Anterior Uvea Research Articles

Subconjunctival administration of mesenchymal stem cells alleviates ocular inflammation in a murine model of corneal alkali burn.

Corneal alkali burns cause extensive damage not only on the cornea but also into the intraocular tissues. As an anti-inflammatory therapy, subconjunctival administration of mesenchymal stem cells (MSCs) for corneal protection after corneal alkali burn has been explored. Little evidence demonstrates the potential of subconjunctival MSCs delivery in protecting the post-burn intraocular tissues. This study aimed to evaluate the therapeutic efficacy of subconjunctival injection of human placental (hP)-MSCs in protecting against ocular destruction after the burn. hP-MSCs were subconjunctivally administered to C57/BL mice after corneal alkali burn. Western blot of iNOS and CD206 was performed to determine the M1, M2 macrophage infiltration in the cornea. Infiltration of inflammatory cells in the anterior uvea and retina were analyzed by flow cytometry. The TUNEL assay or Western blot of Bax and Bcl2 was used to evaluate the anti-apoptotic effects of MSCs. MSCs could effectively facilitate cornea repair by suppressing inflammatory cytokines IL-1β, MCP-1, and MMP9, and polarizing CD206 positive M2 macrophages. Anterior uveal and retinal inflammatory cytokines expression and inflammatory cells infiltration were inhibited in the MSC-treated group. Reduced TUNEL positive staining and Bax/Bcl2 ratio indicated the anti-apoptosis of MSCs. MSC-conditioned medium promoted human corneal epithelial cell proliferation and regulated LPS-stimulated inflammation in RAW 264.7 macrophages, confirming the trophic and immunoregulatory effects of MSCs. Our findings demonstrate that subconjunctival administration of MSCs exerted anti-inflammatory and anti-apoptotic effects in the cornea, anterior uvea, and retina after corneal alkali burn. This strategy may provide a new direction for preventing post-event complications after corneal alkali burn.

Ocular lesions of captive cephalopods.

Ocular lesions are uncommonly reported and described in invertebrate species. In this study, cases from 2 diagnostic laboratories, in which lesions were noted in 33 diagnostic specimens from various species of cephalopods, including octopuses, squid, nautiluses, and cuttlefish, were reviewed. Clinical information and gross lesions were described in a minority of cases. The most common lesion was inflammation of varying severity and was most commonly within the anterior uvea (iris and ciliary papilla), followed by the posterior chamber and lens. More than half of the cases with inflammation had concurrent hyperplastic lesions of the iris and ciliary papilla, including posterior iris epithelial hyperplasia, cystic adenomatous hyperplasia, and/or posterior epithelial cysts. The most common clinical observation was cloudy eyes, which correlated histologically to anterior uveitis in all cases where it was documented. Dermatitis and cutaneous ulceration were the most frequent comorbidities in cases where clinical information was available.

Iris and Ciliary Body Melanocytomas Are Defined by Solitary GNAQ Mutation Without Additional Oncogenic Alterations

To analyze the genetic features of melanocytomas and melanomas of the anterior uvea and assess the value of molecular testing for diagnosis and prognostication. Retrospective case-control study. Patients with melanocytoma (n= 16) and melanoma (n= 19) of the anterior uvea. Targeted next-generation sequencing was performed on formalin-fixed, paraffin-embedded tumor tissue from anterior uveal melanocytic tumors and correlated with clinicopathologic features. Presence or absence of accompanying oncogenic alterations beyond GNAQ/GNA11 and their association with histologic features and local recurrence. Hotspot missense mutations in GNAQ/GNA11 were identified in 91% (32/35) of all cases. None of the melanocytomas with or without atypia demonstrated chromosomal imbalances or additional oncogenic variants beyond GNAQ mutation, and none recurred over a median follow-up of 36 months. Additional alterations identified in a subset of melanomas include mutations in BAP1 (n= 3), EIF1AX (n= 4), SRSF2 (n= 1), PTEN (n=1), and EP300 (n= 1); monosomy 3p (n= 6); trisomy 6p (n= 3); trisomy 8q (n= 2); and an ultraviolet mutational signature (n= 5). Local recurrences were limited to melanomas, all of which demonstrated oncogenic alterations in addition to GNAQ/GNA11 (n= 5). A single melanoma harboring GNAQ and BAP1 mutations and monosomy 3 was the only tumor that metastasized. In this study, anterior segment uveal melanocytomas did not display oncogenic alterations beyond GNAQ/GNA11. Therefore, they are genetically similar to uveal nevi rather than uveal melanoma based on their molecular features known from the literature. Molecular testing can be performed on borderline cases to aidrisk stratification and clinical management decisions.

Canine and feline uveal melanocytic tumours: Histologic and immunohistochemical characteristics of 32 cases

ObjectiveGross, histopathological, and immunohistochemical characteristics of uveal melanocytic neoplasms in dogs and cats were investigated.SamplesThirty‐two enucleated globes with uveal melanocytic neoplasms, 27 from dogs and 5 from cats, were examined.ProceduresMorphological characteristics of uveal melanocytic neoplasms in dogs and cats were evaluated with anti‐PNL2, anti‐Melan‐A, anti‐Ki‐67, anti‐caspase‐3, and anti‐BAP1 immunomarkers. Statistical analysis was performed to compare canine melanocytomas and melanomas.ResultsThe 32 uveal neoplasms were classified as melanocytomas (19/27 in dogs) or melanomas (8/27 in dogs, 5/5 in cats). Most tumours (84%) were located in the anterior uvea. Neoplastic cells were classified as epithelioid, spindle‐shaped, mixed, or special type (balloon and signet ring cells). The percentage of cells with melanin, melanin concentration within cells, anisocytosis and anisokaryosis, mitotic count, lymphocytic inflammation, necrosis, vascular invasion, and glaucoma were also characterized. Anisocytosis, percentage of neoplastic cells with melanin, mitotic count, and indices (proliferation and apoptotic) varied significantly between canine uveal melanomas and melanocytomas; in general, melanomas had greater cell variability, were less pigmented, and had a higher mitotic count. The melanocytic origin of the neoplasms was confirmed by positive anti‐PNL2 immunolabelling (29/32) and positive anti‐Melan‐A immunolabelling (3/32). In canine uveal melanomas, anisocytosis and anisokaryosis correlated with less pigmentation and minimal pigmentation correlated with a high percentage of immunolabelling for caspase‐3.ConclusionsUveal melanocytomas were more common in dogs, and uveal melanomas were more frequent in cats. Anisocytosis, percentage of neoplastic cells with melanin, and mitotic count are important histologic characteristics of malignancy to evaluate in uveal melanocytic neoplasms. The proliferation and apoptotic indices are relevant when comparing malignant tumours with benign tumours.

P22 Between the devil and the deep blue sea – a diagnostic dilemma

P22 Between the devil and the deep blue sea – a diagnostic dilemma

Multiple Congenital Ocular Anomalies in a silver coat Missouri Fox Trotter stallion.

This is the first description of Multiple Congenital Ocular Anomalies (MCOA) in a silver coat Missouri Fox Trotter determined to be heterozygous for the Silver PMEL17 missense mutation associated with MCOA and a silver coat in other breeds. The stallion was treated for meningoencephalitis and bilateral uveitis of unknown origin. A complete ophthalmic examination and ocular ultrasonography were performed. As an incidental finding, the patient exhibited bilateral cystic lesions restricted to the temporal anterior uvea consistent with the Cyst phenotype and was genotyped heterozygous for the Silver mutation. Additionally, 4 other non-silver colored Missouri Fox Trotters were genotyped homozygous for the wild-type allele. Screening for PMEL17 mutation in Missouri Fox Trotters accompanied by ophthalmic phenotype characterization is recommended to determine the allelic frequency and facilitate informed breeding decisions since the silver coat color is particularly popular.

Concurrent lacrimal gland melanocytoma and ocular melanocytosis in a dog.

A 9-y-5-mo-old, spayed female, mixed-breed dog with buphthalmia and elevated intraocular pressure in the left eye, consistent with glaucoma, was evaluated. Black-pigmented, slightly elevated tissue with irregular margins was noted on the dorsolateral aspect of the left globe. Ultrasonography detected a mass, later identified as lacrimal gland, adjacent to the globe and the thickened uvea. The surgically removed lacrimal gland was effaced by dense sheets of melanin-laden cells. Within the enucleated globe, numerous melanin-laden cells infiltrated and expanded the rostral two-thirds thickness of the cornea, the entire anterior uvea (iris and ciliary body), and a rostral portion of the choroid. Melanin-laden cells in the left lacrimal gland and globe showed no nuclear atypia or mitotic figures, and reacted to anti-S100 and anti-melan A antibodies by immunohistochemistry. Our final diagnosis was concurrent lacrimal gland melanocytoma and ocular melanocytosis. The trabecular meshwork of the eye was obliterated by melanin-laden cells, which was the likely cause of glaucoma in this patient. To our knowledge, melanocytoma affecting the lacrimal gland has not been reported previously in a non-human mammalian species. Veterinary clinicians are encouraged to include melanocytoma in the differential list when examining an enlarged lacrimal gland.

Factors of Excessive Proliferation after Trabeculectomy in Pediatric Uveitic Glaucoma

Objective: to study efficacy and factors of excessive proliferation after trabeculectomy (T) in pediatric uveitic glaucoma (UG).Patients and Methods. 102 children aged from 3 to 17.5 years (mean 124.5 ± 2.8 month) with uncontrolled on maximum topical hypotensive therapy open angle or combined (with peripheral anterior synechiae) form of UG underwent T (148 eyes, 180 operations). 76.1 % operations were performed with intraoperative 5-fluorouracil, 8.3 % — with mitomycin C, 6.1 % — with bioresorbable, 1.7 % — with collagen drainage, 7.8 % — without antimetabolites or drainages. Kaplan-Meier survival analysis was performed.Results. Overall absolute (without hypotensive therapy) success probabilities were 67 %, 46 %, 39 %, qualified success (with hypotensive therapy) — 93 %, 72 %, 54 % at 1, 3, 5 years after T respectively. Factors associated with failure were primary location of inflammation in anterior uvea, aphakic or pseudophakic eye, repeat T, bioresorbable drainage (vs. 5-fluorouracil), persistent inflammation after T. Age and uveitis activity at the moment of T, duration hypotensive therapy before primary T, postoperative complications (9.4 %), frequency of postoperative topical steroid had no significant influence on surgical success.Conclusion. T with intraoperative antimetabolites is effective, safe and nowadays may be recommended as first choice operation in pediatric open angle or combined UG.

Pilot study supporting the existence of novel lymphatic channels within the canine anterior uveal tract using Lyve-1 and CD31.

To demonstrate the existence of lymphatics in the canine anterior uvea using lymphatic-specific markers Lyve-1, Prox-1, and podoplanin, the endothelial cell marker CD31, and basement membrane matrix marker collagen IV. Prospective Study. Eight normal globes from animals euthanized for unrelated health problems. Sagittally cut serial sections of six normal canine eyes were immunofluorescence double-stained with Lyve-1 and CD31 and single-stained with colorimetric Prox-1 and collagen IV. Three serial sections from 2 additional eyes were cut in the coronal plane at the level of the ciliary body and immunofluorescence double-stained with Lyve-1 and CD31 to map lymphatic channel distribution. Lymphatics from normal canine lymph nodes were used for validation of podoplanin. Four of 6 of the sagitally sectioned eyes had Lyve-1-positive lymphatic-like structures that were distinct from CD31-positive blood vessels in the iris base and ciliary body. Both of the coronally sectioned globes had Lyve-1-positive lymphatic-like structures in the ciliary body. The location of these structures was evaluated and found to be diffusely present circumferentially around the ciliary body. These results support the existence of lymphatic channels in the anterior uveal tract of the canine eye. This could indicate the presence of a novel uveolymphatic outflow pathway, which may play a role in aqueous humor outflow. Future studies are needed to confirm the existence and elucidate the role of this proposed uveolymphatic outflow pathway and potentially develop novel treatment options for managing glaucoma.

Overview of Non-infectious Uveitis, Mechanisms, Immunopathology, Classification, and General Clinical Findings

Uveitis is the inflammation of the anterior, intermediate, or posterior uvea, the pigmented part of the eye. Uveitis can be infectious or non-infectious presented as autoimmune and immune-mediated. Non-infectious uveitis is the most common type of uveitis. It can be idiopathic or secondary to systemic diseases. Differential diagnosis is important, if early diagnosis and treatment are not applied, permanent eye damage can occur. In this review, an overview of non-infectious uveitis is examined with the mechanism, immunopathology, and classification.

Ophthalmopathologic characterization of multicentric or metastatic neoplasms with an extraocular origin in dogs and cats

To characterize the frequency and distribution of secondary ocular neoplasms in dogs and cats identified during necropsy. A retrospective analysis of necropsy records of dogs and cats was conducted, and cases with metastatic/multicentric neoplasms with an extraocular origin, involving the eyes, were selected. From January 2015 to January 2019, we identified a total of 233 dogs and 100 cats with metastatic disease. Of these, 11.6% (27/233) of the dogs and 13% (13/100) of the cats had ocular metastases. Lymphoma was the most common multicentric neoplasm involving the eyes of both species. In dogs, these neoplasms occurred bilaterally, predominantly in the anterior uvea, and were diffuse large B-cell, T-lymphoblastic, peripheral T-cell not otherwise specified, and lymphocytic B-cell lymphomas. In cats, feline leukemia virus (FeLV)-associated T-cell lymphoma was the most common. Mammary carcinoma was the second most common ocular metastatic neoplasm in bitches, with a predominantly unilateral involvement of the uveal tract. In cats, following lymphoma, pulmonary and squamous cell carcinomas were the most common multicentric/metastatic neoplasms of the eyes. Individual cases of cholangiocarcinoma, hemangiosarcoma, and chemodectoma in dogs, as well as mammary gland cribriform carcinoma, salivary gland carcinoma, and histiocytic sarcoma in cats were detected. The eyes of dogs were mostly affected by lymphoma or mammary gland carcinoma, while those of cats mostly had lymphoma, pulmonary carcinoma, or squamous cell carcinoma as the main metastatic/multicentric neoplasm. To the best of our knowledge, this is the first study to identify intraocular metastatic cholangiocarcinoma and chemodectoma in dogs, aside from identifying salivary gland carcinoma in cats.

Absence of Severe Acute Respiratory Syndrome-Coronavirus-2 RNA in ocular tissues

PurposeTo evaluate the status of ocular donor tissues of a COVID-19 postmortem donor. MethodsSARS-CoV-2 was detected via a pharyngeal swab and broncho-alveolar lavage in the COVID-19 suspect. Postmortem tissue procurement and preparation were performed with personal protective equipment (PPE) and the necessary protective measures. qRT-PCR-testing was performed for the following ocular tissues and fluids: conjunctival fluid swabs, bulbar conjunctiva, corneal epithelium, corneal stroma, corneal endothelium, anterior chamber fluid, lens, iris, vitreous, retina, uvea, sclera, and optic nerve. Informed consent and Institutional Review Board approval was obtained prior to this study (196/2020BO2; Date of approval: 03/26/2020; Ethics Committee of the University of Tuebingen). ResultsIn all ocular tissue and fluid samples no SARS-CoV-2 RNA was detected via qRT-PCR of the confirmed COVID-19 postmortem donor. Conclusions and ImportanceLate-stage COVID-19 patients might not harbor an ocular reservoir of SARS-CoV-2. The risk of transmitting SARS-CoV-2 via ocular tissues and fluids might be low. This may bear future implications for patient management in ophthalmological practice, surgery and transplantation.

Analysis of retinal microvasculature in Fuchs’ uveitis syndrome. Retinal microvasculature in Fuchs’ uveitis

The objective of this study is to quantitatively analyse the foveal microvasculature in eyes with Fuchs' Uveitic Syndrome (FUS), or Fuchs' Heterochromic Iridocyclitis (FHI), by Optical coherence tomography angiography (OCTA). Thirty patients with FUS and 30 healthy volunteer patients (control group) were enrolled in the study. Vascular density (VD) in the superior and deep capillary plexuses (SCP, DCP) were reported and compared between eyes with FUS (FU), fellow eyes (FE) and the control group. Foveal VD and parafoveal VDs in all quadrants of the SCP were significantly lower in the FU group than the FE group and normal eyes (P<0.05). Foveal VDs in the DCP were similar between the three groups (P>0.05); however, parafoveal VDs in all quadrants of the DCP were significantly lower in the FU group than in the FE and control eyes (P<0.05). Foveal and parafoveal VDs in both the SCP and DCP were similar between fellow eyes and the control group. Fuchs' Uveitic Syndrome (Fuchs' Heterochromic Iridocyclitis) affects not only the anterior uvea and vitreous but also the retinal microvasculature. Analysis by OCT-A may enable us to understand the extent of this disease.

Clinical, ultrasonographic, and histopathologic findings in seven horses with Descemet's membrane detachment: A case series

ObjectiveTo describe ultrasonography as a diagnostic method of in vivo Descemet's membrane detachment (DMD) in horses. Animals studied: Seven horses (three Icelandic horses, two Dutch Warmblood horses, one Appaloosa, and one Welsh Pony), presenting with moderate‐to‐severe focal or diffuse corneal edema, in whom DMD was suspected on ultrasonographic examination and confirmed with histopathology, were studied.ProcedureA retrospective analysis of case records of horses with suspected DMD was performed.ResultsMedian age at presentation was 14 years (range 11‐24). Clinical signs in eyes with DMD were unilateral in all horses and included blepharospasm and epiphora (6/7), buphthalmos (5/7), moderate‐to‐severe focal or diffuse corneal edema (7/7), corneal epithelial bullae (4/7), corneal neovascularization (4/7), Haab's striae (2/7), corneal endothelial precipitates (1/7), fibrin in the anterior chamber (1/7), focal cataract (2/7), and pigment deposits on the anterior lens capsule (1/7). During transpalpebral ultrasonography, a distinct linear echogenic structure was noted in the anterior chamber, initially diverging from, and later running parallel to, the posterior lining of the cornea in all eyes studied. In all cases, the cornea was severely thickened and echogenic, consistent with edema, and DMD was suspected. In all horses, the clinical signs progressed and the affected eye was eventually enucleated. Histopathology revealed DMD (7/7), spindle cell proliferation (4/7), Descemet's membrane reformation (3/7), and inflammation of the anterior uvea (5/7). Overall incidence was 1.04%.ConclusionsUltrasonography is an adequate tool in diagnosing DMD in horses. Descemet's membrane detachment should be included in the differential diagnosis in horses with dense focal or diffuse corneal edema.

Tectonic Keratoplasty to Restore the Bulbar Wall after Block Excision of Benign and Malignant Intraocular Tumors.

Purpose To report the surgical treatment and follow-up of tumors of the anterior uvea and epithelial cysts of the anterior chamber in 4 patients submitted to block excision and tectonic corneal graft between 2008 and 2012. Methods This is a retrospective, nonrandomized case series. Two patients were affected by anterior uveal malignant melanoma, and 2 patients were referred to us for large epithelial iris cysts with anterior chamber angle involvement and partial corneal failure. A simultaneous block removal of the lesion and adjacent iris, cornea (when necessary), ciliary body, and sclera was performed; the resulting defect was covered by a tectonic whole thickness corneal graft. Follow-up ranged from 2 to 7 years (mean time: 5 ± 1.6 MD). Results Local control of malignant melanoma was observed during the follow-up, but cataract surgery was planned in both patients and pars plana vitrectomy for vitreous hemorrhage occurred in one case. No recurrence of cysts was detected. After iris cysts excision, a planned second-time surgery was necessary in one patient: optical penetrating keratoplasty, centered on the visual axis, implantation of one refractive IOL (intraocular lens) in the bag, and one cosmetic IOL in the sulcus, to restore the iris diaphragm. Conclusions Block excision followed by the tectonic corneal graft seems to be the treatment of choice for selected cases of epithelial cysts of the anterior chamber and anterior uvea melanomas with epibulbar extension. Further surgery, as a second step, could be required to improve functional results of this challenging technique.

Lassa Virus Targeting of Anterior Uvea and Endothelium of Cornea and Conjunctiva in Eye of Guinea Pig Model.

Lassa virus (LASV), a hemorrhagic fever virus endemic to West Africa, causes conjunctivitis in patients with acute disease. To examine ocular manifestations of LASV, we histologically examined eyes from infected guinea pigs. In fatal disease, LASV immunostaining was most prominent in the anterior uvea, especially in the filtration angle, ciliary body, and iris and in and around vessels in the bulbar conjunctiva and peripheral cornea, where it co-localized with an endothelial marker (platelet endothelial cell adhesion molecule). Antigen was primarily associated with infiltration of T-lymphocytes around vessels in the anterior uvea and with new vessel formation at the peripheral cornea. In animals that exhibited clinical signs but survived infection, eyes had little to no inflammation and no LASV immunostaining 6 weeks after infection. Overall, in this model, LASV antigen was restricted to the anterior uvea and was associated with mild chronic inflammation in animals with severe disease but was not detected in survivors.

Quantitative, noninvasive assessment of intra- and extraocular perfusion by contrast-enhanced ultrasonography and its clinical applicability in healthy dogs.

ObjectiveTo assess quantitative perfusion of intra‐ and extraocular regions of interest (ROIs) in conscious, healthy dogs utilizing contrast‐enhanced ultrasonography (CEUS); to compare varying enhancement with the first and second bolus injection and in the right and left eye; and to determine the most appropriate examination time.ProceduresGray scale ultrasonography and contrast harmonic imaging using sulfur hexafluoride were performed randomly assigned in both eyes in 10 university‐owned beagles. Perfusion parameters including slope time, time to peak (TTP), peak intensity (PI), and area under the curve (AUC) were measured at individually drawn ROIs (retrobulbar cone = ROI 1, choroid‐retina complex = ROI 2, medial = ROI 3, and lateral anterior uvea = ROI 4).ResultsTime‐intensity curve parameters revealed no significant differences in eyes examined by the first or second bolus injection (P > 0.05) or in the right or left eye (P > 0.05). Pooled data from all eyes were analyzed. Peak intensity of ROI 2 was significantly higher compared to all other ROIs (P < 0.001). Area under the curve at ROI 2 was significantly higher compared to all other ROIs (P < 0.05), and AUC at ROI 1 was significantly higher than at ROI 4 (P < 0.05). No significant differences in TTP were observed between different ROIs (P > 0.05). Ratios relative to different ROI sizes showed fastest enhancement in the retrobulbar cone and most intense perfusion in the anterior uveal regions. The first minute after contrast injection provided the highest diagnostic value.ConclusionQuantitative perfusion in nondiseased canine eyes revealed consistent parameters. Application of standardized CEUS protocols may be a promising diagnostic tool to differentiate ocular lesions.

Different composition of intraocular immune mediators in Posner-Schlossman-Syndrome and Fuchs’ Uveitis

Posner-Schlossman-Syndrome (PSS) is clinically characterized by acute, recurrent, mild, unilateral uveitis anterior accompanied by elevated intraocular pressure (IOP). Fuchs´ Uveitis (FU) is a chronic, low-grade-inflammatory disorder, involving anterior uvea and vitreous. The clinical findings show remarkable similarities as well as differences. In our study, we determine the composition of immune mediators in aqueous humor of patients with PSS and FU and evaluate if immune mediators play a crucial role in specific viral intraocular inflammation and IOP rises. Aqueous humor samples from 81 uveitis patients (= eyes) presenting with either PSS or FU were collected at one time point. Local intraocular antibody synthesis to rubella virus was confirmed in 65 patients, whereas 16 were tested positively for human cytomegalovirus. Thirteen patients with PSS and 10 patients with FU were treated with glaucoma medications. Additionally, 11 cataract patients acted as control group. Immune mediator concentrations were measured by Bio-Plex Pro assay. We observed in both PSS (IFN-γ: 174.9 pg/mL; TNF-α: 25.1 pg/mL) and FU (IFN-γ: 25.4 pg/mL; TNF-α: 27.2 pg/mL) groups a significantly increased level of T-helper 1 immune mediators compared to controls (IFN-γ, TNF-α: 0 pg/mL) [median]. Notably, PSS patients (IL-1RA: 73.4 pg/mL; IL-8: 199.4 pg/mL; IL-10: 33.4 pg/mL; IP-10: 126350 pg/mL) showed a stronger and more active ocular inflammatory response, than FU patients (IL-1RA: 4.3 pg/mL; IL-8: 72.4 pg/mL; IL-10: 1.6 pg/mL; IP-10: 57400 pg/mL). Furthermore, a negative correlation between mediators and IOP was seen in the PSS group, potentially caused by acetazolamide-treatment. Our findings show that immune mediators play a crucial role in specific viral intraocular inflammation and influence IOP levels. Remarkable similarities but also significant differences of immune mediator concentrations are apparent in PSS compared to FU. High concentrations of IL-1RA, IL-8, IL-10, and IP-10 correlate with active inflammation in PSS, while FU may trigger chronic inflammation. Our data also substantiated a very similar composition of cytokines in those patients from the PSS group suffering from ocular hypertension and thus offers a potential explanation model for a negative correlation between mediators and IOP.

Physiological characterization of ocular melanosis-affected canine melanocytes.

Cairn terriers with ocular melanosis (OM) accumulate large, heavily pigmented melanocytes in the anterior uvea. Darkly pigmented plaques develop within the sclera, leading us to hypothesize that OM uveal melanocytes may have an abnormal migratory capacity. Globes from OM-affected Cairn terriers and unaffected control eyes enucleated for reasons unrelated to this study were used for immunohistochemistry and to culture melanocytes for invitro cell behavior assays. The scleral plaques of six dogs were immunolabeled for HMB-45, MelanA, PNL2, CD18, CD204, and Iba-1 and compared with the pigment cells accumulated within the irides. Cultured uveal melanocytes from OM-affected and control dogs were compared using conventional assays measuring cell proliferation, invasion capability, and melanin production. Melanocytes isolated from OM eyes had significantly elevated levels of per-cell melanin content and production compared to controls. The majority of pigmented cells in the scleral plaques were HMB45 positive indicating a melanocytic origin. Many were also CD18 positive. No differences were observed between cultured melanocytes from OM-affected and control uvea for standard invitro proliferation or invasion assays. Pigmented cells which accumulate in the sclera of OM-affected Cairn terriers are predominantly melanocytes; however, invitro assays of uveal melanocytes did not reveal differences in migratory behavior between OM and control cells. Migratory behavior of OM-melanocytes may be environment-dependent. We suggest that RNA sequencing and differential expression analysis would be a useful next step in understanding this disease.

Immunohistochemical characterization of feline lymphoplasmacytic anterior uveitis.

To characterize the immune cells present in different forms of feline anterior uveitis. Eyes were obtained from 49 cats diagnosed with chronic idiopathic lymphoplasmacytic anterior uveitis, 7 cats with feline infectious peritonitis (FIP), and 9 cats euthanized for nonocular disease. H&E sections were scored on the level of infiltrate in the anterior uvea. Immunohistochemistry was performed for FoxP3, CD3, and IL-17A, and positive cells were quantified in multiple images of each sample. A generalized estimating equationtested for an association between the level of inflammation and the prevalence of these cell types. Cells stained positive for IL-17A in idiopathic uveitis but not in FIP samples. We found significantly fewer FoxP3+ and CD3+ cells in low-grade compared with high-grade inflammation in idiopathic uveitis or FIP samples (P values all <.005), but no difference between FIP and high-grade samples. Idiopathic, but not FIP-associated, uveitis appears to have Th17 cell involvement. The numbers of FoxP3+ and CD3+ T-cells present appear directly correlated; thus, the severity of disease does not appear directly determined by the numbers of regulatory cells.