Determining posterior vitreous structure by analysis of images obtained by AI-based 3D segmentation and ultrawidefield optical coherence tomography

AimsTo determine the three-dimensional (3D) structure of the vitreous fluid including the posterior precortical vitreous pockets (PPVP), Cloquet’s canal and cisterns in healthy subjects by AI-based segmentation of the vitreous of swept-source optical coherence tomography (OCT) images. In addition, to analyse the vitreous structures over a wide and deep area using ultrawidefield swept-source OCT (UWF-OCT).MethodsTen eyes of six patients with the mean age was 40.7±8.4 years and the mean refractive error (spherical equivalent) was −3.275±2.2 diopters were examined.ResultsIn the UWF OCT images, the structure of the vitreous was observed in detail over 23 mm wide and 5 mm area. AI-guided analyses showed the complex 3D vitreous structures from any angle. Cisterns were observed to overlie the PPVP from the anterior. The morphology and locations of the cisterns varied among the subjects but tended to be similar in the two eyes of one individual. Cisterns joined the PPVPs superior to the macula to form a large trunk. This joined trunk was clearly seen in 3D images even in eyes whose trunk was not detected in the B scan OCT images. In some eyes, the vitreous had a complex appearance resembling an ant nest without large fluid-filled spaces.ConclusionsA combination of UWF-OCT and 3D imaging is very helpful in visualising the complex structure of the vitreous. These technologies are powerful tools that can be used to clarify the normal evolution of the vitreous, pathological changes of vitreous and implications of vitreous changes in various vitreoretinal diseases.

Binocular Indirect Fundus Microscope in Vitreoretinal Surgery

With the rapid development of computer technology, the application of computer technology in various fields is more and more common, and it also plays an increasingly important role in biomedicine. In recent years, microscopic image processing has always been an important part of biomedicine, and binocular indirect fundus microscope is playing an increasingly important role in vitreoretinal surgery. The purpose of this paper is to study the application effect of binocular indirect fundus microscope in vitreoretinal surgery, and to master the role of binocular indirect fundus microscope, which is important for biomedicine. This paper studies the effect of binocular indirect fundus microscope in vitreoretinal surgery through the study of the role of vitreous and binocular indirect fundus microscope, as well as the investigation of experimental methods. It highlights that the effect of binocular indirect fundus microscope is better than that of direct microscope in retinal surgery.The results show that binocular indirect fundus microscope is more suitable for vitreoretinal surgery. 85% of the patients with vitreoretinal surgery have better effect after surgery. No matter from the comparison of visual acuity improvement or retinal thickness, binocular indirect fundus microscope has better effect in vitreoretinal surgery. It also provides reference for how to prevent vitreoretinal diseases disease has positive significance. We expect to produce effective methods as soon as possible to solve the problems related to vitreous diseases, which can bring the bright future to ophthalmic patients.

Topical Triamcinolone Acetonide-Loaded Liposome Formulation Used as an Adjuvant to Intravitreal Ranibizumab Therapy for Neovascular Age-Related Macular Degeneration

Novel strategies have been developed to reduce or avoid intravitreal injections (IVTs) of the antiangiogenic (ranibizumab (RBZ)) and anti-inflammatory (triamcinolone acetonide (TA)) agents used to treat vitreoretinal diseases. One of the strategies includes liposomes. This study evaluated the safety and efficacy of a topical triamcinolone-loaded liposome formulation (TALF) as an adjuvant to intravitreal RBZ therapy in treatment- naïve patients with neovascular age-related macular degeneration (nAMD). Subjects were randomly assigned to the RBZ-TALF or the RBZ-pro re nata (RBZ-PRN) groups. Patients from the RBZ-TALF group were instructed to apply TALF for 12 months after a single dose of RBZ. Patients from the RBZ-PRN group received three monthly RBZ-IVTs. Retreatment with RBZ was considered in the case of nAMD reactivation. Regarding safety, non-ocular abnormalities were observed during TALF therapy. Concerning efficacy, non-significant differences were identified in terms of visual acuity or central foveal thickness when the RBZ-PRN and RBZ-TALF groups were compared. It is worth noting that the average number of RBZ injections was significantly lower in the RBZ-TALF group (2.5 ± 1.4 vs. 6.1 ± 1.3 IVTs; p = 0.0004). Therefore, TALF used as an adjuvant to RBZ reduces the need for RBZ-IVT retreatment with optimal visual and anatomic results.

A 27 - Gauge Microincision Vitrectomy Surgery for Posterior Segment Diseases in a Tertiary Centre, Nepal

Introduction: Transconjunctival micro incision vitrectomy surgery (MIVS) with 23 or 25 gauge instrumentation is more advantageous than traditional 20 gauge surgery. We intended to evaluate the visual outcome, complications and indication of various vitreoretinal diseases using 27 Gauge vitrectomy systems. Methods: This study was a prospective, interventional, non-comparative study conducted in Nepal Eye Hospital from June 2017 to July 2018. Fifty-two patients with various vitreoretinal diseases were recruited. The main outcome measures included corrected distance visual acuity (CDVA) preoperative and postoperative, intraocular pressure (IOP) preoperative and postoperative, indication for vitreoretinal surgery, intraoperative complications, and postoperative complications. Results: Fifty two eyes of 52 patients (26 men and 26 women; mean age, 59 years) underwent 27-gauge pars planavitrectomy. Surgical indications included epiretinal membrane (n = 11), full-thickness macular hole (n = 11), rhegmatogenous retinal detachment [n = 14 (12 vitrectomy only and two vitrectomy with scleral buckle)], vitreous haemorrhage (n = 3), vitreous opacities (n = 3), silicon oil removal (n = 3), proliferative diabetic retinopathy [n = 6 (5 vitreous haemorrhage and one tractional retinal detachment)], posterior IOL dislocation (n = 1). Postoperative complications included transient ocular hypertension in eight eyes (15.39%), transient hypotony in five eyes (9.62%) and vitreous haemorrhage in five eyes (9.62%). No cases of postoperative endophthalmitis, sclerotomy - related tears, or choroidal detachments were encountered in the follow-up period. Mean corrected distance visual acuity improved from 20 / 796 (logarithm of the minimum angle of resolution, 1.60 ± 0.64) preoperatively to 20 / 49 (logarithm of the minimum angle of resolution, 0.42 ± 0.26) postoperatively (p = 0.000,) at final follow up. Conclusions: 27-gauge micro-incision vitrectomy surgery was found to be a safe and effective suture-less surgery with favourable outcomes, in terms of vision.

Comparisons of Vitreal Angiogenic, Inflammatory, Profibrotic Cytokines, and Chemokines Profile between Patients with Epiretinal Membrane and Macular Hole

Objectives. Idiopathic epiretinal membrane (iERM) or idiopathic macular hole (iMH) is frequently used as a “healthy” control in comparison of vitreous cytokines with other vitreoretinal diseases. This study aimed to investigate if there is a difference in vitreal cytokines expression between patients with iERM and iMH. Methods. In this prospective study, all subjects received standard pars plana vitrectomy surgery, and 0.5 ml of native vitreous sample was extracted during the vitrectomy. Luminex technology and enzyme-linked immunosorbent assay were used to profile the concentration of 52 classic angiogenic, inflammatory, and profibrotic cytokines and chemokines. Statistical analyses were performed by the Mann–Whitney U test, followed by multiple comparisons by the Bonferroni correction. Results. Vitreal samples from 13 iERM and 24 iMH were studied. Of the 52 tested cytokines, 41 were similar in expression, and 5 were under the detection limit, while 6 cytokines (MMP-8, Eotaxin, MIP-1a, RANTES, TGF-β2, and IL-4) were differently expressed between two groups ( p < 0.05 ). Nevertheless, these significances disappeared after the adjustment of Bonferroni correction. Conclusion. The tested cytokines showed similar expression between iERM and iMH patients. This indicates that eyes with iERM or iMH can be together served as “healthy” controls.

Topical Triamcinolone Acetonide-Loaded Liposomes Formulation Used as an Adjuvant to Intravitreal Ranibizumab Therapy for Neovascular Age Related Macular Degeneration

Novel strategies have been developed to reduce or to avoid the intravitreal injections (IVTs) of the antiangiogenic (ranibizumab; RBZ) and the anti-inflammatory (triamcinolone acetonide; TA) agents used to treat vitreoretinal diseases. One of the strategies include liposomes. In this study, it was evaluated the safety and efficacy of topical triamcinolone-loaded liposomes formulation (TALF) as an adjuvant to intravitreal RBZ therapy in treatment-naive patients with neovascular age related macular degeneration (nAMD). Subjects were randomly assigned to the RBZ-TALF or the RBZ-pro re nata (RBZ-PRN) group. Patients from the RBZ-TALF group were instructed to apply TALF for a 12-month period after a single dose of RBZ. Patients from the RBZ-PRN group received three monthly RBZ-IVTs. Retreatment with RBZ was considered in case of nAMD reactivation. Related to safety, non-ocular abnormalities were observed during TALF therapy. Owing to the efficacy, non-significant differences are identified in visual acuity or central foveal thickness when the RBZ-PRN and RBZ-TALF groups are compared. Importantly the average number of RBZ injections was significantly lower in the RBZ-TALF group (2.5 &plusmn; 1.4 vs 6.1 &plusmn; 1.3 IVTs; p=0004). Therefore, TALF used as an adjuvant to RBZ reduce the number of RBZ-IVTs retreatment with optimal visual and anatomic results.

Assessment of indicators of quality of life and vision in patients with posterior segment of the eye pathology

Purpose. Comparative analysis of the quality of life profiles in patients with various vitreoretinal diseases. Material and methods. The study included 76 patients with established diseases of the retina and vitreous body aged 17 to 82 years, of which 25 were men and 51 were women. All participants were interviewed using a special questionnaire assessment of vision Visual Functioning Questionnaire 25 (VFQ-25). Quantitative data are processed using descriptive statistics and presented as medians and quartiles. The reliability of differences between patients from different observation groups was confirmed by nonparametric statistics (the Mann–Whitney test). The reliability of the differences was considered established at p<0.05. Results. The results of patients' subjective assessment of various social aspects of their life activity are shown. The results of a comparative assessment of quality of life indicators depending on the diagnosis are given. Conclusion. The quality of life profile of patients with vitreoretinal pathology is characterized by a low assessment of patients ‘General health status and a high level of dependence on external assistance. Patients experience significant difficulties when driving a car. There is also a low level of role difficulties reflecting the individual's adaptive reserves in society. There were significant differences in the levels of assessment of quality of life indicators by respondents with various vitreoretinal diseases on the scales: «General health», «near visual function». Key words: quality of life, diseases of the posterior segment of the eye, VFQ-25 questionnaire, ophthalmological patients.

A simple new technique for the induction of residual posterior vitreous cortex removal and membrane peeling

AIM: To describe a quick, cost-effective alternative to using a scraper to remove the residual posterior vitreous cortex and create an inner limiting membrane (ILM) flap during vitrectomy. METHODS: The surgical technique and a retrospective interventional single-center series of cases were described. A hook was made on the tip of a conventional syringe needle (outer diameter, 0.6 mm; 23 gauge) by bending the needle against a plate. We used this hook to remove the residual posterior vitreous cortex and create an ILM flap during vitrectomy. The efficacy and safety of using this instrument in ophthalmological procedures for a variety of vitreoretinal disorders were evaluated. RESULTS: The hook was effective for removing focal or diffuse residual posterior vitreous cortex in eyes with rhegmatogenous retinal detachment, proliferative diabetic retinopathy, and pathological myopia. It was also successfully used to make a free edge of the ILM and help strip the epiretinal membrane. There were no serious complications associated with using the hook in delicate ophthalmological procedures. CONCLUSION: The hook, made by bending a conventional needle, is a simple and cost-effective instrument for removing residual posterior vitreous vortex and to create epiretinal and ILM flaps during vitrectomy in eyes with various vitreoretinal diseases.

Comparison of safety and effectiveness between 23-gauge and 25-gauge vitrectomy surgery in common vitreoretinal diseases

Purpose To assess and compare safety and effectiveness between 23-gauge and 25-gauge vitrectomy systems for the treatment of common vitreoretinal diseases in non-vitrectomized eyes. Methods Retrospective evaluation of patients who underwent pars plana vitrectomy from April 2018 to December 2019 at the Department of Ophthalmology and Optometry at the Medical University of Vienna (MUV) for the following indications: macular epiretinal membrane, macular hole, macular lamellar hole, vitreous hemorrhage, vitreous opacities, vitreomacular traction syndrome and macular edema. Results 201 eyes of 195 patients that underwent 23-gauge (n = 105 eyes) or 25-gauge (n = 96 eyes) vitrectomy were included in this study. The mean best-corrected visual acuity (BCVA) improved at 1–3 months postoperatively and beyond 3 months in both gauge groups. Risk of any complication within 1 month postoperatively was lower in the 25-gauge group, but the difference was statistically not significant (HR [95% CI]: 0.95 [0.53; 1.70], p = 0.85). Intraocular pressure less than 5 mmHg was observed in 2 eyes (2%) in the 23-gauge group at the first postoperative day. Intraocular pressure elevation over 25 mmHg occurred in 5 eyes (2 eyes, 2%, in 23-gauge and 3 eyes, 3%, in 25-gauge group) at postoperative day 1, between 7 and 28 days in 5 cases (2 eyes, 2%, in 23-gauge and 3 eyes, 3%, in 25-gauge group), and in 2 eyes (2%) of the 23-gauge group at postoperative day 145 and 61, respectively. Retinal detachment occurred in 1 eye (1%) in the 23-gauge and in 3 eyes (3%) in the 25-gauge group. We did not observe any cases of endophthalmitis. Conclusion Results in terms of safety, surgical success and visual outcomes for the treatment of common vitreoretinal surgery indications seem to be comparable between 23-gauge and 25-gauge vitrectomy systems, indicating that the two gauge systems can be used equally in the clinical routine.

Biomechanical properties of retina and choroid: a comprehensive review of techniques and translational relevance

Studying the biomechanical properties of biological tissue is crucial to improve our understanding of disease pathogenesis. The biomechanical characteristics of the cornea, sclera and the optic nerve head have been well addressed with an extensive literature and an in-depth understanding of their significance whilst, in comparison, knowledge of the retina and choroid is relatively limited. Knowledge of these tissues is important not only to clarify the underlying pathogenesis of a wide variety of retinal and vitreoretinal diseases, including age-related macular degeneration, hereditary retinal dystrophies and vitreoretinal interface diseases but also to optimise the surgical handling of retinal tissues and, potentially, the design and properties of implantable retinal prostheses and subretinal therapies. Our aim with this article is to comprehensively review existing knowledge of the biomechanical properties of retina, internal limiting membrane (ILM) and the Bruch’s membrane–choroidal complex (BMCC), highlighting the potential implications for clinical and surgical practice. Prior to this we review the testing methodologies that have been used both in vitro, and those starting to be used in vivo to aid understanding of their results and significance.