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OBJECTIVE: To quantitatively evaluate visual evoked potentials (VEPs) in prosthetic vision and simulated visual reduction. METHODS AND ANALYSIS: Four blind patients implanted with the Argus II retinal prosthesis and seven sighted controls participated. VEPs were recorded with pattern-reversal stimuli (2 cycles of a horizontal square wave grating, 0.1 cycle/degree) at 1.07 reversals per second (rps) for Argus II subjects and 3.37 rps for controls. Argus II patients had both eyes patched, viewing the pattern solely through their implant. Controls viewed the pattern monocularly, either with their best-corrected vision or with simulated visual reduction (field restriction, added blur or reduced display contrast). RESULTS: VEPs recorded in Argus II patients displayed a similar shape to normal VEPs when controls viewed the pattern without simulated visual reduction. In sighted controls, adding blur significantly delayed the P100 peak time by 8.7 ms, 95% CI (0.9, 16.6). Reducing stimulus contrast to 32% and 6% of full display contrast significantly decreased P100 amplitude to 55% (37%, 82%) and 20% (13%, 31%), respectively. Restriction on the field of view had no impact on either the amplitude or the peak latency of P100. CONCLUSION: The early visual cortex in retinal prosthesis users remains responsive to retinal input, showing a similar response profile to that of sighted controls. Pattern-reversal VEP offers valuable insights for objectively evaluating artificial vision therapy systems (AVTSs) when selecting, fitting and training implant users, but the uncertainties in the exact timing and location of electrode stimulation must be considered when interpreting the results.
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Ceguera , Potenciales Evocados Visuales , Prótesis Visuales , Humanos , Potenciales Evocados Visuales/fisiología , Masculino , Femenino , Ceguera/fisiopatología , Persona de Mediana Edad , Anciano , Agudeza Visual/fisiología , AdultoRESUMEN
CASE SUMMARY: The patient is a 42-year-old female who presented with a de novo missense variant in the PRPS1 gene. Her phenotype includes asymmetric retinal dystrophy with sensory esotropia, congenital sensorineural hearing loss, neuropathy, and severe tremors with recent-onset ataxia. This contributes a new presentation of ophthalmic and neurological findings to the literature.
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PURPOSE: We describe three different approaches for lens management in cases of metallic IOFBs involving the posterior segment. METHODS: All consecutive posterior segment metallic IOFB cases from 2012 to 2023 at a single institution were included in this retrospective case series. Surgical outcomes and surgical videos are presented. RESULTS: A total of 25 metallic IOFB cases were included. In 9 cases, there was no significant lens involvement, therefore not requiring lens extraction at the time of IOFB removal. In 8 cases with traumatic cataract, lens extraction sparing the anterior lens capsule was performed with IOFB removal. In 8 cases, both lens extraction and lens capsule removal were required at the time of IOFB removal. CONCLUSION: We demonstrate our algorithm to capsular management in patients who present with IOFB with good visual outcomes in follow-up.
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Background: The path of rehabilitation of an eye after open globe injury (OGI) may require multiple additional secondary surgeries after the initial repair. Although much has been studied regarding the outcomes of secondary surgeries after open globe repair, it can be challenging to understand the possible implications of the surgical rehabilitative process. This retrospective study considers the benefits of the required additional secondary surgeries for a consecutive series of OGI patients. Methods: OGI patients who had at least one additional surgery after the initial open globe repair (OGR) were studied retrospectively. Additional inclusion criteria included: follow up of at least 12 months since the initial injury and at least 3 months since their most recent surgery, and no additional planned interventions. Preoperative visual acuity was compared to final visual acuity. Additionally, the odds of achieving ambulatory vision (≥20/800) and reading vision (≥20/40) were calculated after each indicated consecutive surgery. Results: A cohort of 74 eyes from 73 patients met our inclusion criteria. These patients underwent a mean of two additional surgeries. The mean logMAR VA improved from 2.3 (HM) at presentation to 1.4 (20/150), or a 9-line Snellen equivalent improvement. Upon reaching their final visit status, 50% of patients had achieved ambulatory vision and 30% of patients had achieved reading vision. The odds of achieving ambulatory vision after completion of all the rehabilitative surgical process compared to the vision prior to the secondary rehabilitative surgery were higher (OR: 19.1, 95% CI: 7.9 - 30.4, p = 0.0008) as were the odds of achieving reading vision (OR: 4.6, 95% CI: 0.2 - 9.0, p = 0.04). With subsequent second, third, and fourth additional surgeries, the odds of achieving either ambulatory or reading vision at the final visit compared to their preoperative visual acuities were not significant (p > 0.05) but the visual acuity continued to trend toward visual improvement. Conclusion: Approximately 50% of individuals who required additional surgery at UMN achieved ambulatory vision and 30% achieved reading vision. The odds of visual improvement through the surgical rehabilitative process were very high, with the greatest gains generally achieved after the first surgery.
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In this review, we outline our current understanding of the mechanisms involved in the absorption, storage, and transport of dietary vitamin A to the eye, and the trafficking of rhodopsin protein to the photoreceptor outer segments, which encompasses the logistical backbone required for photoreceptor cell function. Two key mechanisms of this process are emphasized in this manuscript: ocular and systemic vitamin A membrane transporters, and rhodopsin transporters. Understanding the complementary mechanisms responsible for the generation and proper transport of the retinylidene protein to the photoreceptor outer segment will eventually shed light on the importance of genes encoded by these proteins, and their relationship on normal visual function and in the pathophysiology of retinal degenerative diseases.
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Rodopsina , Vitamina A , Rodopsina/metabolismo , Rodopsina/genética , Humanos , Vitamina A/metabolismo , Animales , Células Fotorreceptoras de Vertebrados/metabolismo , Células Fotorreceptoras/metabolismo , Transporte BiológicoRESUMEN
DNA methylation provides a crucial epigenetic mark linking genetic variations to environmental influence. We have analyzed array-based DNA methylation profiles of 160 human retinas with co-measured RNA-seq and >8 million genetic variants, uncovering sites of genetic regulation in cis (37,453 methylation quantitative trait loci and 12,505 expression quantitative trait loci) and 13,747 DNA methylation loci affecting gene expression, with over one-third specific to the retina. Methylation and expression quantitative trait loci show non-random distribution and enrichment of biological processes related to synapse, mitochondria, and catabolism. Summary data-based Mendelian randomization and colocalization analyses identify 87 target genes where methylation and gene-expression changes likely mediate the genotype effect on age-related macular degeneration. Integrated pathway analysis reveals epigenetic regulation of immune response and metabolism including the glutathione pathway and glycolysis. Our study thus defines key roles of genetic variations driving methylation changes, prioritizes epigenetic control of gene expression, and suggests frameworks for regulation of macular degeneration pathology by genotype-environment interaction in retina.
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Metilación de ADN , Degeneración Macular , Humanos , Metilación de ADN/genética , Epigénesis Genética , Epigenoma , Degeneración Macular/genética , RetinaRESUMEN
This retrospective study examines the clinical characteristics and underlying genetic variants that exist in a Leber congenital amaurosis (LCA) patient cohort evaluated at the inherited retinal disease (IRD) clinic at the University of Minnesota (UMN)/M Health System. Our LCA cohort consisted of 33 non-syndromic patients and one patient with Joubert syndrome. We report their relevant history, clinical findings, and genetic testing results. We monitored disease presentation utilizing ocular coherence tomography (OCT) and fundus autofluorescence (FAF). Electroretinogram testing (ERG) was performed in patients when clinically indicated. Next-generation sequencing (NGS) and genetic counseling was offered to all evaluated patients. Advanced photoreceptor loss was noted in 85.7% of the subjects. All patients who underwent FAF had findings of either a ring of macular hypo/hyper AF or peripheral hypo-AF. All patients had abnormal ERG findings. A diagnostic genetic test result was identified in 74.2% of the patients via NGS single-gene testing or panel testing. Two patients in our cohort qualified for Luxturna® and both received treatment at the time of this study. These data will help IRD specialists to understand the genetic variants and clinical presentations that characterize our patient population in the Midwest region of the United States.
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Amaurosis Congénita de Leber , Humanos , Amaurosis Congénita de Leber/genética , Amaurosis Congénita de Leber/terapia , Estudios Retrospectivos , Mutación , Retina/patología , Terapia Genética , LinajeRESUMEN
PURPOSE: To describe the syndromic, clinical, and retinal findings of a patient with an extremely-rare genetic condition known as Hardikar Syndrome (HS) with presentation of optical coherence tomography (OCT), fundus autofluorescence (FAF), fluorescein angiographic (FA), and indocyanine green angiographic (ICG) findings. METHODS: Clinical course was detailed and followed over time with examinations and multimodal imaging. PATIENT AND RESULTS: A 17-year-old patient with HS was referred for possible retinitis pigmentosa. Dilated fundoscopic examination revealed large, multifocal cauliform patches of chorioretinal retinal pigment epithelium (RPE) changes with RPE drop-out involving the macula and periphery in both eyes. Additionally, an inactive choroidal neovascular membrane (CNVM) was present in the left eye. Multimodal imaging with OCT, FAF, FA and ICG correlated with the clinical findings of focal patches of chorioretinal degeneration in both eyes. Additionally, an anomalous finding of the superior retinal arterial vessels filling in tandem with the choroidal was present in the left eye. The patient's clinical findings were consistent with HS, and genetic testing with whole exome sequencing revealed a pathogenic mutation in the MED12 gene, confirming diagnosis. DISCUSSION AND CONCLUSIONS: HS is associated with RPE degeneration, creating focal patches of pigmentary chorioretinal atrophic lesions. Vision loss can occur due to the development of CNVMs. We recommend close evaluation and follow-up for HS patients with multimodal retinal imaging.
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This retrospective study identifies patients with RP at the Inherited Retinal Disease Clinic at the University of Minnesota (UMN)/M Health System who had genetic testing via next generation sequencing. A database was curated to record history and examination, genetic findings, and ocular imaging. Causative pathogenic and likely pathogenic variants were recorded. Disease status was further characterized by ocular coherence tomography (OCT) and fundus autofluorescence (AF). Our study cohort included a total of 199 patients evaluated between 1 May 2015-5 August 2022. The cohort included 151 patients with non-syndromic RP and 48 with syndromic RP. Presenting symptoms included nyctalopia (85.4%) photosensitivity/hemeralopia (60.5%), and decreased color vision (55.8%). On average, 38.9% had visual acuity of worse than 20/80. Ellipsoid zone band width on OCT scan of less than 1500 µm was noted in 73.6%. Ninety-nine percent had fundus autofluorescence (AF) findings of a hypo- or hyper-fluorescent ring within the macula and/or peripheral hypo-AF. Of the 127 subjects who underwent genetic testing, a diagnostic pathogenic and/or likely pathogenic variant was identified in 67 (52.8%) patients-33.3% of syndromic RP and 66.6% of non-syndromic RP patients had a diagnostic gene variant identified. It was found that 23.6% of the cohort had negative genetic testing results or only variants of uncertain significance identified, which were deemed as non-diagnostic. We concluded that patients with RP often present with advanced disease. In our population, next generation sequencing panels identified a genotype consistent with the exam in just over half the patients. Additional work will be needed to identify the underlying genetic etiology for the remainder.
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Secuenciación de Nucleótidos de Alto Rendimiento , Retinitis Pigmentosa , Humanos , Estudios Retrospectivos , Retinitis Pigmentosa/diagnóstico por imagen , Retinitis Pigmentosa/genética , Retina/diagnóstico por imagen , Retina/patología , Tomografía de Coherencia Óptica , Imagen Multimodal , MutaciónRESUMEN
Rods and cones are photoreceptor neurons in the retina that are required for visual sensation in vertebrates, where proper protein localization and compartmentalization are critical for phototransduction and visual function. In human retinal diseases, improper protein transport to the outer segment (OS) or mislocalization of proteins to the inner segment (IS) could lead to impaired visual responses and photoreceptor cell degeneration, causing a loss of visual function. We showed involvement of an unconventional motor protein, MYO1C, in the proper localization of rhodopsin to the OS, where loss of MYO1C in a mammalian model caused mislocalization of rhodopsin to IS and cell bodies, leading to progressively severe retinal phenotypes. In this study, using modeling and docking analysis, we aimed to identify the protein-protein interaction sites between MYO1C and Rhodopsin to establish a hypothesis that a physical interaction between these proteins is necessary for the proper trafficking of rhodopsin and visual function.
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Retina , Rodopsina , Animales , Humanos , Rodopsina/genética , Rodopsina/metabolismo , Retina/metabolismo , Células Fotorreceptoras Retinianas Bastones/metabolismo , Células Fotorreceptoras Retinianas Conos/metabolismo , Transporte de Proteínas/fisiología , Mamíferos/metabolismo , Miosina Tipo I/metabolismoRESUMEN
PURPOSE: To compare patients with acute endophthalmitis after intravitreal injection of vascular endothelial growth factor (VEGF) inhibitors vs. steroids. METHODS: Retrospective single-center, nonrandomized interventional study from 2013 to 2021.Patients underwent vitreous biopsy before initiating treatment and were divided into the following cohorts: (1) anti-VEGF managed medically (T&I-anti-VEGF), (2) anti-VEGF managed by immediate pars plana vitrectomy (PPV-anti-VEGF), and (3) steroid therapy and managed medically or by pars plana vitrectomy (steroid). RESULTS: A total of 141 patients were analyzed. The steroid cohort demonstrated significantly worse presenting (median = 2.80 logarithm of the minimum angle of resolution [logMAR]; P ≤ 0.01) and final (median = 2.30 logMAR) best-corrected visual acuity compared with T&I-anti-VEGF (presenting: median = 2.00 logMAR; final: median = 0.40 logMAR) and pars plana vitrectomy-anti-VEGF cohorts (presenting: median = 2.30 logMAR; final: median = 0.48 logMAR). There was no significant ( P = 0.33) difference in the final best-corrected visual acuity between T&I-anti-VEGF and pars plana vitrectomy-anti-VEGF cohorts. There were no significant ( P ≥ 0.63) differences among cohorts in best-corrected visual acuity before acute endophthalmitis diagnosis (T&I-anti-VEGF: median = 0.40 logMAR; pars plana vitrectomy-anti-VEGF: median = 0.40 logMAR; steroid: median = 0.44 logMAR). Microbial cultures revealed similar profiles for all cohorts. CONCLUSION: Acute endophthalmitis after intravitreal injection steroid therapy had worse outcomes compared with anti-VEGF therapy.
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Endoftalmitis , Factor A de Crecimiento Endotelial Vascular , Humanos , Estudios Retrospectivos , Endoftalmitis/tratamiento farmacológico , Endoftalmitis/etiología , Vitrectomía , Factores de Crecimiento Endotelial Vascular , Esteroides/uso terapéutico , Inyecciones IntravítreasRESUMEN
Age-related macular degeneration (AMD) is the leading cause of blindness in elderly people, with limited treatment options available for most patients. AMD involves the death of retinal pigment epithelium (RPE) and photoreceptor cells, with mitochondria dysfunction being a critical early event. In the current study, we utilized our unique resource of human donor RPE graded for AMD presence and severity to investigate proteome-wide dysregulation involved in early AMD. Organelle-enriched fractions of RPE were isolated from donors with early AMD (n = 45) and healthy age-matched controls (n = 32) and were analyzed by UHR-IonStar, an integrated proteomics platform enabling reliable and in-depth proteomic quantification in large cohorts. A total of 5941 proteins were quantified with excellent analytical reproducibility, and with further informatics analysis, many biological functions and pathways were found to be significantly dysregulated in donor RPE samples with early AMD. Several of these directly pinpointed changes in mitochondrial functions, e.g., translation, ATP metabolic process, lipid homeostasis, and oxidative stress. These novel findings highlighted the value of our proteomics investigation by allowing a better understanding of the molecular mechanisms underlying early AMD onset and facilitating both treatment development and biomarker discovery.
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Degeneración Macular , Epitelio Pigmentado de la Retina , Humanos , Anciano , Epitelio Pigmentado de la Retina/metabolismo , Proteómica , Reproducibilidad de los Resultados , Degeneración Macular/metabolismo , Estrés OxidativoRESUMEN
PURPOSE: To highlight a case of chorioretinitis sclopetaria, with concomitant macular hole formation and orbital emphysema, caused by a commercial-grade pressure washer. METHODS: This is a retrospective case report. RESULTS: A 19-year-old man presented to the emergency department with a left eye injury, incurred after being sprayed with a commercial-grade pressure washer. He endorsed ipsilateral blurred vision, pain, and linear floaters. Left eye visual acuity was 20/40. Dilated fundus examination showed inferior vitreous hemorrhage, retinal whitening, and preretinal, intraretinal, and subretinal hemorrhages, consistent with chorioretinitis sclopetaria. Optical coherence tomography revealed a full-thickness macular hole. Computed tomography scan of the orbits showed subcutaneous and postseptal orbital emphysema. Two months after injury, vitreous and retinal hemorrhages and macular hole resolved. Five months after injury, visual acuity improved to 20/20. CONCLUSION: Chorioretinitis sclopetaria is defined as a full-thickness chorioretinal disruption resulting from a high-velocity projectile passing adjacent to or into the orbit without penetrating the globe. Chorioretinal deformation and ocular comorbidities are influenced by the velocity of the missile and its spatial relationship to the orbit. Although this pattern of injury is typically associated with indirect trauma to the globe by a BB or a bullet, this is the first report of chorioretinitis sclopetaria precipitated by a high-velocity liquid missile.
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Coriorretinitis , Enfisema , Enfermedades Orbitales , Perforaciones de la Retina , Masculino , Humanos , Adulto Joven , Adulto , Perforaciones de la Retina/complicaciones , Estudios Retrospectivos , Coriorretinitis/diagnóstico , Trastornos de la Visión/complicaciones , Hemorragia Retiniana , Tomografía de Coherencia ÓpticaRESUMEN
Age-related macular degeneration (AMD) is the leading cause of irreversible blindness in developed countries, characterized by the death of retinal pigment epithelial (RPE) cells and photoreceptors. Previous studies report an accumulation of damaged and dysfunctional mitochondria in RPE of human donors with AMD. Understanding how damaged mitochondria accumulate in AMD is an important step in discovering disease mechanisms and identifying therapeutic targets. In this report, we assessed mitochondrial fission and fusion by quantifying proteins and measured mitochondrial autophagy (mitophagy) via protein analysis and advanced imaging techniques using mitochondrial targeted mKeima in primary human RPE from donors with or without AMD. We report disease-specific differences in mitochondrial proteins that regulate fission, fusion, and mitophagy that were present at baseline and with treatments to stimulate these pathways. Data suggest AMD RPE utilize receptor-mediated mitophagy as a compensatory mechanism for deficits in the ubiquitin-mediated mitophagy pathway. These changes in mitochondrial homeostasis could lead to the buildup of damaged and dysfunctional mitochondria observed in the RPE of AMD donors.
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Degeneración Macular , Epitelio Pigmentado de la Retina , Humanos , Epitelio Pigmentado de la Retina/metabolismo , Dinámicas Mitocondriales , Estrés Oxidativo , Degeneración Macular/metabolismo , AutofagiaRESUMEN
Age-related macular degeneration (AMD), the leading cause of blindness in the elderly, is characterized by the death of retinal pigment epithelium (RPE) and photoreceptors. One of the risk factors associated with developing AMD is the single nucleotide polymorphism (SNP) found within the gene encoding complement factor H (CFH). Part of the innate immune system, CFH inhibits alternative complement pathway activation. Multi-protein complexes called inflammasomes also play a role in the innate immune response. Previous studies reported that inflammasome activation may contribute to AMD pathology. In this study, we used primary human adult RPE cell cultures from multiple donors, with and without AMD, that were genotyped for the Y402H CFH risk allele. We found complement and inflammasome-related genes and proteins at basal levels in RPE tissue and cell cultures. Additionally, treatment with rotenone, bafilomycin A, and ATP led to inflammasome activation. Overall, the response to priming and activation was similar, irrespective of disease state or CFH genotype. While these data show that the inflammasome is present and active in RPE, our results suggest that inflammasome activation may not contribute to early AMD pathology.
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Degeneración Macular , Epitelio Pigmentado de la Retina , Anciano , Genotipo , Humanos , Inflamasomas/metabolismo , Degeneración Macular/metabolismo , Polimorfismo de Nucleótido Simple , Epitelio Pigmentado de la Retina/metabolismoRESUMEN
Age-related macular degeneration (AMD), the leading cause of irreversible blindness among Americans over 50, is characterized by dysfunction and death of retinal pigment epithelial (RPE) cells. The RPE accumulates iron in AMD, and iron overload triggers RPE cell death in vitro and in vivo. However, the mechanism of RPE iron accumulation in AMD is unknown. We show that high-fat-diet-induced obesity, a risk factor for AMD, drives systemic and local inflammatory circuits upregulating interleukin-1ß (IL-1ß). IL-1ß upregulates RPE iron importers and downregulates iron exporters, causing iron accumulation, oxidative stress, and dysfunction. We term this maladaptive, chronic activation of a nutritional immunity pathway the cellular iron sequestration response (CISR). RNA sequencing (RNA-seq) analysis of choroid and retina from human donors revealed that hallmarks of this pathway are present in AMD microglia and macrophages. Together, these data suggest that inflamed adipose tissue, through the CISR, can lead to RPE pathology in AMD.
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Degeneración Macular , Epitelio Pigmentado de la Retina , Tejido Adiposo/metabolismo , Humanos , Hierro/metabolismo , Degeneración Macular/metabolismo , Estrés Oxidativo , Retina/metabolismo , Epitelio Pigmentado de la Retina/metabolismoRESUMEN
Primary cultures of retinal pigment epithelium (RPE) from human adult donors (haRPE) and induced pluripotent stem cell derived-RPE (iPSC-RPE) are valuable model systems for gaining mechanistic insight and for testing potential therapies for age-related macular degeneration (AMD). This study evaluated the treatment response of haRPE and iPSC-RPE to oxidative stress and potential therapeutics addressing mitochondrial defects. haRPE and iSPC-RPE were derived from donors with or without AMD. Mitochondrial function was measured after treatment with menadione, AICAR, or trehalose and the response to treatment was compared between cell models and by disease status. In a subset of samples, haRPE and iPSC-RPE were generated from the same human donor to make a side-by-side comparison of the two cell models' response to treatment. Disease-specific responses to all three treatments was observed in the haRPE. In contrast, iPSC-RPE had a similar response to all treatments irrespective of disease status. Analysis of haRPE and iPSC-RPE generated from the same human donor showed a similar response for donors without AMD, but there were significant differences in treatment response between cell models generated from AMD donors. These results support the use of iPSC-RPE and haRPE when investigating AMD mechanisms and new therapeutics but indicates that attention to experimental conditions is required.
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BACKGROUND: Rods and cones are photoreceptor neurons in the retina that are required for visual sensation in vertebrates, wherein the perception of vision is initiated when these neurons respond to photons in the light stimuli. The photoreceptor cell is structurally studied as outer segments (OS) and inner segments (IS) where proper protein sorting, localization, and compartmentalization are critical for phototransduction, visual function, and survival. In human retinal diseases, improper protein transport to the OS or mislocalization of proteins to the IS and other cellular compartments could lead to impaired visual responses and photoreceptor cell degeneration that ultimately cause loss of visual function. RESULTS: Therefore, studying and identifying mechanisms involved in facilitating and maintaining proper protein transport in photoreceptor cells would help our understanding of pathologies involving retinal cell degeneration in inherited retinal dystrophies, age-related macular degeneration, and Usher Syndrome. CONCLUSIONS: Our mini-review will discuss mechanisms of protein transport within photoreceptors and introduce a novel role for an unconventional motor protein, MYO1C, in actin-based motor transport of the visual chromophore Rhodopsin to the OS, in support of phototransduction and visual function.