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Biomedicine & Pharmacotherapy =... Nov 2023Humans rely on vision as their most important sense. This is accomplished by photoreceptors (PRs) in the retina that detect light but cannot function without the support... (Review)
Review
Humans rely on vision as their most important sense. This is accomplished by photoreceptors (PRs) in the retina that detect light but cannot function without the support and maintenance of the retinal pigment epithelium (RPE). In subretinal hemorrhage (SRH), blood accumulates between the neurosensory retina and the RPE or between the RPE and the choroid. Blood breakdown products subsequently damage PRs and the RPE and lead to poor vision and blindness. Hence, there is a high need for options to preserve the retina and visual functions. We conducted a systematic review of the literature in accordance with the PRISMA guidelines to identify the cell death mechanisms in RPE and PRs after SRH to deepen our understanding of the pathways involved. After screening 736 publications published until November 8, 2022, we identified 19 records that assessed cell death in PRs and/or RPE in experimental models of SRH. Among the different cell death mechanisms, apoptosis was the most widely investigated mechanism (11 records), followed by ferroptosis (4), whereas necroptosis, pyroptosis, and lysosome-dependent cell death were only assessed in one study each. We discuss different therapeutic options that were assessed in these studies, including the removal of the hematoma/iron chelation, cytoprotection, anti-inflammatory agents, and antioxidants. Further systematic investigations will be necessary to determine the exact cell death mechanisms after SRH with respect to different blood breakdown components, cell types, and time courses. This will form the basis for the development of novel treatment options for SRH.
Topics: Humans; Retinal Pigment Epithelium; Retina; Cell Death; Photoreceptor Cells; Hemorrhage
PubMed: 37742603
DOI: 10.1016/j.biopha.2023.115572 -
Indian Journal of Ophthalmology Sep 2023
Topics: Humans; India; Tissue and Organ Procurement; Eye; Blindness; Cornea
PubMed: 37602596
DOI: 10.4103/IJO.IJO_2096_23 -
BMJ Open Ophthalmology Nov 2023To investigate repeatability of refractive state using a smartphone-based assessment tool, the Near Eye Tool for Refractive Assessment (NETRA).
OBJECTIVE
To investigate repeatability of refractive state using a smartphone-based assessment tool, the Near Eye Tool for Refractive Assessment (NETRA).
METHODS AND ANALYSIS
This study included 279 participants, predominantly female (66.7%) of African descent (49.1%). The age range was 9-63 years with mean age () 22.6 (8.9) years. Two consecutive measurements per eye with the NETRA were measured for both eyes of all participants. However, analyses for the right eyes only are included here. Multivariate statistical analysis included stereo-pair comets and scatterplots with 95% surfaces of constant probability density. Correlation coefficients for repeated samples were determined. Repeatability and agreement for NETRA were assessed with Bland-Altman plots, coefficients of repeatability ([Formula: see text] ; [Formula: see text] is the SD of differences) and intraclass correlation coefficients (ICCs).
RESULTS
Bland-Altman plots, within-subject SD ( ), coefficients of repeatability and ICC indicated that repeated measurements were similar for many but not all eyes and there was good agreement (ICC=0.96) for the spherical coefficient ( =) but less so for antistigmatic coefficients ( = and = ) of power. Although mean differences for repeated samples were almost zero, 95% limits of agreement widths were larger for the stigmatic coefficients. Without cycloplegia, repeatability (2.77 ) was 1.63 D, 0.58 D and 0.56 D for the stigmatic and antistigmatic coefficients, respectively.
CONCLUSION
NETRA is a potentially useful and inexpensive portable method in clinical and primary health settings, and especially in less-developed regions of the world. The subjective nature of the self-refraction task can be challenging for younger individuals, and cycloplegia is recommended for NETRA with such patients.
Topics: Humans; Female; Child; Adolescent; Young Adult; Adult; Middle Aged; Male; Refraction, Ocular; Vision Tests; Cornea; Face; Presbyopia
PubMed: 38007230
DOI: 10.1136/bmjophth-2023-001458 -
Biomolecules Sep 2023We previously reported differential gene expression of the bone morphogenetic protein 2 () in guinea pig retinal pigment epithelium (RPE) after 1 day of hyperopic...
PURPOSE
We previously reported differential gene expression of the bone morphogenetic protein 2 () in guinea pig retinal pigment epithelium (RPE) after 1 day of hyperopic defocus, imposed with a negative contact lens (CLs). The study reported here sought to obtain insights into the temporal profiles of gene expression changes in Bmp2, as well as those of two closely related genes, the inhibitor of DNA binding 3 (Id3) and Noggin (Nog), both during myopia induction and when the CL treatment was terminated to allow recovery from induced myopia.
METHODS
To induce myopia, 2-week-old pigmented guinea pigs (New Zealand strain, n = 8) wore monocular -10 diopter (D) rigid gas-permeable (RGP) CLs for one week, while the other eye served as a control. Ocular measurements were made at baseline, 3 days, and 7 days after the initiation of CL wear, with treatment then being terminated and additional measurements being made after a further 3 days, 1 week, and 2 weeks. Spherical equivalent refractive errors (SERs), axial length (AL), choroidal thickness (ChT), and scleral thickness (ScT) data were collected using retinoscopy, optical biometry (Lenstar), and spectral domain optical coherence tomography (SD-OCT), respectively. RPE samples were collected from both eyes of the guinea pigs after either 1 day or 1 week of CL wear or 1 day or 2 weeks after its termination, and RNA was subsequently isolated and subjected to quantitative real-time PCR (qRT-PCR) analyses, targeting the , , and genes.
RESULTS
Mean interocular differences (treated-control) in AL and SER were significantly different from baseline after 3 and 7 days of CL wear, consistent with induced myopia ( < 0.001 for all cases). Termination of CL wear resulted in the normalization (i.e., recovery) of the ALs and SERs of the treated eyes within 7 days, and the earlier significant ChT thinning with CL wear ( = 0004, day 7) was replaced by rapid thickening, which remained significant on day 7 = 0.009) but had normalized by day 14. The ChT changes were much smaller in magnitude than the AL changes in both phases. Interocular differences in the ScT showed no significant changes. The Bmp2 and Id3 genes were both significantly downregulated with CL wear, after 1 day ( = 0.012 and 0.016) and 7 days ( = 0.002 and 0.005), while Bmp2 gene expression increased and Nog gene expression decreased after the termination of CL wear, albeit transiently, which was significant on 1 day ( = 0.004 and 0.04) but not 2 weeks later. No change in Id3 gene expression was observed over the latter period. The above patterns of myopia induction and recovery validate this negative RGP-CL model as an alternative to traditional spectacle lens models for guinea pigs. The defocus-driven, sign-dependent changes in the expression of the Bmp2 gene in guinea pig RPE are consistent with observations in chicks and demonstrate the important role of BMP2 in eye growth regulation.
Topics: Animals; Guinea Pigs; Bone Morphogenetic Protein 2; Choroid; Myopia; Retinal Pigment Epithelium
PubMed: 37759773
DOI: 10.3390/biom13091373 -
Eye & Contact Lens Dec 2023This study aimed to investigate corneal epithelial and topographic changes caused by two commercial myopia orthokeratology (ortho-k) designs.
OBJECTIVES
This study aimed to investigate corneal epithelial and topographic changes caused by two commercial myopia orthokeratology (ortho-k) designs.
METHODS
Twenty-six subjects fitted with vision shape treatment (VST) lenses and 30 subjects fitted with corneal reshaping therapy (CRT) lenses were reviewed 1 day, 1 week, and 1 month after lens initiation. A spectral-domain optical coherence tomography system was used to create epithelial maps that were in turn used to determine the average epithelial thickness of each zone and the diameter of treatment zone. By measuring the topographic tangential differential map, the treatment zone diameter and the power and width of the high convex zone (HCZ) were obtained. All epithelial thicknesses and topographic corneal variations recorded were analyzed.
RESULTS
At the central zone, the epithelial thickness changes (△ET) decreased significantly after 1 day of ortho-k in two groups. At 2- to 9-mm peripheral zone, ortho-k increased △ET until 1 week in the VST group, whereas it kept increasing in the CRT group after 1 week. At 1 month, the central △ET is -9.51±2.38 mm in the VST group, which was comparable to -8.72±3.43 mm in the CRT group. The nasal HCZ power and the △ET of nasal and inferior nasal were significantly larger in the CRT group. A positive correlation was found between the HCZ power and △ET generated by VST-type lenses inferiorly and temporally. For the CRT group, a positive correlation was found between inferior HCZ power and △ET.
CONCLUSIONS
At the early stage of ortho-k, epithelial thickness and topography change quickly and simultaneously. Epithelial changes were in line with corneal topography reshaping. Epithelial and optical remodelling were affected by different lens types.
Topics: Humans; Orthokeratologic Procedures; Contact Lenses; Cornea; Corneal Topography; Refraction, Ocular
PubMed: 37902624
DOI: 10.1097/ICL.0000000000001045 -
BMJ Open Ophthalmology Nov 2023To explore the current research about the role of optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA) in dysthyroid optic neuropathy... (Meta-Analysis)
Meta-Analysis
PURPOSE
To explore the current research about the role of optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA) in dysthyroid optic neuropathy (DON).
METHODS
Studies in the literature that focused on OCT, OCTA and DON were retrieved by searching PubMed, EMBASE, Cochrane databases and Clinical Trial before 20 June 2023. The methodological quality was assessed using the Newcastle-Ottawa scale. The quantitative calculation was performed using Review Manager V.5.3.
RESULTS
Twelve studies met the eligibility criteria and were included. DON group presented lower macular ganglion cell complex in the overall, superior and inferior hemifields compared with the non-DON group. Furthermore, the ganglion cell layer and inner plexiform layer in DON group was thinner in contrast to the non-DON group. The optic nerve head vessel density was lower in the DON group than that in the non-DON group. A reduction of radial peripapillary capillary vessel density could be seen in the DON group than the non-DON group in overall, inside disc, peripapillary, superior-hemifield, temporal and nasal. Besides, the macular superficial retinal capillary layer of non-DON and DON is lower than the healthy control group.
CONCLUSIONS
This study supported the potential value of OCT and OCTA metrics as novel biomarkers of DON. Ophthalmologists should comprehensively consider the retinal structure and microvasculature in dealing with DON.
ETHICS AND DISSEMINATION
This systematic review included data from published literature and was exempt from ethics approval. Results would be disseminated through peer-reviewed publication and presented at academic conferences engaging clinicians.
PROSPERO REGISTRATION NUMBER
CRD42023414907.
Topics: Humans; Tomography, Optical Coherence; Optic Disk; Angiography; Retinal Ganglion Cells; Optic Nerve Diseases
PubMed: 37996119
DOI: 10.1136/bmjophth-2023-001379 -
Retina (Philadelphia, Pa.) Aug 2023To describe the clinical characteristics and multimodal imaging features of a distinctive subtype of active idiopathic multifocal choroiditis (iMFC) lesions with...
PURPOSE
To describe the clinical characteristics and multimodal imaging features of a distinctive subtype of active idiopathic multifocal choroiditis (iMFC) lesions with grey-yellow chorioretinal lesions surrounded by smaller satellite dots, a presentation referred to as "chrysanthemum lesions."
METHODS
Retrospective, observational, multicenter case series of eyes with active iMFC and chrysanthemum lesions. Multimodal imaging features were reviewed and presented.
RESULTS
Twenty-five eyes from 20 patients (12 women and 8 men), with a mean age of 35.8 ± 17.0 years (range, 7-78 years) were included. Chrysanthemum lesions were equally located in the macula (48.0%) or the mid/far periphery (52.0%). The number of lesions per eye varied from 1 (16.0%) to more than 20 (56.0%). On optical coherence tomography, chrysanthemum lesions showed typical features of iMFC, including subretinal hyperreflective material splitting the retinal pigment epithelium/Bruch membrane. Chrysanthemum lesions were hypoautofluorescent on fundus autofluorescence imaging, hyperfluorescent on fluorescein angiography, hypofluorescent on indocyanine green angiography, and associated with choriocapillaris flow signal deficit on optical coherence tomography angiography.
CONCLUSION
Active iMFC may present with findings resembling chrysanthemum lesions. The distinctive lesion morphology on ophthalmoscopic examination, the large number of lesions, and the high prevalence of exclusive midperipheral and far peripheral involvement may represent a distinctive phenotype of iMFC.
Topics: Humans; Multifocal Choroiditis; Retrospective Studies; Fundus Oculi; Choroiditis; Choroid; Fluorescein Angiography; Tomography, Optical Coherence
PubMed: 37071923
DOI: 10.1097/IAE.0000000000003815 -
Journal of Translational Medicine May 2024Retinal ischemia/reperfusion (RIR) is implicated in various forms of optic neuropathies, yet effective treatments are lacking. RIR leads to the death of retinal ganglion...
BACKGROUND
Retinal ischemia/reperfusion (RIR) is implicated in various forms of optic neuropathies, yet effective treatments are lacking. RIR leads to the death of retinal ganglion cells (RGCs) and subsequent vision loss, posing detrimental effects on both physical and mental health. Apigenin (API), derived from a wide range of sources, has been reported to exert protective effects against ischemia/reperfusion injuries in various organs, such as the brain, kidney, myocardium, and liver. In this study, we investigated the protective effect of API and its underlying mechanisms on RGC degeneration induced by retinal ischemia/reperfusion (RIR).
METHODS
An in vivo model was induced by anterior chamber perfusion following intravitreal injection of API one day prior to the procedure. Meanwhile, an in vitro model was established through 1% oxygen and glucose deprivation. The neuroprotective effects of API were evaluated using H&E staining, spectral-domain optical coherence tomography (SD-OCT), Fluoro-Gold retrograde labeling, and Photopic negative response (PhNR). Furthermore, transmission electron microscopy (TEM) was employed to observe mitochondrial crista morphology and integrity. To elucidate the underlying mechanisms of API, the terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay, flow cytometry assay, western blot, cell counting kit-8 (CCK-8) assay, lactate dehydrogenase (LDH) assay, JC-1 kit assay, dichlorofluorescein-diacetate (DCFH-DA) assay, as well as TMRE and Mito-tracker staining were conducted.
RESULTS
API treatment protected retinal inner plexiform layer (IPL) and ganglion cell complex (GCC), and improved the function of retinal ganglion cells (RGCs). Additionally, API reduced RGC apoptosis and decreased lactate dehydrogenase (LDH) release by upregulating Bcl-2 and Bcl-xL expression, while downregulating Bax and cleaved caspase-3 expression. Furthermore, API increased mitochondrial membrane potential (MMP) and decreased extracellular reactive oxygen species (ROS) production. These effects were achieved by enhancing mitochondrial function, restoring mitochondrial cristae morphology and integrity, and regulating the expression of OPA1, MFN2, and DRP1, thereby regulating mitochondrial dynamics involving fusion and fission.
CONCLUSION
API protects RGCs against RIR injury by modulating mitochondrial dynamics, promoting mitochondrial fusion and fission.
Topics: Retinal Ganglion Cells; Apigenin; Animals; Reperfusion Injury; Neuroprotective Agents; Mitochondrial Dynamics; Male; Apoptosis; Mitochondria; Reactive Oxygen Species; Models, Biological; Mice, Inbred C57BL
PubMed: 38741132
DOI: 10.1186/s12967-024-05260-1 -
Survey of Ophthalmology 2023A persistent epithelial defect (PED) is a corneal epithelial defect that failed to heal after 2weeks. It is a condition that carries much morbidity, and our... (Review)
Review
A persistent epithelial defect (PED) is a corneal epithelial defect that failed to heal after 2weeks. It is a condition that carries much morbidity, and our understanding of PED remains poor, with current treatment methods often having unsatisfactory outcomes. With PEDs becoming more prevalent, more efforts are required to establish reliable treatment modalities. Our reviews describe the causes of PEDs and the different approaches developed to manage them, as well as their associated limitations. Emphasis is placed on understanding various advances in the development of new treatment modalities. We have also described a case of a woman with a background of graft-versus-host disease on long-term topical corticosteroids who developed complicated PED involving both eyes. The current approach to managing PEDs generally involves exclusion of an active infection, followed by treatment modalities that aim to encourage corneal epithelial healing. Success rates, however, remain far from desirable, as treatment remains challenging due to multiple underlying etiologies. In summary, advances in the development of new therapies may be able to facilitate progress in the understanding and treatment of PED.
Topics: Female; Humans; Epithelium, Corneal; Eye Diseases; Combined Modality Therapy; Wound Healing; Cornea; Corneal Diseases
PubMed: 37301520
DOI: 10.1016/j.survophthal.2023.06.001 -
International Journal of Molecular... May 2024The ocular glymphatic system subserves the bidirectional polarized fluid transport in the optic nerve, whereby cerebrospinal fluid from the brain is directed along... (Review)
Review
The ocular glymphatic system subserves the bidirectional polarized fluid transport in the optic nerve, whereby cerebrospinal fluid from the brain is directed along periarterial spaces towards the eye, and fluid from the retina is directed along perivenous spaces following upon its axonal transport across the glial lamina. Fluid homeostasis and waste removal are vital for retinal function, making the ocular glymphatic fluid pathway a potential route for targeted manipulation to combat blinding ocular diseases such as age-related macular degeneration, diabetic retinopathy, and glaucoma. Several lines of work investigating the bidirectional ocular glymphatic transport with varying methodologies have developed diverging mechanistic models, which has created some confusion about how ocular glymphatic transport should be defined. In this review, we provide a comprehensive summary of the current understanding of the ocular glymphatic system, aiming to address misconceptions and foster a cohesive understanding of the topic.
Topics: Humans; Glymphatic System; Animals; Optic Nerve; Retina; Eye; Glaucoma
PubMed: 38891923
DOI: 10.3390/ijms25115734