Immune Analysis Using Vitreous Optical Coherence Tomography Imaging in Rats with Steroid-Induced Glaucoma.

Glaucoma is a multifactorial pathology involving the immune system. The subclinical immune response plays a homeostatic role in healthy situations, but in pathological situations, it produces imbalances. Optical coherence tomography detects immune cells in the vitreous as hyperreflective opacities and these are subsequently characterised by computational analysis. This study monitors the changes in immunity in the vitreous in two steroid-induced glaucoma (SIG) animal models created with drug delivery systems (microspheres loaded with dexamethasone and dexamethasone/fibronectin), comparing both sexes and healthy controls over six months. SIG eyes tended to present greater intensity and a higher number of vitreous opacities (p < 0.05), with dynamic fluctuations in the percentage of isolated cells (10 µm2), non-activated cells (10-50 µm2), activated cells (50-250 µm2) and cell complexes (>250 µm2). Both SIG models presented an anti-inflammatory profile, with non-activated cells being the largest population in this study. However, smaller opacities (isolated cells) seemed to be the first responder to noxa since they were the most rounded (recruitment), coinciding with peak intraocular pressure increase, and showed the highest mean Intensity (intracellular machinery), even in the contralateral eye, and a major change in orientation (motility). Studying the features of hyperreflective opacities in the vitreous using OCT could be a useful biomarker of glaucoma.

Finite Element Analysis of Changes in Deformation of Intraocular Segments by Airbag Impact in Eyes of Various Axial Lengths.

Background: We studied the kinetic phenomenon of an airbag impact on eyes with different axial lengths using finite element analysis (FEA) to sequentially determine the physical and mechanical responses of intraocular segments at various airbag deployment velocities. Methods: The human eye model we created was used in simulations with the FEA program PAM-GENERISTM. The airbag was set to impact eyes with axial lengths of 21.85 mm (hyperopia), 23.85 mm (emmetropia) and 25.85 mm (myopia), at initial velocities of 20, 30, 40, 50 and 60 m/s. The deformation rate was calculated as the ratio of the length of three segments, anterior chamber, lens and vitreous, to that at the baseline from 0.2 ms to 2.0 ms after the airbag impact. Results: Deformation rate of the anterior chamber was greater than that of other segments, especially in the early phase, 0.2-0.4 ms after the impact (P < 0.001), and it reached its peak, 80%, at 0.8 ms. A higher deformation rate in the anterior chamber was found in hyperopia compared with other axial length eyes in the first half period, 0.2-0.8 ms, followed by the rate in emmetropia (P < 0.001). The lens deformation rate was low, its peak ranging from 40% to 75%, and exceeded that of the anterior chamber at 1.4 ms and 1.6 ms after the impact (P < 0.01). The vitreous deformation rate was lower throughout the simulation period than that of the other segments and ranged from a negative value (elongation) in the later phase. Conclusion: Airbag impact on the eyeball causes evident deformation, especially in the anterior chamber. The results obtained in this study, such as the time lag of the peak deformation between the anterior chamber and lens, suggest a clue to the pathophysiological mechanism of airbag ocular injury.

Desired properties of polymeric hydrogel vitreous substitute.

Vitreous replacement is a commonly employed method for treating a range of ocular diseases, including posterior vitreous detachment, complex retinal detachment, diabetic retinopathy, macular hole, and ocular trauma. Various clinical substitutes for vitreous include air, expandable gas, silicone oil, heavy silicone oil, and balanced salt solution. However, these substitutes have drawbacks such as short retention time, cytotoxicity, high intraocular pressure, and the formation of cataracts, rendering them unsuitable for long-term treatment. Polymeric hydrogels possess the potential to serve as ideal vitreous substitutes due to their structure-mimicking to natural vitreous and adjustable mechanical properties. Replacement with hydrogels as the tamponade can help maintain the shape of the eyeball, apply pressure to the detached retina, and ensure the metabolic transport of substances without impairing vision. This literature review examines the required properties of artificial vitreous, including the optical properties, rheological properties, expansive force action, and physiological and biochemical functions of chemically and physically crosslinked hydrogels. The strategies for enhancing the biocompatibility and injectability of hydrogels are also summarized and discussed. From a clinical ophthalmology perspective, this paper presents the latest developments in vitreous replacement, providing clinicians with a comprehensive understanding of hydrogel clinical applications, which offers guidance for future design directions and methodologies for hydrogel development.

Results of office-based fluid-air exchange for postvitrectomy hemorrhage in diabetic retinopathy

ABSTRACT Purpose: This study aimed to evaluate the efficacy and clinical outcomes of a one-way fluid-air exchange procedure for the treatment of postvitrectomy diabetic vitreous hemorrhage in patients with proliferative diabetic retinopathy. Methods: This retrospective study included 233 patients with proliferative diabetic retinopathy, who underwent vitrectomy. A one-way fluid-air exchange procedure was performed in 24 eyes of 24 (10.30%) patients with persistent vitreous cavity rebleeding after the operation. Preprocedural and postprocedural best-corrected visual acuity values were achieved. Complications occurring during and after the procedure were analyzed. Results: Significant visual improvement was observed 1 month after the one-way fluid-air exchange procedure (2.62 ± 0.60 LogMAR at baseline vs. 0.85 ± 0.94 LogMAR at postprocedure, p<0.0001). Moreover, 19 (79.17%) eyes needed the procedure once, and 5 (20.83%) eyed had the procedure more than twice. In 3 (12.50%) eyes, reoperation was eventually required because of persistent rebleeding despite several fluid-air exchanges. No complication was observed during the follow-up. Conclusions: The one-way fluid-air exchange procedure can be an excellent alternative to re-vitrectomy for patients with proliferative diabetic retinopathy suffering from postvitrectomy diabetic vitreous hemorrhage by removing the hemorrhagic contents directly and achieving fast recovery of visual function without apparent complications.

Long-term evaluation of the efficacy and safety of Nd:YAG laser vitreolysis for symptomatic vitreous foaters / Avaliação de longo prazo da eficácia e segurança da vitreólise com Nd:YAG laser para moscas volantes sintomáticas

ABSTRACT Purpose: This study aimed to evaluate the long-term safety and efficacy of neodymium-doped yttrium aluminum garnet (Nd:YAG) vitreolysis for symptomatic vitreous floaters as it remains a controversial procedure due to insufficient robust evidence in the literature for the maintenance of the results and absence of adverse effects. Methods: This is an observational extension to the previously presented prospective, randomized, double-blind clinical trial. Eight of thirteen subjects who underwent vitreolysis with YAG laser returned for a late reevaluation, 18 months after the procedure, to evaluate the efficacy and safety of the procedure. Results: All patients maintained the improvement in symptomatology noted after the procedure, with 25% showing complete improvement and a similar proportion (37.5%) reporting significant or partial improvement. Objective improvement in opacity was similar to that found at 6 months follow-up. The NEI-VFQ 25 quality of life questionnaire showed no statistically significant difference in responses between the 6th and 18th month. No adverse effects were noted on clinical examination or reported by patients. Conclusion: Vitreolysis efficacy observed at 6 months of follow-up was maintained until the eighteenth month, with all patients reporting improvement from the pre-procedure state. No late adverse effects were noted. A larger randomized clinical trial is needed to confirm the safety of the procedure.

RESUMO Objetivos: Avaliar a segurança e eficácia a longo prazo da vitreólise com Nd:YAG laser para moscas volantes sintomáticas, uma vez que permanece como um procedimento controverso devido a falta de evidência científica robusta sobre a manutenção dos resultados e ocorrência de efeitos adversos. Métodos: Este estudo é uma extensão observacional de um ensaio clínico prospectivo, randomizado, duplo cego, previamente publicado. Oito de treze pacientes que foram submetidos a vitreólise com YAG laser foram acompanhados para uma reavaliação tardia, dezoito meses após o procedimento, para avaliar a eficácia e segurança do procedimento. Resultados: Todos os pacientes mantiveram a melhora na sintomatologia notada ao final do procedimento original, com 25% dos casos apresentando melhora completa, e uma proporção semelhante (37,5%) demonstrando melhora significativa ou parcial. A melhora objetiva na opacidade foi similar ao achado no seguimento original de 6 meses. O questionário de qualidade de vida NEI-VFQ 25 não demonstrou diferença estatisticamente significativa nas respostas entre o sexto e o décimo oitavo mês de acompanhamento. Nenhum efeito adverso foi notado no exame clínico ou reportado pelos pacientes. Conclusão: A eficácia da vitreólise observada ao sexto mês do acompanhamento foi mantida até o décimo oitavo mês, com todos os pacientes notando algum grau de melhora quando comparado ao estado pré procedimento. Nenhum efeito adverso tardio foi notado. Um ensaio clínico randomizado maior é necessário para confirmar a segurança do procedimento.

Vitreous metastasis from cutaneous melanoma: diagnosis and management / Metástase vítrea de melanoma cutâneo: diagnóstico e tratamento

ABSTRACT Purpose: To report the clinical findings, treatments, and outcomes in a series of patients with vitreous metastasis from cutaneous melanoma. Methods: This single-center, retrospective, interventional case series included patients with biopsy-confirmed vitreous metastasis from cutaneous melanoma diagnosed between 1997 and 2020. Standard 23- or 25-gauge pars plana vitrectomy was performed for diagnostic sampling. Sclerotomies were treated with double or triple freeze-thaw cryotherapy. Perioperative intravitreal injections of melphalan (32 µg/0.075 mL) were administered, when indicated. Visual acuity, intraocular pressure, and systemic and ocular treatment responses were reported. Results: Five eyes of five patients with unilateral vitreous metastasis from cutaneous melanoma were identified. The median age at diagnosis was 84 (range, 37-88) years. The median follow-up after ophthalmic diagnosis was 28 (8.5-36) months; one patient did not have a follow-up. The initial visual acuity ranged from 20/30 to hand motions. Baseline clinical findings included pigmented or non-pigmented cellular infiltration of the vitreous (5/5), anterior segment (4/5), and retina (3/5). Four patients had secondary glaucoma. Systemic therapy included checkpoint inhibitor immunotherapy (n=3, all with partial/complete response), systemic chemotherapy (n=2), surgical resection (n=3), and radiation (n=2). The median time from primary diagnosis to vitreous metastasis was 2 (2-15) years. One patient had an active systemic disease at the time of vitreous metastasis. The final visual acuity ranged from 20/40 to no light perception. Ophthalmic treatment included vitrectomy in all five patients, intravitreal administration of melphalan in three, and intravitreal administration of methotrexate in one. One patient required enucleation, and histopathology revealed extensive invasion by melanoma cells. Conclusions: Vitreous metastasis from cutaneous melanoma can present as a diffuse infiltration of pigmented or non-pigmented cells into the vitreous and may be misdiagnosed as uveitis. Diagnostic pars plana vitrectomy and periodic intravitreal chemotherapy may be indicated.

RESUMO Objetivo: Descrever os achados clínicos, tratamentos, e desfechos em uma série de pacientes com me tástases vítreas de melanoma cutâneo. Métodos: Série retrospectiva de casos de único centro com intervenção. Pacientes incluídos tiveram seu diagnóstico de MVMC confirmado por biópsia entre 1997 e 2020. Vitrectomia via pars plana com 23 ou 25 gauge foram realizadas para obter espécimens. Esclerotomias foram tratadas com crioterapia em duplo ou triplo congelamento. Injeção intravítrea perioperatória de melfalano (32 ug/0,075 mL) foi administrada quando necessário. Foram relatados acuidade visual, pressão intraocular, resposta terapêutica sistêmica e ocular. Resultados: Cinco olhos de 5 pacientes com metástases vítreas de melanoma cutâneo unilateral foram identificados. Idade média de diagnóstico foi 84 anos (variando de 37-88). Seguimento médio após diagnóstico oftalmológico foi 28 (8,5-36) meses; 1 paciente não teve acompanhamento. Acuidade visual inicial variou de 20/30 a movimentos de mão. Achados clínicos iniciais incluíram infiltração de células pigmentadas e não-pigmentadas no vítreo (5/5), segmento anterior (4/5), e retina (3/5). Quatro pacientes tiveram glaucoma secundário. Tratamento sistêmico incluiu imunoterapia com inibidores da via de sinalização (3 - todos com resposta parcial/completa), quimioterapia sistêmica (2), ressecção cirúrgica (3), e irradiação (2). Intervalo médio entre diagnóstico primário e metástases vítreas foi 2 (2-15) anos. Um paciente teve doença sistêmica ativa simultânea as metástases vítreas. Acuidade visual final variou entre 20/40 e SPL. Tratamento oftalmológico incluiu vitrectomia nos 5 pacientes, melfalano intravítreo em 3 e metotrexato intravítreo em 1. Um paciente precisou de enucleação. A histopatologia revelou invasão celular extensa de melanoma. Conclusões: Metástases vítreas de melanoma cutâneo pode se manifestar como uma infiltração difusa de células pigmentadas e não-pigmentadas no vítreo e erroneamente diagnosticada como uveites. Vitrectomia diagnóstica e quimioterapia intravítrea periódica podem estar indicadas.

Study on maintenance of eyeball morphology by foldable capsular vitreous body in severe ocular trauma.

OBJECTIVES: To explore the feasibility and safety of using a foldable capsular vitreous body (FCVB) in managing severe ocular trauma and silicone oil-dependent eyes. METHODOLOGY: This is a retrospective study of 61 ocular trauma patients (61 eyes) who presented to the Department of Eye Emergency, Hebei Eye Hospital from May 1, 2018, to May 31, 2019, including 51 male patients (51 eyes) and 10 female patients (10 eyes) with an average age of 44.98 ± 14.60 years old. The oldest patient was 75 years old, and the youngest was 8 years old. These cases represented 51 eyes with severe eyeball rupture and 10 eyes with severe, complicated ocular trauma, which became silicone oil-dependent after the operation. These patients received FCVB implants, and data regarding their visual acuity, intraocular pressure, changes in eye axis, cornea, retina, and FCVB state were recorded after the operation. RESULTS: In all patients, the FCVB was properly positioned and well supported with the retina. All 61 patients cleared a follow-up window of 1-36 months with no reports of important changes in their visual acuity. Among the patients, 91.8% reported normal intraocular pressure, the retinal reattachment rate reached 100%, and the eyeball atrophy control rate reached 100%. There was no report of rupture of the FCVB, allergies to silicone, intraocular infection, intraocular hemorrhage, silicone oil emulsification, or sympathetic ophthalmia. CONCLUSIONS: Foldable capsular vitreous bodies (FCVBs) designed to mimic natural vitreous bodies are suitable as long-term ocular implants that can provide sustained support for the retina without the need for any special postoperative postures. Their barrier function may effectively prolong the retention time of the tamponade and prevent various complications caused by direct contact of the eye tissues with the tamponade.

[Vitreous body in the treatment of exudative age-related macular degeneration : The medium is the message]. / Glaskörper bei der Therapie der exsudativen altersabhängigen Makuladegeneration : Das Medium ist die Message.

BACKGROUND: Intravitreal anti-vascular endothelial growth factor (VEGF) is the standard treatment for exudative age-related macular degeneration (AMD). The constitution of the vitreomacular interface varies greatly in cases of attached (with or without traction) or detached vitreous body, which can impact the effectiveness of the anti-VEGF treatment. OBJECTIVE: Based on the current literature this article displays the current state of the science on whether the constitution of the vitreous body has an effect on the anti-VEGF treatment. MATERIAL AND METHODS: The published data extracted from current trials and post hoc analyses concerning this topic are presented and put into the clinical context. RESULTS: The presence of a vitreomacular adhesion reduces the efficacy of anti-VEGF treatment of exudative AMD. Posterior vitreous body detachment represents a positive prognostic factor concerning the efficacy of anti-VEGF treatment but not necessarily the prognosis for visual acuity. CONCLUSION: Patients with attached vitreous body need a more intensive treatment monitoring compared to patients with detached vitreous body. Therefore, in eyes with initial posterior vitreous body detachment receiving a treat and extend regimen, the interval between anti-VEGF injections can be extended to 4 instead of 2 weeks without endangering the success of treatment.

Forward Light Scattering of First to Third Generation Vitreous Body Replacement Hydrogels after Surgical Application Compared to Conventional Silicone Oils and Vitreous Body.

To treat certain vitreoretinal diseases, the vitreous body, a hydrogel composed of mostly collagen and hyaluronic acid, must be removed. After vitrectomy surgery, the vitreous cavity is filled with an endotamponade. Previously, pre-clinical hydrogel-based vitreous body substitutes either made from uncrosslinked monomers (1st generation), preformed crosslinked polymers (2nd generation), or in situ gelating polymers (3rd generation) have been developed. Forward light scattering is a measure of Stray light induced by optical media, when increased, causing visual disturbance and glare. During pinhole surgery, the hydrogels are injected into the vitreous cavity through a small 23G-cannula. The aim of this study was to assess if and to what extent forward light scattering is induced by vitreous body replacement hydrogels and if Stray light differs between different generations of vitreous body hydrogel replacements due to the different gelation mechanisms and fragmentation during injection. A modified C-Quant setup was used to objectively determine forward light scattering. In this study, we found that the 1st and 3rd generation vitreous body replacements show very low stray light levels even after injection (2.8 +/- 0.4 deg2/sr and 0.2 +/- 0.2 deg2/sr, respectively) as gel fragmentation and generation of interfaces is circumvented. The 2nd generation preformed hydrogels showed a permanent increase in stray light after injection that will most likely lead to symptoms such as glare when used in patients (11.9 +/- 0.9 deg2/sr). Stray light of the 2nd generation hydrogels was 3- and 2-fold increased compared to juvenile and aged vitreous bodies, respectively. In conclusion, this significant downside in the forward light scattering of the 2nd generation hydrogels should be kept in mind when developing vitreous body replacement strategies, as any source of stray light should be minimized in patients with retinal comorbidities.

Role of the Vitreous in Retinal Pathology: A Narrative Review.

The vitreous body is an anatomically and biochemically complex structure. Because of its proximity and firm adherence to the retina, researchers have examined the link between these two structures and how their individual pathologies might be connected. Several experimental and clinical studies have already demonstrated the important role of vitreous in the pathogenesis of retinal disorders. This narrative review highlights the role of the vitreous in retinal diseases and the improvements that have been made since the introduction of optical coherence tomography. This leads to a better understanding of vitreoretinal diseases and demonstrates its determinant role in other retinal pathologies, such as diabetic retinopathy or age-related macular degeneration. As we deepen our knowledge of the vitreous's structure, function, and abnormal conditions, we can better link the changes in diseases and identify effective treatments.

An Inverse Method to Determine Mechanical Parameters of Porcine Vitreous Bodies Based on the Indentation Test.

The vitreous body keeps the lens and retina in place and protects these tissues from physical insults. Existing studies have reported that the mechanical properties of vitreous body varied after liquefaction, suggesting mechanical properties could be effective parameters to identify vitreous liquefaction process. Thus, in this work, we aimed to propose a method to determine the mechanical properties of vitreous bodies. Fresh porcine eyes were divided into three groups, including the untreated group, the 24 h liquefaction group and the 48 h liquefaction group, which was injected collagenase and then kept for 24 h or 48 h. The indentation tests were carried out on the vitreous body in its natural location while the posterior segment of the eye was fixed in the container. A finite element model of a specimen undertaking indentation was constructed to simulate the indentation test with surface tension of vitreous body considered. Using the inverse method, the mechanical parameters of the vitreous body and the surface tension coefficient were determined. For the same parameter, values were highest in the untreated group, followed by the 24 h liquefaction group and the lowest in the 48 h liquefaction group. For C10 in the neo-Hookean model, the significant differences were found between the untreated group and liquefaction groups. This work quantified vitreous body mechanical properties successfully using inverse method, which provides a new method for identifying vitreous liquefactions related studies.

[Age-related changes in human vitreous]. / Vozrastnye izmeneniya steklovidnogo tela.

There are two main age-related changes that can occur in the vitreous body of healthy individuals throughout life: liquefaction (synchesis) and aggregation of collagen fibrils into dense bundles (syneresis). Progressive age-related degradation leads to posterior vitreous detachment (PVD). At present many classifications of PVD exist, in which authors relied either on the morphological features, or on the differences in pathogenesis before and after widespread use of OCT. The course of PVD can be either normal or anomalous. Physiological PVD induced by age-related vitreous changes progresses in specific stages. The review emphasizes that PVD can occur initially not only in the central zone of the retina, but also on the periphery with further spread to the posterior pole. Anomalous PVD can lead to various negative effects on the retina, as well as on the vitreous as a result of traction in the area of vitreoretinal interface.

A pilot clinical study of complex rhegmatogenous retinal detachment treatment via foldable capsular buckle scleral buckling.

BACKGROUND: To evaluate the feasibility of and identify problems in treating complex rhegmatogenous retinal detachment using foldable capsular buckle scleral buckling. METHODS: This prospective clinical study enrolled five patients with complex rhegmatogenous retinal detachment treated with foldable capsular buckle scleral buckling at the 988th Hospital of People's Liberation Army Joint Logistic Force, China. During the 24-week follow-up period, the patients underwent measurements of their best-corrected visual acuity, slit-lamp examination, indirect ophthalmoscopy, and visual field testing. Additionally, B-ultrasound and fundus photography of the patients' retinal reattachments helped evaluate the treatment's post-surgery efficacy. We determined the safety of foldable capsular buckle scleral buckling based on infection, eye pain, diplopia, elevated intraocular pressure, and other postoperative severe complications. RESULTS: All five patients' complex rhegmatogenous retinal detachments were successfully treated and evaluated via B-ultrasound and fundus photography after surgery. Visual acuity was enhanced in four patients 24 weeks after surgery, while the remaining patients developed diplopia after surgery. No other complications were observed. CONCLUSION: This pilot study preliminarily determined that foldable capsular buckle scleral buckling is feasible for efficient and safe treatment of complex rhegmatogenous retinal detachment. These results support this surgery as a potential and novel alternative to current extraocular procedures for treating complex rhegmatogenous retinal detachment. TRIAL REGISTRATION: The prospective observational clinical study protocol was approved by the Institutional Review Board and Ethics Committee and registered at the clinical research center in the 988th Hospital of People's Liberation Army Joint Logistic Force, China (9,882,019,000).

Oxidative Stress, Inflammatory, Angiogenic, and Apoptotic molecules in Proliferative Diabetic Retinopathy and Diabetic Macular Edema Patients.

The aim of this study is to evaluate molecules involved in oxidative stress (OS), inflammation, angiogenesis, and apoptosis, and discern which of these are more likely to be implicated in proliferative diabetic retinopathy (PDR) and diabetic macular edema (DME) by investigating the correlation between them in the plasma (PLS) and vitreous body (VIT), as well as examining data obtained from ophthalmological examinations. Type 2 diabetic (T2DM) patients with PDR/DME (PDRG/DMEG; n = 112) and non-DM subjects as the surrogate controls (SCG n = 48) were selected according to the inclusion/exclusion criteria and programming for vitrectomy, either due to having PDR/DME or macular hole (MH)/epiretinal membrane (ERM)/rhegmatogenous retinal detachment. Blood samples were collected and processed to determine the glycemic profile, total cholesterol, and C reactive protein, as well as the malondialdehyde (MDA), 4-hydroxynonenal (4HNE), superoxide dismutase (SOD), and catalase (CAT) levels and total antioxidant capacity (TAC). In addition, interleukin 6 (IL6), vascular endothelial growth factor (VEGF), and caspase 3 (CAS3) were assayed. The VITs were collected and processed to measure the expression levels of all the abovementioned molecules. Statistical analyses were conducted using the R Core Team (2022) program, including group comparisons and correlation analyses. Compared with the SCG, our findings support the presence of molecules involved in OS, inflammation, angiogenesis, and apoptosis in the PLS and VIT samples from T2DM. In PLS from PDRG, there was a decrease in the antioxidant load (p < 0.001) and an increase in pro-angiogenic molecules (p < 0.001), but an increase in pro-oxidants (p < 0.001) and a decline in antioxidants (p < 0.001) intravitreally. In PLS from DMEG, pro-oxidants and pro-inflammatory molecules were augmented (p < 0.001) and the antioxidant capacity diminished (p < 0.001), but the pro-oxidants increased (p < 0.001) and antioxidants decreased (p < 0.001) intravitreally. Furthermore, we found a positive correlation between the PLS-CAT and the VIT-SOD levels (rho = 0.5; p < 0.01) in PDRG, and a negative correlation between the PSD-4HNE and the VIT-TAC levels (rho = 0.5; p < 0.01) in DMEG. Integrative data of retinal imaging variables showed a positive correlation between the central subfield foveal thickness (CSFT) and the VIT-SOD levels (rho = 0.5; p < 0.01), and a negative correlation between the CSFT and the VIT-4HNE levels (rho = 0.4; p < 0.01) in PDRG. In DMEG, the CSFT displayed a negative correlation with the VIT-CAT (rho = 0.5; p < 0.01). Exploring the relationship of the abovementioned potential biomarkers between PLS and VIT may help detecting early molecular changes in PDR/DME, which can be used to identify patients at high risk of progression, as well as to monitor therapeutic outcomes in the diabetic retina.

Clinical Efficacy and Safety of Foldable Capsular Vitreous Body Implant Surgery in 22 Cases of Silicone Oil-dependent Eyes.

OBJECTIVE: This study aimed to evaluate the clinical efficacy and safety of foldable capsular vitreous body (FCVB) implant surgery in silicone oil-dependent eyes. METHODS: A total of 22 participants with silicone oil-dependent eyes who received treatment with FCVB implant surgery between January 2019 and June 2020 were included in this retrospective study. The intraocular pressure (IOP), best-corrected visual acuity (BCVA), demographic data, and any recorded complications were evaluated. RESULTS: The postoperative IOP (12.73±4.20 mmHg) was significantly improved (P=0.03) compared to the preoperative IOP (10.23±3.69 mmHg) (the main endpoint). There was no significant difference (P=0.33) in the final BCVA preoperation and 3rd month postoperation (the secondary endpoint). The most common postoperative complication was hyphema. Other common postoperative complications included corneal opacity, a shallow anterior chamber, and a low IOP. CONCLUSION: FCVB implant surgery is a safe and effective method for treating silicone oil-dependent eyes; however, attention should be paid to the prevention and timely treatment of complications.

Expression levels of ROS and Atg proteins in the vitreous in rhegmatogenous retinal detachment.

AIM: To detect the concentrations of reactive oxygen species (ROS), transient receptor potential mucin-1 (TRPML1), and autophagy-related (Atg) proteins (LC3-I, LC3-II, and Beclin1) in vitreous humor of patients with simple rhegmatogenous retinal detachment (RRD). METHODS: RRD patients enrolled as the RRD group, and patients with idiopathic macular hole (IMH) and idiopathic macular epiretinal membrane (IMEM) were enrolled as control group. The levels of ROS, TRPML1, LC3-I, LC3-II, and Beclin1 in vitreous humor of patients in the RRD and control groups were detected by enzyme-linked immunosorbent assay (ELISA). RESULTS: The RRD group included 28 eyes 28 patients and had a higher concentration of ROS in vitreous humor (631.86±18.05 vs 436.34±108.22 IU/mL, P<0.05). The ROS level in patients with a wide retinal detachment (RD) extent (RD range ≥1/2) was higher than that with a narrow RD extent (RD range<1/2, P<0.05). ROS concentration was negatively correlated with RD time (r=-0.46, P=0.01). The expression levels of LC3-I and Beclin1 significantly decreased in RRD (P<0.05), but there were no correlations with the RD time, RD extent, or macular involvement. CONCLUSION: In eyes with RRD, the concentration of ROS in vitreous humor increases and the expression levels of Atg proteins decrease, reflecting possibly that autophagy is inhibited.

Ex Vivo Visualization of Distribution of Intravitreal Injections in the Porcine Vitreous and Hydrogels Simulating the Vitreous.

The characterization of intravitreal dosage forms with regard to their behavior in vivo is usually explored in preclinical development through animal studies. In vitro vitreous substitutes (VS) to simulate the vitreous body for preclinical investigations have so far been insufficiently studied. To determine a distribution or concentration in the mostly gel-like VS, extraction of the gels is required in many cases. This destroys the gels, which makes a continuous investigation of the distribution impossible. In this work, the distribution of a contrast agent in hyaluronic acid agar gels and polyacrylamide gels was studied by magnetic resonance imaging and compared with the distribution in ex vivo porcine vitreous. The porcine vitreous served as a surrogate for human vitreous since both are similar in their physicochemical properties. It was shown that both gels do not completely represent the porcine vitreous body, but the distribution in the polyacrylamide gel is similar to that in the porcine vitreous body. In contrast, the distribution throughout the hyaluronic acid agar gel is much faster. It was also shown that anatomical features such as the lens and the interfacial tension to the anterior eye chamber could have an influence on the distribution that is difficult to reproduce using in vitro VS. However, with the presented method, new in vitro VS can be investigated continuously without destruction in the future, and thus their suitability as a substitute for the human vitreous can be verified.

Foldable capsular vitreous body indications, complications, and outcomes: a systematic review.

PURPOSE: Foldable capsular vitreous body (FCVB) is an emerging vitreous substitute that has been recently introduced to treat various advanced vitreoretinal conditions including severe ocular trauma, complicated retinal detachment (RD), and proliferative vitreoretinopathy. METHODS: Review protocol was prospectively registered at PROSPERO (CRD42022342310). A systematic literature search using PubMed, Ovid MEDLINE, and Google Scholar for articles published until May 2022 was performed. The search included the following keywords: foldable capsular vitreous body, FCVB, artificial vitreous substitutes, and artificial vitreous implants. Outcomes included indications of FCVB, anatomical success rates, postoperative intraocular pressure (IOP), best-corrected visual acuity (BCVA), and complications. RESULTS: A total of 17 studies that utilized FCVB up to May 2022 were included. FCVB was used intraocularly as a tamponade or extraocularly as a macular/scleral buckle for various retinal conditions including severe ocular trauma, simple and complex RD, silicone oil-dependent eyes, and highly myopic eyes with foveoschisis. FCVB was reported to be successfully implanted in the vitreous cavity of all patients. Final retinal reattachment rate ranged from 30 to 100%. Postoperative IOP improved or was maintained in most eyes, with low postoperative complication rates. Improvement in BCVA ranged from 0 to 100% of subjects. CONCLUSION: Indications of FCVB implantation have recently widened to include multiple advanced ocular conditions such as complex RD, but also include simpler conditions as uncomplicated RD. FCVB implantation showed good visual and anatomical outcomes, few IOP fluctuations, and a good safety profile. Larger comparative studies are required to further evaluate FCVB implantation.

[The possibility of diagnosing the prescription of death in the study of embalmed corpses by the method of spin probes. (Experimental study)]. / Vozmozhnost' diagnostiki davnosti nastupleniya smerti pri issledovanii zabal'zamirovannykh trupov metodom spinovykh zondov. (Eksperimental'noe issledovanie).

THE AIM OF THE STUDY: Is to establish the possibility of studying the vitreous body of the eye from embalmed corpses using the spin probe method to develop diagnostic criteria for the prescription of death coming. The article presents data showing the possibility of diagnosing the prescription of death coming by the method of spin probes with the examination of the vitreous body of the eye from embalmed corpses. A total of 510 spectra obtained during incubation of the 1-oxyl-4-oxo-2.2.6.6-tetramethyl-piperidin spin probe in the vitreous body were studied. Measurements of each of the 6 objects were carried out daily for 10 days after embalming. The prospects of studying the vitreous body by spin probes in embalmed corpses for the development of diagnostic criteria for the prescription of death coming up to 4 days from the moment of embalming have been established.

Relationship between regression of the hyaloid vessels and development of retinal vessels in mice / 中华实验眼科杂志

Objective:To explore the process of regression of the hyaloid vessels and development of retinal vessels in C57BL/6J mice and the relationship between them.Methods:Seventy-five healthy SPF C57BL/6J mice on postnatal day 1 (P1) were selected and divided into control group (65 mice) and oxygen-induced retinopathy (OIR) model group (10 mice) by the random number table method.No treatment was given to control group.Mice in OIR model group were continuously fed in (75±3)% oxygen for 5 days from P7 and in normoxic condition for 5 days from P12.In control group, 5 mice were randomly selected and killed from P1 to P12 and P17, and the eyeballs were collected.In OIR model group, 5 mice were randomly selected and killed on P12 and P17, and the eyeballs were collected.The number of hyaloid arteries (HA), vasa hyaloidea propria (VHP), and tunica vasculosa lentis (TVL) of mice at different time was observed with a microscope.Another 5 adult mice aged 15 months old were selected to detect the vitreous vasculature using optical coherence tomography.The relationship between retinal astrocytes and retinal vascular development, VHP was observed by immunofluorescence staining.This study was approved by the Ethics Committee of Nankai Hospital (No.NKYY-DWLL-2021-070). The use and care of experimental animals followed the Regulations for the Administration of Affairs Concerning Experimental Animals and the ARVO statement.Results:In control group, HA did not degenerate rapidly during eyeball development, which still presented even 15 months after birth.The number of VHP reduced rapidly from P4 to P8, and tended to be stable at 2.33±1.32 on P10 and 1.80±0.92 on P17.The number of TVL reduced rapidly from P5 to P9, reduced to 2.30±1.42 on P10, with most of the TVL blood vessels being transparent without blood supply, and decreased to 0.30±0.48 on P17.Under the guidance of astrocytes, the retinal vessels of mice grew from the optic disc to the peripheral retina from P1 to P8, forming the primary retinal vascular layer.During the development of retinal superficial vessels, VHP showed synchronous regression and the decreased density and thinner diameter in the area covered by retinal vessels.VHP detached from the retina when retinal vessels developed to the peripheral retina, and there was no structural overlap between astrocytes and VHP.In OIR model group, the number of VHP increased from 2.14±0.90 on P12 to 4.60±1.35 on P17 and the number of TVL increased from 2.90±1.55 on P12 to 5.80±1.75 on P17, showing statistically significant differences ( t=4.188, P<0.001; t=4.668, P<0.001). There was no significant difference in the number of VHP and TVL between the two groups on P12 ( t=0.429, P=0.232; t=1.116, P=0.134). The number of VHP and TVL were significantly larger in OIR model group than in control group on P17 ( t=5.422, 9.574; both at P<0.001). Conclusions:In the vitreous vascular system of mice, the regression of VHP and TVL tends to be stable 10 days after birth, and the regression of HA was not obvious.The normal regression of vitreous vessels in mice depends on the normal development of retinal vessels and astrocytes.Retinal hypoxia delays vitreous vascular regression.