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

Abstract

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.

Keywords: foldable capsular vitreous body; retinal detachment; silicone oil; vitreous substitute.

Figure 1

(A) Preparation of FCVB for implantation. The air tightness of the FCVB capsule was checked with a syringe needle through the valve. The capsule then was aspirated to a vacuum state, and adjusted to a special shape; then, the capsule was three-folded like a spindle. (B) Procedure for the FCVB implantation surgery. a, Pars plana vitrectomy was performed. b, A scleral cut was made, and the folded FCVB was placed in the vitreous cavity. c, SO was injected into the capsule through the valve. d, The valve was fixed onto the sclera.

Figure 2

Efficacy of 3-year FCVB with SO implantation in three cases. (A–C) Fundus and OCT images of each patient. All three patients had severe RD at baseline. The fundus was visible and clear in all three cases, and there were no obvious differences between the images at the 2- and 3-year follow-ups, indicating that the FCVB-supported fundus was stable during the 3-year follow-up. OCT showed that the contact between the FCVB and retina was smooth, although the retinal thickness was decreased and the retinal structure was altered to some extent compared to the retina of the control eyes. The arrow indicates the 60-mm thick capsular membrane. (D) Graded scores of visual acuity at each time point after the FCVB implantation. Visual acuity was graded according to the following system: NLP as 0, LP as 1, HM as 2, FC as 3, ≥0.05 as 4, and ≥0.1 as 5. The scores showed slight fluctuations, but the visual acuity of the three patients slightly increased compared to those at baseline. (E) IOP values and IOP differences between the untreated and treated eyes. The IOP was significantly elevated in Cases 1 and 3 immediately after the FCVB implantation, whereas it remained steady in Case 2. By the end of the 3-year follow-up, the IOPs of the treated and control eyes were not different in Cases 1 and 2, whereas the IOP in Case 3 was 5 mm Hg lower than that of the control eye. The differences between the untreated and treated eyes showed a tendency to decrease with time.

Figure 3

Safety of 3-year FCVB with SO implantation in the three cases. (A–C) Anterior segment imaging showed no observable inflammation. (D–F) Ultrasound biomicroscopy showed smooth contact of the FCVB with the ciliary bodies and no crushing of these bodies. (G) Number of corneal endothelial cells. There was no statistically significant difference in the density of the corneal endothelial cells between baseline and 3 years after FCVB implantation.