Structure and mechanics of the vitreoretinal interface

Retinopathy of Prematurity (ROP): An Overview of Biomarkers in Various Samples for Prediction, Diagnosis, and Prognosis

Retinopathy of Prematurity (ROP) is a proliferative retinal vascular disease marked by abnormal development of retinal vessels in low birth weight preterm infants. It is one of the leading causes of blindness in preterm infants. Current ROP screening methods impose high demands on both the equipment and the expertise of ophthalmologists, which limits their widespread application, particularly in secondary hospitals and remote areas. Thus, the identification of relevant biomarkers and the development of simpler detection methods are important and promising. Non-invasive or minimally invasive sampling methods, along with biomarkers possessing high sensitivity and specificity, could greatly enhance neonatal screening, facilitate early diagnosis, and improve prevention of blindness in preterm infants. This review provides relevant medical insights for clinical practice. This review explored, compares and analyzes various sampling sources. It compares and analyzes research on ROP-related biomarkers derived from these samples.

Distinguishing features of microvascular abnormalities in high myopia retinoschisis via multimodal imaging

PURPOSE

To report the differences between microvascular abnormalities (MVAs) and retinal vasculitis in patients with high myopia (HM) and retinoschisis and discuss the efficacy of treatments, including corticosteroids, and posterior vitreous detachment (PVD).

METHODS

We enrolled seven patients with HM retinoschisis in the Department of Ophthalmology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology. Multimodal imaging features of MVAs were examined using ultrawide scanning laser ophthalmoscopy, swept-source optical coherence tomography (SS-OCT), SS-OCT angiography (SS-OCTA), and fundus fluorescein angiography (FFA). Clinical characteristics and responses to corticosteroid therapy and PVD are reported.

RESULTS

Multimodal imaging features of MVAs varied with the severity of retinoschisis. Some patients showed no significant MVAs via FFA and SS-OCTA. In the other patients, MVAs were visualized on en-face OCT and SS-OCTA, and fluorescence leakage was observed on FFA, which mimicked retinal vasculitis. MVAs accompanied by paravascular retinoschisis were observed on OCT around the vascular arch, and corticosteroid therapy showed no significant effect.

CONCLUSIONS

MVAs in adults with HM differ according to retinoschisis severity. MVAs are distinct from retinal vasculitis and may not be effectively treated with corticosteroids. Vitrectomy-induced or spontaneous PVD may be a better viable therapeutic option for vision-threatening complications in patients with HM.

TRANSLATIONAL RELEVANCE

Multimodal imaging features of retinal MVAs in HM retinoschisis are significant for therapeutic options in patients with vision-threatening complications and provide a new research direction for investigating the molecular mechanisms underlying these conditions.

Detailed structural abnormalities associated with a novel VCAN variant in a family with versican vitreoretinopathy

PURPOSE

To understand the retina micropathology in a family with a novel variant in VCAN.

METHODS

Two sisters ages 16 (proband) and 18 years old and their 48-year-old father underwent comprehensive ophthalmic evaluations. Multimodal imaging was performed with spectral domain optical coherence tomography, ultrawide field short-wavelength fundus autofluorescence, and pseudocolor imaging.

RESULTS

Cataracts were present in the sisters along with a penetrant retinal phenotype in all three patients with vitreoretinal ring opacities and traction, peripheral pigmentary clumps, lattice-like features, retinoschisis, foveal ectopia, and nasal displacement of vessels. There were regions with inner retinal thinning with spared outer retina, likely a consequence of vitreoretinal traction, that contrasted with large areas of profound photoreceptor degeneration, but with a rather normal or thickened inner retina. A previously unreported heterozygous variant in intron 7 of VCAN (c.4004-2A>C) segregated with the phenotype in the proband and her father.

CONCLUSIONS

Segregation of a versican-associated vitreoretinopathy supports the pathogenicity of the VCAN variant. The patterns of structural abnormalities support classical mechanisms of disease that involve local vitreoretinal traction, as well as possible alternative developmental and/or degenerative changes of the retina, RPE, and/or choroid that result from the primary molecular defect.

Classification of peripheral vitreoretinal interface lesions using spectral-domain optical coherence tomography with guidance of ultrawide field imaging

Purpose

This study aimed to classify peripheral vitreoretinal interface (VRI) lesions using optical coherence tomography (OCT) and to compare these findings with those obtained by ultra-widefield (UWF) pseudocolor imaging.

Method

Peripheral OCT images of VRI lesions were obtained using spectral domain OCT system with a steerable probe guided by UWF images. Two independent investigators categorized the OCT images into four groups based on the extent of vitreoretinal traction and the presence of retinal breaks. Differences in OCT-based categorization between the same lesion types visualized by UWF imaging were also compared.

Results

Of the total 82 patients, 105 peripheral lesions were included in this study. The inter-observer agreement for the classification of UWF and OCT images demonstrated good consistency, with kappa values of 0.949 ± 0.025 and 0.836 ± 0.042, respectively. In the OCT classification of VRI lesions, 18 (17.1%) cases were category A, 28 (26.7%) cases were category B1, 30 (28.6%) cases were category B2, and 29 (27.6%) cases were category C. Of the 37 vitreoretinal tuft lesions, 32.4% were classified as category B2 and 16.2% as category C, according to peripheral OCT classification. Similarly, 37.8% of 40 snail track and lattice degeneration lesions were classified as category B2, and 16.2% as category C.

Conclusion

The VRI lesions can demonstrate considerable variability when visualized with peripheral OCT among the same lesion types visualized through UWF imaging. Classification of peripheral OCT images may provide a more effective evaluation of the risk of lesion progression.

Vitreoschisis-induced vitreous cortex remnants in proliferative vitreoretinopathy: A comprehensive review from basic research to clinical practice

Proliferative vitreoretinopathy (PVR) significantly impacts the prognosis of rhegmatogenous retinal detachment (RRD), one of the most critical and increasing causes of vision loss in the Western world. Despite advancements in surgical instruments and techniques, the failure rate due to PVR remains substantial, necessitating additional surgeries and often leading to unsatisfactory visual outcomes. This comprehensive review explores the role of vitreoschisis-induced vitreous cortex remnants (VCR) as a critical, previously under-recognised factor contributing to PVR. Vitreoschisis, a phenomenon where the inner lamellae of the posterior vitreous cortex detach while the outermost layers remain attached to the retina, creates VCR that may contain hyalocytes and serve as scaffolds for fibrocellular proliferation. These remnants are difficult to visualise without triamcinolone acetonide (TA) staining, leading to their frequent lack of recognition in clinical practice. Moreover, removing VCR can be challenging and time-consuming, often requiring meticulous surgical techniques to avoid retinal damage and ensure complete elimination. This review consolidates insights from basic research and clinical practice, emphasising the importance of complete vitreous removal and effective VCR detection and removal to mitigate PVR risks. It highlights the histopathological and clinical evidence supporting the hypothesis that VCR, containing hyalocytes, play a pivotal role in preretinal membrane formation. The review also discusses epidemiological data, surgical management strategies and potential future directions, including improved visualisation techniques and the development of new surgical tools and methods. This review aims to improve surgical outcomes and reduce the frequency and burden of RRD-related complications by addressing VCR as a critical factor in PVR.

Hyperuricemia and epiretinal pathologies: a review of pathophysiological links and clinical implications

Hyperuricemia (HUA), defined by elevated serum uric acid levels, is well-established in its association with systemic conditions like gout and cardiovascular diseases. Recently, however, emerging research has revealed a potential connection between HUA and ocular disorders, particularly epiretinal pathologies. This review investigates the pathophysiological mechanisms linking HUA to epiretinal conditions, including epiretinal membrane formation, macular edema, and retinal vascular diseases. By thoroughly analyzing current literature, this review seeks to deepen the understanding of the relationship between HUA and epiretinal disorders, with the aim of informing new therapeutic strategies and enhancing patient outcomes.

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.

The adhesion behavior of the retina

Ocular diseases and treatment related to rhegmatogenous retinal detachment (RRD) are highly correlated with retinal adhesion behavior. Therefore, this paper proposes to study the adhesion behavior of the intact retina. This can provide theoretical guidance for the treatment and research of retinal detachment (RD) related diseases. To systematically analyze this aspect, two experiments were performed on the porcine retina. The pull-off test combined with the modified JKR theory was used to study the adhesion behavior of the vitreoretinal interface, while the peeling test was used to study the adhesion behavior of the chorioretinal interface. In addition, the adhesion phase involved in the pull-off test was simulated and analyzed by building the corresponding finite element method (FEM). The experimental results of adhesion force on the vitreoretinal interface were obtained by pull-off test with five sizes of rigid punch. The experimental value of the pull-off force F_PO tends to increase gradually with increasing punch radius in the range of 0.5-4 mm. A comparison of the experimental results with the simulation results shows that they are in a well agreement. And there is no statistical difference between the experimental and theoretical values of the pull-off force F_PO. In addition, the values of retinal adhesion work were also obtained by pull-off test. Interestingly, there is a significant scale effect of the retinal work of adhesion. Finally, the peeling test gave a maximum peeling strength T_Max of about 13 mN/mm and a stable peeling strength T_D of about 11 mN/mm between the retina and the choroid. The pull-off test well shows the process of retinal traction by the diseased vitreous at the beginning of RRD. A comparison of the experimental results with the finite element results verifies the accuracy of the simulation. The peeling test well investigated the adhesion behavior between the retina and the choroid and obtained key biomechanical data (peeling strength, etc.). The combination of the two experiments allows a more systematic study of the whole retina. This research can provide more complete material parameters for finite element modeling of retina-related diseases, and it also can provide the theoretical guidance for individualized design of retinal repair surgery.

The effect of vitreomacular interface in neovascular age-related macular degeneration treated with intravitreal injection of anti-VEGF

BACKGROUND

The purpose of this study is to study the effect of repeated intravitreal injection of anti-vascular endothelial growth factor (anti-VEGF) drugs on vitreomacular interface.

METHODS

Neovascular age-related macular degeneration patients who received intravitreal injections of anti-VEGF drugs were included. Eyes with severe vitreous opacity, uveitis, complicated cataract surgery and previous vitrectomy were excluded. Vitreomacular interface, best corrected visual acuity (BCVA) and central retinal thickness (CRT) assessment were performed once a month for at least 3 months. The nature and time of the change event are recorded. Groups were divided according to whether vitreomacular interface change events occurred. To analyse the risk factors of vitreomacular interface changes and their influence on treatment effect.

RESULTS

A total of 87 eyes were evaluated. Vitreomacular interface change event occurred in 9 eyes. Pre-existing vitreomacular interface abnormality (VMIA) was a risk factor for the VMI change (P = 0.033, OR = 16.518, 95% CI: 1.258 to 216.939). 60% of interface events occurred in the first 3 months of treatment. The final BCVA of eyes with vitreomacular interface unchanged was significantly higher than that at baseline (P = 0.001), and the final CRT was also significantly lower than that at baseline (P < 0.001). The final CRT of eyes vitreomacular interface changed was significantly lower than that at baseline (P = 0.015), however, there was no statistical significance in BCVA (P = 0.468).

CONCLUSION

Intravitreal injection of anti-VEGF drugs has a certain probability to cause changes in the vitreomacular interface, and the risk is higher in eyes with pre-existing vitreomacular interface abnormality. The effect of intravitreal injections on the vitreomacular interface was concentrated in the first three injections, and subsequent increases in the number of injections did not significantly increase the risk of vitreomacular interface abnormality. Ophthalmologists should increase attention to the vitreomacular interface in the early stages of anti-VEGF therapy and counsel patients accordingly.