Light adaptation enables the vertebrate visual system to operate over a wide range of ambient illumination. Regulation of phototransduction in photoreceptors is considered a major mechanism underlying light adaptation. However, various types of neurons and glial cells exist in the retina, and whether and how all retinal cells interact to adapt to light/dark conditions at the cellular and molecular levels requires systematic investigation. Therefore, we utilized single-cell RNA sequencing to dissect retinal cell-type-specific transcriptomes during light/dark adaptation in mice. The results demonstrated that, in addition to photoreceptors, other retinal cell types also showed dynamic molecular changes and specifically enriched signaling pathways under light/dark adaptation. Importantly, Müller glial cells (MGs) were identified as hub cells for intercellular interactions, displaying complex cell‒cell communication with other retinal cells. Furthermore, light increased the transcription of the deiodinase Dio2 in MGs, which converted thyroxine (T4) to active triiodothyronine (T3). Subsequently, light increased T3 levels and regulated mitochondrial respiration in retinal cells in response to light conditions. As cones specifically express the thyroid hormone receptor Thrb, they responded to the increase in T3 by adjusting light responsiveness. Loss of the expression of Dio2 specifically in MGs decreased the light responsive ability of cones. These results suggest that retinal cells display global transcriptional changes under light/dark adaptation and that MGs coordinate intercellular communication during light/dark adaptation via thyroid hormone signaling.
Animals ; Mice ; Dark Adaptation ; Light ; Retina ; Retinal Cone Photoreceptor Cells/metabolism* ; Adaptation, Ocular ; Neuroglia/physiology* ; Cell Communication ; Thyroid Hormones

PURPOSE: We investigated structural changes in the retina by using optical coherence tomography (OCT) in a feline model of retinal degeneration using iodoacetic acid (IAA).METHODS: We examined 22 eyes of 11 felines over 2 years of age. The felines had fasted for 12 hours and were intravenously injected with IAA 20 mg/kg of body weight. OCT (Spectralis OCT) was performed at the point where the ends of the retinal vessels collected in the lateral direction from the optic nerve head and area centralis. Similarly, OCT was performed four times at 1-week intervals following injections, at which point the felines were sacrificed and histologic examinations were performed. Using OCT, the thickness of each layer of the retina was measured.RESULTS: The average body weight of the three male and eight female felines investigated in this study was 1.61 ± 0.19 kg. The mean total retinal thickness of the felines before injection was 221.32 ± 9.82 µm, with a significant decrease in the retinal thickness at 2, 3, and 4 weeks following injections of 186.41 ± 35.42, 174.56 ± 31.94, and 175.35 ± 33.84 µm, respectively (p = 0.028, 0.027, and 0.027, respectively). The thickness of the outer nuclear layer was 57.49 ± 8.03 µm before injection and 29.26 ± 17.87, 25.62 ± 13.88, and 31.60 ± 18.38 µm at 2, 3, and 4 weeks, respectively, after injection (p = 0.028, 0.028, 0.046, respectively).CONCLUSIONS: In a feline model of retinal degeneration using IAA, the total retinal thickness and the thickness of the outer nuclear layer were shown to decrease significantly on OCT.
Angiography ; Body Weight ; Female ; Humans ; Iodoacetic Acid ; Male ; Optic Disk ; Photoreceptor Cells, Vertebrate ; Retina ; Retinal Degeneration ; Retinal Vessels ; Retinaldehyde ; Tomography, Optical Coherence

Spherical neural mass (SNM) is a mass of neural precursors that have been used to generate neuronal cells with advantages of long-term passaging capability with high yield, easy storage, and thawing. In this study, we differentiated neural retinal progenitor cells (RPCs) from human induced pluripotent stem cells (hiPSC)-derived SNMs. RPCs were differentiated from SNMs with a noggin/fibroblast growth factor-basic/Dickkopf-1/Insulin-like growth factor-1/fibroblast growth factor-9 protocol for three weeks. Human RPCs expressed eye field markers (Paired box 6) and early neural retinal markers (Ceh-10 homeodomain containing homolog), but did not photoreceptor marker (Opsin 1 short-wave-sensitive). Reverse transcription polymerase chain reaction revealed that early neural retinal markers (Mammalian achaete-scute complex homolog 1, mouse atonal homolog 5, neurogenic differentiation 1) and retinal fate markers (brain-specific homeobox/POU domain transcription factor 3B and recoverin) were upregulated, while the marker of retinal pigment epithelium (microphthalmia-associated transcription factor) only showed slight upregulation. Human RPCs were transplanted into mouse (adult 8 weeks old C57BL/6) retina. Cells transplanted into the mouse retina matured and expressed markers of mature retinal cells (Opsin 1 short-wave-sensitive) and human nuclei on immunohistochemistry three months after transplantation. Development of RPCs using SNMs may offer a fast and useful method for neural retinal cell differentiation.
Animals ; Cell Differentiation ; Humans* ; Immunohistochemistry ; Induced Pluripotent Stem Cells ; Methods ; Mice ; Neurons ; Photoreceptor Cells, Vertebrate ; Polymerase Chain Reaction ; Retina ; Retinal Pigment Epithelium ; Retinaldehyde* ; Reverse Transcription ; Stem Cells* ; Transcription Factors ; Up-Regulation

Solar retinopathy is an injury of the retinal photoreceptors due to excessive exposure to the solar radiation. Diagnosis of the disease is challenging and requires combination of a detailed history and imaging modalities. This case report focuses on a 55-year-old fruit picker with an irreversible central scotoma of the right eye. A diagnosis of solar retinopathy was made based on history but mainly by several imaging modalities, such as optical coherence tomography (OCT), infrared (IF) imaging of the fundus and fundus autofluorescence (FAF). Electroretinogram (ERG)showed flattened and reduced waves in both scotopic and photopic response. Fundus angiography (FA) revealed no obvious telangectatic vessels. In conclusion, solar retinopathy is a disease where multimodal imaging may play an important role in the diagnosis. The condition may be irreversible thus advocating protective eyewear is mandatory in patients who are chronically exposed to the sun.
Photoreceptor Cells, Vertebrate

PURPOSE: Sildenafil citrate, is an oral tablet demonstrating efficacy for maintaining an erection in males with erectile dysfunction by inhibiting phosphodiesterase type 5 (PDE5). In the present study, we report 1 case of a transient color anomaly with visual field defect after an overdose of sildenafil citrate. CASE SUMMARY: One patient, a 39-year-old female, with no significant medical history other than previous major depressive disorder, visited an outpatient department due to the visual field defect that began after taking 30 tablets of sildenafil citrate (50 mg) 3 days earlier. A number of ophthalmologic tests were administered including visual acuity test, color vision test, fundus photography and the measurement of retinal structure with optical coherent tomography and her condition was monitored. The best corrected visual acuity was 1.0 in both right and left eyes in her first visit. The color anomaly and a central scotoma of both eyes were detected in the visual field test, while significant signs were not observed after evaluation using optical coherent tomography and fundus photography. After 5 weeks, the visual acuity was not affected, the color anomaly symptom disappeared and the focal visual field defect was present although improved. CONCLUSIONS: Transient color anomaly and persistent central scotoma caused by an overdose ingestion of sildenafil has not been reported in Korea, The related mechanisms may involve the inhibition of PDE5 on ganglion cells and bipolar cells in the retina and interruption of phosphodiesterase type 6 (PDE6) function in both rods and cones.
Adult ; Citric Acid* ; Color Vision ; Cyclic Nucleotide Phosphodiesterases, Type 6 ; Depressive Disorder, Major ; Eating ; Erectile Dysfunction ; Female ; Ganglion Cysts ; Humans ; Korea ; Male ; Outpatients ; Photography ; Photoreceptor Cells, Vertebrate ; Retina ; Retinaldehyde ; Scotoma ; Tablets ; Visual Acuity ; Visual Field Tests ; Visual Fields* ; Sildenafil Citrate

OBJECTIVETo observe the morphological changes of photoreceptor cells in rats with retinitis pigmentosa (RP) induced by N-methyl-N-Nitrosourea (MNU) and the effects of acupuncture against it.

METHODSA total of 16 SD rats were treated with one-time intraperitoneal injection of MNU (50 mg/kg) to induce RP, and randomly divided into an acupuncture group and a model group, 8 rats in each one. In addition, 4 rats were selected as a control group. After model establishment, rats in the acupuncture group were treated with acupuncture at "Xinming-1" (Extra) and "Jingming" (BL 1) for 30 min, once a day for 7 days; rats in the model group and control group received no treatment, and the feeding conditions and fixation were identical as the acupuncture group. 2 h after the end of intervention, rats were sacrificed by cervical dislocation to observe the morphological changes of rhodopsin, rod terminals and rod bipolar cells.

RESULTSDue to the loss of retina photoreceptor cells induced by MNU in rats, in the model group the rhodopsin was stained in residual cell bodies, and there were sporadic rod terminals and little rod bipolar cells; outer segments, inter segments, cell bodies and cell terminals were all affected at different levels. The distribution of rhodopsin was also changed in the acupuncture group, showing more bodies of photoreceptor cells, and the residual rod terminals and rod bipolar cells were more than those in the model group; the injury of retina was less than that in the model group.

CONCLUSIONMNU could lead to a comprehensive injury to the morphology of photoreceptor cells, however, acupuncture is capable of inhibiting morphological changes of photoreceptor cells induced by MNU.

Acupuncture Therapy ; Animals ; Humans ; Male ; Photoreceptor Cells ; cytology ; Rats ; Rats, Sprague-Dawley ; Retinitis Pigmentosa ; physiopathology ; therapy

The ubiquitous Na, K-ATPase is a membrane-bound ion pump located in the plasma membrane in all animal cells and plays an essential role in a variety of cellular functions. Studies in several organisms have shown that this protein regulates different aspects of embryonic development and is responsible for the pathogenesis of several human diseases. Na, K-ATPase is an important factor for retinal development, and combinations of the isoforms of each of its subunits are expressed in different cell types and determine its functional properties. In this study, we performed RT-PCR assay to determine temporal expression and in situ hybridization to determine spatial expression of Na, K-ATPase beta2 isoform (atp1b2) in Xenopus laevis. Focusing on retinal expression to distinguish the specific expression domain, we used retinal marker genes sox4, sox11, vsx1, and . Xenopus atp1b2 was expressed from late gastrulation to the tadpole stage. Using whole mount in situ hybridization, we showed that Xenopus atp1b2 was expressed broadly in the eye, the whole surface ectoderm, and gills. In situ hybridization on sections revealed detailed and specific expression in the outer nuclear layer of the retina, which consists of two major classes of photoreceptors, rods and cones, surface ectoderm, pharyngeal epithelium, and gills. These findings indicate that atp1b2 may play an important role for the development of Xenopus retina.
Animals ; Cell Membrane ; Ectoderm ; Embryonic Development ; Epithelium ; Female ; Gastrulation ; Gills ; Humans ; In Situ Hybridization ; Ion Pumps ; Larva ; Pregnancy ; Protein Isoforms ; Retina* ; Retinal Rod Photoreceptor Cells ; Retinaldehyde ; Xenopus laevis ; Xenopus*

PURPOSE: To report a case of oxaliplatin (Eloxatin(R))-related ocular toxicity in a patient with advanced stomach cancer. CASE SUMMARY: A 43-year-old female with advanced stomach cancer experienced visual symptoms during the treatment with oxaliplatin on a XELOX schedule (a combination of oxaliplatin and capecitabine). After 1 cycle of chemotherapy, she complained of blurred vision and visual field defects in both eyes. Visual field tests showed a bilateral concentric field defect and the electroretinogram revealed a marked reduction of responses in both eyes. On the second cycle of chemotherapy, oxaliplatin was discontinued due to suspicious ocular toxicity. Her visual symptoms improved and visual field test showed normal results 1 month after oxaliplatin discontinuation. However, 3 months after oxaliplatin discontinuation, electroretinogram remained abnormal despite the progressive improvement. CONCLUSIONS: Platinum-based antineoplastic agents such as oxaliplatin should be administered with caution because oxaliplatin can cause damage to the retinal photoreceptors and the optic nerve. Early detection of ocular toxicity and discontinuation of oxaliplatin therapy could prevent severe and irreversible visual loss.
Adult ; Antineoplastic Agents ; Appointments and Schedules ; Drug Therapy ; Female ; Humans ; Optic Nerve ; Photoreceptor Cells, Vertebrate ; Stomach Neoplasms ; Visual Field Tests ; Visual Fields

OBJECTIVE: To determine the relationship between hypothyroidism and color vision deficiency among Filipinos ages 20-60 years
DESIGN AND METHODS: A cross-sectional study was performed on 91 biochemically hypothyroid and euthyroid patients seen at the Makati Medical Center from July to December 2013. All subjects underwent the Ishihara color test, followed by the Farnsworth-Munsell D15 test if this was positive. The patient who tested positive in the Farnsworth-Munsell D15 test was referred to an ophthalmologist to rule out any anatomic problem, and was excluded from the study if found to have any. Fisher's exact test assessed the significant correlation between hypothyroidism and color vision deficiency. A p-value less than 0.05 was considered significant.
RESULTS: Of the 91 patients that were included in the study, the average age was 42 years, majority (87%) were females, and 41% were biochemically hypothyroid. All euthyroid patients (100%) had normal color vision, while one hypothyroid patient (3.0%) tested positive for color vision deficiency (p-value 0.407).
CONCLUSION: Based on this study, the hypothyroid state of the patients had no effect on their color vision, unlike those seen in rodents, probably because mature human cones are not as easily affected by changes in thyroid hormone levels.

Human ; Male ; Female ; Middle Aged ; Adult ; Color Vision Defects ; Color Vision ; Ophthalmologists ; Retinal Cone Photoreceptor Cells ; Thyroid Hormones ; Hypothyroidism

PURPOSE: To investigate the morphologic changes in the outer retina of patients with cone dystrophy, using spectral-domain optical coherence tomography (SD-OCT). METHODS: The medical records of 15 cone dystrophy patients examined from January 2007 to January 2012 were reviewed retrospectively. All patients underwent ophthalmic evaluation including best-corrected visual acuity (BCVA), color vision testing, fundus examination, full-field standard electroretinography (ERG), multifocal (mf) ERG, and SD-OCT. Qualitative and quantitative SD-OCT data and ERG responses were analyzed and compared among the patient categories and the normal control group. RESULTS: There were 4 major categories of SD-OCT findings, based on the status of the ellipsoid portion of the photoreceptor inner segment (ISe), outer segment (OS) contact cylinder, and retinal pigment epithelium (RPE) layer. Category 0 showed no structural abnormalities. Category 1 showed foveal ISe loss and obscurity of the border between the ISe band and the external limiting membrane (ELM). Category 2 showed foveal thinning and focal foveal ISe disruption with an intact ELM. Category 3 showed foveal thickening and perifoveal disruption of the ISe layer. Category 1 to 3 showed OS contact cylinder layer absence and RPE thickening. The patients in category 0 tended to be younger (mean, 10.0 years) than those in categories 1 to 3 (mean, 17.6 years), although this difference was not statistically significant. Category 1 to 3 patients exhibited statistically significant thinning of the central retina and outer nuclear layer and thickening of the RPE layer relative to the category 0 and normal control group. There was a significant correlation between the central foveal thickness and BCVA in the patients with cone dystrophy. ERG and mfERG responses did not differ significantly among the different cone dystrophy categories. CONCLUSIONS: The morphologic features of cone dystrophy as revealed by SD-OCT, could be categorized as either normal or 1 of 3 different types of outer retinal changes. The presence of normal retinal structures in young cone dystrophy patients with functional impairment (category 0) indicates that electrophysiologic studies are superior to current imaging modalities for the early diagnosis of cone dystrophy. The characteristic SD-OCT findings in cone dystrophy patients may aid in differential diagnosis and be useful for future research on the pathology of cone dystrophy.
Adolescent ; Adult ; Child ; Child, Preschool ; Electroretinography ; Female ; Fluorescein Angiography ; Fundus Oculi ; Humans ; Male ; Middle Aged ; Ophthalmoscopy ; Reproducibility of Results ; Retinal Cone Photoreceptor Cells/*pathology ; Retinal Dystrophies/*pathology/physiopathology ; Retrospective Studies ; Tomography, Optical Coherence/*methods ; Visual Acuity ; Young Adult