Technical Standards of a Foldable Capsular Vitreous Body in Terms of Mechanical, Optical, and Biocompatible Properties

Precise prediction of size of a foldable capsular vitreous body via computerized three-dimensional ocular reconstruction in severe retinal detachment

BACKGROUND

This study aimed to precisely predict the size and silicone oil injection of a foldable capsular vitreous body (FCVB) via computerized three-dimensional (3D) ocular reconstruction in the treatment of severe retinal detachment in China.

METHODS

The 3D software Unigraphics NX was applied to determine the volume of the inner cavity with 16-30 mm axial length, assigning the anterior and posterior chambers, the FCVB sizes, and the silicone oil injection volume, and modeling the data between the axial length and the FCVB size. In clinical practice, IOL Master was applied to accurately measure the axial length of the contralateral healthy eye to anchor the anterior-posterior and horizontal diameters of the operated eye in horizontal position CT, and compared with the model to recommend the FCVB size and silicone oil amount, and the clinical effect was validated in cases across five hospitals in China.

RESULTS

For the axial length of 16-30 mm, the volume of the inner cavity is 1.2 ml-8.4 ml. FCVB size and silicone oil volume were recommended based on this volume of the inner cavity. Of 253 cases, we noted 11 cases implanted with AV-10P and 1.05 ± 0.21 ml of silicone oil, 41 with AV-12P and 1.58 ± 0.18 ml of silicone oil, 163 with AV-13.5P and 2.48 ± 0.29 ml of silicone oil, 31 with AV-15P and 3.57 ± 0.39 ml of silicone oil, and 7 with AV-17P and 5.71 ± 0.81 ml of silicone oil. There was no significant difference in postoperative visual acuity scores compared with preoperative (P = 0.097), postoperative IOP(10.29 ± 0.57mmHg)was slightly higher than preoperative IOP (9.76 ± 0.48 mmHg), but there was still no statistically significant difference between the two comparisons (P = 0.405).

CONCLUSION

Three-dimensional reconstruction prediction is a good solution for eyeballs with obvious individualized changes in severe retinal detachment, and this method helps doctors standardize FCVB size selection and the silicone oil amount for patients.

Efficacy and visual outcomes of the foldable capsular buckle scleral buckling in rhegmatogenous retinal detachment

Objective

To investigate the difference in the effectiveness and refraction of the foldable capsular buckle (FCB) in rhegmatogenous retinal detachment (RRD).

Methods

Six patients with simple RRD were treated for FCB scleral buckling at Xiamen Eye Center of Xiamen University from October 2023 to February 2024. The parameters assessed included demographic data, clinical data such as preoperative ocular axis, corneal endothelial count, macular foveal thickness, operative time, preoperative and final follow-up intro ocular pressure (IOP), retinal attachment status, and postoperative complications. Refractive change before and after surgery, including sphere, cylinder degree, spherical equivalent, and absolute spherical equivalent difference were compared.

Results

All six patients with sound retinal reattachment after FCB scleral buckling, including two men and four women, mean age 41.33 ± 12.40 years old, duration before surgery onset to 7.17 ± 7.16 days, FCB mean operation time 36.67 ± 13.07 min, Preoperative IOP mean 13.35 ± 2.64 mmHg and mean 21.12 ± 8.09 mmHg of final follow-up IOP; there was no significant difference between preoperative IOP and follow-up IOP (p = 0.050). The preoperative sphere range was -6.25 to +2.50 D, and the cylinder range was -2.50 to +1.00 D; the absolute spherical equivalent difference before and after was 1.60 ± 1.69 degrees.

Conclusion

FCB can achieve retinal reattachment and restore visual function in cases of RRD. The shorter duration of external scleral buckle compression with FCB suggests that FCB scleral buckling holds greater promise in the clinical treatment of RRD caused by retinal tears.

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.

Advances in Polysaccharide- and Synthetic Polymer-Based Vitreous Substitutes

The vitreous humour is a gel-like structure that composes the majority of each eye. It functions to provide passage of light, be a viscoelastic dampener, and hold the retina in place. Vitreous liquefaction causes retinal detachment and retinal tears requiring pars plana vitrectomy for vitreous substitution. An ideal vitreous substitute should display similar mechanical, chemical, and rheological properties to the natural vitreous. Currently used vitreous substitutes such as silicone oil, perfluorocarbon liquids, and gases cannot be used long-term due to adverse effects such as poor retention time, cytotoxicity, and cataract formation. Long-term, experimental vitreous substitutes composed of natural, modified and synthetic polymers are currently being studied. This review discusses current long- and short-term vitreous substitutes and the disadvantages of these that have highlighted the need for an ideal vitreous substitute. The review subsequently focuses specifically on currently used polysaccharide- and synthetic polymer-based vitreous substitutes, which may be modified or functionalised, or employed as the derivative, and discusses experimental vitreous substitutes in these classes. The advantages and challenges associated with the use of polymeric substitutes are discussed. Innovative approaches to vitreous substitution, namely a novel foldable capsular vitreous body, are presented, as well as future perspectives related to the advancement of this field.

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.

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.

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.

Comparison of Viscoelastic Substance Injection Versus Air Filling in the Anterior Chamber During Foldable Capsular Vitreous Body (FCVB) Implant Surgery: A Prospective Randomized Controlled Trial

INTRODUCTION

To compare the outcomes of viscoelastic substance injection with air filling in the anterior chamber during foldable capsular vitreous body (FCVB) implant surgery in patients with severe retinal disease.

METHODS

Thirty eyes with severe retinal diseases were randomly divided into two groups. In the viscoelastic group, 0.15-0.2 mL of 1.7% sodium hyaluronate was injected into the anterior chamber after FCVB implantation; in the air group, the anterior chamber was maintained by filling the air after FCVB implant surgery. The eyes of treated patients were examined during a 24-week follow-up appointment. Data, including intraocular pressure (IOP), the difference between preoperative and postoperative IOP, and postoperative complications, were recorded.

RESULTS

Data collected from 27 eyes were used in the final analysis. The IOP of the air group was lower than that of the viscoelastic group from the first to third postoperative day (P < 0.01). Moreover, the difference between preoperative and postoperative IOP in the viscoelastic group was significantly smaller than that in the air group from the first to third postoperative day (P < 0.01). After the 1st postoperative week, postoperative IOP values were similar in the two groups (P > 0.05). Postoperative complications in the air group and the viscoelastic group included corneal blood staining (1 eye vs. 0 eyes), transient postoperative diffuse hemorrhage (5 eyes vs. 1 eye), inflammation reaction (9 eyes vs. 4 eyes), and postoperative fibrin exudation (4 eyes vs. 1 eye), respectively.

CONCLUSION

The use of viscoelastic substances in the anterior chamber during FCVB implant surgery was associated with less fluctuation in postoperative IOP and could reduce postoperative complications.

REGISTRATION NUMBER

ChiCTR-TNC-00000396.

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.

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

Background

Foldable capsular vitreous body (FCVB) was designed to treat severe retinal detachment. The aim of this study was to evaluate the efficacy and safety of the implantation of foldable capsular vitreous body in 1-year follow-up.

Methods

A retrospective analysis was conducted for 20 patients with severe ocular trauma or silicone oil (SO) dependent eyes underwent vitrectomy and FCVB implantation in a 1-year follow-up. All treated eyes were peformed clinical examinations involved the visual acuity (VA) examination, Goldmann applanation tonometer, noncontact specular microscopy, fundus photography, B-Scan examination and optical coherence tomography (OCT). The groups were compared with t-test and the McNemar - Bowker test.

Results

In 1-year follow-up, 20 eyes were evaluated in the study. FCVB well supported the vitreous retina in all treated eyes, and 6 treated eyes achieved retinal reattachment 12 months after FCVB implantation. There were no significant differences in VA before and after FCVB implantation (P = 1.000). In addition, the postoperative IOP markedly elevated from the preoperative IOP of 12.90 ± 7.06 mmHg to 15.15 ± 3.36 mmHg (P = 0.000017). The intraocular pressure (IOP) of 10 eyes maintained at a normal level after surgeries. The other 10 eyes showed slightly lower IOP within the acceptable level. Though two patients developed keratopathy and ocular inflammation respectively, other treated eyes were symmetric with fellow eyes showing satisfactory appearance. Moreover, there was no SO emulsification or leakage happened in the observation.

Conclusions

FCVB implantation was an effective and safe treatment in the eyes with severe retinal detachment.

Risk Factors for Trauma-Related Eviscerations: Analysis of 821 Cases

Evisceration is the end therapeutic approach for the treatment of severe ocular trauma cases, and it is a tremendous loss for patients. In this study, we explored the changing trends in the number of surgeries performed, demographic data and ocular features, and risks for early evisceration, aiming to provide more data for the additional prevention and management strategies for this catastrophic problem. This was a retrospective study that included patients who underwent ocular evisceration at the Zhongshan Ophthalmic Center between January 2013 and December 2017. A total of 1229 evisceration cases were reviewed, and only trauma-related eviscerations were analyzed. Etiology, demographic data, ocular features, and hospitalization time were evaluated. The total number of trauma-related eviscerations recorded in the past five years was 821 cases. The number of surgeries performed was almost constant each year (164 ± 17 cases); 35% of the patients were less than ten years old at the time of the original ocular injury and 69% of them were male. Endophthalmitis led to significantly early evisceration compared with cases without endophthalmitis (P < 0.05). The group with a history of silicone oil tamponade showed a significantly longer surgical interval between trauma and evisceration than did the nonsilicone oil tamponade group (P < 0.05). Day-case hospitalization for evisceration increased from 0% to 32% over the past five years. The results of the present study show that the number of ocular trauma-related eviscerations performed in the past five years was almost unchanged and boys under ten are highly susceptible. This study also demonstrates that endophthalmitis leads to significantly early evisceration, and silicone oil tamponade may postpone ocular atrophy. Based on the study data, day-case surgery is safe for evisceration management.

Influence of super-hydrophobic silicone rubber substrate on the growth and differentiation of human lens epithelial cells

Materials with low cell adhesion are advantageous for production of replacement intraocular lens (IOL) to prevent posterior capsular opacification (PCO). We evaluated the feasibility of compression molding for manufacture of silicone rubber with super-hydrophobic surface and low cell infiltrative characteristics compared to ordinary hydrophobic silicone rubber. Silicone specimens with complex surface topology (super-hydrophobic) or smooth surfaces (hydrophobic) were manufactured by vacuum deforming and molding. Contact angle, microscopic surface structure, and transparency were evaluated. Super-hydrophobic and smooth samples were compared for effects on proliferation, adhesion, and morphology of human lens epithelial cells (hLECs). Epithelial-mesenchymal transition (EMT) was examined by immunofluorescence expression of fibronectin (Fn), Alpha-smooth muscle actin (α-SMA), and vimentin. The surface contact angle of super-hydrophobic silicone was greater than that of smooth silicone (153.8° vs. 116°). The super-hydrophobic surface exhibited a micron-scale palisade structure under scanning electron microscopy (unit length, width, and height of 80, 25, and 25 μm, respectively). However, cell number per 50 × microscopic field on super-hydrophobic surfaces was markedly reduced 24 and 72 h post-seeding compared to smooth surfaces (p < 0.01). Cells were cuboidal or spherical after 72h on super-hydrophobic surfaces, and exhibited numerous surface microvilli with fluff-base polarity, while cells on smooth surfaces exhibited morphological characteristics of EMT. Expression levels of the α-SMA and vimentin were reduced on super-hydrophobic surfaces compared to smooth surfaces. Super-hydrophobic silicon inhibits proliferation, adhesion, and EMT of hLECs, properties that may prevent fibrosis following cataract surgery.

MACULAR BUCKLING USING A THREE-ARMED SILICONE CAPSULE FOR FOVEOSCHISIS ASSOCIATED WITH HIGH MYOPIA

PURPOSE

To investigate the safety and efficacy of a novel macular buckling technique on foveoschisis in highly myopic eyes.

METHODS

Highly myopic eyes with foveoschisis, posterior staphyloma, and axial length greater than 26.5 mm, but without a full-thickness macular hole, were included. Macular buckling was performed in the included eyes using a three-armed adjustable silicon capsule.

RESULTS

Eight eyes from eight patients (five women) were enrolled in this study. The mean follow-up period was 11.6 (range 9-14) months. After surgery, the best-corrected visual acuity was improved in 7/8 (87.5%) eyes, optical coherence tomography imaging showed gradual anatomic improvement of macula over time. The final best-corrected visual acuity gained 21.5 early treatment diabetes retinopathy study letters from baseline on average (P = 0.014). Postoperatively, the most common complications were transiently elevated intraocular pressure (62.5%) and asymptomatic abduction limitation (100%), and the most serious complication was hemorrhagic choroidal detachment (25%).

CONCLUSION

Macular buckling with a three-armed adjustable silicone capsule resulted in anatomic and visual improvement in eyes with myopic foveoschisis.

Intraocular silicone implant to treat chronic ocular hypotony-preliminary feasibility data

PURPOSE

Ocular hypotony secondary to proliferative vitreoretinopathy-related retinal detachment, trauma or inflammation is difficult to treat. Besides endotamponades such as silicone oil, vitreous implants such as iris diaphragms or balloons have been developed to stabilize the eye and to prevent phthisis of the globe. Vitreous implants tested thus far exhibit a seam at the attachment site of the hemispheres, or micropores. This manuscript reports the development of a seamless silicone balloon implant without micropores, which can be filled with silicone oil and surface-modified to improve its biocompatibility. Developed for intraocular placement in the management of chronic hypotony and phthisis prevention, it may also be suitable for tamponading retinal detachments.

METHODS

Silicone was used as the basic structure for the fabrication of a seamless balloon-shaped intraocular implant, which was coated by employing a six-arm star-shaped (sP) macromer of a copolymer of 80 % ethylene oxide (EO) and 20 % propylene oxide (PO) with conjugated functional terminal isocyanate groups, NCO-sP(EO-stat-PO), with and without heparin. Three variants of implants, which differ in their surfaces, were manufactured: uncoated silicone, NCO-sP (EO-stat-PO) coated silicone and heparin-NCO-sP (EO-stat-PO) coated silicone implants. To exert a tamponade effect, the implant was filled with silicone oil and its properties were studied.

RESULTS

Seamless thin balloon implants made of silicone, which are considered biocompatible and intrinsically resistant to biological attacks in vivo, could be fabricated in different sizes. The silicone oil-filled implant can mimic the mechanism of buoyant force and high surface tension of silicone oil, which is the only long-term vitreous substitute currently available. The silicone oil-filled implant can also mimic the natural vitreous body by occupying the entire posterior segment.

CONCLUSIONS

The intraocular silicone implant as an alternative long-term treatment of chronic ocular hypotony might offer a new option for clinical ophthalmological practice. In vivo studies need to be performed to collect more data on the implant's long-term mechanical and optical properties, as well as long-term biocompatibility.

In Vitro Cell Models for Ophthalmic Drug Development Applications

Tissue engineering is a rapidly expanding field that aims to establish feasible techniques to fabricate biologically equivalent replacements for diseased and damaged tissues/organs. Emerging from this prospect is the development of in vitro representations of organs for drug toxicity assessment. Due to the ever-increasing interest in ocular drug delivery as a route for administration as well as the rise of new ophthalmic therapeutics, there is a demand for physiologically accurate in vitro models of the eye to assess drug delivery and safety of new ocular medicines. This review summarizes current existing ocular models and highlights the important factors and limitations that need to be considered during their use.

Three-Year Efficacy and Safety of a Silicone Oil-Filled Foldable-Capsular-Vitreous-Body in Three Cases of Severe Retinal Detachment

Purpose

We previously designed a novel foldable capsular vitreous body (FCVB) to treat severe retinal detachment and evaluated its performance in a 1-year follow up study. The purpose of this study was to determine the efficacy and safety of a silicone oil (SO)-filled FCVB in a 3-year follow-up.

Methods

Standard three-port pars plana vitrectomy was performed, and the FCVB was triple folded and implanted in the vitreous cavity of three eyes. The SO then was injected into the capsule to support the retina. The eyes were examined using Goldmann applanation tonometry, fundus photography, optical coherence tomography (OCT), noncontact specular microscopy, and ultrasound biomicroscopy over a 3-year implantation period.

Results

At the 3-year follow-up, retinal reattachment was achieved in all three cases, with steady intraocular pressure. The visual acuity showed slight fluctuations, and it was slightly increased compared to baseline. Optical coherence tomography revealed decreased retinal thickness and an altered retinal structure in the implanted eyes compared to the control eyes. No keratopathy, glaucoma, SO leakage, SO emulsification, or other apparent complications occurred during the observation period.

Conclusion

The SO-filled FCVB was effective and safe as a vitreous substitute in three eyes over a 3-year observation period.

Translational Relevance

Silicone oil emulsification is a severe complication after retinal detachment surgery. On the basis of animal experiments, we investigated a new strategy and product, the FCVB, to overcome this complication. In this pilot study, FCVB limited SO emulsification and migration. This study could lay the foundation for a further multicenter clinical trial.

The efficacy and safety of a novel posterior scleral reinforcement device in rabbits

PURPOSE

To evaluate the efficacy and safety of posterior scleral reinforcement (PSR) device for myopia suppression in rabbits' eyes.

METHODS

PSR surgery was performed on the normal 12 8-week-old New Zealand white rabbits' right eyes. To determine efficacy of the device, ophthalmic examination would be taken at pre-operation and post-operation (1 week, 1 month, 3 months, 6 months, and 1 year), such as A-ultrasound, diopter and B-ultrasound. Evaluation of safety were based on the following indicators: intraocular pressure (IOP), slit lamp, fundus photography, fundus fluorescein angiography and pathological examination after surgery. The efficacy and safety of PSR device were evaluated by comparison (treated eyes and contralateral eyes) of pre and post-operation.

RESULTS

The novel PSR device could significantly shorten axial length (preoperative axial length: 16.36 ± 0.14 mm, postoperative 1 week, 1 month, 3 months, 6 months and 1 year axial lengths: 15.03 ± 0.28 mm, 15.23 ± 0.32 mm, 15.39 ± 0.31 mm, 15.45 ± 0.22 mm and 15.45 ± 0.22 mm; P=0.00037<0.001) in the treated eyes (right eyes) after surgery. At different postoperative time points, the B-ultrasound images showed that the PSR located in appropriate position and supported the posterior sclera very well. At the same time, IOP of treated eyes kept a relatively stable level (preoperative IOP: 12.56 ± 2.01 mmHg, postoperative IOP: ranging from 11.33 ± 1.23 mmHg to 13.44 ± 2.19 mmHg, P>0.05) post-operation 1 year. During observation period, there was no significant inflammatory reaction and complications such as anterior chamber flare, empyema, endophthalmitis, vitreous hemorrhage, retina detachment and retinal choroid neovascularization by slit lamp, fundus photography and fundus fluorescein angiography. In addition, there were no pathologic changes be found by comparison treated eyes group and contralateral group eyes based on pathological examinations.

CONCLUSIONS

In vivo study, effectively and safely, the novel PSR device can inhibit rabbits' axial length elongation during postoperative 1 year. This study demonstrates that this novel PSR could be a potential treatment approach for myopia.

Vitreous substitutes: challenges and directions

The natural vitreous body has a fine structure and complex functions. The imitation of the natural vitreous body by vitreous substitutes is a challenging work for both researchers and ophthalmologists. Gases, silicone oil, heavy silicone oil and hydrogels, particularly the former two vitreous substitutes are clinically widely used with certain complications. Those, however, are not real artificial vitreous due to lack of structure and function like the natural vitreous body. This article reviews the situations, challenges, and future directions in the development of vitreous substitutes, particularly the experimental and clinical use of a new artificial foldable capsular vitreous body.

Preliminary study on retinal vascular and oxygen-related changes after long-term silicone oil and foldable capsular vitreous body tamponade

Silicone oil has been the only long-term vitreous substitute used in the treatment of retinal detachment since 1962 by Cibis. Nevertheless, its effects on retinal vascular morphology and oxygen supply to the retina are ambiguous in current research. We previously invented a foldable capsular vitreous body (FCVB) to use as a new vitreous substitute in the treatment of severe retinal detachment, but its effects on the retinal vessel were unknown. Therefore, in this study, a standard three-port pars plana vitrectomy (PPV) was performed on the right eye of each rabbit and then silicone oil and FCVB were injected into the vitreous cavity as vitreous substitutes. After 180 days of retention, the retinal vascular morphology did not display any distinct abnormalities, and hypoxia-induced factor-1alpha (HIF-1α) and vascular endothelial growth factor (VEGF) did not vary markedly during the observation period in silicone oil tamponade- and FCVB-implanted eyes. This study may suggest that silicone oil and FCVB tamponade in rabbit eyes did not cause retinal vascular pathologic changes or retinal hypoxia for 180 days.

Vitreous substitutes: the present and the future

Vitreoretinal surgery has advanced in numerous directions during recent years. The removal of the vitreous body is one of the main characteristics of this surgical procedure. Several molecules have been tested in the past to fill the vitreous cavity and to mimic its functions. We here review the currently available vitreous substitutes, focusing on their molecular properties and functions, together with their adverse effects. Afterwards we describe the characteristics of the ideal vitreous substitute. The challenges facing every ophthalmology researcher are to reach a long-term intraocular permanence of vitreous substitute with total inertness of the molecule injected and the control of inflammatory reactions. We report new polymers with gelification characteristics and smart hydrogels representing the future of vitreoretinal surgery. Finally, we describe the current studies on vitreous regeneration and cell cultures to create new intraocular gels with optimal biocompatibility and rheological properties.

A novel vitreous substitute of using a foldable capsular vitreous body injected with polyvinylalcohol hydrogel

Hydrogels may be the ideal vitreous substitutes due to their wonderful physical features and biocompatibility. However, their drawbacks, short residence time, and biodegradation in vivo, have led to the fact that none of them have been approved for clinical use. In this study, we developed a novel approach of using a foldable capsular vitreous body (FCVB) injected with polyvinylalcohol (PVA) hydrogel as a vitreous substitute for long-term tamponade. The 3% PVA hydrogel that was cross-linked by gamma irradiation showed good rheological and physical properties and had no toxicity in vitro. After 180 days retention, the 3% PVA hydrogel inside FCVB remained transparent and showed good viscoelasticity without biodegradation and showed good biocompatibility and retina support. This new approach may develop into a valuable tool to improve the stability performance of PVA hydrogel as a vitreous substitute and to extend the application function of FCVB for long-term implantation in vitreous cavity.

Comprehensive analysis of inflammatory immune mediators of the intraocular fluid aspirated from the foldable capsular vitreous body filled-eyes

PURPOSE

To analyze the level of human inflammatory immune mediators in the intraocular fluid aspirated from foldable capsular vitreous body (FCVB) filled-eyes during FCVB removal surgery, 3 months after implantation.

METHODS

8 samples of intra-FCVB fluids (n = 8) were collected from 8 FCVB filled patients in our previous FCVB exploratory clinical trial. The intra-FCVB fluids were aspirated from the FCVB filled-eyes during the FCVB removal surgeries at the third month. For the control groups, the vitreous fluids were collected from patients with idiopathic macular hole (n = 9) or rhegmatogenous retinal detachment (n = 6) during pars plana vitrectomy. A multiplex immunoassay was used to determine levels of 9 cytokines (IL-1β, IL-2, IL-6, IL-8, IL-10, IL-17, TNF-α, IFN-γ and VEGF) in these samples. The VEGF level of some intra-FCVB fluids (n = 6) were re-tested using enzyme-linked immunosorbent assay (ELISA).

RESULTS

In the intra-FCVB fluids, 9 cytokines concentrations of most samples (n = 5) measured by Multiplex immunoassay showed low values, except for Patient 02, 06, and 09. The VEGF concentrations of some intra-FCVB fluids (n = 6) tested by ELISA were in accordance with Multiplex immunoassay results. For all eight patients (n = 8), the concentrations of IL-1β, IL-2, IL-6, TNF-α, IFN-γ and VEGF were slightly higher as compared to the idiopathic macular hole control group. While, the concentrations of IL-8, IL-10, and IL-17 were not statistically significant different compared with the idiopathic macular hole control samples. Most cytokines concentrations (IL-2, IL-6, IL-8, IL-10, IL-17, TNF-α, IFN-γ, VEGF) were not statistically significant different compared to the rhegmatogenous retinal detachment control group except IL-1β.

CONCLUSIONS

The FCVB had sufficient porosity to allow cytokines to pass through. This study first discovered that the FCVB possesses favorable permeability of proteins in the human eye.

Evaluation of the levofloxacin release characters from a rabbit foldable capsular vitreous body

The authors have manufactured a novel rabbit foldable capsular vitreous body (FCVB). The aim of this study was to determine whether this rabbit FCVB can release levofloxacin in vitro and in vivo, and to evaluate the release characteristics. In vitro, the rabbit FCVB with levofloxacin 500 μg/mL was immersed in cups of modified Franz diffusion cells. Following this, 200 μL of liquid was aspirated at intervals from 10 minutes to 24 hours. In vivo, the FCVB with levofloxacin was implanted into the right eyes of five rabbits. After implantation, the aqueous humor was aspirated on days 1, 7, 14, 28, and 56. The levofloxacin concentrations in the cups and aqueous humor samples were detected by high-performance liquid chromatography–tandem mass spectrometry. The FCVB was observed under a scanning electron microscope. The results showed that the released levofloxacin was stabilized at 20 ng/mL at time points from 10 minutes to 24 hours in vitro. In vivo, levofloxacin concentrations in the aqueous humor were 132, 50, 39, 11, and 15 ng/mL on days 1, 7, 14, 28, and 56, respectively. In the FCVB capsules, 300 nm apertures were observed. These results suggest the rabbit FCVB released levofloxacin stably in vitro and sustainably in vivo. This study provides a novel combined approach, with the FCVB as a vitreous substitute and drug delivery system for the treatment of bacterial endophthalmitis.

Artificial organs 2010: a year in review

In this Editor's Review, articles published in 2010 are organized by category and briefly summarized. As the official journal of The International Federation for Artificial Organs, The International Faculty for Artificial Organs, and the International Society for Rotary Blood Pumps, Artificial Organs continues in the original mission of its founders "to foster communications in the field of artificial organs on an international level."Artificial Organs continues to publish developments and clinical applications of artificial organ technologies in this broad and expanding field of organ Replacement, Recovery, and Regeneration from all over the world. We take this time also to express our gratitude to our authors for offering their work to this journal. We offer our very special thanks to our reviewers who give so generously of time and expertise to review, critique, and especially provide such meaningful suggestions to the author's work whether eventually accepted or rejected and especially to those whose native tongue is not English. Without these excellent and dedicated reviewers the quality expected from such a journal could not be possible. We also express our special thanks to our Publisher, Wiley-Blackwell, for their expert attention and support in the production and marketing of Artificial Organs. In this Editor's Review, that historically has been widely received by our readership, we aim to provide a brief reflection of the currently available worldwide knowledge that is intended to advance and better human life while providing insight for continued application of technologies and methods of organ Replacement, Recovery, and Regeneration. We look forward to recording further advances in the coming years.

Protein kinase Cα downregulation via siRNA-PKCα released from foldable capsular vitreous body in cultured human retinal pigment epithelium cells

We previously found that downregulation of protein kinase Cα (PKCα) can inhibit retinal pigment epithelium (RPE) cell proliferation involved in the development of proliferative vitreoretinopathy (PVR). In this study, we tested whether PKCα could be downregulated via small interfering RNA (siRNA)-PKCα released from foldable capsular vitreous body (FCVB) in cultured human RPE cells. SiRNA-PKCα content, determined by ultraviolet (UV) spectrophotometer, was released from FCVB containing 200, 300, 400, 500, and 600 nm siRNA-PKCα in a time-dependent manner from 1 to 96 hours and a dose-dependent manner at five concentrations. The content (y) had a good linear relationship with time (x), especially in the 600 nm siRNA-PKCα group (y = 16.214x, R² = 0.9809). After treatment with siRNA-PKCα released from FCVBs, the PKCα was significantly decreased by RT-PCR, Western blot, and immunofluorescence analysis in RPE cells. These results indicate that PKCα was significantly downregulated by siRNA-PKCα released from FCVB in human RPE cells and provide us with a new avenue to prevent PVR.

Evaluation of supporting role of a foldable capsular vitreous body with magnetic resonance imaging in the treatment of severe retinal detachment in human eyes

PURPOSE

To determine the supporting role of a novel foldable capsular vitreous body (FCVB) with magnetic resonance imaging (MRI) in the treatment of severe retinal detachment in human eyes.

METHODS

The study examined nine eyes of nine patients. Among the nine eyes, five had suffered penetrating injuries while four had suffered contusions of the eyeball involving large defects of the retina or choroids. A standard three-port pars plana vitrectomy was performed, FCVB was triple-folded and sent into the vitreous cavity; balanced salt solution (BSS) was injected into the capsule to support the retina. Three cardinal axes of nine eyes were examined using MRI at baseline and at the 3-month follow up.

RESULTS

MRI revealed that the signal intensity of the FCVB was similar to the normal vitreous body, with low-signal intensity on T1-weighted image and high-signal intensity on T2-weighted image. In three pre-operative silicone oil- or heavy silicone oil-filled eyes, FCVBs were not fully inflated, and eyeball deformation was observed in one eye. Shifts of three cardinal axes of three eyes (horizontal, anteroposterior, and vertical) according to MRI, were -4.33, -4.67, and -2.67 mm. In the remaining six eyes, FCVBs were well distributed in the vitreous cavity and evenly supported the retina; the cardinal axes of the eyes were similar to pre-operation. Shifts of three cardinal axes of six eyes were -0.34, -0.34, and -0.34 mm. In a total of nine eyes, shifts of three cardinal axes were -1.67, -1.77, and -1.11 mm. Statistically significant difference showed only between the horizontal axis of nine eyes pre-operatively and post-operatively (P1=0.041, P2=0.058, P3=0.123).

CONCLUSION

This study demonstrated the effectiveness of MRI to monitor the supporting role of an FCVB in the treatment of severe retinal detachment in human eyes.