surfaces and causing obstruction of the iridocorneal angles, leading to secondary glaucoma. To the authors' knowledge, this is the first report of iridociliary cysts in wildlife species.

Iridociliary cysts masquerading as neoplasia in cats: a morphologic review of 14 cases.

OBJECTIVE: To report 14 neoplasia-free feline eyes enucleated for suspected intraocular neoplasia containing only iridociliary cysts. To analyze clinical findings that may have led veterinarians to suspect neoplasia in these globes. PROCEDURES: The archives at the Comparative Ocular Pathology Laboratory of Wisconsin (COPLOW) were searched to identify neoplasia-free feline globes enucleated for suspected neoplasia. Clinical data were obtained from medical records, veterinarian surveys, and COPLOW submission forms. All samples were examined grossly and histologically. RESULTS: All eyes were free of neoplasia and contained one or more iridociliary cysts. Nine of 14 globes were enucleated by or based on the recommendation of a board-certified veterinary ophthalmologist. In eight of 14 cases, the submitting clinician listed melanoma as the only suspected diagnosis; in six of 14 cases, 'tumor' or 'mass' was listed. Clinical examination revealed a darkly pigmented intraocular mass in 11 of 14 cases. The mass was clinically perceived to be within the iris in seven of 14 cases. When examined histologically, 11 of 14 eyes contained multiple cysts, 13 of 14 contained multiloculated cysts, eight of 14 had a hyperplastic iris pigmented epithelium or cysts with thick black walls, and five of 14 had cysts prolapsed into the anterior chamber. CONCLUSIONS: Although most iridociliary cysts in cats are easily diagnosed on clinical examination, a subset may be mistaken for neoplasia. In cases of suspected iris melanoma, iridociliary cysts should be considered as a differential diagnosis, especially if a mass appears to emanate from behind the iris, dyscoria is present, or if similar changes are noted in the contralateral eye.

Uveal cysts in domestic cats: a retrospective evaluation of thirty-six cases.

OBJECTIVE: The aim of this retrospective study was to investigate uveal cysts in domestic cats by identifying prevalence, predispositions, location, presumed etiologies, and sequelae. ANIMALS STUDIED: The clinical databases of two referral hospitals (The Animal Health Trust in the UK and Animal Eye Care in Australia) were searched to identify cats that had been diagnosed with uveal cysts, either as an incidental finding or as the reason for referral. Thirty-six cases were found. PROCEDURES: The signalment of the patients was recorded, along with any relevant previous clinical history, treatment, follow-up, and sequela. The data were compared with the unaffected feline populations examined by ophthalmologists in the two hospitals over the same 10-year time period. RESULTS: Thirty-six cats were affected, from a total examined population of 5017 (prevalence 0.72%). Twenty-one of the 36 cats were Burmese. The two centers examined 516 Burmese cats in the same time period, giving an incidence in Burmese cats of 4.1%. The mean age of affected cats at presentation was 10.25 years (SD = 4.12 years), and female cats accounted for 23 of 36 of the cases. Only 2 of 36 cats had concurrent intraocular disease. CONCLUSIONS: Uveal cysts in domestic cats are rare ophthalmic findings, and in most cases, they do not cause any clinical problems The Burmese breed is overrepresented in the data, with a relatively high prevalence of uveal cysts.

Comparison of ultrasound biomicroscopy and standard ocular ultrasonography for detection of canine uveal cysts.

OBJECTIVE: To compare ultrasound biomicroscopy (UBM) with standard ocular ultrasonography for detection of canine uveal cysts and to determine the sensitivity, specificity, and interobserver agreement for detection of uveal cysts with UBM. SAMPLE: 202 enucleated eyes from 101 dogs. PROCEDURES: 2 examiners examined 202 eyes by means of UBM (50 MHz) to identify uveal cysts. A board-certified radiologist then examined 98 of the 202 eyes by means of standard ocular ultrasonography (7- to 12-MHz linear transducer). Subsequently, 1 examiner dissected all 202 eyes under magnification from an operating microscope to definitively identify uveal cysts. Each examiner was masked to other examiners' findings. Sensitivity, specificity, and interobserver agreement were calculated for detection of cysts by UBM. RESULTS: Cysts were detected by use of UBM in 55 of 202 (27%) eyes by one examiner and 29 of 202 (14%) eyes by the other. No cysts were detected in the 98 eyes examined with standard ocular ultrasonography. Dissection results revealed that cysts were present in 64 of 202 (32%) eyes, including 29 of 98 (30%) eyes examined by standard ocular ultrasonography. Mean sensitivity of UBM for cyst detection was 47%; mean specificity was 92%. Uveal cysts not identified with UBM were often small (mean diameter, 490 üm). Interobserver agreement was high (κP = 0.81). CONCLUSIONS AND CLINICAL RELEVANCE: UBM was more effective than standard ocular ultrasonography for detection of uveal cysts in enucleated eyes. Small-diameter cysts were difficult to visualize even with UBM.

Validity of aqueocentesis as a component of anterior uveitis investigation in dogs and cats.

OBJECTIVE: To describe aqueocentesis cytopathology results from dogs and cats presenting for uveitis investigation and to determine whether this is a useful and safe procedure. ANIMAL STUDIED: Dogs and cats presenting for investigation of anterior uveitis (April 2008-December 2013). PROCEDURES: Aqueous was collected via limbal entry under sedation/general anesthesia, for cytopathology and occasionally bacterial culture or polymerase chain reaction (PCR) testing. Further workup included blood testing (hematology, biochemistry, and serology), diagnostic imaging, nonocular cytopathology, and available histopathology. RESULTS: Fifty-six dogs and 39 cats were included in the study. An aqueous cytopathologic diagnosis of lymphoma (or discrete cell neoplasia) was made in six dogs and seven cats, and a diagnosis of large cell carcinoma made in one dog. This diagnosis of lymphoma was confirmed by ocular histopathology in two dogs and one cat; nonocular cytopathology corroborated lymphoma in another three dogs and five cats. Lymphoma was not evident on aqueous cytopathology but confirmed on nonocular histopathology in two dogs and by cytopathology in one cat. Additionally, aqueous cytopathology in three cats suggested, but was not considered diagnostic of, lymphoma; one of these cats had a confirmatory diagnosis of lymphoma on subsequent clinical investigation. Aqueous humor cytopathology alone was not diagnostic in non-neoplastic anterior uveitis cases, but supplemented the clinical picture with other systemic diagnostic tests. No clinically important complications were reported in association with aqueocentesis. CONCLUSIONS: Aqueocentesis is performed readily with minimal risk. The results were primarily useful in aiding a diagnosis of lymphoma in both dogs and cats.

Prevalence of uveal cysts and pigmentary uveitis in Golden Retrievers in three Midwestern states.

OBJECTIVE: To determine the prevalence of uveal cysts and pigmentary uveitis (PU) in Golden Retrievers in 3 Midwestern states. DESIGN: Prospective cross-sectional study. ANIMALS: 164 American Kennel Club-registered Golden Retrievers in the states of Illinois, Indiana, and Michigan. PROCEDURES: For all dogs, biomicroscopic and binocular indirect ophthalmoscopic examinations of both eyes were performed after pupillary dilation. A finding of pigment deposition in a radial pattern or in zones on the anterior aspect of the lens capsule of 1 or both eyes was required for a diagnosis of PU. RESULTS: Eighty of the 328 (24.4%) eyes and 57 of the 164 (34.8%) dogs had visible uveal cysts. Of those 80 eyes with cysts, 41 (51.3%) had a single cyst located nasally and posterior to the iris, 33 (41.3%) had multiple uveal cysts, and 6 (75%) had a single, free-floating cyst. A diagnosis of PU was made for 9 (5.5%) dogs. CONCLUSIONS AND CLINICAL RELEVANCE: Prevalences of uveal cysts (34.3%) and PU (5.5%) in the examined Golden Retrievers were both higher than prevalences reported previously (5.4% for uveal cysts and 1.5% for PU) in the Canine Eye Registry Foundation's 2009 All-Breeds Report. Study findings have indicated that PU is not a rare condition and should be considered as a differential diagnosis for Golden Retrievers with ocular disease.

Glaucoma associated with uveal cysts and goniodysgenesis in American Bulldogs: a case series.

We present a series of three American Bulldogs with clinical signs of glaucoma and intraocular inflammation accompanied by bilateral uveal cysts and abnormal gonioscopic findings. All dogs proved refractory to medical management and were enucleated. Histopathologic findings were similar in all three and included significant preiridal fibrovascular membranes and mononuclear inflammatory infiltrates in the anterior uvea. On microscopic evaluation, cysts appeared to arise primarily from the ciliary body and iridociliary sulcus, with smaller cysts also budding from the posterior iris. Pigment dispersion was variable but consistent, involving deposition of a small number of pigment-laden cells in the dependent trabecular meshwork. Cataract formation was not noted. Glaucoma associated with uveal cysts has been described previously in Golden Retrievers and Great Danes, although clinical and histopathologic findings in those breeds are not identical to those described here. American Bulldogs with uveal cysts should have gonioscopy performed and should be monitored carefully for signs of increased intraocular pressure and intraocular inflammation. Furthermore, documentation of cyst-associated glaucoma in a third breed suggests clinicians should exercise caution in dismissing uveal cysts in dogs as incidental findings.

Amelanotic uveal cyst in a Yorkshire terrier dog.

The diagnostic challenge presented by an amelanotic uveal cyst with an atypical appearance in a 9-year-old Yorkshire terrier dog is reported. The dog was presented with a peculiar cystic neoformation adherent to the edge of the pupil of the right eye. The cyst wall was attached to the pupillary margin and it was bean-shaped, measuring approximately 4.5 × 2.5 mm. It was white in colour with several red striations and a small brown spot in the middle, which conferred on it a peculiar appearance. The cyst could not be transilluminated and partially impaired vision. Apart from that, the ophthalmic exam revealed no other abnormalities and the eye showed no signs of inflammation. Ocular ultrasound revealed the cystic nature of the neoformation. During paracentesis of the anterior chamber, the cyst was deflated and both the cyst wall and fluid were aspirated. The tissue obtained was sent for a histological examination and was considered as corresponding to a uveal cyst. The dog improved from the post-operative uveitis without any complication and after 24 months of follow-up showed no recurrences.

Feline early life ocular disease.

OBJECTIVES: Histomorphologic changes in six globes from six cats, which experienced early life ocular disease of undetermined etiology, are described. DESIGN: A retrospective morphologic study of six eyes from six cats with early life ocular surface disease of unknown etiology, from 2002 to 2006 extracted from a pathology collection, which includes 2200 feline submissions. PROCEDURE: Sections of affected globes, stained with H&E were examined with a light microscope. RESULTS: The mean age of the affected cats, at the time of enucleation, was 7.5 months ranging from 7 weeks to 2 years. The cats were one male, one female, one male neutered, and one female spayed cat. For the remaining two cats the sex was not known. All cats were DSH. Significant histomorphologic findings included collapse of the globe in all cases and a broad corneal perforation with protrusion of the anterior uvea, which was epithelialized in all cases. Three cases revealed uveal hematopoiesis in the anterior and posterior uvea. All cases had recognizable corneal tissue at the limbus on both sides. Inflammation in all cases consisted of variable but generally mild uveitis and no eyes had endophthalmitis. Four of the globes had no recognizable lens tissue. Three of the cats had symblepharon formation described as part of the clinical condition. The other three cases had no mention of symblepharon. CONCLUSIONS: These cases are considered to represent changes associated with early life corneal ablation of unknown etiology. Uveal prolapse, mild inflammation, and symblepharon are considered to be either secondary or caused by the same destructive primary event that affected the cornea. These cases are the first cases we are aware of with uveal extramedullary hematopoiesis in cats. Careful consideration of cell morphology is necessary to distinguish this condition from round cell neoplasms or inflammation.

Use of high-resolution ultrasound as a diagnostic tool in veterinary ophthalmology.

The recent development of a 20-MHz, high-frequency ultrasound probe has allowed tissue to be visualized at resolutions of 20 to 80 microm, which is similar to a low-power histologic view. This high degree of resolution, however, limits tissue penetration to 5 to 10 mm, which is ideal for examination of the anterior segment of the eye. The detail provided by high-resolution ultrasound readily permits the clinician to distinguish between various anterior segment entities that may appear similar but are treated quite differently, such as anterior uveal tumors, iridociliary cysts, and iris bombé. High-frequency ultrasound is also a valuable aid in creating a surgical plan for treatment of ocular disorders in which the cornea is opaque, such as feline corneal sequestrum and tumor invasion into the cornea. Other applications of this technology include elucidation of the pathogenesis of glaucoma in veterinary patients and evaluation of regions of the lens that are difficult to examine directly.