Study on the effectiveness and safety of Foldable Capsular Vitreous Body implantation

Refinements in the use of silicone oil as an intraocular tamponade

It is over 60 years since Paul Cibis et al. reported the experimental use of liquid silicone in the surgical management of retinal detachment. Initial experiences were complicated by significant side-effects associated with the impurities in the non-medical grade commercial silicone oils deployed at the time. These were substantially reduced (but not eliminated) by the adoption of refined high-viscosity medical grade silicone oils. Two of the major complications associated with silicone tamponade are (i) the variability of focus due to its movement and higher refractive index, and (ii) progressive emulsification, particularly with low viscosity oils. This article reviews recent and ongoing research on the causes of emulsification of intra-ocular silicone oil to understand the causes better and thereby reduce this risk, especially for those eyes where permanent tamponade is the only current option for retaining vision.

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.

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.

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.

Study on the efficacy and safety of foldable capsular vitreous body in the severe retinal detachment eyes

BACKGROUND

This study was to evaluate the efficacy and safety of the implantation of foldable capsular vitreous body (FCVB) in severe retinal detachment eyes.

METHODS

A retrospective study in retinal detachment eyes was performed at Shandong Provincial Hospital Affiliated to Shandong First Medical University. A standard three-port pars plana vitrectomy was performed, and the FCVB was triple folded and implanted into the vitreous cavity. The silicone oil (SO) was then injected into the capsule of the FCVB to support the retina and eye. During the follow-up period, The treated eyes were examined by ophthalmoscopy, fundus photography, and tonometry. B-scan ultrasonography, optical coherence tomography (OCT), and computed tomography (CT), were also performed.

RESULTS

From May 2020 to November 2021, 31 cases with severe retinal detachment were enrolled in the study. The postoperative follow-up time gradient ranged from 1 to 72 weeks, At various observation time points during the 72 weeks after surgery, The postoperative IOP was maintained at around 10 mmhg at various time points, with a slight decrease compared to the preoperative IOP (14.2 ± 4.6 mmHg n = 18), and was statistically significant. 9 of 31 patients had clear refractive media, both fundus and OCT showed retinal reattachment, OCT showed the 200 μm thick FCVB capsule support retina. The remaining 22 patients with unclear refractive media, B-scan showed arcuate hyperechoes in front of the retina. There was also no significant difference in visual acuity compared to preoperative. The FCVB was well positioned in the vitreous cavity, and no serious complications such as endophthalmitis, glaucoma, silicone oil emulsification, product exposure, or sympathetic uveitis were found.

CONCLUSIONS

FCVB has retinal support with certain ability to maintain IOP and eye morphology and avoid eye removal in patients with severe retinal detachment during the 72-week observation period.

Clinical Application of Foldable Capsular Vitreous Bodies in the Treatment of Severe Ocular Trauma and Silicone Oil Dependent Eyes

Purpose

This study aimed to assess the application of a foldable capsular vitreous body (FCVB) in the treatment of severe ocular trauma and silicone oil (SO) dependent eyes.

Methods

A retrospective analysis was performed on the clinical application of FCVB in the treatment of severe ocular trauma and SO dependent eyes. The results of best-corrected visual acuity and intraocular pressure (IOP) evaluation, B-scan ultrasonography or color Doppler ultrasonography, ultrasound biomicroscopy, and anterior segment photography were recorded during follow-up. A paired t-test was used to compare the difference in IOP before and after FCVB implantation.

Results

Seven eyes of seven patients were included in the 6-month follow-up. In all cases, B-scan ultrasonography and ultrasound biomicroscopy showed that FCVB adapted closely to the globe wall and ciliary body, thus supporting the retina. Visual acuity did not improve, except in one case from LP to HM. The mean ± SD IOP was 8.5 ± 1.90 mm·Hg prior to FCVB implantation and 10.43 ± 0.98 mm·Hg after implantation, with no significant difference between these measurements (P=0.095). Five of the seven patients developed differing degrees of corneal opacity and keratopathy.

Conclusions

FCVB implantation may be a safe and effective method for the treatment of severe ocular trauma and SO dependent eyes. However, FCVB cannot prevent the phthisis of the traumatic eyes. In addition, corneal opacity and keratopathy are potentially serious complications after surgery. Appropriate case selection and proper surgical timing are required for further investigation.

Evaluation of Foldable Capsular Vitreous Body Implantation Surgery

Background

Foldable capsular vitreous body (FCVB), a novel artificial vitreous substitute product, has been used clinically in recent years. The aim of this study was to evaluate the outcomes and complications of FCVB implantation surgery during the postoperative period.

Methods

We performed a prospective, nonrandomized study from November 2021 to March 2022. Eight patients with severe retinal detachment that could not be easily reattached were included in this study. Before and after surgery, visual acuity (VA), intraocular pressure (IOP), slit-lamp microscopy, optical coherence tomography (OCT), B-scan and CT were performed.

Results

After the operation, the FCVB was well distributed in the vitreous cavity and supported the retina according to the B-scan and CT images. During the follow-up period, no vitreous hemorrhage or retinal detachment was found in any of the patients. On the first postoperative day, the average IOP increased from 9.6 ± 7.7 mmHg preoperatively to 13.8 ± 14.3 mmHg. Although the IOP of two patients fell outside the normal range, IOP was finally held steady after the fifth postoperative day in all cases. In addition, three patients (37.5%) experienced eye ache, and after taking a Saridon tablet, the pain was greatly alleviated. Moreover, no adverse events, such as silicone oil (SO) spillage and emulsification or serious complications, were observed.

Conclusion

The current vitreous substitute FCVB is effective and safe for treating complicated retinal detachments in ophthalmic applications. Further multiple-center clinical designs should focus on indications and complications of FCVB during long-term follow-up periods.

FOLDABLE CAPSULAR VITREOUS BODY IMPLANTATION FOR COMPLICATED RETINAL DETACHMENT CAUSED BY SEVERE OCULAR TRAUMA

PURPOSE

To explore the effectiveness, safety and psychological impact of foldable capsular vitreous body (FCVB) implantation for complicated retinal detachment caused by severe ocular trauma.

METHODS

This was a prospective, single-arm, surgical interventional case series study. A standard 3-port 23-gauge pars plana vitrectomy was performed, and the FCVB was implanted into the vitreous cavity. Observed indicators, including the best-corrected visual acuity, intraocular pressure (IOP), retinal reattachment, complications, and patient satisfaction, were analyzed to evaluate the study.

RESULTS

A total of 28 cases (eyes) were enrolled, with a mean follow-up of 16.93 ± 9.67 months and an average age of 51.11 ± 10.14 years, including 22 men (78.57%). The FCVB was successfully implanted, and the retina was reattached in all cases. The postoperative best-corrected visual acuity improved in 7 cases, and remained unchanged in 21 cases ( P > 0.05). The average IOP was 7.01 ± 2.43 mmHg before surgery and 8.54 ± 2.93 mmHg after surgery ( P < 0.05). Complications such as FCVB displacement, endophthalmitis, secondary glaucoma, silicone oil emulsification, and escape did not occur during the follow-up period. Patients with FCVB implantation are highly satisfied. Most patients feel hope, positive, and optimistic about life.

CONCLUSION

Foldable capsular vitreous body implantation for complicated retinal detachment caused by severe ocular trauma is effective and safe, and it allows patients to face life positively and optimistically.

SILICONE OIL-FILLED FOLDABLE CAPSULAR VITREOUS BODY VERSUS SILICONE OIL ENDOTAMPONADE FOR TREATMENT OF NO LIGHT PERCEPTION AFTER SEVERE OCULAR TRAUMA

PURPOSE

To compare the anatomical and functional outcomes of silicone oil (SO)-filled foldable capsular vitreous body (FCVB) and SO endotamponade in vitrectomy for patients with no light perception after ocular trauma.

METHODS

A total of 64 patients (64 eyes) with no light perception caused by severe ocular trauma were divided into FCVB and SO groups based on the surgical treatment. The main outcome measurements were retinal reattachment rate, intraocular pressure, best-corrected visual acuity, and number of operations.

RESULTS

Both the FCVB group (29 eyes) and the SO group (35 eyes) showed significant improvement in postoperative best-corrected visual acuity and intraocular pressure. The two groups showed no significant differences in final intraocular pressure and the retinal reattachment rate. The postoperative vision (≥LP) in the FCVB group was significantly worse than in the SO group (FCVB [4/29] vs. SO [18/35], P = 0.003). However, the number of surgeries in the FCVB group was significantly lower than in the SO group (FCVB [1.10] vs. SO [2.23], P < 0.001).

CONCLUSION

Vitrectomy combined with SO endotamponade shows better short-term improvement in the treatment of no light perception caused by severe ocular trauma. However, SO-filled FCVB can effectively prevent many complications caused by direct SO endotamponade, such as secondary surgeries or SO dependence.

Outcomes of a Foldable Capsular Vitreous Body Implantation: A Retrospective Study

Background

The vitreous body is an important part of the ocular body fluid. A foldable capsular vitreous body (FCVB) is designed to treat chronic adverse complications in severe ocular trauma and silicone oil-dependent eyes. This study is aimed at investigating a method for implanting an FCVB, its postoperative efficacy, and clinical value.

Methods

A retrospective analysis was performed on data from 18 patients who underwent vitrectomy and FCVB implantation for severe ocular trauma and silicone oil-dependent eyes between March 2019 and May 2020. All treated eyes underwent clinical examinations involving the best-corrected visual acuity, intraocular pressure, FCVB position, anterior segment photography, and wide-angle fundus photography regularly after surgery.

Results

Eighteen eyes from 18 patients were enrolled in this study. A total of 2.00–4.20 (3.46 ± 0.78) ml of silicone oil were injected into the FCVB during surgery. The patients were followed up at 1, 2, and 4 weeks and 3, 6, and 12 months after surgery. Twelve months after surgery, visual acuity improved in 7 (38.89%) eyes. In contrast, 10 (55.56%) eyes showed no obvious improvement, and 1 (5.56%) eye had decreased vision. Intraocular pressure at 12 months was 10.13 ± 3.52 mmHg, which was comparable to that before the surgery (t = 0.38, P = 0.71). The anterior chamber depth examined by slit lamp was 2.00–3.00 cornea thickness (CT) in 7 eyes, 1.00–2.00 CT in 2 eyes, and <1.00 CT in one eye. The anterior chamber disappeared in eight eyes. There were eight eyes with clear cornea, four eyes with localized opacity, and two eyes with obvious gray-white opacity. There was no case of severe FCVB deflection, rupture, or exposure during the observation period.

Conclusion

FCVB implantation is an effective and safe treatment for eyes with severe ocular trauma and silicone oil-dependent eyes. It may support retinal reattachment, slow down eyeball atrophy, reduce the risk of chronic adverse complications such as corneal endothelial decompensation, and maintain intraocular pressure and preoperative visual function.

Evaluation of the long-term effect of foldable capsular vitreous bodies in severe ocular rupture

AIM

To evaluate the long-term effect of foldable capsular vitreous body (FCVB) in the treatment of severe ocular rupture to provide a practical basis for clinical selection.

METHODS

A total of 26 patients (26 eyes), 23 men and 3 women, with severe ocular rupture who underwent FCVB implantation between March 2018 and September 2018 were retrospectively analysed. All open ocular wounds located in zone III, with preoperative visual acuity grade IV and above (Snellen less than 4/200). The best corrected visual acuity (BCVA), intraocular pressure (IOP), cornea, anterior chamber, iris, lens, choroid, and retina were evaluated before and after the surgery. The subjective feeling and the location of FCVB were also assessed.

RESULTS

The average age of the 26 patients was 36y (20-60y). Postoperative follow-up was from 10 to 14mo. At the end of follow up, BCVA was light perception (LP) in 10 cases, no light perception (NLP) in 13 cases, hand motions (HM) in 3 cases. IOP was 11±5 mm Hg. Corneal degeneration was in 3 cases and corneal endothelial dystrophy was in 7 cases. Shallow anterior chamber was in 8 cases and hyphema was in 8 cases. Organized membrane in the pupil was in 14 cases. Epiphora occurred in 3 cases. FCVB drainage tube exposed in 3 cases. All FCVBs were in their normal location and no rejection occurred.

CONCLUSION

FCVB implantation is a long-term effective treatment and may provide a practical selection for severe ocular rupture.

Reattachment After Foldable Capsular Vitreous Body Implantation in Severe Retinal Detachment Eyes

Purpose

To evaluate the clinical effectiveness and safety of foldable capsular vitreous body (FCVB) implantation for severe retinal detachment.

Methods

A retrospective analysis was performed on 26 patients with severe ocular trauma and one with recurrent retinal detachment. Clinical data-including surgery success, complications, retinal reattachment, vision, and intraocular pressure (IOP)-were analyzed for patients who underwent 23G pars plana vitrectomy and FCVB implantation combined with silicone oil tamponade.

Results

The mean follow-up period was 10.44 ± 2.68 months. All surgeries were smooth; the FCVBs were properly positioned and supported the retina well, and the retinal reattachment rate reached 92.59%. At the six-month follow-up, preoperative (1.30 ± 1.20) and postoperative (0.63 ± 0.79) vision was significantly different (t = 3.03, P = 0.005), and the postoperative IOP (7.93 ± 3.57 mm Hg) was lower than the preoperative IOP (13.98 ± 10.72 mm Hg) (t = 2.74, P = 0.01). Among 20 patients followed up for >12 months, preoperative (1.20 ± 0.95) and postoperative (0.75 ± 0.91) visions were significantly different (t = 1.831, P = 0.005), and the postoperative IOP (9.85 ± 6.48 mm Hg) was lower than the preoperative IOP (14.85 ± 12.17 mm Hg) (t = 1.82, P = 0.01). No endophthalmitis, sympathetic ophthalmia, and rejection of FCVB occurred during follow-up.

Conclusions

FCVB combined with silicone oil tamponade showed good efficacy and safety in severe retinal detachment treatment during the follow-up period.

Translational Relevance

Vitreous substitution is deemed a highly challenging and interesting research topic in ophthalmology. Traditional method such as silicone oil tamponade often causes various complications such as silicone oil emulsification, silicone oil migration, and corneal degeneration. The foldable capsular vitreous body as a novel vitreous substitute combined silicone oil injection into it can stay in the eyeball for a long time without obvious complications.

Polymeric hydrogel as a vitreous substitute: current research, challenges, and future directions

Vitreoretinal surgery is an essential approach to treat proliferative diabetic vitreopathy, retinal detachment, retinal tear, ocular trauma, and macular holes. The removal of the natural vitreous and the replacement with substitutes are critical steps for retina reattachment. Vitreous substitutes including silicone oil (SiO), air, sulfur hexafluoride (SF₆), and perfluoropropane (C₃F₈), have been widely applied in clinical practice. However, these substitutes are reported to cause complications such as emulsification, high intraocular pressure, and lens opacification. Polymeric hydrogels are a kind of material with favorable physical, mechanical properties, and adaptable biocompatibility, thus being highly expected to be ideal vitreous substitutes. Despite years of research, very few polymeric hydrogels can be applied practically in the vitreous cavity. In this review, we focus on the development of polymeric natural-based hydrogels and synthetic hydrogels. Particularly, we pay attention to recent advances in the novel stimuli-response and self-assembly supramolecular hydrogels. Characterized by easy injectability and long residence time, this kind of hydrogel becomes the potentially promising candidates for ideal vitreous substitutes. Finally, we evaluate the current challenges and provide the future directions of vitreous substitutes.

Foldable capsular vitreous body implantation for treatment of traumatic retinal detachment: two case reports

Retinal detachment caused by severe ocular trauma is a type of refractory vitreoretinal disease. Current treatment methods include vitrectomy combined with silicone oil tamponade. However, long-term use of silicone oil tamponade has various complications, including a risk of silicone oil dependence that eventually leads to eyeball atrophy and enucleation. Foldable capsular vitreous bodies (FCVBs) offer a good solution for these problems. However, FCVBs have not been used in large-scale clinical applications and few cases have been reported in the published literature. The main use of FCVBs, based on current evidence, is in the treatment of the relatively few (but important) patients whose eyes have no visual potential; the aim of treatment in these patients is globe preservation, rather than restoration of vision. Here, we describe two patients who underwent FCVB implantation. The findings in these patients indicated that FCVBs can effectively support the vitreous cavity and detached retina. FCVB implantation may thus offer a safe and effective method for treatment of severe retinal detachment, avoiding the inconvenience caused by silicone oil dependence and enucleation. To confirm its long-term usefulness in clinical applications, many additional case reports are needed.

Silicone oil in vitreoretinal surgery: indications, complications, new developments and alternative long-term tamponade agents

Silicone oil (SO) has been used as a long-term tamponade agent in the treatment of complicated vitreoretinal diseases for about half a century, during which time many advances in surgical techniques and technologies have been made. This review summarizes the chemical and physical properties of SO, its indications and complications, including particularly emulsification. The mechanisms and risk factors for emulsification are discussed, as well as novel strategies for its effective removal. Finally, the review focuses on new improved formulations of SO, including research into slow-release pharmacological agents within SO and provides an overview of alternatives to SO for the purpose of long-term tamponade that are being developed.

Polymeric hydrogels as a vitreous replacement strategy in the eye

Vitreous endo-tamponades are commonly used in the treatment of retinal detachments and tears. They function by providing a tamponading force to support the retina after retina surgery. Current clinical vitreous endo-tamponades include expansile gases (such as sulfur hexafluoride (SF₆) and perfluoropropane (C₃F₈)) and also sislicone oil (SiO). They are effective in promoting recovery but are disadvantaged by their lower refractive indices and lower densities as compared to the native vitreous, resulting in immediate blurred vision after surgery and necessitating patients to assume prolonged face-down positioning respectively. While the gas implants diffuse out over time, the SiO implants are non-biodegradable and require surgical removal. Therefore, there is much demand to develop an ideal vitreous endo-tamponade that can combine therapeutic effectiveness with patient comfort. Polymeric hydrogels have since attracted much attention due to their favourable properties such as high water content, high clarity, suitable refractive indices, suitable density, tuneable rheological properties, injectability, and biocompatibility. Many design strategies have been employed to design polymeric hydrogel-based vitreous endo-tamponades and they can be classified into four main strategies. This review seeks to analyse these various strategies and evaluate their effectiveness and also propose the key criteria to design successful polymeric hydrogel vitreous endo-tamponades.

Macro- and Microscale Properties of the Vitreous Humor to Inform Substitute Design and Intravitreal Biotransport

Research on the vitreous humor and development of hydrogel vitreous substitutes have gained a rapid increase in interest within the past two decades. However, the properties of the vitreous humor and vitreous substitutes have yet to be consolidated. In this paper, the mechanical properties of the vitreous humor and hydrogel vitreous substitutes were systematically reviewed. The number of publications on the vitreous humor and vitreous substitutes over the years, as well as their respective testing conditions and testing techniques were analyzed. The mechanical properties of the human vitreous were found to be most similar to the vitreous of pigs and rabbits. The storage and loss moduli of the hydrogel vitreous substitutes developed were found to be orders of magnitude higher in comparison to the native human vitreous. However, the reported modulus for human vitreous, which was most commonly tested in vitro, has been hypothesized to be different in vivo. Future studies should focus on testing the mechanical properties of the vitreous in situ or in vivo. In addition to its mechanical properties, the vitreous humor has other biotransport mechanisms and biochemical functions that establish a redox balance and maintain an oxygen gradient inside the vitreous chamber to protect intraocular tissues from oxidative damage. Biomimetic hydrogel vitreous substitutes have the potential to provide ophthalmologists with additional avenues for treating and controlling vitreoretinal diseases while preventing complications after vitrectomy. Due to the proximity and interconnectedness of the vitreous humor to other ocular tissues, particularly the lens and the retina, more interest has been placed on understanding the properties of the vitreous humor in recent years. A better understanding of the properties of the vitreous humor will aid in improving the design of biomimetic vitreous substitutes and enhancing intravitreal biotransport.