Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “retinal development”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,423 records · Page 79Linked to original sources
PubMed2002

Characterization of genetically modified human retinal pigment epithelial cells developed for in vitro and transplantation studies.

PURPOSE: To develop, by specific genetic modification, a differentiated human retinal pigment epithelial (RPE) cell line with an extended life span that can be used for investigating their function in vitro and for in vivo transplantation studies. METHODS: Primary human RPE cells were genetically modified by transfecting with a plasmid encoding the simian virus (SV)40 large T antigen. After characterization, two cell lines, designated h1RPE-7 and h1RPE-116, were chosen for further investigation, along with the spontaneously derived RPE cell line ARPE-19. Factors reported to be important in RPE and photoreceptor cell function and survival in vivo were examined. RESULTS: Both h1RPE-7 and h1RPE-116 cells exhibited epithelial morphology, expressed cytokeratins, and displayed junctional distribution of ZO-1, p100-p120 and beta-catenin. The cells expressed mRNA for RPE65 and cellular retinaldehyde-binding protein (CRALBP) and the trophic and growth factors brain-derived neurotropic factor (BDNF), ciliary neurotrophic factor (CNTF), basic fibroblast growth factor (bFGF), pigment epithelium-derived factor (PEDF), nerve growth factor (NGF), platelet-derived growth factor (PDGF)-alpha, insulin-like growth factor (IGF)-1, and vascular endothelial growth factor (VEGF). Secreted BDNF, bFGF, and VEGF, but not CNTF, were identified in cell supernatants. The cell lines constitutively expressed HLA-ABC, CD54, CD58, and CD59. After activation with IFN-gamma both HLA-ABC and CD54 were upregulated, and the expression of HLA-DR was induced. Both cell lines failed to express CD80, CD86, CD40, or CD48 in vitro and in a mixed lymphocyte reaction were unable to induce T-cell proliferation. Fas ligand (CD95L) was not detected in vitro by RT-PCR. Similar results were obtained with the ARPE-19 cell line. CONCLUSIONS: RPE lines h1RPE-7 and h1RPE-116 retain many of the morphologic and biochemical characteristics of RPE cells in vivo and may serve as a source of cells for in vitro analysis of RPE cell function, as well as for orthotopic transplantation studies.

Antigens, Polyomavirus Transforming↗
PubMedDate not supplied

Retinal pigment epithelial tear involving the fovea with preserved visual function.

Tears of the retinal pigment epithelium are known to occur either spontaneously or after laser photocoagulation in eyes with retinal pigment epithelium detachment. A 65-year-old man with preexisting retinal pigment epithelium detachment developed a retinal pigment epithelium tear after dye laser retinal photocoagulation. The tear gradually expanded to involve the fovea, but his best-corrected visual acuity remained 0.7 in the left eye during 20 months. Optical coherence tomography showed a defect of the retinal pigment epithelium with absence of regeneration. Scanning laser ophthalmoscopy revealed his fixation approached intact retinal pigment epithelium, but was still beneath the fovea. This case may indicate that the retinal pigment epithelium directly beneath the central macula is not essential for maintenance of the overlying foveal function under some conditions.

Aged↗
PubMed1997

Cytomegalovirus retinitis in patients with AIDS in Europe. AIDS in Europe Study Group.

The incidence of cytomegalovirus (CMV) retinitis and risk factors associated with the condition were studied in patients with the acquired immune deficiency syndrome (AIDS) in a multicenter retrospective cohort study of 6458 patients from 52 centers in 17 countries in Europe. Cytomegalovirus retinitis was diagnosed in 154 patients (2.4%) at the time of AIDS diagnosis, the probability of this diagnosis being significantly higher for those with CD4+ cell counts of < 100/mm3 (3.4%) than with counts of 100-200/mm3 (1.3%) or > 200/mm3 (0.8%). The rate of developing CMV retinitis after AIDS diagnosis was 9.4 per 100 patient years of follow-up. Multivariate analysis showed that risk behavior was significantly associated with the risk of developing CMV retinitis: lower for intravenous drug users [relative risk (RR) 0.47] and those engaged in "other risk behavior" (RR 0.58) than for homosexual men. The risk of developing CMV retinitis after AIDS diagnosis was significantly associated with CD4+ cell count at the time of AIDS diagnosis: for counts < 100/mm3 (RR 2.90) and from 100 to 200/mm3 (RR 2.13), there was a higher risk than for counts > 200/mm3. Patients with Pneumocystis carinii pneumonia, toxoplasmosis, or extraocular CMV infection at time of AIDS diagnosis exhibited an increased risk of developing CMV retinitis. Patients treated with zidovudine exhibited an increased rate of CMV retinitis: RR was 1.75 during and 2.87 after the second year of treatment as compared to those who had not received zidovudine. Median survival after CMV retinitis at time of AIDS diagnosis was eight months.

AIDS-Related Opportunistic Infections↗
PubMed1999

Retinal detachment associated with a macular hole in severely myopic eyes.

PURPOSE: To investigate factors associated with extensive retinal detachment in severely myopic eyes with a macular hole. METHOD: Fifty-two consecutive eyes with a macular hole and severe myopia were retrospectively studied. RESULTS: An extensive retinal detachment, defined as extending beyond the cuff of subretinal fluid, was observed in 37 eyes (71%). Extensive retinal detachment developed in 36 (95%) of 38 eyes with a posterior staphyloma and in one (7%) of 14 eyes without a posterior staphyloma (P<.0001). Extensive retinal detachment also developed in 32 (89%) of 36 eyes with complete posterior vitreous detachment and in five (31%) of 16 eyes without posterior vitreous detachment (P<.0001). CONCLUSION: Posterior staphyloma rather than anteroposterior vitreomacular traction may contribute to the development of retinal detachment associated with a macular hole in severely myopic eyes.

Adult↗
PubMedDate not supplied

Retinal tears associated with panuveitis and Behçet's disease.

To report retinal tears formation in 3 eyes of 2 patients with active panuveitis and Behçet's disease. We describe 2 patients that were diagnosed and treated for Behçet's disease with active panuveitis. Retinal tears developed while the inflammation was active. The patients were treated with topical, oral steroids, and cyclosporine therapy for bilateral panuveitis. One patient presented with a retinal tear located at the periphery of the active retinal lesion. The other had multiple tears associated with active retinal lesions in both eyes. Argon laser photocoagulation was performed in both patients as soon as the tears were detected. Ocular inflammation was controlled with this therapy, and only a few mild flare-ups occurred. The patients have been followed up for 8 and 16 months, respectively. During this period no new retinal tears have developed. Although retinal tear formation is rarely associated with Behçet's panuveitis, the clinician should be aware of this as a possible complication. When structural changes are present in the vitreous, detailed ophthalmoscopy is indicated to assess for retinal tears. If a tear is detected in a patient with panuveitis and Behçet's disease, laser photocoagulation therapy should be performed immediately to prevent retinal detachment.

Adult↗
PubMed2001

Incidence of retinal detachment and visual outcome in eyes presenting with posterior vitreous separation and dense fundus-obscuring vitreous hemorrhage.

PURPOSE: To determine visual outcomes and the incidence of retinal detachment in eyes presenting with posterior vitreous separation and dense fundus-obscuring vitreous hemorrhage. DESIGN: Retrospective consecutive noncomparative interventional case series. PARTICIPANTS: Thirty-six eyes (15 right eyes and 21 left eyes) of 34 patients (18 female and 16 male) ranging in age from 42 to 94 years. Mean follow-up was 14 months. METHODS: A comparison of the best-corrected initial visual acuities versus final visual acuities after spontaneous resolution of vitreous hemorrhage or surgical intervention. The number of eyes that were found to have retinal tears or that had a rhegmatogenous retinal detachment develop was documented. Logarithm of the minimum angle of resolution-converted visual acuities was used for comparison. Categorical data were analyzed by Fisher's exact test, and population means were compared by Student's t test. MAIN OUTCOME MEASURES: Final mean visual acuities, number of eyes with at least one retinal tear, location of retinal tears, number of eyes that had retinal detachment develop, and the number of eyes repaired with scleral buckling surgery and/or pars plana vitrectomy. RESULTS: Twenty-four of 36 eyes (67%) were found to have at least one retinal break (range, 0-4 breaks), with 88% of breaks located in the superior retina. Eleven eyes (31%) had more than one retinal break. Fourteen of 36 eyes (39%) had a rhegmatogenous retinal detachment develop that was repaired with pars plana vitrectomy and scleral buckling. An additional 14 eyes (39%) underwent vitrectomy for nonclearing vitreous hemorrhage. The incidence of retinal detachment in eyes with a history of retinal detachment in the contralateral eye was 75% (P = 0.04). Seven of 14 eyes (50%) with retinal detachment had coexisting proliferative vitreoretinopathy. Most retinal breaks and detachments occurred in emmetropic or myopic eyes. For all 36 eyes the mean preoperative visual acuity was 20/1233, and the mean final visual acuity was 20/62 (P < 0.0001). Eyes that had a macula-off retinal detachment develop had worse final visual outcomes (20/264; P = 0.01), as did eyes that had proliferative vitreoretinopathy develop (20/129; P = 0.04). CONCLUSIONS: Acute, spontaneous, nontraumatic posterior vitreous separation with dense fundus-obscuring vitreous hemorrhage is associated with a high incidence of retinal tears and detachment. Close follow-up with clinical examination and ultrasonography is necessary, because many of these eyes may eventually require surgical intervention. Aggressive management with early vitrectomy should be considered when there is a history of retinal detachment in the contralateral eye.

Adult↗
PubMed2005

Tbx2b is essential for neuronal differentiation along the dorsal/ventral axis of the zebrafish retina.

The mechanisms by which retinal neurons are patterned along the dorsal/ventral axis remain largely unknown, yet this patterning is integral for the topographic mapping of visual space. With an interest in elucidating the mechanisms that regulate the development of this retinal axis, we have characterized a T-box family transcription factor, Tbx2b, during zebrafish retinogenesis. Tbx2b is expressed throughout all phases of retinal development with a striking asymmetry of distribution highest dorsally to lowest ventrally. To examine Tbx2b function during retinal development, two morpholino antisense oligonucleotides were created; one blocking the translational start site of Tbx2b and the other interfering with Tbx2b mRNA splicing. Injection of either of these morpholinos resulted in profound defects in the development of the dorsal retina. By using molecular markers for neuronal subtypes, the ventral retina contained all cell types, whereas in the dorsal retina, only retinal ganglion cells expressed markers of differentiation. The cells of the dorsal retina were postmitotic, however, as demonstrated by a lack of BrdUrd incorporation during the normal periods of retinal differentiation. Markers for dorsal and ventral retinal compartments were also expressed normally in Tbx2b morphants. Combined, these observations suggest that the cellular mechanisms regulating neuronal differentiation within the retina are asymmetric about the dorsal/ventral axis and that Tbx2b mediates this process within the dorsal retina.

Animals↗
PubMed1985

Retinal burns from experimental laser iridotomy.

Simulated argon laser iridotomy was performed in 12 cynomolgus monkey eyes to evaluate the effectiveness of the Abraham iridectomy lens in preventing inadvertent retinal burns. At 600 milliwatts, only two of the three eyes developed small retinal burns using the Abraham lens, whereas three eyes developed larger retinal burns without the Abraham lens. At 1000 milliwatts, retinal burns occurred with or without the Abraham lens, but the size and intensity of the burns were reduced with the lens.

Animals↗
PubMed2003

Cloning, expression and characterization of the murine Efemp1, a gene mutated in Doyne-Honeycomb retinal dystrophy.

Development of the bone and cartilage structures is one of the best-studied systems for epithelial-mesenchymal interaction as well as proliferation and differentiation. In a screen for genes differentially expressed in mice deficient for transcription factor AP-2alpha, we have identified a gene which, based on its homology to the human EFEMP-1 gene was designated Efemp1. It encodes for six repeats similar to the domain of the epidermal growth factor. Sequence comparison with EFEMP1 genes of human and rat revealed that the three proteins share a high amino acid identity (92%), suggesting a conserved function during vertebrate development. However, there is no EFEMP1ortholog annotated in sequence databases of other non-mammalian species indicating that it might have evolved in higher vertebrates only. Analysis of the murine genomic locus revealed that the gene is encoded by 11 exons, which are spread over 80 kb of distance on murine chromosome 11A4. The multidomain protein structure may indicate that Efemp1 protein interacts with extracellular matrix components and serves to connect and integrate the function of multiple partner molecules. The gene is expressed in the embryo proper starting from day 9.5 to day 18.5 of murine development. In situ analyses showed that Efemp1 is found in condensing mesenchyme, giving rise to bone and cartilage as well as in developing bone structures of the cranial and the axial skeleton. These results will help in further defining the role of Efemp1 during murine embryogenesis.

Amino Acid Sequence↗
PubMed2006

A chick retinal proteome database and differential retinal protein expressions during early ocular development.

Proteomics approach as a research tool has gained popularity in a growing number of basic and clinical researches. However, proteomic research has yet to gain significant momentum in eye research. Hence, we decided to build a retinal proteome database using postnatal retinal tissue from chick, a commonly used animal model in eye research. Employing 2-D gels with the coverage of 3-10 pH gradients, we were able to resolve hundreds of proteins from young chick retinae. Among them, 155 high abundant proteins were identified by Peptide Mass Fingerprinting (PMF) after the Matrix-Assisted Laser Desorption Ionization-Time-of-Flight Mass Spectrometry (MALDI-TOF MS). These proteins were then classified according to their functions. Making use of the retinal database, we were able to identify several differentially expressed proteins that might be involved in early retinal development by comparing the 2-DE maps of chick retinal tissues (3, 10, and 20 days after hatching). With the current proteomics approach, we not only documented the most abundant soluble proteins in the chick retinal tissue, but also demonstrated the dynamic protein expression changes during early ocular development. This represents one of the first steps in building a complete protein database in chick retinae which is applicable to the study of eye diseases from a few selected protein candidates to the whole proteome. Proteomic technology may provide a high throughput platform for advancing eye research in the feasible future.

Animals↗
PubMed1992

2.5 years survival with sequential ganciclovir/foscarnet treatment in a patient with acquired immune deficiency syndrome and cytomegalovirus retinitis.

The case with the longest survival time (30 months) after the diagnosis of cytomegalovirus retinitis in a group of 53 patients with the acquired immune deficiency syndrome and cytomegalovirus retinitis (median survival time 8.4 months) is described. The patient developed cytomegalovirus retinitis in his left eye and received intravenous virustatic treatment for 29.5 months. Treatment was started with ganciclovir. After withdrawal from maintenance treatment, a relapse of cytomegalovirus retinitis occurred, which was again successfully treated with ganciclovir. A secondary cataract developed, and cataract extraction was performed. After 12.5 months on treatment with ganciclovir, a change to foscarnet was necessary because of neutropenia. Maintenance treatment with foscarnet was well tolerated for 17 months. The cytomegalovirus retinitis showed no signs of reactivation during this period. Vision in the right eye was preserved until death, and no sign of cytomegalovirus retinitis developed in the right eye. This case report demonstrates that an unusual long survival time is possible in a patient sequentially treated with ganciclovir and foscarnet.

AIDS-Related Opportunistic Infections↗
PubMed1993

[Retinal hemodynamics in patients with arterial hypertension].

Arterial hypertension is a risk factor for the development of retinal, cerebral and renal microangiopathy. Therefore, a prospective study was started to investigate the progression of retinal microangiopathy in hypertensive patients. Initially, 254 patients were examined in a cross-sectional study. Following an ophthalmological examination, retinal hemodynamics were quantified by means of video-fluorescence angiography. Moreover, blood fluidity (hematocrit, plasma viscosity and erythrocyte aggregation) was analyzed. The severity of the retinal changes was defined according to the Neubauer classification. One hundred (40%) patients showed retinal changes corresponding to stage I; 133 (52%) were classified as stage II. Hypertensive retinopathy (stage III and IV) was encountered in 20 (8%) patients. Arm-retina time was significant prolonged among the hypertensive patients compared with a control group. Arteriovenous passage time showed no significant differences between hypertensive patients and reference values. Plasma viscosity was significantly increased in hypertensive patients and showed a significant increase with progression of the retinal changes. Hematocrit and erythrocyte aggregation were normal among the patients studied. The present findings show an alteration in blood fluidity among hypertensive patients, whereas retinal microcirculation showed no significant disturbances. Follow-up studies are planned to assess the development of retinal microcirculatory changes among hypertensive patients.

Adult↗
PubMed2005

Transgenic expression of leukemia inhibitory factor (LIF) blocks normal vascular development but not pathological neovascularization in the eye.

PURPOSE: Vascular development in the eye has been described as a complex process involving both vasculogenesis and angiogenesis. Multiple cell types are involved in the process including angioblasts, vascular endothelial cells, astrocytes, pericytes, and Muller glial cells. This suggests that multiple growth factors and cytokines are required to regulate retinal vascular development. Leukemia inhibitory factor (LIF) is a member of the interleukin 6 family of cytokines. LIF is expressed during inflammation and has been reported to affect vascular development in culture; however, its effects in vivo have not been demonstrated. The purpose of this study was to determine how LIF could regulate ocular vascular development. METHODS: We have analyzed ocular vascular development in transgenic mice that express LIF in the ocular lens from embryonic day 11. RESULTS: In transgenic mice, LIF reduced development of embryonic vasculature in the eye, and inhibited retinal vascular development. Inhibition in vivo was independent of vascular endothelial cell growth factor (VEGF) expression. In older transgenic mice, the absence of a retinal vasculature resulted in retinal ischemia and elevated VEGF levels. The upregulation of VEGF resulted in the proliferation of pathological vascular membranes in the vitreous and neovascularization penetrating the retina, which in turn resulted in tractional retinal detachment. CONCLUSIONS: LIF is a potent inhibitor of retinal vascular development. These transgenic mice will be useful as a model of persistent fetal vasculature and to study the mechanism for the development of neovascular membranes in the vitreous and could be used to develop inhibitors of tractional detachment.

Animals↗
PubMed1980

The role of melatonin and dopamine in retinal physiology.

The effect of melatonin treatment on the development of retinal damage induced by continuous high intensity illumination (CHII) was investigated. Melatonin-treated rats developed more severe impairment of retinal structures compared with controls. In a similar study rats treated with bromocriptine, a potent stimulator of dopamine receptors, developed far less damage in their retinas during and after CHII compared with nontreated animals. Bromocriptine also increased the survival of retinas in rats with hereditary retinal degeneration (RCS strain).

Animals↗
PubMed1991

Is nerve growth factor required for the survival of retinal ganglion cells during development?

Staining for nerve growth factor receptor was observed in the ferret's retinal ganglion cell layer, optic nerve and tract, and in the lateral geniculate nucleus and superficial layers of the superior colliculus in the prenatal period, but had disappeared by birth. Thus the incidence of this transient staining does not correspond with the ganglion cell death that is known to occur in the ferret retina during the first postnatal week.

Animals↗
PubMed1992

Myeloid body development in the chick retinal pigment epithelium.

Previous investigations have reported a correlation between outer segment disk phagocytosis by the retinal pigment epithelium (RPE), and the formation of myeloid bodies, which are lamellar specializations of the smooth endoplasmic reticulum of the RPE. To further test the hypotheses that MBs are directly related to the process of outer segment shedding, we have undertaken to study the development of the retinal pigment epithelium in the chick utilizing a morphometric ultrastructural approach with specific attention to the timing of outer segment disk shedding and the formation of myeloid bodies. This study has demonstrated a temporal relationship between the initiation of photoreceptor outer segment disk shedding in the chick embryo and the occurrence of myeloid bodies. We have shown that photoreceptor outer segment disk shedding and phagocytosis by the RPE has been initiated in a substantial proportion of the retina by day 18 of development. Myeloid body formation does not begin until two days later at embryonic day 20, and is preceded by the development within the RPE of flattened areas of the normally tubular SER (templates), which we believe represent the precursors of myeloid body formation. Temporal development of outer segment phagocytosis, lamellar SER (template) occurrence and myeloid body formation are all statistically significant at the 95% level.

Animals↗
PubMed1985

Regional changes in retinal pigment epithelial cell density during ocular development.

The density of retinal pigment epithelial (RPE) cells in various parts of the posterior segment of developing human eyes was examined. The material for study consisted of 19 autopsy eyes, ranging in age from the sixth gestational month to 6 postnatal years. Whereas RPE cell density gradually increased in the macular area up to 6 months of age, cell density dropped in all other areas of the posterior segment through the first 2 postnatal years. The decrease in cell density was especially marked near the ora serrata. Mitotic figures were rarely seen and only found in the eyes of preterm infants. The author concludes that the increase in total surface area of the RPE during the period studied is primarily accounted for by changes in the regional density of the existing cell population. A centripetal shifting of cells toward the macular area from more peripheral areas would account for the increasing density in the posterior pole.

Child↗
PubMed1992

Radioautographic study on DNA synthesis of the retina and retinal pigment epithelium of developing mouse embryos.

We report the changes of proliferative activity of the retina and retinal pigment epithelium (RPE) of mouse embryos by detecting cells in the S-phase by light microscopic radioautography using 3H-thymidine. The eyes germs of mouse embryos at the embryonic days 9.5 (E 9.5), E 11.5, E 13.0, E 15.5, E 18.5 of gestational ages, were used for this experiment. Small pieces of the ocular tissues were labelled with 3H-TDR in vitro and light microscopic radioautographs were prepared. The labeling indices of the respective regions of tissues were calculated. Both tissues of retina and RPE showed high percentages of labeling indices from 10% to 50% through the developmental stages. The labeling indices of both tissues in earlier stages were generally higher than those of later stages, and gradually decreased in the later stages. However, the retina and RPE showed different courses of the changes of labeling indices respectively during the embryonic development. In the retina, the labeling indices in the vitreal portions were more than those in the scleral portions during the earlier developmental stages. However, in the later stages, the indices of scleral portions were more than those in the vitreal portions. Comparing the three regions of retina, the labeling indices of the anterior regions were generally higher than those of the equatorial and posterior regions, especially in the vitreal portion. Remarkable differences among three regions were not found in the scleral portion. In the RPE, the labeling indices gradually increased in the anterior region, but decreased in the equatorial and the posterior regions through all the developmental stages. The proliferation of both retina and RPE in the central region occurred earlier than those of the peripheral region.

Animals↗