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International Journal of Molecular... Feb 2021Photoreceptors are the light-sensing cells of the retina and the major cell type affected in most inherited retinal degenerations. Different metabolic pathways sustain...
Photoreceptors are the light-sensing cells of the retina and the major cell type affected in most inherited retinal degenerations. Different metabolic pathways sustain their high energetic demand in physiological conditions, particularly aerobic glycolysis. The principal metabolome of the mature retina has been studied, but only limited information is available on metabolic adaptations in response to key developmental events, such as eye opening. Moreover, dynamic metabolic changes due to retinal degeneration are not well understood. Here, we aimed to explore and map the ocular metabolic dynamics induced by eye opening in healthy (wild type) or -mutant (retinal degeneration 1, Rd1) mice, in which photoreceptors degenerate shortly after eye opening. To unravel metabolic differences emerging before and after eye opening under physiological and pathophysiological conditions, we performed nuclear magnetic resonance (NMR) spectroscopy-based metabolome analysis of wild type and Rd1 retina and vitreous/lens. We show that eye opening is accompanied by changes in the concentration of selected metabolites in the retina and by alterations in the vitreous/lens composition only in the retinal degeneration context. As such, we identify NAcetylaspartate as a potential novel vitreous/lens marker reflecting progressive retinal degeneration. Thus, our data can help elucidating mechanisms underlying key events in retinal physiology and reveal changes occurring in pathology, while highlighting the importance of the vitreous/lens in the characterization of retinal diseases.
Topics: Animals; Cyclic Nucleotide Phosphodiesterases, Type 6; Disease Models, Animal; Lens, Crystalline; Metabolome; Mice; Mutation; Retina; Retinal Degeneration; Vitreous Body
PubMed: 33652907
DOI: 10.3390/ijms22052345 -
Survey of Ophthalmology 2015It is widely accepted that the origin of subretinal fluid in rhegmatogenous retinal detachment (RRD) is liquid vitreous and that posterior vitreous detachment (PVD) and... (Review)
Review
It is widely accepted that the origin of subretinal fluid in rhegmatogenous retinal detachment (RRD) is liquid vitreous and that posterior vitreous detachment (PVD) and associated retinal tears are caused by vitreoretinal traction from intra-ocular currents, contraction of collagen fibers, and gravity. These explanations, however, are incomplete. We present a new synthesis of experimental and clinical evidence, updating understanding of fundamental pathophysiological processes in RRD. Misdirected aqueous flow is shown to more convincingly explain the origin of subretinal fluid in clinical RRD, to be the most likely cause of acute PVD and retinal tear formation, and also to contribute to initial detachment of the retina at retinal tears. Misdirected aqueous flow in RRD is a pathophysiological process, rather than the "aqueous misdirection syndrome", and occurs without visible anterior chamber shallowing or acute glaucoma.
Topics: Aqueous Humor; Humans; Retinal Detachment; Retinal Perforations; Subretinal Fluid; Vitreous Body; Vitreous Detachment
PubMed: 25223495
DOI: 10.1016/j.survophthal.2014.07.002 -
Retina (Philadelphia, Pa.) Feb 2022The causes of floaters include posterior vitreous detachment and fundus hemorrhage, both of which are risk factors for retinal tears. We observed the vitreous of...
PURPOSE
The causes of floaters include posterior vitreous detachment and fundus hemorrhage, both of which are risk factors for retinal tears. We observed the vitreous of patients with floaters using swept source optical coherence tomography.
METHODS
Fundus examination was performed, and the vitreous was observed using swept source optical coherence tomography in 202 eyes of 202 patients with floaters. Patients with uveitis, diabetic retinopathy, and other fundus diseases were excluded.
RESULTS
Swept source optical coherence tomography revealed posterior vitreous detachment in 145 of 202 eyes (71.8%) and dot reflex like stardust in the vitreous in 42 of 202 eyes (20.8%). Posterior vitreous detachment occurred in 35 of 42 eyes (83.3%) and 110 of 160 eyes (68.8%) in the stardust (+) and stardust (-) groups, respectively; a significant difference was observed (P <0.001). In the stardust (+) group, 11 of 42 eyes (26.2%) had retinal tears with posterior vitreous detachment and 21 of 42 eyes (50.0%) had fundus hemorrhage. Three of 160 eyes (1.9%) and 4 of 160 eyes (2.5%) in the stardust (-) group had retinal tears with posterior vitreous detachment and fundus hemorrhage, respectively. Both tears and fundus hemorrhage were more frequent in the stardust (+) group than in the stardust (-) group (P <0.001).
CONCLUSION
The stardust sign on swept source optical coherence tomography indicates the risk of retinal tear.
Topics: Adult; Aged; Aged, 80 and over; Female; Fundus Oculi; Humans; Male; Middle Aged; Prospective Studies; Retinal Perforations; Tomography, Optical Coherence; Vitreous Body; Vitreous Detachment; Young Adult
PubMed: 35050930
DOI: 10.1097/IAE.0000000000003317 -
Experimental Eye Research Nov 2021Vitreous humor (VH) is not considered as a critical structure in the radiotherapy planning process. In the present study, an experimental animal model was performed to...
Vitreous humor (VH) is not considered as a critical structure in the radiotherapy planning process. In the present study, an experimental animal model was performed to examine the effects of radiotherapy on VH. The right eyes of twelve New Zealand rabbits were irradiated to 60 Gy in 3 fractions in accordance with the scheme used in the treatment of uveal melanoma in our clinic, and contralateral (left) eyes were considered as control. Weekly ophthalmologic examination was performed after irradiation, for three months. At the end of the third month, enucleation and vitreous collection were conducted. The vitreous samples were subjected to metabolomic analyses, ELISA analyses, viscosity measurements, and electron microscopic examination. In control and experimental vitreous samples, 275 different metabolites were identified, and 34 were found to differ significantly between groups. In multivariate analyzes, a clear distinction was observed between control and irradiated vitreous samples. Pathway analysis revealed that nine pathways were affected, and these pathways were mainly related to amino acid metabolism. A significant decrease was observed in the expressions of type II, V, and XI collagens in protein level in the ELISA. There was a non-significant decrease in type IX collagen and viscosity. Electron microscopic examination revealed disrupted collagen fibrillar ultra-structure and dispersed collagen fragments in the experimental vitreous. An intact vitreous is essential for a healthy eye. In this study, we observed that radiation causes changes in the vitreous that may have long-term consequences.
Topics: Animals; Body Fluids; Collagen; Male; Melanoma; Neoplasms, Experimental; Rabbits; Uveal Neoplasms; Vitreous Body
PubMed: 34688623
DOI: 10.1016/j.exer.2021.108802 -
Current Opinion in Ophthalmology May 2017This article reviews current advancements in vitreoretinal surgical machines. (Review)
Review
PURPOSE OF REVIEW
This article reviews current advancements in vitreoretinal surgical machines.
RECENT FINDINGS
The most recent advancement in vitreoretinal surgical machines include 27-gauge vitrectomy probes, new cutter designs, higher cut rate, improved intraocular pressure control, new endoillumination technologies, and combined anterior/posterior segment capabilities.
SUMMARY
With recent advancements in vitreoretinal surgical machines, surgical incisions have become less traumatic and fluidics control has led to a more controlled posterior segment vitrectomy.
Topics: Eye Diseases; Humans; Retinal Diseases; Vitrectomy; Vitreoretinal Surgery; Vitreous Body
PubMed: 28257298
DOI: 10.1097/ICU.0000000000000369 -
Biomolecules Dec 2021Vitreous fluid is commonly collected for toxicological analysis during forensic postmortem investigations. Vitreous fluid is also often analyzed for potassium, sodium,...
Vitreous fluid is commonly collected for toxicological analysis during forensic postmortem investigations. Vitreous fluid is also often analyzed for potassium, sodium, chloride and glucose for estimation of time since death, and for the evaluation of electrolyte imbalances and hyperglycemia, respectively. Obtaining such results in the early phase of a death investigation is desirable both in regard to assisting the police and in the decision-making prior to the autopsy. We analyzed vitreous fluid with blood gas instruments to evaluate/examine the possible impact of different sampling and pre-analytical treatment. We found that samples from the right and left eye, the center of the eye as well as whole vitreous samples gave similar results. We also found imprecision to be very low and that centrifugation and dilution were not necessary when analyzing vitreous samples with blood gas instruments. Similar results were obtained when analyzing the same samples with a regular multi-analysis instrument, but we found that such instruments could require dilution of samples with high viscosity, and that such dilution might impact measurement accuracy. In conclusion, using a blood gas instrument, the analysis of postmortem vitreous fluid for electrolytes and glucose without sample pretreatment produces rapid and reliable results.
Topics: Autopsy; Humans; Postmortem Changes; Potassium; Sodium; Vitreous Body
PubMed: 35053180
DOI: 10.3390/biom12010032 -
Clinical & Experimental Ophthalmology Mar 2023Although early detection is critical, diagnosing vitreoretinal lymphoma (VRL) remains difficult. We sought to assess the potential diagnostic value of spectral-domain... (Review)
Review
BACKGROUND
Although early detection is critical, diagnosing vitreoretinal lymphoma (VRL) remains difficult. We sought to assess the potential diagnostic value of spectral-domain optical coherence tomography (SD-OCT) in VRL.
METHODS
We reviewed the clinical records and pre-treatment SD-OCT images of biopsy-confirmed VRL and uveitis patients, with primary involvement of the sub-retinal pigment epithelium (RPE) and the outer retina, including acute syphilitic posterior placoid chorioretinitis (ASPPC), chronic stage sympathetic ophthalmitis (SO), and idiopathic multifocal choroiditis (MFC).
RESULTS
We included 45 eyes of 45 VRL patients and 40 eyes of 40 uveitis patients (17 ASPPC eyes, eight chronic SO eyes, and 15 MFC eyes). On SD-OCT, lymphoma cell infiltration was observed in various retinal layers, most commonly in the sub-RPE (80%) and sub-retinal space (62%). Highly sensitive features for VRL as compared to uveitis included vitreous cells (93%), focal hyper-reflective sub-retinal infiltration (51%), and diffuse RPE elevations (56%). The features strongly specific for VRL included preretinal deposits (92.5%), intra-retinal infiltration (except the incomplete vertical hyper-reflective type, 100%), banded hyper-reflective sub-retinal infiltration (90%), and confluent RPE detachments (100%). We identified an approach to VRL diagnosis based on these SD-OCT findings: (1) two highly sensitive features plus one strongly specific feature; or (2) one highly sensitive feature plus two strongly specific features, demonstrated a sensitivity of 80% and specificity of 95% for VRL.
CONCLUSIONS
The SD-OCT may enable the detection of detailed lymphoma infiltration characteristics and provide significant supplemental value for VRL diagnosis, particularly when combining highly sensitive and specific VRL-associated SD-OCT features.
Topics: Humans; Tomography, Optical Coherence; Retinal Neoplasms; Vitreous Body; Retina; Chorioretinitis; Eye Neoplasms; Lymphoma; Syphilis; Retrospective Studies; Fluorescein Angiography
PubMed: 36567492
DOI: 10.1111/ceo.14197 -
Current Opinion in Ophthalmology May 2017Visualization remains a critical factor in successful ocular surgery.Here we review new technology that has the potential to allow for safer and more efficient retinal... (Review)
Review
PURPOSE OF REVIEW
Visualization remains a critical factor in successful ocular surgery.Here we review new technology that has the potential to allow for safer and more efficient retinal surgery.
RECENT FINDINGS
Vitreoretinal surgery poses unique visualization challenges such as the need for specialized optical systems and the delicate and microscopic features of retinal structures. Better retinal visualization allows for new approaches to increasingly complex retinal cases. Wide-angle viewing has allowed stereopic visualization of the peripheral retina. Improved lighting systems have shown better safety profiles and can facilitate bimanual techniques. The potential to improve surgical decision making has been shown with intraoperative imaging such as optical coherence tomography.
SUMMARY
Although some of the benefits of these developments have yet to be proven, improved technology for visualization during retinal surgery will hopefully allow for safer and more efficient surgeries.
Topics: Humans; Retina; Tomography, Optical Coherence; Vitreoretinal Surgery; Vitreous Body
PubMed: 28306625
DOI: 10.1097/ICU.0000000000000368 -
Ophthalmology Feb 2018Despite posterior vitreous detachment being a common ocular event affecting most individuals in an aging population, there is little consensus regarding its precise...
PURPOSE
Despite posterior vitreous detachment being a common ocular event affecting most individuals in an aging population, there is little consensus regarding its precise anatomic definition. We investigated the morphologic appearance and molecular composition of the posterior hyaloid membrane to determine whether the structure clinically observed enveloping the posterior vitreous surface after posterior vitreous detachment is a true basement membrane and to postulate its origin. Understanding the relationship between the vitreous (in both its attached and detached state) and the internal limiting membrane of the retina is essential to understanding the cause of rhegmatogenous retinal detachment and vitreoretinal interface disorders, as well as potential future prophylactic and treatment strategies.
DESIGN
Clinicohistologic correlation study.
PARTICIPANTS
Thirty-six human donor globes.
METHODS
Vitreous bodies identified to have posterior vitreous detachment were examined with phase-contrast microscopy and confocal microscopy after immunohistochemically staining for collagen IV basement membrane markers, in addition to extracellular proteins that characterize the vitreoretinal junction (fibronectin, laminin) and vitreous gel (opticin) markers. The posterior retina similarly was stained to evaluate the internal limiting membrane. Findings were correlated to the clinical appearance of the posterior hyaloid membrane observed during slit-lamp biomicroscopy after posterior vitreous detachment and compared with previously published studies.
MAIN OUTCOME MEASURES
Morphologic appearance and molecular composition of the posterior hyaloid membrane.
RESULTS
Phase-contrast microscopy consistently identified a creased and distinct glassy membranous sheet enveloping the posterior vitreous surface, correlating closely with the posterior hyaloid membrane observed during slit-lamp biomicroscopy in patients with posterior vitreous detachment. Immunofluorescent confocal micrographs demonstrated the enveloping membranous structure identified on phase-contrast microscopy to show positive stain results for type IV collagen. Immunofluorescence of the residual intact internal limiting membrane on the retinal surface also showed positive stain results for type IV collagen.
CONCLUSIONS
The results of this study provide immunohistochemical evidence that the posterior hyaloid membrane is a true basement membrane enveloping the posterior hyaloid surface. Because this membranous structure is observed only after posterior vitreous detachment, the results of this study indicate that it forms part of the internal limiting membrane when the vitreous is in its attached state.
Topics: Adult; Aged; Aged, 80 and over; Basement Membrane; Collagen; Female; Humans; Imaging, Three-Dimensional; Immunohistochemistry; Male; Microscopy, Acoustic; Microscopy, Confocal; Middle Aged; Prospective Studies; Vitrectomy; Vitreous Body; Vitreous Detachment
PubMed: 28867131
DOI: 10.1016/j.ophtha.2017.08.001 -
Retina (Philadelphia, Pa.) Aug 2022To evaluate the degenerative findings including cistern formation in the premacular vitreous using optical coherence tomography.
PURPOSE
To evaluate the degenerative findings including cistern formation in the premacular vitreous using optical coherence tomography.
METHODS
A novel enhanced vitreous imaging method by which four A-scans at each position were averaged before the Fourier transform increased the image quality per frame so that subsequent image registration for averaging could occur. Analysis of B-scans and volume-rendered images of eyes in subjects of various ages was performed.
RESULTS
There were 43 eyes of 23 subjects ranging in age from 23 to 68 years. The texture in the vitreous images suggests specific orientations of the vitreous fibers in the macular region; there were fibers circumferential to the retina immediately anterior to the premacular bursa. The pattern of the vitreous fibers seemed less well-defined internal to the zone of circumferential fibers. In younger eyes, there were striations oriented in a roughly inferior to superior direction in this zone. In older eyes, there were striations in the same orientation but actually were alternating zones of vitreous synchysis and syneresis. In these same eyes, numerous cisterns appeared at various levels in the vitreous gel. With extensive vitreous condensation and synchysis, definition of the premacular bursa was lost.
CONCLUSION
With this novel method of enhanced vitreous imaging, the vitreous seemed to have stereotypic patterns of degeneration. The formation of vitreous syneresis and synchysis may be related to organization architecture of the vitreous, including the pattern of vitreous collagen deposition, and the effects of eye motion through decades of time.
Topics: Adult; Aged; Healthy Volunteers; Humans; Middle Aged; Retina; Tomography, Optical Coherence; Vitreous Body; Young Adult
PubMed: 35333841
DOI: 10.1097/IAE.0000000000003474