Choroidal neovascularization secondary to ocular penetration during retrobulbar anesthesia and its treatment.

Retrobulbar anesthesia is still used before ocular surgery; however, it has various complications including ocular penetration. The penetration/perforation of the globe can cause complications such as endophthalmitis, retinal detachment, and scotoma. Choroidal neovascularization (CNV) is rarely seen, following choroidal rupture in penetrating eye injuries. Here, we present a patient who underwent a pars plana vitrectomy for vitreous hemorrhage secondary to ocular penetration during a retrobulbar injection for cataract surgery. This patient later developed CNV at the penetration site during follow-up. Physicians should remember that CNV can occur as an unusual late complication of ocular penetration during retrobulbar anesthesia.

Introduction

The retrobulbar anesthesia is still important in providing local anesthesia during eye surgery despite the increased use of peribulbar, subtenon, and topical anesthesia. Complications of this procedure include local and systemic complications such as retrobulbar hemorrhage, retinal detachment, macular toxicity, endophthalmitis, globe perforation/penetration, globe rupture, and central nervous system complications.[123] Ocular penetration can develop as a rare complication.[45] This complication can be noticed during the procedure or afterward. When scleral penetration or perforation develops, the immediate control of intraocular pressure and consultation with a vitreoretinal surgeon are required. In this report, we present a patient who had undergo a pars plana vitrectomy (PPV) for vitreous hemorrhage secondary to ocular penetration during a retrobulbar injection for cataract surgery. This patient ultimately developed a choroidal neovascularization (CNV) at the penetration site during the follow-up period. Importantly, a CNV can occur as unusual late complication of ocular penetration during retrobulbar anesthesia.

Case Report

A 74-year-old male patient was referred to our clinic with the diagnosis of globe penetration during retrobulbar anesthesia (lidocaine hydrochloride 20 mg/ml) for phacoemulsification surgery on the left eye. The physician completed the procedure, noticed a loss of the red reflex, and suspected globe penetration. On examination, the best-corrected visual acuity (BCVA) was 20/25 in the right eye using Snellen lines and hand movements in the left eye. Intraocular pressures were normal in both eyes. The right anterior segment and fundus were normal. Anterior segment examination revealed a clear cornea and centralized intraocular lens in the left eye. The left fundus could not be seen due to the dense vitreous hemorrhage on posterior segment examination. B-scan ultrasound revealed that the left retina and choroid were attached. The left eye axial length was 22.10 mm. An emergency PPV was performed and an incomplete posterior vitreous detachment was noticed. A small, round retinal hole (the penetration site) approximately two disc diameters inferotemporal to the optic disc was observed, and endophotocoagulation was applied; silicon oil was then injected into the eye. In the early period, after this procedure, the patient's BCVA (Snellen) was 20/200, which decreased to counting fingers 2 months postoperatively. A subretinal hemorrhage was seen at the penetration site on fundus examination, and CNV development was assumed [Figure 1]. Optical coherence tomography revealed pigment epithelial detachment, subretinal fluid, and fibrosis in the left eye, consistent with CNV [Figure 2]. Fundus fluorescein angiography revealed an occult CNV and fibrosis in the juxtafoveal area [Figure 3]. According to the patient's first doctor, before cataract surgery, the left fundus examination was normal. Intravitreal ranibizumab (0.5 mg; Lucentis®, Novartis) was administered as three monthly injections. The first dose was applied into the silicone oil-filled eye. The silicon oil was removed at the postoperative 3rd month. The CNV had regressed at the 6-month follow-up after the injections, but the final visual acuity in the left eye remained at the level of counting fingers at 1 m due to the fibrovascular subretinal scar development [Figure 4].

Figure 1

Central fibrosis and subretinal hemorrhage in the area consistent with the penetration site, which was paracentral to the macula, following pars plana vitrectomy

Figure 2

Hyperfluorescent appearance consistent with classic choroidal neovascularization and fibrotic retraction is observed with fluorescein angiography

Figure 3

Choroidal neovascularization, subretinal fluid, and fibrosis are observed in the macula with optical coherence tomography

Figure 4

Fibrovascular subretinal scar are observed in the macula with optical coherence tomography at the 6th-month follow-up after the injections

Discussion

Retrobulbar anesthesia has a higher complication risk than other local ocular surgical anesthesia method but provides good akinesia.[5] The ocular penetration/perforation risk during retrobulbar and peribulbar injection varies between 1/1000 and 1/4000.[5] This risk during local anesthesia is increased by eye-related factors such as axial length >24.0 mm and posterior staphyloma.[46] In our case, high myopia and posterior staphyloma were absent. Ocular penetration can lead to subretinal bleeding, severe proliferative vitreoretinopathy, and retinal detachment in untreated cases.[34] In such cases, areas inferonasal and inferotemporal to the optic disc are usually reported as penetration sites, as in our case.[345] Visual results are usually unfavorable when retinal detachment develops with a vitreous hemorrhage.

Clinically, scleral perforation/penetration can present with severe pain at the injection site, intraocular bleeding, restlessness, visual loss, loss of the red reflex, and increase or decrease in intraocular pressure.[4] PPV is recommended if the vitreous hemorrhage does not resolve and retinal detachment develops. Wadood et al.[4] emphasized that early PPVs may provide better visual results. We performed an early PPV before retinal detachment development.

The risk factors responsible for CNV development, following choroidal rupture, are controversial. Advanced age, macular rupture, and a larger rupture area were risk factors for CNV development in one study.[7] The penetration site in our case was in the macula, supporting its role as a risky area for CNV development.[67] There are a limited number of articles on CNV development secondary to choroidal ruptures occurring due to open eye injuries.[28] Observation, photocoagulation, photodynamic treatment, intravitreal anti-vascular endothelial growth factor (anti-VEGF) administration, and surgical excision are possible treatment options for CNVs due to traumatic choroidal ruptures.[278] There is no consensus on intravitreal anti-VEGF dosages or number of doses for CNV treatment in vitrectomized or silicone oil-filled eyes.[28] Furthermore, although a previous study reported the pharmacokinetics of bevacizumab in silico ne oil-filled eyes may display a lower bioavailability,[9] there is no study on ranibizumab in this regard. We used a standard dose (0.5 mg per 0.05 mL) of intravitreal ranibizumab for treating CNV. While the CNV of our case became inactive with three doses of intravitreal ranibizumab, the visual acuity remained at severely diminished levels.

We have presented a rare case that underwent PPV for scleral penetration and vitreous hemorrhage that developed during retrobulbar anesthesia and was followed by CNV, which was treated with three doses of intravitreal anti-VEGF. It is also possible to use peribulbar anesthesia as it has been reported to have the same effectiveness as retrobulbar anesthesia when used with hyaluronidase which increases the tissue diffusion of the local anesthetic.[10] Patients should be informed before surgery of possible local anesthesia complications, including those rarely seen. Follow-up examinations of cases developing scleral penetration/perforation are important in terms of the secondary complications that may develop.

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