Retina

Retina Publications

Maleki A, Fernandez CC, Philip AM, Manhapra A, Chang PY, Foster SC. Acute macular neuroretinopathy in a patient with birdshot chorioretinopathy after intravitreal triamcinolone suspension injection. Eur J Ophthalmol 2022;:11206721221124653.Abstract
PURPOSE: To report a case of acute macular neuroretinopathy (AMN) after intravitreal triamcinolone acetonide (TRIESENCE®) injection for cystoid macular edema secondary to birdshot chorioretinopathy. METHOD: A case report. PATIENT: A 62-year-old female. RESULTS: The patient presented with acutely decreased vision and a ring scotoma around her central vision three days after intravitreal triamcinolone acetonide (TRIESENCE®) injection for cystoid macular edema in her right eye (OD) secondary to birdshot chorioretinopathy. She had undergone pars plana vitrectomy, cataract extraction, and secondary intraocular lens implantation OD three months prior to the recent injection. Best-corrected visual acuity (BCVA) was 20/1000 OD and 20/50 OS. Intraocular pressure was 21 mmHg OD and 12 mmHg OS. Fluorescein angiography demonstrated a hypofluorescent area in the perifoveal zone OD. Optical coherence tomography OD depicted hyperreflective areas in the outer nuclear layer, outer plexiform layer, and retinal pigment epithelium. We diagnosed her with AMN OD and started her on brimonidine three times a day OD. She came back a week later with resolved scotoma and her vision improved to 20/60 OD. Five weeks later, BCVA was 20/40 and Intraocular pressures (IOP) was 12 mmHg OD. CONCLUSIONS AND IMPORTANCE: Intravitreal triamcinolone injection may be a cause of AMN with cystoid macular edema (CME) and borderline-high intraocular pressure. Brimonidine may be an effective treatment for these patients in the early course of the disease.
Sanjurjo-Soriano C, Erkilic N, Damodar K, Boukhaddaoui H, Diakatou M, Garita-Hernandez M, Mamaeva D, Dubois G, Jazouli Z, Jimenez-Medina C, Goureau O, Meunier I, Kalatzis V. Retinoic acid delays initial photoreceptor differentiation and results in a highly structured mature retinal organoid. Stem Cell Res Ther 2022;13(1):478.Abstract
BACKGROUND: Human-induced pluripotent stem cell-derived retinal organoids are a valuable tool for disease modelling and therapeutic development. Many efforts have been made over the last decade to optimise protocols for the generation of organoids that correctly mimic the human retina. Most protocols use common media supplements; however, protocol-dependent variability impacts data interpretation. To date, the lack of a systematic comparison of a given protocol with or without supplements makes it difficult to determine how they influence the differentiation process and morphology of the retinal organoids. METHODS: A 2D-3D differentiation method was used to generate retinal organoids, which were cultured with or without the most commonly used media supplements, notably retinoic acid. Gene expression was assayed using qPCR analysis, protein expression using immunofluorescence studies, ultrastructure using electron microscopy and 3D morphology using confocal and biphoton microscopy of whole organoids. RESULTS: Retinoic acid delayed the initial stages of differentiation by modulating photoreceptor gene expression. At later stages, the presence of retinoic acid led to the generation of mature retinal organoids with a well-structured stratified photoreceptor layer containing a predominant rod population. By contrast, the absence of retinoic acid led to cone-rich organoids with a less organised and non-stratified photoreceptor layer. CONCLUSIONS: This study proves the importance of supplemented media for culturing retinal organoids. More importantly, we demonstrate for the first time that the role of retinoic acid goes beyond inducing a rod cell fate to enhancing the organisation of the photoreceptor layer of the mature organoid.
Baldwin G, Sokol JT, Ludwig CA, Miller JB. A Comparative Study of Traditional Scleral Buckling to a New Technique: Guarded Light Pipe with Heads-Up Three-Dimensional Visualization. Clin Ophthalmol 2022;16:3079-3088.Abstract
Purpose: The guarded light pipe is a recently described alternative endoillumination technique to chandelier illumination. We sought to compare the outcomes of scleral buckling (SB) under indirect ophthalmoscopy (ID) to heads-up three-dimensional visualization with a guarded light pipe (3DGLP). Methods: A retrospective comparative study was performed, including 47 eyes that underwent SB for rhegmatogenous retinal detachment (RRD) repair with either traditional ID (n = 31) or 3DGLP (n = 16). Results: The single surgery anatomic success rate was 87.0% in the ID group and 87.5% in the 3DGLP group. The final anatomic success rate was 100% in both groups. The median (interquartile range) post-operative logMAR was 0.10 (0.0-0.20) in the ID group and 0.08 (0.02-0.69) in the 3DGLP group (p = 0.51). The median operative time was 107 (94-123) minutes in the ID group and 100 (90-111) minutes in the 3DGLP group (p = 0.25). Among eyes that underwent subretinal fluid drainage, the operative time was significantly longer in the ID group compared to the 3DGLP group, 113 (100-135) minutes vs 93 (85-111) minutes (p = 0.035). There were no post-operative complications in the ID group and one complication of self-resolving vitreous hemorrhage associated with a malfunctioning cryoprobe in the 3DGLP group (p = 0.34). There were no cases of post-operative cataract progression in either group. Conclusion: Compared to traditional SB, 3DGLP improves ergonomics and educational value with similar anatomical, visual, intra and post-operative outcomes and may result in shorter operative time in cases requiring subretinal fluid drainage.
Chapman JJ, Heidary G, Gise R. An overview of peripapillary hyperreflective ovoid mass-like structures. Curr Opin Ophthalmol 2022;Abstract
PURPOSE OF REVIEW: The purpose of this review is to provide an overview of the ophthalmic findings associated with peripapillary hyperreflective ovoid mass-like structures (PHOMS) in both adult and pediatric patients. RECENT FINDINGS: PHOMS have recently been identified in a number of different ophthalmic disease entities ranging from nonpathologic to pathologic, including but not limited to anatomic abnormalities (tilting in myopia), optic nerve head drusen, optic disc edema from inflammation (optic neuritis, white dot syndromes), vascular insults (ischemic optic neuropathy, retinal vascular occlusion), and papilledema. The mechanism underlying the formation of PHOMS has not been fully elucidated although it has been hypothesized that PHOMS occur secondary to axoplasmic stasis from crowding at the optic nerve head. SUMMARY: Although the clinical significance of the presence of PHOMS remains unclear, PHOMS are associated with several disease processes. Understanding the mechanism behind their formation and their impact on optic nerve head structure and visual function may be relevant in patients with optic nerve head pathology. The presence of PHOMS may also correlate with disease severity and duration. Future studies to evaluate whether the formation of PHOMS may be useful as an early indicator of disease or a prognostic tool are warranted.
Lennikov A, Yang M, Chang K, Pan L, Saddala MS, Lee C, Ashok A, Cho K-S, Utheim TP, Chen DF. Direct modulation of microglial function by electrical field. Front Cell Dev Biol 2022;10:980775.Abstract
Non-invasive electric stimulation (ES) employing a low-intensity electric current presents a potential therapeutic modality that can be applied for treating retinal and brain neurodegenerative disorders. As neurons are known to respond directly to ES, the effects of ES on glia cells are poorly studied. A key question is if ES directly mediates microglial function or modulates their activity merely via neuron-glial signaling. Here, we demonstrated the direct effects of ES on microglia in the BV-2 cells-an immortalized murine microglial cell line. The low current ES in a biphasic ramp waveform, but not that of rectangular or sine waveforms, significantly suppressed the motility and migration of BV-2 microglia in culture without causing cytotoxicity. This was associated with diminished cytoskeleton reorganization and microvilli formation in BV-2 cultures, as demonstrated by immunostaining of cytoskeletal proteins, F-actin and β-tubulin, and scanning electron microscopy. Moreover, ES of a ramp waveform reduced microglial phagocytosis of fluorescent zymosan particles and suppressed lipopolysaccharide (LPS)-induced pro-inflammatory cytokine expression in BV-2 cells as shown by Proteome Profiler Mouse Cytokine Array. The results of quantitative PCR and immunostaining for cyclooxygenase-2, Interleukin 6, and Tumor Necrosis Factor-α corroborated the direct suppression of LPS-induced microglial responses by a ramp ES. Transcriptome profiling further demonstrated that ramp ES effectively suppressed nearly half of the LPS-induced genes, primarily relating to cellular motility, energy metabolism, and calcium signaling. Our results reveal a direct modulatory effect of ES on previously thought electrically "non-responsive" microglia and suggest a new avenue of employing ES for anti-inflammatory therapy.
Zeng R, Vingopoulos F, Wang M, Bannerman A, Wescott HE, Baldwin G, Katz R, Koch T, Elze T, Kim LA, Vavvas DG, Husain D, Miller JB. Structure-function association between contrast sensitivity and retinal thickness (total, regional, and individual retinal layer) in patients with idiopathic epiretinal membrane. Graefes Arch Clin Exp Ophthalmol 2022;Abstract
PURPOSE: To investigate structure-function associations between retinal thickness, visual acuity (VA), and contrast sensitivity (CS), using the quantitative contrast sensitivity function (qCSF) method in patients with idiopathic epiretinal membrane (ERM). METHODS: Retrospective, cross-sectional observational study. Patients with a diagnosis of idiopathic ERM were included. Patients underwent complete ophthalmic examination, spectral-domain optical coherence tomography imaging (SD-OCT) (SPECTRALIS® Heidelberg), and CS testing using the qCSF method. Outcomes included area under the log CSF (AULCSF), contrast acuity (CA), and CS thresholds at 1, 1.5, 3, 6, 12, and 18 cycles per degree (cpd). RESULTS: A total of 102 eyes of 79 patients were included. Comparing standardized regression coefficients, retinal thickness in most ETDRS sectors was associated with larger reductions in AULCSF, CA, and CS thresholds at 3 and 6 cpd than those in logMAR VA. These differences in effect on VA and CS metrics were more pronounced in the central subfield and inner ETDRS sectors. Among the retinal layers, increased INL thickness had the most detrimental effect on visual function, being significantly associated with reductions in logMAR VA, AULCSF, CA, and CS thresholds at 3 and 6 cpd (all p < .01), as well as at 1.5 and 12 cpd (p < .05). CONCLUSION: Retinal thickness seems to be associated with larger reductions in contrast sensitivity than VA in patients with ERM. Measured with the qCSF method, contrast sensitivity may serve as a valuable adjunct visual function metric for patients with ERM.
Shi H, Yin Z, Koronyo Y, Fuchs D-T, Sheyn J, Davis MR, Wilson JW, Margeta MA, Pitts KM, Herron S, Ikezu S, Ikezu T, Graham SL, Gupta VK, Black KL, Mirzaei M, Butovsky O, Koronyo-Hamaoui M. Regulating microglial miR-155 transcriptional phenotype alleviates Alzheimer's-induced retinal vasculopathy by limiting Clec7a/Galectin-3+ neurodegenerative microglia. Acta Neuropathol Commun 2022;10(1):136.Abstract
Single cell RNA sequencing studies identified novel neurodegeneration-associated microglial (MGnD/DAM) subtypes activated around cerebral amyloid plaques. Micro-RNA (miR)-155 of the TREM2-APOE pathway was shown to be a key transcriptional regulator of MGnD microglial phenotype. Despite growing interest in studying manifestations of Alzheimer's disease (AD) in the retina, a CNS organ accessible to noninvasive high-resolution imaging, to date MGnD microglia have not been studied in the AD retina. Here, we discovered the presence and increased populations of Clec7a+ and Galectin-3+ MGnD microglia in retinas of transgenic APPSWE/PS1L166P AD-model mice. Conditionally targeting MGnD microglia by miR-155 ablation via the tamoxifen-inducible CreERT2 system in APPSWE/PS1L166P mice diminished retinal Clec7a+ and Galectin-3+ microglial populations while increasing homeostatic P2ry12+ microglia. Retinal MGnD microglia were often adhering to microvessels; their depletion protected the inner blood-retina barrier and reduced vascular amyloidosis. Microglial miR-155 depletion further limits retinal inflammation. Mass spectrometry analysis revealed enhanced retinal PI3K-Akt signaling and predicted IL-8 and Spp1 decreases in mice with microglia-specific miR-155 knockout. Overall, this study identified MGnD microglia in APPSWE/PS1L166P mouse retina. Transcriptional regulation of these dysfunctional microglia mitigated retinal inflammation and vasculopathy. The protective effects of microglial miR-155 ablation should shed light on potential treatments for retinal inflammation and vascular damage during AD and other ocular diseases.
Moussa K, Begaj T, Ma K, Barrantes PC, Eliott D, Sobrin L. Systemic lymphoma masquerading as Vogt-Koyanagi-Harada syndrome: Report of a case with multimodal imaging and histopathology. Am J Ophthalmol Case Rep 2022;27:101643.Abstract
Purpose: To report a case of systemic diffuse large B cell lymphoma presenting with ocular manifestations and neurologic findings resembling Vogt-Koyanagi-Harada syndrome. Observations: A 51-year-old Caucasian man presented with headache, ear pain, and blurry vision in both eyes. He was found to have bilateral exudative retinal detachments. After a short period of initial improvement with high dose systemic corticosteroid, his condition significantly worsened. An extensive work-up, including a kidney biopsy, led to a diagnosis of systemic diffuse large B cell lymphoma. He had excellent recovery following treatment with appropriate chemotherapy. Conclusions and Importance: Systemic malignancy may present with ocular manifestations and may masquerade as another diagnosis. An unexpected clinical course may suggest an alternative diagnosis. A broad systemic work-up including an evaluation for malignancy should be considered for patients presenting with unexplained exam or systemic findings.
Wong KA, Benowitz LI. Retinal Ganglion Cell Survival and Axon Regeneration after Optic Nerve Injury: Role of Inflammation and Other Factors. Int J Mol Sci 2022;23(17)Abstract
The optic nerve, like most pathways in the mature central nervous system, cannot regenerate if injured, and within days, retinal ganglion cells (RGCs), the neurons that extend axons through the optic nerve, begin to die. Thus, there are few clinical options to improve vision after traumatic or ischemic optic nerve injury or in neurodegenerative diseases such as glaucoma, dominant optic neuropathy, or optic pathway gliomas. Research over the past two decades has identified several strategies to enable RGCs to regenerate axons the entire length of the optic nerve, in some cases leading to modest reinnervation of di- and mesencephalic visual relay centers. This review primarily focuses on the role of the innate immune system in improving RGC survival and axon regeneration, and its synergy with manipulations of signal transduction pathways, transcription factors, and cell-extrinsic suppressors of axon growth. Research in this field provides hope that clinically effective strategies to improve vision in patients with currently untreatable losses could become a reality in 5-10 years.

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