Ocular Histopathology Research Articles

Expert consensus on the diagnosis and treatment of immunoglobulin-G4 related ophthalmic disease (2024 edition)

Immunoglobulin-G4 related ophthalmic disease (IgG4-ROD) is an immune-mediated fibroin flammatory condition characterized by ocular mass lesions and elevated plasma IgG4 level. Since all the ocular tissues can be involved, and it can be accompanied by multiple organ and systemic diseases, the diagnosis and treatment require multidisciplinary collaboration. The Oculoplastic and Orbital Disease Group of Chinese Ophthalmological Society of Chinese Medical Association and the Chinese Rheumatology Association convened experts in ophthalmology, and rheumatology and immunology, and formulated "Expert consensus on the diagnosis and treatment of immunoglobulin-G4 related ophthalmic disease (2024 edition)" for the diagnosis and treatment of IgG4-ROD based on domestic and international studies and experience. The consensus mainly standardized the diagnostic criteria of IgG4-ROD from the aspects of ocular imaging, serum IgG4 level and ocular histopathology, and recommended the methods and indications of drug therapy (glucocorticoids, immunosuppressants and biologics) and surgical treatment.

Comparison of Glutathione Nanoparticles, CoEnzyme Q10, and Fish Oil for Prevention of Oxygen-Induced Retinopathy in Neonatal Rats.

Notch ligands and receptors are important for cell specification and angiogenesis, but their role in oxygen-induced retinopathy (OIR) is not well studied. Delta-like ligand (DLL)-4/Notch inhibits angiogenesis, while Jagged-1/Notch promotes angiogenesis. We tested the hypothesis that early supplementation with antioxidants and/or fish oil curtails severe OIR by inducing DLL-4/Notch and reducing Jagged-1/Notch. Newborn rats were exposed to brief intermittent hypoxia (IH) during hyperoxia, during which they received daily oral supplements of (1) fish oil, (2) coenzyme Q10 (CoQ10) in olive oil (OO), (3) glutathione nanoparticles (nGSH), (4) fish oil + CoQ10, or (5) OO (controls) from birth (P0) to P14. At P14, the pups were placed in room air (RA) until P21, with no further treatment. Oxidative stress, apoptosis, ocular histopathology, and Notch signaling were assessed. Neonatal IH resulted in severe retinal damage consistent with retinopathy of prematurity (ROP). Retinal damage was associated with induced oxidative stress and Jagged-1/Notch signaling, as well as reduced DLL-4/Notch signaling. All treatments reversed these outcomes, but nGSH produced the most beneficial outcomes. Severe OIR promoted the induction of Jagged-1/Notch and curtailed DLL-4/Notch, which was an effect that could be reversed with nGSH supplementation. These findings may indicate a potential alternate pathway for ROP treatment and/or prevention.

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

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

Preliminary evaluation of safety and migration of immune activated mesenchymal stromal cells administered by subconjunctival injection for equine recurrent uveitis.

Equine recurrent uveitis (ERU), an immune mediated disease characterized by repeated episodes of intra-ocular inflammation, affects 25% of horses in the USA and is the most common cause of glaucoma, cataracts, and blindness. Mesenchymal stromal cells (MSCs) have immunomodulatory properties, which are upregulated by preconditioning with toll-like receptor agonists. The objective was to evaluate safety and migration of TLR-3 agonist polyinosinic, polycytidylic acid (pIC)-activated MSCs injected subconjunctivally in healthy horses prior to clinical application in horses with ERU. We hypothesized that activated allogeneic MSCs injected subconjunctivally would not induce ocular or systemic inflammation and would remain in the conjunctiva for >14 days. Bulbar subconjunctiva of two horses was injected with 10 × 106 pIC-activated (10 μg/mL, 2 h) GFP-labeled MSCs from one donor three times at two-week intervals. Vehicle (saline) control was injected in the contralateral conjunctiva. Horses received physical and ophthalmic exams [slit lamp biomicroscopy, rebound tonometry, fundic examination, and semiquantitative preclinical ocular toxicology scoring (SPOTS)] every 1-3 days. Systemic inflammation was assessed via CBC, fibrinogen, and serum amyloid A (SAA). Horses were euthanized 14 days following final injection. Full necropsy and histopathology were performed to examine ocular tissues and 36 systemic organs for MSC presence via IVIS Spectrum. Anti-GFP immunohistochemistry was performed on ocular tissues. No change in physical examinations was noted. Bloodwork revealed fibrinogen 100-300 mg/dL (ref 100-400) and SAA 0-25 μg/mL (ref 0-20). Ocular effects of the subjconjucntival injection were similar between MSC and control eyes on SPOTS grading system, with conjunctival hypermia, chemosis and ocular discharge noted bilaterally, which improved without intervention within 14 days. All other ocular parameters were unaffected throughout the study. Necropsy and histopathology revealed no evidence of systemic inflammation. Ocular histopathology was similar between MSC and control eyes. Fluorescent imaging analysis did not locate MSCs. Immunohistochemistry did not identify intact MSCs in the conjunctiva, but GFP-labeled cellular components were present in conjunctival phagocytic cells. Allogeneic pIC-activated conjunctival MSC injections were well tolerated. GFP-labeled tracking identified MSC components phagocytosed by immune cells subconjunctivally. This preliminary safety and tracking information is critical towards advancing immune conditioned cellular therapies to clinical trials in horses.

Evaluation of trabecular meshwork-specific promoters in vitro and in vivo using scAAV2 vectors expressing C3 transferase.

To evaluate the potential of two trabecular meshwork (TM)-specific promoters, Chitinase 3-like 1 (Ch3L1) and matrix gla protein (MGP), for improving specificity and safety in glaucoma gene therapy based on self-complementary AAV2 (scAAV2) vector technologies. An scAAV2 vector with C3 transferase (C3) as the reporter gene (scAAV2-C3) was selected. The scAAV2-C3 vectors were driven by Ch3L1 (scAAV2-Ch3L1-C3), MGP (scAAV2-MGP-C3), enhanced MGP (scAAV2-eMGP-C3) and cytomegalovirus (scAAV2-CMV-C3), respectively. The cultured primary human TM cells were treated with each vector at different multiplicities of infections. Changes in cell morphology were observed by phase contrast microscopy. Actin stress fibers and Rho GTPases/Rho-associated protein kinase pathway-related molecules were assessed by immunofluorescence staining, real-time quantitative polymerase chain reaction and Western blot. Each vector was injected intracamerally into the one eye of each rat at low and high doses respectively. In vivo green fluorescence was visualized by a Micron III Retinal Imaging Microscope. Intraocular pressure (IOP) was monitored using a rebound tonometer. Ocular responses were evaluated by slit-lamp microscopy. Ocular histopathology analysis was examined by hematoxylin and eosin staining. In TM cell culture studies, the vector-mediated C3 expression induced morphologic changes, disruption of actin cytoskeleton and reduction of fibronectin expression in TM cells by inhibiting the Rho GTPases/Rho-associated protein kinase signaling pathway. At the same dose, these changes were significant in TM cells treated with scAAV2-CMV-C3 or scAAV2-Ch3L1-C3, but not in cells treated with scAAV2-eMGP-C3 or scAAV2-MGP-C3. At low-injected dose, the IOP was significantly decreased in the scAAV2-Ch3L1-C3-injected eyes but not in scAAV2-MGP-C3-injected and scAAV2-eMGP-C3-injected eyes. At high-injected dose, significant IOP reduction was observed in the scAAV2-eMGP-C3-injected eyes but not in scAAV2-MGP-C3-injected eyes. Similar to scAAV2-CMV-C3, scAAV2-Ch3L1-C3 vector showed efficient transduction both in the TM and corneal endothelium. In anterior segment tissues of scAAV2-eMGP-C3-injected eyes, no obvious morphological changes were found except for the TM. Inflammation was absent. In scAAV2-transduced TM cells, the promoter-driven efficiency of Ch3L1 is close to that of cytomegalovirus, but obviously higher than that of MGP. In the anterior chamber of rat eye, the transgene expression pattern of scAAV2 vector is presumably affected by MGP promoter, but not by Ch3L1 promoter. These findings would provide a useful reference for improvement of specificity and safety in glaucoma gene therapy using scAAV2 vector.

Type I Interferon Signaling Is Critical During the Innate Immune Response to HSV-1 Retinal Infection.

Acute retinal necrosis (ARN) is a herpesvirus infection of the retina with blinding complications. In this study, we sought to create a reproducible mouse model of ARN that mimics human disease to better understand innate immunity within the retina during virus infection. C57Bl/6J wild type (WT) and type I interferon receptor-deficient (IFNAR-/-) mice were infected with varying amounts of herpes simplex virus type 1 (HSV-1) via subretinal injection. Viral titers, optical coherence tomography (OCT) and fundus photography, the development of encephalitis, and ocular histopathology were scored and compared between groups of WT and IFNAR-/- mice. The retina of WT mice could be readily infected with HSV-1 via subretinal injection resulting in retinal whitening and full-thickness necrosis as determined by in vivo imaging and histopathology. In IFNAR-/- mice, HSV-1-induced retinal pathology was significantly worse when compared with WT mice, and viral titers were significantly elevated within two days after infection and persisted to day 5 after infection within the retina. These results were also observed in the brain where there were significantly higher viral titers and frequency of encephalitis in IFNAR-/- when compared to WT mice. Collectively, these findings show that our new mouse model of ARN mimics human disease and can be used to study innate immunity within the retina. We conclude that type I interferons are critical in containing HSV-1 locally within retinal tissues and prohibiting spread into the brain.

Clinical and pathologic evaluation of chorioretinal lesions in wild owl species.

Investigate histopathology and spectral-domain optical coherence tomography (OCT) imaging of wild owls with chorioretinitis and identify any potential correlation with an infectious etiology. Ophthalmic examination and retinal OCT imaging were performed on fifteen great horned (Strix varia) and barred (Bubo virginianus) owls (30 eyes) with chorioretinitis and five owls with normal eyes (10 eyes). Testing to investigate the presence of potential infectious diseases included a complete blood count, biochemistry, protein electrophoresis, West Nile virus (WNV) plaque reduction neutralization test, Toxoplasma gondii modified direct agglutination test, WNV RT-PCR, and Avian Influenza RT-PCR. A necropsy was performed on all owls, including ocular histopathology. Fundus lesions included retinal detachment (7/15 owls), depigmented lesions (12/15), pigment clumping (8/15), and retinal tear (4/15). All birds were negative for WNV and Avian Influenza on RT-PCR. Of the owls with chorioretinitis, 3/15 were seropositive for WNV and 7/15 for T.gondii. Optical coherence tomography of 25/30 affected eyes revealed outer retinal lesions (19/25 eyes), retinal detachment (16/25), and retinal tears (3/25). Histopathological examination revealed outer nuclear layer atrophy (19/30 eyes), retinal detachment (18/30), retinal tears (7/30), suprachoroidal hemorrhage (12/30), scleral rupture (3/30), and ossicle fracture (3/30). Although 20% of birds were seropositive for WNV and 46.6% for T.gondii, histopathologic findings supported that the posterior segment lesions in the study group were likely due to blunt ocular trauma rather than an infectious etiology. The results of OCT imaging and histopathology documented retinal changes most consistent with blunt ocular trauma.

Correlations Between Retinal Optical Coherence Tomography and Histopathology in Preclinical Safety Assessment of Ocular Therapies.

Twelve studies that involved intravitreal or subretinal test article administration in multiple laboratory animal species and employed both OCT and histopathologic assessment were identified. These data were compared to determine the degree of correlation for each identified abnormality. Severity of observed OCT and histopathological changes ranged from minimal to severe, with moderate and severe changes having a higher rate of agreement between the 2 techniques. Changes to well-defined structures, including the retinal blood vessels, optic nerve, and retinal pigment epithelium, also showed a strong correlation. There was a strong correlation between OCT and histopathology in both intravitreal and subretinal injection studies, demonstrating the value of collaboration between the study ophthalmologist and pathologist and offering translatable means to monitor pharmacological or toxicological effects in preclinical toxicological studies.

Evaluation of the Safety and Long-term Scleral Biomechanical Stability of UVA Cross-linking on Scleral Collagen in Rhesus Monkeys.

To investigate the changes of retinal and choroidal parameters, scleral biomechanical strength, and ocular histopathology after scleral ultraviolet-A (UVA) cross-linking (CXL) in rhesus monkeys eyes, and to evaluate the safety and long-term biomechanical stability of scleral CXL for preventing myopia from progressing further in clinic. Six 3-year-old male rhesus monkeys (12 eyes) were randomized to receive UVA-CXL procedures applied on the superotemporal equatorial sclera. Optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA) were used for examination before and 1 week and 1, 3, 6, and 12 months after CXL. The stress-strain behaviors of equatorial scleral strips were analyzed 12 months postoperatively by a biomaterial tester. Hematoxylin-eosin and terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) staining were performed 12 months postoperatively. For central retinal thickness, choroidal thickness, and flow density of central retinal superficial vascular networks, no statistical difference was noted between CXL eyes and control eyes at 12 months postoperatively (P > .05). The biomechanical stability of sclera was increased. The scleral stress and Young modulus at 8% strain corresponded to 184% and 183%, respectively, of the control values at 12 months (each P < .001). No retinal damage was detected on histology in scleral CXL eyes. There was no obvious difference between scleral CXL eyes and control eyes by hematoxylin-eosin and TUNEL staining (P > .05). Scleral CXL with riboflavin/UVA in rhesus monkey eyes could strengthen the biomechanical properties of scleral tissues and maintain the stability for 12 months postoperatively. The UVA-CXL on the sclera of rhesus monkey eyes seems to be effective and safe. [J Refract Surg. 2020;36(10):696-702.].

Outer retinal involvement in N-methyl-D-aspartate-induced inner retinal injury in rabbits assessed by optical coherence tomography.

This study was aimed to investigate morphological alteration of the retina with N-methyl-D-aspartate (NMDA)-induced injury in rabbits by optical coherence tomography (OCT). The right and left eyes of a total of 12 rabbits received single-intravitreal injection of vehicle and NMDA, respectively. Four out of the 12 animals underwent OCT and quantification of plasma microRNA repeatedly (4, 48, and 168 hr after dosing), followed by ocular histopathology at the end of the study. Ocular histopathology was also conducted in the eyes collected 4 or 48 hr after dosing from 4 animals at each time period. OCT revealed hyper-reflective ganglion cell complex and thickened inner retina in NMDA-treated eyes 4 hr after dosing; the inner retina shifted to thinning at later time points. The eyes given NMDA also exhibited greater thickness of the outer retina, which contains photoreceptors, after treatment, and thickened and obscured ellipsoid zone 168 hr after dosing. The plasma levels of miR-182 and miR-183, which are known to be highly expressed in photoreceptors, were higher 4 hr after dosing than pre-dosing values. Histopathologically, NMDA-induced inner retinal damage was confirmed: single-cell necrosis was observed in the ganglion cell layer and the inner nuclear layer 4 hr after dosing, the incidence of which decreased thereafter. At 168 hr after dosing, reduced number of ganglion cells was noted. No change was histopathologically observed in the outer retina. In conclusion, our results suggest involvement of photoreceptors in NMDA-induced inner retinal injury. Additionally, OCT revealed acute inner retinal findings suggestive of temporary edema.

Efficacy and safety of a novel naltrexone treatment for dry eye in type 1 diabetes

BackgroundDry eye disease (DED) is a prevalent complication of diabetes and presents as reduced tear production and/or increased corneal surface sensitivity often with secondary ocular surface changes. This study examined the safety and efficacy of a proprietary new eye drop formulation for topical treatment of DED.MethodsType 1 diabetes (T1D) was established in male Sprague-Dawley rats to study the efficacy and safety of the investigational compound that contained 20 μg/ml of naltrexone (NTX). Tear production was measured by the Schirmer’s 1 test, and ocular surface sensitivity was measured using an aesthesiometer. Diabetic rats received twice daily applications of a single drop (~ 0.02 ml) of the proprietary formulation (NTX-001) or vehicle onto one eye. For comparison, some diabetic rats received eye drops containing NTX in sterile Vigamox®. Safety was monitored by assessment of ocular histopathology in naïve male rats and naïve male rabbits receiving twice daily treatment of two drops for 30 days.ResultsDry eye in T1D rats was reversed within hours of a single treatment of NTX-001, and over a period of 10 days NTX-001 restored corneal sensitivity and reversed dry eye relative to values measured in diabetic rats receiving vehicle. In comparison to NTX dissolved in Vigamox®, the proprietary NTX-001 was more effective at reversing dry eye. Safety studies in naïve rats and rabbits revealed no visible ocular pathology after 30 days of treatment.ConclusionsAn investigational new eye drop containing 20 μg/ml NTX effectively reversed tear film deficits and restored corneal surface sensitivity in diabetic animals without causing toxic side effects.

Assessment of phototoxicity in pigmented Long-Evans rat: sparfloxacin and 8-methoxypsoralen

The aim of the present work was to evaluate the effects of photo-activated toxicity induced after administration of two known melanin-binding phototoxic compounds, sparfloxacin (SPX) and 8-methoxypsoralen (8-MOP), followed or not by UVA/Vis exposure, in pigmented rats (Long Evans: LE) and albino rats (Sprague Dawley: SD). Groups of three rats were treated with SPX or 8-MOP by oral gavage for six consecutive days. Irradiated animals were submitted to a UVA/Vis light dose standardized to 10 J/cm2 UVA daily. Clinical signs, cutaneous reactions and body weight were monitored throughout the study period. Ear biopsy weight, lymph node weight and lymph node cell count were determined at necropsy. Ophthalmologic examinations were performed before the first treatment and on the day of sacrifice. Microscopic examinations were performed on skin biopsies and eyes. Phototoxicity was demonstrated for both SPX and 8-MOP in the pigmented and albino strains, in terms of auricular irritation, lymph node weight and proliferation index, cutaneous reactions and ocular histopathology. LE rats were less sensitive than SD rats, especially at the ocular level, supporting the notion that pigmentation may provide protection against photo-activation. The pigmented rat may be a more relevant model than the albino rat for human safety evaluation.

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

ObjectiveTo describe aqueocentesis cytopathology results from dogs and cats presenting for uveitis investigation and to determine whether this is a useful and safe procedure.Animal StudiedDogs and cats presenting for investigation of anterior uveitis (April 2008–December 2013).ProceduresAqueous 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.ResultsFifty‐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.ConclusionsAqueocentesis is performed readily with minimal risk. The results were primarily useful in aiding a diagnosis of lymphoma in both dogs and cats.

Retinal dysplasia in American pit bull terriers--phenotypic characterization and breeding study.

The purpose of this study was to investigate the inheritance and phenotype of retinal dysplasia (RD) in the American pit bull terrier. A breeding colony established from a single female pure-bred American pit bull terrier dog with RD. A female pure-bred American pit bull terrier with RD was donated to the Veterinary Hospital of Federal University of Paraná, Curitiba, Brazil. A breeding colony was established and the phenotype and inheritance of the condition investigated. Regular ophthalmic examinations and fundus photography were performed on three generations of offspring from the founder animal. Some animals were additionally studied by optical coherence tomography. Ocular histopathology was performed on some animals from the colony. Fifty-seven offspring were produced in two generations from the affected founder female. Thirty-two were diagnosed with RD and showed a spectrum of severity of lesions including multifocal, and or geographic lesions and some developed retinal detachment. Histologic examination demonstrated retinal folds, rosettes, and areas of retinal detachment. The affected dogs were shorter in stature than the unaffected littermates. Breeding studies suggested the trait has an autosomal dominant mode of inheritance. DNA testing showed that the affected dogs were negative for the known gene mutations for canine dwarfism with RD. This is a report of a novel inherited form of RD that affects American pit bull terriers.

Ocular and histologic findings in a series of children with infantile pompe disease treated with enzyme replacement therapy.

To report the ophthalmologic and histologic findings in a series of children with infantile Pompe disease treated with enzyme replacement therapy (ERT). Records of children with infantile Pompe disease treated with ERT who had at least one complete ophthalmic examination and the ocular histopathology of children with infantile Pompe disease who were treated with ERT were reviewed. The patients' clinical history, including external ocular examination, ocular alignment and motility, dilated fundus examination, and cycloplegic refraction, was evaluated. A literature review was performed for ophthalmologic findings in infantile Pompe disease using PubMed. The clinical findings of 13 children were included and the ocular histopathology of 3 children with infantile Pompe disease who were treated with ERT were reviewed. Forty-six percent (6 of 13) had bilateral ptosis, 23% (3 of 13) had strabismus, 62% (8 of 13) had myopia, and 69% (9 of 13) had astigmatism. On histologic examination, there was vacuolar myopathy affecting the extraocular muscles, ciliary body, and iris smooth muscle and glycogen accumulation in corneal endothelial, lens epithelium, and retinal ganglion cells, and within lysosomes of scleral fibroblasts. It is important that ophthalmic providers are aware of the high prevalence of myopia, astigmatism, and ptosis in children with infantile Pompe disease treated with ERT because they are potentially amblyogenic but treatable factors.

Platelet-derived growth factor (PDGF)-C inhibits neuroretinal apoptosis in a murine model of focal retinal degeneration

Platelet-derived growth factor (PDGF)-C is a member of the PDGF family and is critical for neuronal survival in the central nervous system. We studied the possible survival and antiapoptotic effects of PDGF-C on focal retinal lesions in Ccl2−/−/Cx3cr1−/− on C57BL/6N [Crb1rd8] (DKO rd8) background mice, a model for progressive and focal retinal degeneration. We found no difference in transcript and protein expression of PDGF-C in the retina between DKO rd8 mice and wild type (WT, C57BL/6N). Recombinant PDGF-CC protein (500 ng/eye) was injected intravitreally into the right eye of DKO rd8 mice with phosphate-buffered saline as controls into the left eye. The retinal effects of PDGF-C were assessed by fundoscopy, ocular histopathology, A2E levels, apoptotic molecule analysis, and direct flat mount retinal vascular labeling. We found that the PDGF-CC-treated eyes showed slower progression or attenuation of the focal retinal lesions, lesser photoreceptor and retinal pigment epithelial degeneration resulting in better-preserved photoreceptor structure. Lower expression of apoptotic molecules was detected in the PDGF-CC-treated eyes than in controls. In addition, no retinal neovascularization was observed after PDGF-CC treatment. Our results demonstrate that PDGF-C potently ameliorates photoreceptor degeneration via the suppression of apoptotic pathways without inducing retinal angiogenesis. The protective effects of PDGF-C suggest a novel alternative approach for potential age-related retinal degeneration treatment.

Pigment Epithelium-Derived Factor Reduces Apoptosis and Pro-Inflammatory Cytokine Gene Expression in a Murine Model of Focal Retinal Degeneration

AMD (age-related macular degeneration) is a neurodegenerative disease causing irreversible central blindness in the elderly. Apoptosis and inflammation play important roles in AMD pathogenesis. PEDF (pigment epithelium-derived factor) is a potent neurotrophic and anti-inflammatory glycoprotein that protects the retinal neurons and photoreceptors against cell death caused by pathological insults. We studied the effects of PEDF on focal retinal lesions in DKO rd8 (Ccl2−/−/Cx3cr1−/− on C57BL/6N [Crb1rd8]) mice, a model for progressive, focal rd (retinal degeneration). First, we found a significant decrease in PEDF transcript expression in DKO rd8 mouse retina and RPE (retinal pigment epithelium) than WT (wild-type, C57BL/6N). Next, cultured DKO rd8 RPE cells secreted lower levels of PEDF protein in the media than WT. Then the right eyes of DKO rd8 mice were injected intravitreously with recombinant human PEDF protein (1 μg), followed by a subconjunctival injection of PEDF (3 μg) 4 weeks later. The untreated left eyes served as controls. The effect of PEDF was assessed by fundoscopy, ocular histopathology and A2E {[2,6-dimethyl-8-(2,6,6-trimethyl-1-cyclohexen-1-yl)-1E,3E,5E,7E-octatetra-enyl]-1-(2-hydroxyethyl)-4-[4-methyl-6(2,6,6-trimethyl-1-cyclohexen-1-yl) 1E,3E,5E,7E-hexatrienyl]-pyridinium} levels, as well as apoptotic and inflammatory molecules. The PEDF-treated eyes showed slower progression or attenuation of the focal retinal lesions, fewer and/or smaller photoreceptor and RPE degeneration, and significantly lower A2E, relative to the untreated eyes. In addition, lower expression of apoptotic and inflammatory molecules were detected in the PEDF-treated than untreated eyes. Our results establish that PEDF potently stabilizes photoreceptor degeneration via suppression of both apoptotic and inflammatory pathways. The multiple beneficial effects of PEDF represent a novel approach for potential AMD treatment.

Molecular Identification of Bacterial DNA in the Chorioretinal Scars of Chronic Granulomatous Disease

Chronic granulomatous disease (CGD) is an inherited disorder characterized by defects in phagocyte-derived nicotinamide adenine dinucleotide phosphate oxidase. It is typically diagnosed in childhood and leads to severe, recurrent bacterial or fungal infections. Chorioretinal lesions are the most common ocular manifestation. We sought to determine whether there are infectious agents in CGD-associated chorioretinopathy. Medical records and ocular histopathology from CGD cases from January 1983 to January 2012 at the National Institutes of Health were retrospectively reviewed. Chorioretinal cells from normal and lesional tissues of the same eye were microdissected. Primers for Staphylococcus epidermidis, Staphylococcus aureus, Pseudomonas aeruginosa, Burkholderia sp., and a panbacterial 16S ribosomal DNA were used for polymerase chain reaction. Seventeen CGD patients had ocular tissues (16 autopsied cases and 1 chorioretinal biopsy) examined. Of these 17, 8 demonstrated CGD-associated chorioretinal lesions in at least one eye on histopathology. Of these 8, 7 showed amplification of 16S ribosomal DNA within the lesion; of these 7, two also amplified S. epidermidis and one P. aeruginosa. One had no bacterial DNA amplified. Importantly, no microbial DNA was amplified from the normal, non-lesional ocular tissues of these 8 cases. Furthermore, only 1 of the 9 eyes without chorioretinopathy had amplified Burkholderia DNA, that patient had a history of Burkholderia infection. We detected bacterial DNA in 7 of 8 (88%) cases with CGD-associated chorioretinopathy and only in 1 normal ocular tissue of 17 CGD cases. Bacterial infection may play a role in the pathogenesis of CGD-associated chorioretinal lesions.

A retrospective survey of the ocular histopathology of the pinniped eye with emphasis on corneal disease

A retrospective review of globes from 70 pinnipeds submitted to the Comparative Ocular Pathology Laboratory of Wisconsin (COPLOW) describing the type and frequency of ocular disease. The study included 50 California sea lions, four animals listed only as 'sea lion', nine Northern elephant seals, five harbor seals, 1 Northern fur seal, and 1 Hooded seal. Globes were classified by microscopic findings. Categories were not mutually exclusive. The largest category was corneal disease (63 globes from 40 pinnipeds). The second largest was cataractous changes (35 globes from 23 pinnipeds). Additional ocular diseases included traumatic ocular injuries (nine globes from eight animals), phthisis bulbi (nine globes from eight pinnipeds), neoplasia (nine globes from six adult California sea lions), amyloid deposition in the corneal stroma, ciliary body, or both locations (five globes from four pinnipeds), and fungal disease (three globes from two pinnipeds). Pinnipeds with corneal disease were further categorized: stromal pathology (39 globes from 27 pinnipeds); epithelial pathology (37 globes from 27 pinnipeds); Descemet's pathology (11 globes from eight pinnipeds); endothelial attenuation or absence (33 globes from 22 pinnipeds); presence of retrocorneal membranes (15 globes from 10 pinnipeds); anterior synechia (eight globes from six animals), and keratitis (seven globes from five pinnipeds). This is the first report of ocular amyloid in pinniped eyes. All cases of neoplasia were in a pattern suggesting metastatic disease. In this study, there was a higher prevalence of ocular disease in captive pinnipeds, particularly in the posterior cornea.

Uveodermatologic lymphoma in two young related Portuguese water dogs

Canine lymphoma (CL) is one of the most common forms of spontaneous canine neoplasia. Improved understanding of the genetic and environmental factors associated with CL may provide benefits for the study of non-Hodgkin's and Hodgkin's lymphoma in humans. Uveodermatologic lymphoma is reported in a single household of Portuguese water dog, and the etiology is discussed. A 1-year-old female intact Portuguese water dog was referred to the Ophthalmology Service of the Veterinary Teaching Hospital of the Autonomous University of Barcelona because of acute blepharospasm of the right eye in association with a multinodular dermatosis. Physical and ophthalmological examination and a complete diagnostic work-up, including skin and ocular histopathology and immunohistochemistry, were performed. Three months prior, in Galicia (Spain), 1200 km away from Barcelona, a male dog of the same litter showed very similar oculodermatological clinical signs and skin histopathology, and immunohistochemistry were obtained. The clinical diagnoses were anterior exudative uveitis, iridal masses, and secondary glaucoma. Histopathology and immunohistochemistry revealed a nonepitheliotropic lymphoma rich in B cell in dog 1 and rich in T cell in dog 2. It is proposed that an underlying genetic predisposition could have played a role in the development of lymphoma in these two young related dogs.