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1.
Saudi J Ophthalmol ; 38(2): 112-122, 2024.
Article in English | MEDLINE | ID: mdl-38988778

ABSTRACT

Silicone oil (SO) emulsification is a significant concern in vitreoretinal surgery, leading to various complications. Despite the high prevalence of SO emulsification within the eye, there is currently no standardized method for its early detection. The recent introduction of widefield (WF) imaging and ultra-WF (UWF) imaging with navigated central and peripheral optical coherence tomography (OCT) techniques have shown promising results in providing high-resolution images of the peripheral vitreous, vitreoretinal interface, retina, and choroid. This enhanced visualization capability enables the early identification of emulsified SO droplets, facilitating a proactive therapeutic approach, and mitigating associated adverse events. This comprehensive literature review aims to provide an updated overview of the topic, focusing on the role of WFimaging and UWF imaging and navigated central and peripheral swept-source OCT (SS-OCT) in the early detection and management of SO emulsification. The review discusses the current understanding of SO emulsification, its associated complications, and the limitations of existing detection methods. In addition, it highlights the potential of WF and UWF imaging and peripheral OCT as advanced imaging modalities for improved visualization of SO emulsification. This review serves as a valuable resource for clinicians and researchers, providing insights into the latest advancements in the field of vitreoretinal surgery and the promising role of WF imaging and UWF imaging and navigated central and peripheral SS-OCT in the management of SO.

2.
Saudi J Ophthalmol ; 38(2): 101-111, 2024.
Article in English | MEDLINE | ID: mdl-38988788

ABSTRACT

PURPOSE: To assess central and peripheral retinal and choroidal diseases using ultra-widefield (UWF) fundus imaging in combination with navigated central and peripheral cross-sectional and three-dimensional (3D) swept source optical coherence tomography (SS-OCT) scans. METHODS: Retrospective study involving 332 consecutive patients, with a nearly equal distribution of males and females. The mean age of patients was 52 years (range 18-92 years). Average refractive error was -3.80 D (range +7.75 to -20.75 D). RESULTS: The observations in this study demonstrate the efficacy of peripheral navigated SS-OCT in assessing various ocular conditions. The technology provides high-quality images of the peripheral vitreous, vitreoretinal interface, retina, and choroid, enabling visualization of vitreous floaters and opacities, retinal holes and tears, pigmented lesions, and peripheral retinal degenerations. 3D OCT scans enhance the visualization of these abnormalities and improve diagnostic and therapeutic decisions. CONCLUSION: Navigated central and peripheral cross-sectional and 3D SS-OCT scans offer significant complementary benefits in the assessment and management of retinal diseases. Their addition to UWF imaging provides a comprehensive view of central and peripheral ocular structures, aiding in early detection, precise anatomical measurements, and objective monitoring of disease progression. In addition, this technology serves as a valuable tool for patient education, a teaching tool for trainees, and documentation for medico-legal purposes.

3.
J Neuroinflammation ; 21(1): 168, 2024 Jul 03.
Article in English | MEDLINE | ID: mdl-38961498

ABSTRACT

BACKGROUND: The eye is a highly specialized sensory organ which encompasses the retina as a part of the central nervous system, but also non-neural compartments such as the transparent vitreous body ensuring stability of the eye globe and a clear optical axis. Hyalocytes are the tissue-resident macrophages of the vitreous body and are considered to play pivotal roles in health and diseases of the vitreoretinal interface, such as proliferative vitreoretinopathy or diabetic retinopathy. However, in contrast to other ocular macrophages, their embryonic origin as well as the extent to which these myeloid cells might be replenished by circulating monocytes remains elusive. RESULTS: In this study, we combine transgenic reporter mice, embryonic and adult fate mapping approaches as well as parabiosis experiments with multicolor immunofluorescence labeling and confocal laser-scanning microscopy to comprehensively characterize the murine hyalocyte population throughout development and in adulthood. We found that murine hyalocytes express numerous well-known myeloid cell markers, but concomitantly display a distinct immunophenotype that sets them apart from retinal microglia. Embryonic pulse labeling revealed a yolk sac-derived origin of murine hyalocytes, whose precursors seed the developing eye prenatally. Finally, postnatal labeling and parabiosis established the longevity of hyalocytes which rely on Colony Stimulating Factor 1 Receptor (CSF1R) signaling for their maintenance, independent of blood-derived monocytes. CONCLUSION: Our study identifies hyalocytes as long-living progeny of the yolk sac hematopoiesis and highlights their role as integral members of the innate immune system of the eye. As a consequence of their longevity, immunosenescence processes may culminate in hyalocyte dysfunction, thereby contributing to the development of vitreoretinal diseases. Therefore, myeloid cell-targeted therapies that convey their effects through the modification of hyalocyte properties may represent an interesting approach to alleviate the burden imposed by diseases of the vitreoretinal interface.


Subject(s)
Macrophages , Mice, Transgenic , Vitreous Body , Yolk Sac , Animals , Mice , Vitreous Body/cytology , Yolk Sac/cytology , Macrophages/metabolism , Mice, Inbred C57BL , Receptors, Granulocyte-Macrophage Colony-Stimulating Factor/metabolism , Receptors, Granulocyte-Macrophage Colony-Stimulating Factor/genetics , Animals, Newborn
4.
Ophthalmol Retina ; 2024 Jul 20.
Article in English | MEDLINE | ID: mdl-39038541

ABSTRACT

PURPOSE: To evaluate outcomes of eyes with post-cataract surgery endophthalmitis that were managed without microbial cultures. DESIGN: This retrospective, single-center comparative cohort study identified all cases of endophthalmitis after cataract surgery presenting between February 1, 2014, and November 1, 2022. SUBJECTS: All eyes presenting with presumed endophthalmitis requiring in-office treatment with intravitreal antibiotics and either a vitreous or aqueous tap were included. METHODS: Endophthalmitis cases were divided into the "culture group" if the vitreous or aqueous specimens were sent for microbiologic sampling or into the "no culture group" if an aqueous or vitreous tap was performed but not sent for microbiologic sampling. MAIN OUTCOME MEASURES: Best corrected visual acuity (VA) 12 months following endophthalmitis presentation, incidence of retinal detachment, and need for subsequent procedures. RESULTS: Of the 232 endophthalmitis cases identified, 196 (85%) were in the "culture group" and 36 (15%) were in the "no culture group". At endophthalmitis presentation, eyes in the "culture group" had a mean (SD) logMAR VA [Snellen Equivalent] of 2.14 (0.8) [20/2760] and mean (SD) logMAR VA in the "no culture group" was 1.93 (0.8) [20/1702] (p=0.185). At 12-month follow up, mean (SD) logMAR VA for the "culture group" was 0.80 (1.0) [20/126] and 0.41 (0.5) [20/50] in the "no culture group" (adjusted difference = 0.41, 95% CI = -0.043 - 0.857, p=0.076). Twenty of 196 (10%) eyes in the "culture group" developed secondary retinal detachments within 12 months of presentation compared to 0 in the "no culture group" (p=0.045). CONCLUSIONS: Eyes with endophthalmitis following cataract surgery managed without microbiologic cultures have similar visual outcomes to eyes managed with microbiologic cultures and may be less likely to develop secondary retinal detachments. This may be an acceptable strategy to manage endophthalmitis after cataract surgery when prompt access to a microbiologic facility is unavailable.

5.
Biopolymers ; : e23612, 2024 Jul 12.
Article in English | MEDLINE | ID: mdl-38994706

ABSTRACT

Natural-derived biomaterials can be used as substrates for the growth, proliferation, and differentiation of cells. In this study, bovine vitreous humor as a biological material was cross-linked to silk fibroin with different concentration ratios to design a suitable substrate for corneal tissue regeneration. The cross-linked samples were evaluated with different analyses such as structural, physical (optical, swelling, and degradation), mechanical, and biological (viability, cell adhesion) assays. The results showed that all samples had excellent transparency, especially those with higher silk fibroin content. Increasing the ratio of vitreous humor to silk fibroin decreased mechanical strength and increased swelling and degradation, respectively. There was no significant difference in the toxicity of the samples, and with the increase in vitreous humor ratio, adhesion and cell proliferation increased. Generally, silk fibroin with vitreous humor can provide desirable characteristics as a transparent film for corneal wound healing.

6.
Forensic Sci Res ; 9(3): owae023, 2024 Sep.
Article in English | MEDLINE | ID: mdl-39006154

ABSTRACT

Ethanol blood analysis is the most common request in forensic toxicology, and some studies point to positive results in approximately one-third of all unnatural deaths. However, distinguishing sober deaths from drunk deaths is not as simple as it may seem. This technical, clinical, and forensic interpretation is proposed to interpret the ethanol toxicological results, discussing several artefacts and pitfalls that must be considered, namely focusing on driving under the influence. This work is presented with a practical and objective approach, aiming to alleviate the complexities associated with clinical, physiological, pathophysiological, and toxicological aspects to enhance comprehension, practicality, and applicability of its content, especially to courts. Particularly the physical integrity of the body, the postmortem interval, putrefactive signs, anatomic place of blood collection, alternative samples such as vitreous humour and urine, the possibility of postmortem redistribution, the inclusion of preservatives in containers, and optimal temperature conditions of shipment are among some of the aspects to pay attention. Although several biomarkers related to postmortem microbial ethanol production have been proposed, their translation into forensic routine is slow to be implemented due to the uncertainties of their application and analytical difficulties. Specifically, in the interpretation of ethanol toxicological results, "not everything that can be counted counts and not everything that counts can be counted" (attributed to Albert Einstein).

7.
Ophthalmic Genet ; : 1-4, 2024 Jul 17.
Article in English | MEDLINE | ID: mdl-39016001

ABSTRACT

BACKGROUND: Heterogeneity can impact biomarker identification. Thus, we investigated the somatic copy number alterations (SCNAs) of individual tumor cells in the vitreous humor of a retinoblastoma patient using single-cell whole-genome profiling and explored the genomic concordance among vitreous and aqueous humor, vitreous seeds, and tumor. METHODS: Aqueous humor (AH), vitreous humor (VH), and tumor biopsy were obtained from an enucleated globe with retinoblastoma and vitreous seeding. Micromanipulation was used to manually isolate 39 live single tumor cells from vitreous seeds harvested from the VH. The SCNA profiles of these individual cells were generated via whole-genome sequencing and analyzed alongside profiles from the tumor mass and cell-free DNA (cfDNA) from AH and VH. RESULTS: Heatmap of VH single-cell SCNA profiles demonstrates heterogeneity among individual vitreous seeds with one clearly dominant subclone (23 of 37 cells). The SCNA profiles from the cells in this subclone demonstrate an average concordance of 98% with cfDNA profiles from acellular AH and VH and with the tumor profile. CONCLUSIONS: Our findings reveal some heterogeneity among single-cell SCNA profiles in individual VH seeds. Despite this heterogeneity, the dominant vitreous subclone exhibits extremely (>98%) high concordance with the SCNA profile from tumor and AH, suggesting AH cfDNA is representative of the dominant genomic subclone. This may facilitate tumoral biomarker identification via the AH. This preliminary work supports the potential of applying single-cell technology to VH seeds in retinoblastoma as a platform to study tumor subclones, which may provide insight into the genomic complexity of disease.

8.
Cesk Slov Oftalmol ; 80(Ahead of print): 1001-1008, 2024.
Article in English | MEDLINE | ID: mdl-38997208

ABSTRACT

PURPOSE: Evaluation of the effectiveness of pneumatic vitreolysis in disrupting vitreomacular traction in our own cohort of patients. METHODOLOGY: Prospective follow-up of 21 eyes of 18 patients with focal VMT (adhesion width < 1500 µm) who underwent intravitreal injection of 0.3 ml of 100% perfluoropropane between January 2015 and December 2020. The patients were observed for 90 days. RESULTS: Release of VMT was achieved on the 28th day of observation in 15 out of 21 eyes (71.4%), and by the 90th day in 19 out of 21 eyes (90.5%). The average width of adhesion in our patients was 382 µm (±212 µm). Average best corrected visual acuity in our cohort was initially 0.77 (±0.21), after 28 days 0.74 (±0.30), and after 3 months 0.82 (±0.21). At the end of the follow-up period, we did not observe a statistically significant improvement in vision. Macular holes developed in two eyes, but spontaneously closed within 1 month of observation, and no more complications were observed in the cohort. CONCLUSION: Pneumatic vitreolysis by intravitreal injection of C3F8 gas is an effective and inexpensive option for the management of symptomatic vitreomacular traction. The incidence of serious adverse events in our follow-up was significantly lower than in recently published series. The method of management should be selected individually according to the parameters of adhesion, macular hole and associated ocular pathologies.


Subject(s)
Fluorocarbons , Intravitreal Injections , Humans , Fluorocarbons/administration & dosage , Male , Female , Aged , Prospective Studies , Visual Acuity , Middle Aged , Vitreous Body , Vitreous Detachment , Follow-Up Studies , Aged, 80 and over , Retinal Diseases
9.
Ophthalmol Retina ; 2024 Jun 29.
Article in English | MEDLINE | ID: mdl-38950656

ABSTRACT

PURPOSE: To describe the retinal and vitreous changes in eyes showing myopic macular schisis (MMS) improvement when vitrectomy was not performed and identify triggering factors. DESIGN: Retrospective observational study. SUBJECTS: Patients with non-operated myopic macular schisis METHODS: The records of patients with MMS who were followed without performing surgery for more than 6 months were retrospectively reviewed, and the eyes showing an anatomical improvement were included. MMS evolution was analyzed quantitatively (central foveal thickness [CFT], parafoveal thickness, maximum height) and qualitatively (presence/absence of foveal detachment, lamellar hole, epiretinal membrane, choroidal neovascularization, inner and outer retinoschisis, vitreous status) at baseline and at the final visit. An anatomical improvement was defined as a decrease in CFT by at least 50 µm. MAIN OUTCOME MEASURE: The rate anatomical improvement of MMS without performing vitrectomy and the morphological changes observed in these cases. RESULTS: In a cohort of 74 non-operated eyes with MMS, MMS improved in 14 eyes (19%) after a mean follow-up of 55 ± 38 months (range: 8-138). In these improved cases, the mean decrease in CFT was 153 ± 166 µm (range: 24-635, p=0.005) and a complete resolution of MMS was observed in 9 eyes (64%). In 9 eyes (64%), the improvement was associated with visible vitreous changes in the macular area on the OCT scans. The mean visual acuity, which was already good at baseline (20/50, 0.4 ± 0.2 LogMAR), increased at the last visit (20/40, 0.3 ± 0.3 LogMAR) but without reaching significance. CONCLUSION: This long-term follow-up analysis showed that almost 20% of MMS in eyes without indication for surgery could improve over time. In most cases, the improvement was associated with an apparent resolution of vitreous tensions.

10.
Clin Interv Aging ; 19: 1153-1162, 2024.
Article in English | MEDLINE | ID: mdl-38952872

ABSTRACT

Background: To investigate association between optic disc parameters analyzed by optical coherence tomography (OCT) and occurrence of peripheral retinal tears in patients with symptomatic posterior vitreous detachment (PVD). Methods: This cross-sectional study enrolled 75 patients with symptoms of acute PVD, who were allocated into two groups based on whether a peripheral retinal tear occurred or not. Results: When comparing the average retinal nerve fiber layer (RNFL) thickness (µm) between retinal tear and control groups, it was shown that patients with a retinal tear have a significantly higher (87.18 [95% confidence interval (CI), 84.47 to 89.9] vs 81.14 [95% CI, 77.81 to 84.46], P = 0.005) average RNFL thickness. Furthermore, we observed a significant difference (0.13, 0.06 to 0.22 vs 0.07, 0.04 to 0.1, P = 0.036, Mann-Whitney U-test) in the size of cup volume (mm3) between the tear and control groups, respectively. Linear regression showed a significant decrease (P = 0.029) in average RNFL thickness with increasing age, but without a significant difference between the two groups. There was no statistically significant difference between the tear and control groups in terms of rim area, disc area, and average cup-to-disc ratio. Conclusion: Patients with a higher average RNFL thickness and larger cup volume measured by OCT were more prone to develop a peripheral retinal tear. Increased peripapillary average RNFL thickness due to trauma and subsequent inflammation, possibly related to the more adherent posterior hyaloid membrane to the retina, may also indicate strengthened adhesions in the areas of the peripheral retina where retinal tears occur. OCT analysis of the optic nerve head may be used in everyday clinical practice as a predictor of the development of peripheral retinal tears in patients with symptomatic PVD.


Subject(s)
Nerve Fibers , Optic Disk , Retinal Perforations , Tomography, Optical Coherence , Vitreous Detachment , Humans , Cross-Sectional Studies , Male , Female , Vitreous Detachment/diagnostic imaging , Middle Aged , Optic Disk/diagnostic imaging , Retinal Perforations/diagnostic imaging , Aged , Nerve Fibers/pathology , Adult , Linear Models
11.
Cureus ; 16(5): e59633, 2024 May.
Article in English | MEDLINE | ID: mdl-38832188

ABSTRACT

Stickler syndrome is a genetic disorder characterized by collagen abnormalities leading to various ocular manifestations, such as retinal detachment. We present two cases of siblings clinically diagnosed with Stickler syndrome who exhibited retinal detachment. Case 1, a seven-year-old girl, and case 2, her 14-year-old brother, both displayed severe myopia and other clinical signs consistent with Stickler syndrome. Despite their ages, neither case showed evidence of posterior precortical vitreous pocket (PPVP) on imaging or during surgical intervention. These findings suggest a potential relationship between collagen abnormalities and PPVP dysplasia in Stickler syndrome.

12.
Eur J Ophthalmol ; : 11206721241261099, 2024 Jun 13.
Article in English | MEDLINE | ID: mdl-38870390

ABSTRACT

PURPOSE: To compare the staining properties of Monoblue inner limiting membrane (ILM) View and Monoblue DUAL View (study products) vital stains during vitrectomy surgery to those of ILM Blue or Membrane Blue Dual (control products). METHODS: In this study, 105 patients were included in the Ophthalmic Clinic of the University Hospitals Leuven from September 2021 to April 2022. For prospective data collection in this study, patients were randomized between a control group (ILM Blue or Membrane Blue Dual, manufactured and commercialized by DORC®) and a study group (Monoblue ILM View or Monoblue DUAL View, manufactured and commercialized by Arcadophta®-BVI®). For retrospective data collection, patients were divided into similar surgery groups. Efficacy was analyzed using a binary subjective evaluation of the visualization of stained membranes during vitrectomy. The rate and severity of potential adverse events related to the study products were tracked, allowing both treatment groups to be compared with the corresponding control groups (ILM Blue and Membrane Blue Dual). RESULTS: Based on the results and findings, none of the comparisons (primary outcomes) were statistically significant, showing similar efficacy of the dyes used. The study products were found to be safe in this study since no serious adverse events were reported. CONCLUSIONS: The present findings indicate that the Monoblue ILM View and Monoblue DUAL View dyes can safely be used during vitrectomy to stain the ILM and/or epiretinal membrane (ERM) when removal is needed.

13.
Am J Ophthalmol ; 2024 Jun 11.
Article in English | MEDLINE | ID: mdl-38871266

ABSTRACT

PURPOSE: To assess the consistencies of anti-Toxocara IgG (T-IgG) and Goldmann-Witmer coefficient (GWC) between paired aqueous humor (AH) and vitreous samples from patients with clinically-suspected ocular toxocariasis (OT). DESIGN: Inter-test reliability assessment. METHODS: A total of 47 patients with clinically-suspected OT who underwent vitrectomy were included. AH, vitreous and serum samples from each patient were collected and levels of specific T-IgG in them were detected. The association and agreement of T-IgG and GWC between AH and vitreous were evaluated. The area under the receiver operating characteristic curve (AUROC) was generated to assess the diagnostic performance of AH. RESULTS: The T-IgG levels and GWC values in vitreous were higher than those in AH (P = 0.023 and P = 0.029, respectively), but similar positivity rates in the T-IgG (P = 1.000) and GWC>3 (P = 1.000) were apparent between vitreous and AH. In addition, there was a positive correlations between the AH and vitreous T-IgG levels (rs = 0.944, P < 0.001) and the GWC values (rs = 0.455, P = 0.022). Moreover, the consistencies between AH and vitreous samples in their T-IgG and GWC positivity rates were almost perfect (both, κ = 0.915, 95% CI, 0.799-1.000) in both. The AUROC reached 0.991, with a 95% confidence interval of 0.971-1.000. The best cut-off value for accurate OT diagnosis was found at 1.434, yielding 96% sensitivity and 100% specificity. CONCLUSIONS: Our findings demonstrate that AH and vitreous samples had significant correlations and perfect agreements for both T-IgG and GWC, suggesting that the AH may serve as a proxy for vitreous to provide a safer, earlier, and more convenient screening of OT.

14.
J Clin Med ; 13(12)2024 Jun 18.
Article in English | MEDLINE | ID: mdl-38930094

ABSTRACT

Background: To investigate anatomical and functional changes of the macula caused by epiretinal membrane (ERM) peeling procedures in patients with or without posterior vitreous detachment (PVD). Methods: This is a multicentric prospective observational study on thirty-seven (37) patients affected by symptomatic ERM who underwent 25-gauge pars plana vitrectomy (PPV), induction of a PVD (as needed) and peeling of both the internal limiting membrane (ILM) and ERM. Optical coherence tomography-angiography (OCT-A) (RS 3000, Nidek, Japan) and microperimetry (MP-3, Nidek, Japan) were performed; central retinal thickness (CRT), foveal avascular zone (FAZ) area and perimeter, vessel density and perfusion density, retinal sensitivity and fixation stability (as a total mean retinal sensitivity (MRS), and MRS in the ellipse area and bivariate contour ellipse area (BCEA)) were recorded at baseline and up to postoperative month 3. Results: Eyes were classified as having complete PVD (51.4%) or incomplete PVD (48.6%). At baseline, patients with incomplete PVD had worse best-corrected distance visual acuity (BCDVA), total MRS, MRS in the ellipse area and BCEA, and higher CRT than patients with complete PVD. At month 3, the differences in BCDVA between the two groups remained statistically significant, with patients with incomplete PVD having worse results (difference: 0.199 logMAR, p < 0.001). The difference in the MRS in the ellipse area was statistically significant at month 3 (-3.378 Db, p = 0.035), with greater improvement in patients with complete PVD. Conclusions: Our study shows that patients with incomplete PVD have worse conditions at baseline than patients with complete PVD, and the differences in visual acuity and retinal sensitivity were maintained postoperatively.

15.
J Clin Med ; 13(11)2024 May 30.
Article in English | MEDLINE | ID: mdl-38892935

ABSTRACT

Background: Swept-source anterior segment optical coherence tomography (SS-AS-OCT) is a suitable examination for the vitreolenticular interface. Methods: In a prospective study using Anterion (Heidelberg Engineering, Heidelberg, Germany), 102 eyes of 102 patients were examined in pupil dilation, preoperatively and 6 times over 1-year follow-up. Preoperatively anterior hyaloid membrane (AHM) visibility was determined with Imaging App with high reliability. Postoperatively capsular bag-AHM distance was measured on six points by using Metrics App. Results: The AHM was visible in 18.6% preoperatively and postoperatively as well (Group 1), 49% of the preoperatively adherent AHMs became visible (Group 2A), 32.4% remained attached (Group 2B). Group 1: the average deepest point on the first day was 782.5 ± 324.1 microns, and it significantly differed from the later follow-up values. Group 2A: the average deepest value was 184.1 ± 220.1 microns, and there was no statistically significant difference between the postoperative visit values. The difference between the groups was statistically significant at every location and at each time point. Conclusions: AS-SS-OCT can be used to check BS both preoperatively (with limitations) and postoperatively.

17.
Exp Eye Res ; 245: 109972, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38871164

ABSTRACT

In previous work, we have shown that the lens acts a reservoir of the antioxidant glutathione (GSH), capable of exporting this antioxidant into the ocular humors and potentially protecting the tissues of the eye that interface with these humors from oxidative stress. In this study, we have extended this work by examining whether the lens acts as a source of ascorbic acid (AsA) to maintain the high levels of AsA known to be present in the ocular humors either by the direct export of AsA into the humors and/or by functioning as a recycling site for AsA, via the direct uptake of oxidised ascorbate (DHA) from the humors, its regeneration to AsA in the lens and then its subsequent export back into the humors. To test this, human lenses of varying ages were cultured for 1 h under hypoxic conditions and AsA/DHA levels measured in the media and in the lens. Human lenses were also cultured in compartmentalised chambers to determine whether efflux of AsA/DHA occurs at the anterior or posterior surface. Immunohistochemistry was performed on human donor lenses and sections labelled with antibodies against GLUT1, a putative DHA uptake transporter. Vitreous humor was collected from patients undergoing vitrectomy who either had a natural clear lens, an artificial intraocular implant (IOL) or a cataractous lens, and AsA/DHA and GSH and oxidised GSH (GSSG) measured. We found that cultured human donor lenses released both AsA and DHA into the media. Culturing of lenses in a compartmentalised chamber revealed that AsA and DHA efflux occurs at both surfaces, with relatively equal amounts of AsA and DHA released from each surface. The posterior surface of the lens was shown to express the GLUT1 transporter. Analysis of vitreous samples from patients undergoing vitrectomy revealed that vitreous GSH and AsA levels were similar between the natural lens group, IOL and cataractous lens group. Taken together, while human donor lenses were shown to export AsA and DHA into the surrounding media, the amount of AsA and DHA released from donor lenses was low and not sufficient to sustain the high levels of total AsA normally present in the humors. This suggests that although the lens is not the main source for maintaining high levels of AsA in the ocular humors, the lens may help to support local AsA levels close to the lens.


Subject(s)
Ascorbic Acid , Lens, Crystalline , Tissue Donors , Vitreous Body , Humans , Ascorbic Acid/metabolism , Lens, Crystalline/metabolism , Vitreous Body/metabolism , Aged , Middle Aged , Adult , Glutathione/metabolism , Aged, 80 and over , Glucose Transporter Type 1/metabolism , Aqueous Humor/metabolism
18.
Int J Biol Macromol ; 275(Pt 1): 133467, 2024 Jun 28.
Article in English | MEDLINE | ID: mdl-38945319

ABSTRACT

Hyaluronic acid (HA) serves as a vitreous substitute owing to its ability to mimic the physical functions of native vitreous humor. However, pure HA hydrogels alone do not provide sufficient protection against potential inflammatory risks following vitrectomy. In this study, HA was crosslinked with 1,4-butanediol diglycidyl ether (BDDE) to form HA hydrogels (HB). Subsequently, the anti-inflammatory agent epigallocatechin gallate (EGCG) was added to the hydrogel (HBE) for ophthalmic applications as a vitreous substitute. The characterization results indicated the successful preparation of HB with transparency, refractive index, and osmolality similar to those of native vitreous humor, and with good injectability. The anti-inflammatory ability of HBE was also confirmed by the reduced expression of inflammatory genes in retinal pigment epithelial cells treated with HBE compared with those treated with HB. In a New Zealand white rabbit model undergoing vitreous substitution treatment, HBE 50 (EGCG 50 µM addition) exhibited positive results at 28 days post-surgery. These outcomes included restored intraocular pressure, improved electroretinogram responses, minimal increase in corneal thickness, and no inflammation during histological examination. This study demonstrated the potential of an injectable HA-BDDE cross-linked hydrogel containing EGCG as a vitreous substitute for vitrectomy applications, offering prolonged degradation time and anti-inflammatory effects postoperatively.

19.
Clin Ophthalmol ; 18: 1651-1654, 2024.
Article in English | MEDLINE | ID: mdl-38855015

ABSTRACT

Symptomatic vitreous opacities (SVO, "floaters") in the mobile, aging vitreous that substantially interfere with daily visual activities (DVA) constitute degenerative vitreous syndrome (DVS). DVS is best distinguished from common "nuisance" floaters by use of "floater stories" written by presenting patients describing their symptoms. Here I discuss why vitreous opacity vitrectomy, though curative, has been adopted only belatedly and is still controversial, and I describe my long-term experience with its use for this disease.

20.
Surv Ophthalmol ; 2024 Jun 15.
Article in English | MEDLINE | ID: mdl-38885759

ABSTRACT

Vitreous, one of the largest components of the human eye, mostly contains water. Despite decades of studying the vitreous structure, numerous unanswered questions still remain, fueling ongoing active research. We attempt to provide a comprehensive overview of the current understanding of the development, morphology, biochemical composition, and function of the vitreous. We emphasize the impact of the vitreous structure and composition on the distribution of drugs. Fast developing imaging technologies, such as modern optical coherence tomography, unlocked multiple new approaches, offering the potential for in vivo study of the vitreous structure. They allowed to analyze in vivo a range of vitreous structures, such as posterior precortical vitreous pockets, Cloquet canal, channels that interconnect them, perivascular vitreous fissures, and cisterns. We provide an overview of such imaging techniques and their principles and of some challenges in visualizing vitreous structures. Finally, it explores the potential of combining the latest technologies and machine learning to enhance our understanding of vitreous structures.

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