Internal closure of a posterior perforation using amniotic membrane: A novel surgical technique

A 57-year-old man was referred to our centre due to corneal and lens injury caused by a metallic foreign body that was released during sawing. Iris and lens fragments were plugging the corneal defect, and the anterior chamber was collapsed. The visual acuity was limited to light perception. CT imaging suggested that a metallic foreign body was located intraocularly resting on top of the retina (Figure 1a). The patient was then brought to theatre (surgery was performed by senior retinal surgeon KF). Here, the cornea was closed with 10.0 nylon sutures (Figure 1b) and the lens and iris remnants were removed allowing the reformation of the anterior chamber. Pars plana vitrectomy was performed to remove the vitreous haemorrhage. Internal limiting membrane (ILM) was peeled revealing a large metallic foreign body that had perforated the posterior choroid and sclera, settling in the retrobulbar space. The foreign body was stuck and could not be manoeuvred with a forceps or magnet, as it was firmly attached to the orbital bone. Therefore, it was decided to leave the foreign body since it could not be safely removed without causing further damage. We performed a limited chorioretinectomy to achieve haemostasis by removing bleeding vessels adjacent to the defect. In addition to controlling haemorrhage, this approach may help reduce the risk of proliferative vitreoretinopathy (PVR) at the wound margins and minimize the risk of gas embolism associated with the use of gas tamponade. To repair the choroid and posterior sclera, two large amniotic membranes were used as a plug. Because small amniotic membranes might have been washed out easily, two large membranes were necessary to ensure internal plugging. Two large (uncut) membranes of thawed freeze-dried amnion were used. The first one was inserted into the posterior perforation defect using two 23G Eckhardt forceps, while the infusion was maintained at 20 mmHg. The second membrane was placed flat over the defect and beneath the surrounding residual retina (Figure 1c), also using two 23G Eckhardt forceps. The epithelial layer of the amnion was placed facing the retina to promote optimal adherence of the membrane to the retinal surface. Air-fluid exchange was done slowly with drainage of fluid away from the amnion membranes, to avoid their displacement. To avoid leakage of harmful substances in the orbit, 15% perfluoropropane (C3F8) gas was used as tamponade and silicone oil and perfluorocarbon liquid were not used during surgery. Routine intravitreal vancomycin and ceftazidime were left to prevent endophthalmitis. Post-operative medication consisted of topical prednisolone acetate, atropine, ofloxacin and oral co-trimoxazole. One month after the initial surgery, the patient developed a total retinal detachment. A pars plana vitrectomy was performed with internal ILM peeling. Intraoperatively, the amniotic membrane was found to be in situ. Silicone oil tamponade was used. Two months later, a recurrent retinal detachment was observed with the macula still attached. PVR grade C2 was noted in the inferior retina and over the macula. Therefore, an inferior retinectomy was performed between the 4 and 8 o'clock positions, and silicone oil was again used as a tamponade. Notably, no PVR had formed at the perforation site. Six months later, the silicone oil was removed and residual epiretinal membrane was removed in three quadrants. A tamponade of 5% C3F8 gas was then instilled. The metallic foreign body remained in the orbit without complications. The patient was strictly advised to avoid magnetic fields such as MRI devices. At the consultation at 1 year postoperatively, the eye had remained intact with normal intraocular pressure, attached retina and remaining visual function. At that point in time, maximal visual acuity was Snellen 20/200, measured with a scleral contact lens. The patient is currently awaiting a scleral-fixated implant lens. Posterior choroidoscleral perforation is a rare but serious ocular injury that typically results from high-velocity trauma, such as penetrating foreign bodies. It can lead to significant vision impairment if not promptly and properly managed, as it poses a risk of retinal detachment and intraocular infection (Sharma et al., 2018). Ingrowth of fibrovascular tissue through a posterior wound can cause serious PVR, further increasing the risk of retinal detachment. Given the complicated accessibility, surgical management of posterior choroidoscleral perforation poses significant challenges. In our case, we did not anticipate a posterior defect during surgery, as CT imaging had indicated that the foreign body was located intravitreally. Importantly, CT imaging can produce location discrepancies due to scattering artefacts. In this case, it was not feasible to remove the foreign body from the orbit. Given that intraorbital metallic foreign bodies are typically well tolerated (Ho et al., 2004), we chose to leave it in place, which had not led to any complications at the long-term follow-up visit. Conventionally, we close scleral perforations using 5-0 or 6-0 vicryl sutures with an amnion, Tenon's or scleral patch externally. However, since the perforation in this case was located very posteriorly, this approach was not feasible, as extensive manipulation of the eye carried a significant risk of intraoperative bleeding and further ocular damage. Given the large size of the defect, conservative management was also not a viable option due to the high likelihood of hypotonia and eventual phthisis. To address the extensive posterior defect, we utilized an amniotic membrane as an internal plug, which was readily available. To our knowledge, this is the first successful attempt using an internal approach with amniotic membrane alone, without a scleral graft, to treat a posterior perforation. Previous reports have demonstrated the use of amniotic membrane in conjunction with donor or autologous scleral grafts and fibrin glue (Celo et al., 2023; Rodríguez-Ares et al., 1999). In our experience, two large sheets of amniotic membrane were adequate to effectively close the large posterior defect internally. An added benefit of amniotic membrane is its ability to promote wound healing, alongside its anti-inflammatory and antimicrobial properties (Jirsova & Jones, 2017). We believe that the amniotic membrane does not fully resorb and remains in situ as a transparent plaster in the defect, which was observed at 1 month after placement (Figure 1d). In conclusion, the use of amniotic membranes for the internal closure of choroidoscleral perforations represents a promising and straightforward approach to preserve ocular integrity following trauma. Video S1.The procedure was commenced using an infusion line via the anterior chamber. Subsequently, trocars were placed and vitrectomy was performed to clear the vitreous haemorrhage. The internal limiting membrane was peeled and a limited chorioretinectomy was performed. The posterior perforation site was then inspected. An uncut amniotic membrane was inserted into the posterior defect, followed by placement of a second uncut amniotic membrane flat over the area. Air-fluid exchange was carried out and sclerotomy wounds were closed with 6-0 Vicryl sutures. At the end of the procedure, a 15% C3F8 gas tamponade was left in the eye. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.