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At least 19 recordsLinked to original sources

Retinal periphlebitis in patients with acquired immunodeficiency syndrome with cytomegalovirus retinitis mimics acute frosted retinal periphlebitis.

Acute frosted retinal periphlebitis is an inflammatory condition of unknown origin characterized by marked perivenular infiltration in otherwise healthy patients. We encountered seven patients with acquired immunodeficiency syndrome who exhibited visual loss associated with an unusual diffuse retinal periphlebitis very similar in appearance to acute frosted retinal periphlebitis. Each patient developed a thick inflammatory infiltrate surrounding the retinal venules, creating a frosted appearance. Two cases were bilateral. All patients had areas of more typical cytomegalovirus retinitis in their involved eye(s). Five of six patients treated with ganciclovir sodium showed improvement not only of the cytomegalovirus retinitis but also of the periphlebitis. Although we do not have histopathologic evidence that cytomegalovirus was the cause of these cases of periphlebitis, we believe that periphlebitis may be a previously unrecognized finding of cytomegalovirus retinitis in patients with acquired immunodeficiency syndrome. So far, there is no evidence implicating cytomegalovirus as the cause of acute frosted retinal periphlebitis in healthy patients.

Acquired Immunodeficiency Syndrome

[Retinal detachment after perforating eye injuries. III. Analysis of retinal detachment after perforating eye injuries and determination of the characteristics of the retinal detachment after perforating eye injuries].

In 1977-1987 the authors operated, using the cryosurgical method post-traumatic retinal detachment in 69 patients. Retinal detachment developed in 37 patients after simple perforation of the eye by a foreign intraocular body. In all patients the perforation penetrated as far as the vitreous space. In patients with retinal detachment the authors investigated the following: the patient's age, refraction, period of retinal detachment, extent of retinal detachment, the state of the macula, the characteristics of the retinal defect (site, size and number), type of retinal detachment and associated adverse factors. In the characteristics of retinal detachment after perforating eye injuries the first place was held by prognostically adverse vitreous traction in 73.9%.

Adolescent

Retinal Proteome Profiling of Inherited Retinal Degeneration Across Three Different Mouse Models Suggests Common Drug Targets in Retinitis Pigmentosa.

Inherited retinal degenerations (IRDs) are a leading cause of blindness among the population of young people in the developed world. Approximately half of IRDs initially manifest as gradual loss of night vision and visual fields, characteristic of retinitis pigmentosa (RP). Due to challenges in genetic testing, and the large heterogeneity of mutations underlying RP, targeted gene therapies are an impractical largescale solution in the foreseeable future. For this reason, identifying key pathophysiological pathways in IRDs that could be targets for mutation-agnostic and disease-modifying therapies (DMTs) is warranted. In this study, we investigated the retinal proteome of three distinct IRD mouse models, in comparison to sex- and age-matched wild-type mice. Specifically, we used the Pde6βRd10 (rd10) and RhoP23H/WT (P23H) mouse models of autosomal recessive and autosomal dominant RP, respectively, as well as the Rpe65-/- mouse model of Leber's congenital amaurosis type 2 (LCA2). The mice were housed at two distinct institutions and analyzed using LC-MS in three separate facilities/instruments following data-dependent and data-independent acquisition modes. This cross-institutional and multi-methodological approach signifies the reliability and reproducibility of the results. The large-scale profiling of the retinal proteome, coupled with in vivo electroretinography recordings, provided us with a reliable basis for comparing the disease phenotypes and severity. Despite evident inflammation, cellular stress, and downscaled phototransduction observed consistently across all three models, the underlying pathologies of RP and LCA2 displayed many differences, sharing only four general KEGG pathways. The opposite is true for the two RP models in which we identify remarkable convergence in proteomic phenotype even though the mechanism of primary rod death in rd10 and P23H mice is different. Our data highlights the cAMP and cGMP second-messenger signaling pathways as potential targets for therapeutic intervention. The proteomic data is curated and made publicly available, facilitating the discovery of universal therapeutic targets for RP.

Animals

Retinal detachment and retinal holes in retinitis pigmentosa sine pigmento.

Retinal detachment and retinal holes in two family members with retinitis pigmentosa sine pigmento are reported. We believe these are the first such cases reported in the literature. We describe the presenting symptoms and management, including cryotherapy, scleral buckling procedure, and sulfur hexafluoride injection (SF6), resulting in stable visual acuity in one case and retinal reattachment and improved visual acuity in the other case.

Adult

Observations on the retinal pigment epithelium and retinal macrophages in experimental retinal detachment.

After experimental retinal detachment in rabbits macrophages are a prominent feature in the subretinal space or within the retina. Two sources for these macrophages are identified. The retinal pigment epithelium (RPE) may undergo metaplasia and actively 'bud'; the evolving macrophage is then formed by a vitreal protrusion of the cytoplasm of an RPE cell which is 'nipped off' by lateral protrusions from adjacent cells. In addition, in regions of RPE proliferation, blood-borne cells were found in Bruch's membrane and among the mass of proliferated RPE cells, suggesting that blood-borne cells may pass from the choroidal circulation through Bruch's membrane and the RPE layer.

Animals

Adult rat retinal glia in vitro: effects of in vivo crush-activation on glia proliferation and permissiveness for regenerating retinal ganglion cell axons.

The effects of optic nerve crush on adult rat retinal glia activation were studied in vitro. In adult rats the optic nerves were crushed and the corresponding retinae were explained 5 to 7 days later and cultured in vitro. The glial response of retinae with precrushed optic nerves was compared to the glial response of retinae without prior optic nerve crush. As a consequence of crush-axotomy more glial cells migrated out from retinal explants and covered significantly larger areas of the substratum than glia from noncrushed retinae. Migration of immunohistochemically distinguishable Vimentin-positive Müller cells and glial fibrillary acidic protein-positive astrocytes could be observed in both types of cultures. Astrocytes as well as Müller cells incorporated bromodeoxyuridine after explantation. In noncrushed retinal explants Thy 1.1-immunopositive flat cells were much more frequent and the relative proportion of glial cells was much lower than in crush-activated cultures. In a second set of experiments the ability of adult rat retinal glia to support retinal ganglion cell regeneration was examined. Normal retinal explants (without optic nerve crush) which usually do not substantially regenerate axons were cultured on retinal glia from normal and crush-activated explants. Both glia preparations supported axon growth from retinal explants after 3 days in vitro. Neuritic growth was significantly better when retinal explants from normal adult rats were cultured on crush-activated retinal glia as compared to glia derived from noncrushed retinae. It is concluded that activated adult rat retinal glia, unlike adult glia found in other brain regions, support adult rat retinal ganglion cell regeneration in vitro.

Animals

Combined branch retinal artery and central retinal vein obstruction.

We observed seven patients with the unusual combination of a central retinal vein obstruction in conjunction with a simultaneous branch retinal artery obstruction. The patients presented with sectoral retinal whitening, as well as diffuse peripapillary and superficial retinal hemorrhages. In five of the seven patients, the retinal hemorrhages appeared most florid in the territory of the obstructed arteriole, resulting initially in the consideration that these cases represented a combined branch retinal artery and branch retinal vein obstruction. In all cases, however, the presence of dilated, tortuous veins with diffuse retinal hemorrhages, in addition to generalized delay in arteriovenous transit on fluorescein angiography, localized the venous blockage to the central retinal vein. No intra-arterial retinal emboli were visualized. Initially, five of the seven patients suffered markedly diminished visual function; although visual acuity returned to near normal in all but two patients. In the two patients with non-resolving, markedly impaired visual acuity, neovascularization of the iris complicated the clinical course. Both of these patients were treated with panretinal photocoagulation, with resolution of the iris neovascularization. These seven patients highlight another variation of combined arterial and venous retinal vascular disease.

Adult

Reciprocal retinal transplantation: a tool for the study of an inherited retinal degeneration.

The pathogenesis of retinal degeneration in rd mutant mice has been extensively studied, the gene responsible for the defect has been cloned, and the neural retina has been identified as the primary site for the degeneration. However, the possible contributory role of the ocular environment in this form of retinal degeneration remains undetermined. Retinal transplantation, which provides the opportunity to implant the neural retinal into a genetically defined intraocular environment, was used to examine this possibility. A reciprocal retinal transplantation paradigm was designed based on three experimental groups: (1) normal immature retina transplanted into rd/rd mutant eyes, (2) rd/rd immature retina transplanted into normal eye, and (3) normal immature retina transplanted into normal eyes. The rates of survival and histological characteristics of the grafts were compared between the three groups. At post-transplantation Day 3 (PTD 3), there were no differences between the three groups. Between PTD 10 and 15, the retinal grafts in group 1 showed degeneration. In contrast, the retinal grafts in groups 2 and 3 survived and developed well. At PTD 30, the retinal grafts in both groups 1 and 2 showed degeneration, but the retinal grafts in group 3 survived and remained differentiated well. These results suggest that the retinal degeneration of rd mice may be caused by both a deficit of the neural retina and intraocular environmental changes which are elicited either as a result of mutation or as a sequel to retinal degeneration.

Animals

Biosynthesis of all-trans-retinoic acid from retinal. Recognition of retinal bound to cellular retinol binding protein (type I) as substrate by a purified cytosolic dehydrogenase.

An NAD-dependent rat liver cytosolic dehydrogenase accepted as substrate retinal generated in situ by microsomes from retinol bound to excess CRBP (cellular retinol binding protein, type I). This activity, which was not retained by anion-exchange chromatography at pH 9.15, was designated P1. P1 activity increased 2.5-fold, with no statistically significant change in its K or Hill coefficient, in liver cytosol from rats fed a retinoid-deficient diet. Orally dosed retinoic acid partially suppressed the increase. Activities chromatographically similar to hepatic P1 were observed in cytosols from rat kidney and testes. P1, purified from rat liver cytosol, had a pI of approximately 8.3, migrated as a tetramer (214 kDa) on a Sephadex G-200 column, and had a subunit molecular mass of 55 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. With free retinal it catalyzed a maximum rate of retinoic acid synthesis of 265 nmol/min/mg of protein and exhibited allosteric kinetics with a K of 0.76 +/- 0.35 microM and a Hill coefficient of 1.5 +/- 0.13 (mean +/- S.D., n = 4). Substrate inhibition was noted with retinal concentrations greater than 6 microM. The purified enzyme not only recognized retinal generated by microsomes as substrate, but also recognized retinal bound to CRBP. The rates of retinoic acid synthesis from CRBP-retinal, with a series of increasing apoCRBP concentrations, exceeded the rates that would be supported by the free retinal present. The CRBP-retinal complex exhibited allosteric kinetics (K, 0.13 microM; Hill coefficient, 1.75; averages of duplicates) in the presence of excess apoCRBP (the ratio total CRBP/total retinal at each concentration of retinal was 2). This enzyme is likely to play a significant role in retinoic acid synthesis in vivo, because it participates in the synthesis of retinoic acid from a physiologically occurring form of retinol (holoCRBP), reflects retinoid status, and is distributed in extrahepatic tissues in addition to liver. These results also suggest a novel role for CRBP in retinoid metabolism, facilitating the conversion of retinal into retinoic acid.

Aldehyde Oxidoreductases

Role of HIV and CMV in the pathogenesis of retinitis and retinal vasculopathy in AIDS patients.

Cotton-wool spots and cytomegalovirus (CMV) retinitis are seen frequently in AIDS patients. Human immunodeficiency virus (HIV) infection of the retina has been proposed as a mechanism for the high incidence of retinal pathology. An autopsy study of the eyes from 25 consecutive cases of AIDS was performed using gross examination, light microscopy, trypsin digestion of retinal vasculatures, and immunohistochemistry to evaluate the possible role of HIV, as well as CMV, in the pathogenesis of retinitis and retinal vasculopathy. Brain tissue was studied in the first 20 of these cases to evaluate any correlation between retinal and central nervous system pathology. CMV retinitis was observed in 15 cases (60%). Cotton-wool spots were seen in nine cases (36%). CMV encephalitis was detected in four cases, whereas HIV encephalitis was noted in five cases. We were unable to demonstrate a correlation between CMV retinitis and CMV encephalitis. However, the number of cases studied was small, and the frequency of CMV encephalitis was low. On the other hand, bilateral CMV retinitis demonstrated a correlation to HIV encephalitis (P less than 0.005, Fisher's exact test). HIV infection of the retina was not detected by typical morphologic changes or immunohistochemistry. Immunohistochemistry localized CMV infection solely to areas of active retinitis. These findings suggest that bilateral CMV may serve as a marker of HIV encephalitis, possibly indicating a severely immunodepressed state.(ABSTRACT TRUNCATED AT 250 WORDS)

Acquired Immunodeficiency Syndrome

Antibody indications of secondary and superimposed retinal hypersensitivity in retinitis pigmentosa.

Antibody reactions with recognized retinopathy-inducing retinal antigens may be interpreted to reflect ongoing autoimmune events responsible for some forms of vision loss. We sought evidence of secondary and superimposed retinal hypersensitivity indicated by such antibody reactivity in a random group of patients with retinitis pigmentosa. We identified patterns of immunologic reactivity within members of a group of 52 patients with retinitis pigmentosa, which suggests some patients with retinitis pigmentosa may experience consequential superimposed retinal hypersensitivity. Identifying subgroups of patients with retinitis pigmentosa who exhibit indications of retinal hypersensitivity to known uveitopathogenic retinal proteins may permit the reduction of their rate of retinal degradation by immunomodulation.

Adult

[Retinal nerve fiber layer photography in retinal vein occlusion].

In six eyes we found typical signs that could serve as criteria for the differentiation of ischemic from non-ischemic retinal branch vein occlusion. Perimetry showed a mean defect (in the affected area) of more than 10 dB in eyes with defects in the retinal nerve fiber layer in contrast with 5 dB on one eye without nerve fiber defects. Secondly, fluorescein angiography showed ischemic areas in all eyes examined with localized defects in the photographs of the retinal nerve fiber layer. Damage of the retinal nerve fiber layer was observed before capillary obliteration could be detected by fluorescein angiography. Thirdly, semiquantitative optic disc morphometry demonstrated that using the difference between pallor and excavation as the only sign in ascending optic atrophy is not always useful. Fourthly, photography of the retinal nerve fiber layer showed that there is no correlation between the extension of the ischemic area and the sector angle of the defect of the retinal nerve fiber layer. Photography of the retinal nerve fiber layer can differentiative ischemic from non-ischemic retinal branch vein occlusion because of the qualitative detection of localized retinal nerve fiber layer defects. Consequently, this method is not only of great clinical importance for the diagnosis of different optic lesions, but is also useful for the prognosis and management of occlusion of the retinal branch vein.

Female

Diurnal variations in the electroretinographic c-wave and retinal melatonin content in rats with inherited retinal dystrophy.

The inability of retinal pigment epithelium to phagocytose shed photoreceptor disks is a cause of retinal degeneration in the Royal College of Surgeons rat; retinal pigment epithelial phagocytosis and disk shedding are regulated by the diurnal rhythm of retinal melatonin level. The diurnal rhythms of the electroretinogram (particularly that of the retinal pigment epithelial potential, the electroretinographic c-wave) and retinal melatonin content were thus investigated in Royal College of Surgeons rats from postnatal day 17 to 24, the period preceding retinal degeneration. The amplitudes of both the b- and c-waves of the electroretinogram fell significantly during the peak time of rod disk shedding and rose after the time of expected light off in the control and dystrophic rats. While the b-wave rhythms did not differ between the two strains, diurnal changes in the c-wave were significantly less distinct in the dystrophic rats than in controls. This difference may reflect lack of phagocytosis in dystrophic rats. Furthermore, the ERG c-wave was significantly larger and prolonged, and the retinal melatonin content higher, in dystrophic rats of this age group than in controls. It appears that retinal melatonin metabolism may play an important role in the maintenance of retinal pigment epithelial and photoreceptor function.

Animals