15 results on '"Alon, Kahana"'
Search Results
2. Orbital corticosteroid injections for the treatment of active thyroid eye disease
- Author
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Kevin T. Eid, Peter M. Kally, and Alon Kahana
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graves orbitopathy ,corticosteroid ,orbital ,thyroid ,Kenalog ,clinical activity ,Medicine - Abstract
PurposeTo study the efficacy of orbital injections of triamcinolone acetonide mixed 1:1 with dexamethasone in the treatment of active thyroid eye disease.MethodsPatients that received orbital injection(s) of triamcinolone acetonide mixed 1:1 with dexamethasone for thyroid eye disease were included in this retrospective study. Demographic and clinical data were collected from the pre-treatment and 1 month follow up evaluations. Clinical data included subjective pain and diplopia scores, best-corrected visual acuity, Intraocular pressure, extraocular motility, clinical activity score, Hertel exophthalmometry, and upper eyelid margin to reflex distance.ResultsFifteen patients, 33 orbital injections, were included in the study. The average patient age was 59.2 years (SD ± 13.0) and 89% female. Subjectively, 67% of patients reported improvement of orbital pain and pressure versus 28% stable and 5% worse (p
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- 2024
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3. Spatiotemporal analysis of glioma heterogeneity reveals COL1A1 as an actionable target to disrupt tumor progression
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Andrea Comba, Syed M. Faisal, Patrick J. Dunn, Anna E. Argento, Todd C. Hollon, Wajd N. Al-Holou, Maria Luisa Varela, Daniel B. Zamler, Gunnar L. Quass, Pierre F. Apostolides, Clifford Abel, Christine E. Brown, Phillip E. Kish, Alon Kahana, Celina G. Kleer, Sebastien Motsch, Maria G. Castro, and Pedro R. Lowenstein
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Science - Abstract
It is essential to improve our understanding of the features that influence aggressiveness and invasion in high grade gliomas (HGG). Here, the authors characterize dynamic anatomical structures in HGG called oncostreams, which are associated with tumor growth and are regulated by COL1A1.
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- 2022
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4. Globe dislocation and optic nerve avulsion following all-terrain vehicle accidents
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Amro Omari, Anaïs L. Carniciu, Maya Desai, Olivia Schimmel, Dianne M. Schlachter, Robert Folberg, and Alon Kahana
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All terrain vehicles ,Globe dislocation ,Optic nerve avulsion ,Ophthalmology ,RE1-994 - Abstract
Purpose: Open-air motor vehicles present unique trauma risks to the eyes and face. We describe two patients who suffered a crash while riding an all-terrain vehicle (ATV), leading to globe dislocation with optic nerve avulsion in order to raise awareness about the risks associated with ATV accidents. Observations: In both cases, the injury was caused by high-speed trauma to the orbit involving a tree branch. One patient sustained a life threatening arrythmia requiring a short stay in the intensive care unit, and both patients required emergent surgical management and eventual socket reconstruction. Conclusions and Importance: These cases highlight the need for greater advocacy on behalf of rider safety. The authors encourage ophthalmologists to counsel patients who use ATVs to wear helmets, seatbelts, and protective eyewear to prevent these types of injuries in the future.
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- 2022
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5. Analysis of residual disease in periocular basal cell carcinoma following hedgehog pathway inhibition: Follow up to the VISORB trial.
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Shelby P Unsworth, Christina F Tingle, Curtis J Heisel, Emily A Eton, Christopher A Andrews, May P Chan, Scott C Bresler, and Alon Kahana
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Medicine ,Science - Abstract
Basal cell carcinoma (BCC) is a common skin cancer caused by deregulated hedgehog signaling. BCC is often curable surgically; however, for orbital and periocular BCCs (opBCC), surgical excision may put visual function at risk. Our recent clinical trial highlighted the utility of vismodegib for preserving visual organs in opBCC patients: 67% of patients displayed a complete response histologically. However, further analysis of excision samples uncovered keratin positive, hedgehog active (Gli1 positive), proliferative micro-tumors. Sequencing of pre-treatment tumors revealed resistance conferring mutations present at low frequency. In addition, one patient with a low-frequency SMO W535L mutation recurred two years post study despite no clinical evidence of residual disease. Sequencing of this recurrent tumor revealed an enrichment for the SMO W535L mutation, revealing that vismodegib treatment enriched for resistant cells undetectable by traditional histology. In the age of targeted therapies, linking molecular genetic analysis to prospective clinical trials may be necessary to provide mechanistic understanding of clinical outcomes. Trial Registration: ClinicalTrials.gov Identifier: NCT02436408.
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- 2022
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6. Twist3 is required for dedifferentiation during extraocular muscle regeneration in adult zebrafish.
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Yi Zhao, Ke'ale W Louie, Christina F Tingle, Cuilee Sha, Curtis J Heisel, Shelby P Unsworth, Phillip E Kish, and Alon Kahana
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Medicine ,Science - Abstract
Severely damaged adult zebrafish extraocular muscles (EOMs) regenerate through dedifferentiation of residual myocytes involving a muscle-to-mesenchyme transition. Members of the Twist family of basic helix-loop-helix transcription factors (TFs) are key regulators of the epithelial-mesenchymal transition (EMT) and are also involved in craniofacial development in humans and animal models. During zebrafish embryogenesis, twist family members (twist1a, twist1b, twist2, and twist3) function to regulate craniofacial skeletal development. Because of their roles as master regulators of stem cell biology, we hypothesized that twist TFs regulate adult EOM repair and regeneration. In this study, utilizing an adult zebrafish EOM regeneration model, we demonstrate that inhibiting twist3 function using translation-blocking morpholino oligonucleotides (MOs) impairs muscle regeneration by reducing myocyte dedifferentiation and proliferation in the regenerating muscle. This supports our hypothesis that twist TFs are involved in the early steps of dedifferentiation and highlights the importance of twist3 during EOM regeneration.
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- 2020
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7. Midkine-a functions as a universal regulator of proliferation during epimorphic regeneration in adult zebrafish.
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Nicholas B Ang, Alfonso Saera-Vila, Caroline Walsh, Peter F Hitchcock, Alon Kahana, Ryan Thummel, and Mikiko Nagashima
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Medicine ,Science - Abstract
Zebrafish have the ability to regenerate damaged cells and tissues by activating quiescent stem and progenitor cells or reprogramming differentiated cells into regeneration-competent precursors. Proliferation among the cells that will functionally restore injured tissues is a fundamental biological process underlying regeneration. Midkine-a is a cytokine growth factor, whose expression is strongly induced by injury in a variety of tissues across a range of vertebrate classes. Using a zebrafish Midkine-a loss of function mutant, we evaluated regeneration of caudal fin, extraocular muscle and retinal neurons to investigate the function of Midkine-a during epimorphic regeneration. In wildtype zebrafish, injury among these tissues induces robust proliferation and rapid regeneration. In Midkine-a mutants, the initial proliferation in each of these tissues is significantly diminished or absent. Regeneration of the caudal fin and extraocular muscle is delayed; regeneration of the retina is nearly completely absent. These data demonstrate that Midkine-a is universally required in the signaling pathways that convert tissue injury into the initial burst of cell proliferation. Further, these data highlight differences in the molecular mechanisms that regulate epimorphic regeneration in zebrafish.
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- 2020
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8. Temporally distinct transcriptional regulation of myocyte dedifferentiation and Myofiber growth during muscle regeneration
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Ke’ale W. Louie, Alfonso Saera-Vila, Phillip E. Kish, Justin A. Colacino, and Alon Kahana
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Transcriptome ,RNA-sequencing ,Cell reprogramming ,Zebrafish ,Stem cell ,Polycomb ,Biotechnology ,TP248.13-248.65 ,Genetics ,QH426-470 - Abstract
Abstract Background Tissue regeneration requires a series of steps, beginning with generation of the necessary cell mass, followed by cell migration into damaged area, and ending with differentiation and integration with surrounding tissues. Temporal regulation of these steps lies at the heart of the regenerative process, yet its basis is not well understood. The ability of zebrafish to dedifferentiate mature “post-mitotic” myocytes into proliferating myoblasts that in turn regenerate lost muscle tissue provides an opportunity to probe the molecular mechanisms of regeneration. Results Following subtotal excision of adult zebrafish lateral rectus muscle, dedifferentiating residual myocytes were collected at two time points prior to cell cycle reentry and compared to uninjured muscles using RNA-seq. Functional annotation (GAGE or K-means clustering followed by GO enrichment) revealed a coordinated response encompassing epigenetic regulation of transcription, RNA processing, and DNA replication and repair, along with protein degradation and translation that would rewire the cellular proteome and metabolome. Selected candidate genes were phenotypically validated in vivo by morpholino knockdown. Rapidly induced gene products, such as the Polycomb group factors Ezh2 and Suz12a, were necessary for both efficient dedifferentiation (i.e. cell reprogramming leading to cell cycle reentry) and complete anatomic regeneration. In contrast, the late activated gene fibronectin was important for efficient anatomic muscle regeneration but not for the early step of myocyte cell cycle reentry. Conclusions Reprogramming of a “post-mitotic” myocyte into a dedifferentiated myoblast requires a complex coordinated effort that reshapes the cellular proteome and rewires metabolic pathways mediated by heritable yet nuanced epigenetic alterations and molecular switches, including transcription factors and non-coding RNAs. Our studies show that temporal regulation of gene expression is programmatically linked to distinct steps in the regeneration process, with immediate early expression driving dedifferentiation and reprogramming, and later expression facilitating anatomical regeneration.
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- 2017
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9. Extraocular muscle regeneration in zebrafish requires late signals from Insulin-like growth factors.
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Alfonso Saera-Vila, Ke'ale W Louie, Cuilee Sha, Ryan M Kelly, Phillip E Kish, and Alon Kahana
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Medicine ,Science - Abstract
Insulin-like growth factors (Igfs) are key regulators of key biological processes such as embryonic development, growth, and tissue repair and regeneration. The role of Igf in myogenesis is well documented and, in zebrafish, promotes fin and heart regeneration. However, the mechanism of action of Igf in muscle repair and regeneration is not well understood. Using adult zebrafish extraocular muscle (EOM) regeneration as an experimental model, we show that Igf1 receptor blockage using either chemical inhibitors (BMS754807 and NVP-AEW541) or translation-blocking morpholino oligonucleotides (MOs) reduced EOM regeneration. Zebrafish EOMs regeneration depends on myocyte dedifferentiation, which is driven by early epigenetic reprogramming and requires autophagy activation and cell cycle reentry. Inhibition of Igf signaling had no effect on either autophagy activation or cell proliferation, indicating that Igf signaling was not involved in the early reprogramming steps of regeneration. Instead, blocking Igf signaling produced hypercellularity of regenerating EOMs and diminished myosin expression, resulting in lack of mature differentiated muscle fibers even many days after injury, indicating that Igf was involved in late re-differentiation steps. Although it is considered the main mediator of myogenic Igf actions, Akt activation decreased in regenerating EOMs, suggesting that alternative signaling pathways mediate Igf activity in muscle regeneration. In conclusion, Igf signaling is critical for re-differentiation of reprogrammed myoblasts during late steps of zebrafish EOM regeneration, suggesting a regulatory mechanism for determining regenerated muscle size and timing of differentiation, and a potential target for regenerative therapy.
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- 2018
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10. Persistent macular puckering following excision of causative orbital tumor
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Curtis J. Heisel, David N. Zacks, and Alon Kahana
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Ophthalmology ,RE1-994 - Abstract
Purpose: To describe the clinical course of a patient with a retrobulbar orbital tumor causing myopic shift and macular pucker. Observation: Following complete surgical removal of a retrobulbar orbital cavernous hemangioma, the myopic shift improved but the macular pucker persisted even 3 years after orbital surgery, with no sign of tumor recurrence. Conclusion and importance: Chorioretinal folds secondary to chronic mechanical force from an orbital tumor may persist long after the tumor is removed. This case may assist ophthalmologists in their discussions with, and counseling of, patients regarding visual prognosis following excision of orbital tumors that are causing retinal changes. Keywords: Cavernous hemangioma, Macular pucker, Choroidal folds, Orbit tumor, Orbit mass
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- 2018
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11. 3131 ONCOSTREAMS: NOVEL DYNAMICS PATHOLOGICAL MULTICELLULAR STRUCTURES INVOLVED IN GLIOBLATOMA GROWTH AND INVASION
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Andrea Comba, Patrick Dunn, Anna E Argento, Padma Kadiyala, Sebastien Motsch, Phillip Kish, Alon Kahana, Daniel Zamler, Karin Muraszko, Maria G Castro, and Pedro R Lowenstein
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Medicine - Abstract
OBJECTIVES/SPECIFIC AIMS: Oncostreams represent a novel growth pattern of GBM. In this study we uncovered the cellular and molecular mechanism that regulates the oncostreams function in GBM growth and invasion. METHODS/STUDY POPULATION: We studied oncostreams organization and function using genetically engineered mouse gliomas models (GEMM), mouse primary patient derived GBM model and human glioma biopsies. We evaluated the molecular landscape of oncostreams by laser capture microdissection (LCM) followed by RNA-Sequencing and bioinformatics analysis. RESULTS/ANTICIPATED RESULTS: Oncostreams are multicellular structures of 10-20 cells wide and 2-400 μm long. They are distributed throughout the tumors in mouse and human GBM. Oncostreams are heterogeneous structures positive for GFAP, Nestin, Olig2 and Iba1 cells and negative for Neurofilament. Using GEMM we found a negative correlation between oncostream density and animal survival. Moreover, examination of patient’s glioma biopsies evidenced that oncostreams are present in high grade but no in low grade gliomas. This suggests that oncostreams may play a role in tumor malignancy. Our data also indicated that oncostreams aid local invasion of normal brain. Transcriptome analysis of oncostreams revealed 43 differentially expressed (DE) genes. Functional enrichment analysis of DE genes showed that “collagen catabolic processes”, “positive regulation of cell migration”, and “extracellular matrix organization” were the most over-represented GO biological process. Network analysis indicated that Col1a1, ACTA2, MMP9 and MMP10 are primary target genes. These genes were also overexpressed in more malignant tumors (WT-IDH) compared to the less malignant (IDH1- R132H) tumors. Confocal time lapse imagining of 3D tumor slices demonstrated that oncostreams display a collective motion pattern within gliomas that has not been seen before. DISCUSSION/SIGNIFICANCE OF IMPACT: In summary, oncostreams are anatomically and molecularly distinctive, regulate glioma growth and invasion, display collective motion and are regulated by the extracellular matrix. We propose oncostreams as novel pathological markers valuable for diagnosis, prognosis and designing therapeutics for GBM patients.
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- 2019
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12. Natural variability of Kozak sequences correlates with function in a zebrafish model.
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Steven J Grzegorski, Estelle F Chiari, Amy Robbins, Phillip E Kish, and Alon Kahana
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Medicine ,Science - Abstract
In eukaryotes, targeting the small ribosomal subunit to the mRNA transcript requires a Kozak sequence at the translation initiation site. Despite the critical importance of the Kozak sequence to regulation of gene expression, there have been no correlation studies between its natural variance and efficiency of translation. Combining bioinformatics analysis with molecular biology techniques, and using zebrafish as a test case, we identify Kozak sequences based on their natural variance and characterize their function in vivo. Our data reveal that while the canonical Kozak sequence is efficient, in zebrafish it is neither the most common nor the most efficient translation initiation sequence. Rather, the most frequent natural variation of the Kozak sequence is almost twice as efficient. We conclude that the canonical Kozak sequence is a poor predictor of translation efficiency in different model organisms. Furthermore, our results provide an experimental approach to testing and optimizing an important tool for molecular biology.
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- 2014
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13. Phenothiourea sensitizes zebrafish cranial neural crest and extraocular muscle development to changes in retinoic acid and IGF signaling.
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Brenda L Bohnsack, Donika Gallina, and Alon Kahana
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Medicine ,Science - Abstract
1-Phenyl 2-thiourea (PTU) is a tyrosinase inhibitor commonly used to block pigmentation and aid visualization of zebrafish development. At the standard concentration of 0.003% (200 µM), PTU inhibits melanogenesis and reportedly has minimal other effects on zebrafish embryogenesis. We found that 0.003% PTU altered retinoic acid and insulin-like growth factor (IGF) regulation of neural crest and mesodermal components of craniofacial development. Reduction of retinoic acid synthesis by the pan-aldehyde dehydrogenase inhibitor diethylbenzaldehyde, only when combined with 0.003% PTU, resulted in extraocular muscle disorganization. PTU also decreased retinoic acid-induced teratogenic effects on pharyngeal arch and jaw cartilage despite morphologically normal appearing PTU-treated controls. Furthermore, 0.003% PTU in combination with inhibition of IGF signaling through either morpholino knockdown or pharmacologic inhibition of tyrosine kinase receptor phosphorylation, disrupted jaw development and extraocular muscle organization. PTU in and of itself inhibited neural crest development at higher concentrations (0.03%) and had the greatest inhibitory effect when added prior to 22 hours post fertilization (hpf). Addition of 0.003% PTU between 4 and 20 hpf decreased thyroxine (T4) in thyroid follicles in the nasopharynx of 96 hpf embryos. Treatment with exogenous triiodothyronine (T3) and T4 improved, but did not completely rescue, PTU-induced neural crest defects. Thus, PTU should be used with caution when studying zebrafish embryogenesis as it alters the threshold of different signaling pathways important during craniofacial development. The effects of PTU on neural crest development are partially caused by thyroid hormone signaling.
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- 2011
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14. Microanatomy of adult zebrafish extraocular muscles.
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Daniel S Kasprick, Phillip E Kish, Tyler L Junttila, Lindsay A Ward, Brenda L Bohnsack, and Alon Kahana
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Medicine ,Science - Abstract
Binocular vision requires intricate control of eye movement to align overlapping visual fields for fusion in the visual cortex, and each eye is controlled by 6 extraocular muscles (EOMs). Disorders of EOMs are an important cause of symptomatic vision loss. Importantly, EOMs represent specialized skeletal muscles with distinct gene expression profile and susceptibility to neuromuscular disorders. We aim to investigate and describe the anatomy of adult zebrafish extraocular muscles (EOMs) to enable comparison with human EOM anatomy and facilitate the use of zebrafish as a model for EOM research. Using differential interference contrast (DIC), epifluorescence microscopy, and precise sectioning techniques, we evaluate the anatomy of zebrafish EOM origin, muscle course, and insertion on the eye. Immunofluorescence is used to identify components of tendons, basement membrane and neuromuscular junctions (NMJs), and to analyze myofiber characteristics. We find that adult zebrafish EOM insertions on the globe parallel the organization of human EOMs, including the close proximity of specific EOM insertions to one another. However, analysis of EOM origins reveals important differences between human and zebrafish, such as the common rostral origin of both oblique muscles and the caudal origin of the lateral rectus muscles. Thrombospondin 4 marks the EOM tendons in regions that are highly innervated, and laminin marks the basement membrane, enabling evaluation of myofiber size and distribution. The NMJs appear to include both en plaque and en grappe synapses, while NMJ density is much higher in EOMs than in somatic muscles. In conclusion, zebrafish and human EOM anatomy are generally homologous, supporting the use of zebrafish for studying EOM biology. However, anatomic differences exist, revealing divergent evolutionary pressures.
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- 2011
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15. Treatment of central retinal vein occlusion with triamcinolone acetonide: an optical coherence tomography study.
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Michael Ip, Alon Kahana, and Michael Altaweel
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RETINAL (Visual pigment) , *ARTERIAL occlusions , *VASCULAR diseases - Abstract
Central retinal vein occlusion is one of the most common retinal vascular disorders. Many patients have decreased visual acuity as a result of macular edema. We report a retrospective review of 8 patients at the University of Wisconsin with macular edema from CRVO who were treated with an intravitreal injection of triamcinolone acetonide. Optical coherence tomography (OCT) was used to help assess the effect of this intervention. Mean baseline visual acuity was 20/500. Mean visual acuity at the 3-month follow up was 20/220. The average gain in visual acuity was 3.3 lines (range -1 to +10). Four of 8 patients experienced a visual acuity gain of 2 or more lines at the 3-month follow up. Four of 8 patients were unchanged (within 2 lines of baseline) at the 3-month follow up. No patient had a decrease in visual acuity (2 or more line decrease from baseline). Seven of 8 patients had complete resolution of macular edema on clinical examination at the 3-month follow up. No adverse effects such as cataract, glaucoma, retinal detachment or endophthalmitis were noted. We conclude that intravitreal injection of triamcinolone acetonide may be a safe and effective treatment in some patients with macular edema due to CRVO. Optical coherence tomography demonstrated significant anatomic improvement in the majority of patients with macular edema due to CRVO treated with intravitreal injection of triamcinolone acetonide. [ABSTRACT FROM AUTHOR]
- Published
- 2003
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