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

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.

A novel approach for 25-gauge transconjunctival sutureless vitrectomy to evaluate vitreous substitutes in rabbits

AIM

To improve the standard three-port vitrectomy for establishing and evaluating an endotamponade model in rabbits.

METHODS

Three ports were prepared near the third eyelid of rabbits, and the infusion port was placed at the inferior nasal quadrant with the inserted cannula linking with a self-designed handheld rigid infusion catheter. All right eyes of rabbits underwent a modified 25-gauge vitrectomy and were subsequently filled with balanced salt solution, silicone oil, and eight-arm polyethylene glycols (8-arm PEGs) hydrogel separately for comparison. Ophthalmic examinations were performed regularly to record the changes after the surgery.

RESULTS

Successful vitrectomy was achieved among 44 chinchilla rabbits. The mean operation time was 4.51±1.25min. Four eyes (9.1%) presented limited lens touch and two eyes (4.5%) showed retinal touch during surgery. Incision leakage was found in three eyes (6.8%) after surgery. There was no endophthalmitis, hemorrhage, or retinal detachment during the observation period and ophthalmic examinations after the implantation of vitreous substitutes.

CONCLUSION

The modified technique of the standard vitrectomy applied in the endotamponade model in rabbits shows excellent safety and practicality.

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.

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.