The presence of retained intraocular metallic fragments after phacoemulsification is well documented.1,2 The fragments can arise from the phaco needle or from a second instrument. Small phaco needle fragments can be chipped off by vibration and wear against the irrigation sleeve, although this is rare with modern fabrication techniques.1–3 Fragments can be released from second instruments when they come in contact with the phaco tip, and metal fatigue can lead to complete fracture, usually at the tip, resulting in an intraocular foreign body.4
One third of cataract surgeons experience intraoperative fracture of the tip of the second instrument during their career.4 Visualization and removal of intraocular foreign bodies located in the anterior chamber can be achieved with intraoperative gonioscopy, and those located in the vitreous cavity can be removed by vitrectomy using posterior segment viewing systems. In these cases, removal is the preferred management.5,6 However, intraocular foreign bodies in the ciliary sulcus may be harder to remove due to difficulties with visualization. Sulcus intraocular foreign bodies can remain stationary, particularly if they are lodged in the ciliary processes. Furthermore, they tend to be inert, which is why some have argued against their removal (D.A. John, MD, et al., “Management of Intraocular Foreign Bodies,” EyeNet, September 2009, pages 31–32).7
We report a case of a broken chopper tip in the ciliary sulcus discovered after phacoemulsification. The broken tip initially appeared to be stable but ultimately dislodged into the anterior chamber, requiring removal.
A 66-year-old man had phacoemulsification and intraocular lens implantation in the left eye. After phacoemulsification, the tip of the Rosen chopper was missing. It was not visualized in the eye. The surgery was completed, and plain films followed by computed tomography (CT) scans of the orbits were taken to rule out a retained intraocular foreign body. The images revealed a 2.0 mm metallic foreign body located temporally in the ciliary sulcus (Figure 1). The patient was taken back to the operating room the same day; however, the fragment could not be retrieved.
The postoperative course was uneventful, and the patient achieved a corrected distance visual acuity of 20/25 with normal intraocular pressures and a quiet anterior chamber. Two months postoperatively, the chopper tip could still not be visualized on examination; however, ultrasound biomicroscopy (UBM) scans confirmed that the fragment remained stationary (Figure 2). Thus, a reasonable argument could be made to leave it in place. However, the patient was referred to a center equipped with endoscopic visualization equipment for additional evaluation and possible removal of the fragment from the ciliary sulcus. By 8 months after the initial cataract surgery, the fragment had migrated into the anterior chamber and was sitting in the inferior angle (Figure 3). The patient was prescribed pilocarpine and advised to sleep with his head elevated to prevent posterior migration of the fragment.
Intraoperatively, the chopper tip was visualized in the inferior angle using an Osher surgical gonioscopy posterior pole lens (Ocular Instruments) (Video available at www.jcrsjournal.org). Intracameral acetylcholine chloride was instilled to further constrict the pupil and reduce the risk for posterior migration of the intraocular foreign body. Sodium hyaluronate 1.0% (Provisc) was injected to maintain the anterior chamber. The foreign body was removed under direct visualization using Ahmed micrograspers (MicroSurgical Technology) (Figures 4 and 5). The ophthalmic viscosurgical device was then removed using a dry aspiration technique. The patient did well postoperatively, maintaining 20/25 visual acuity.
Studies in which metallic intraocular foreign bodies after cataract surgery were not removed show that they are well tolerated.1,2,7 However, the studies were not designed to specifically evaluate the long-term effects of the foreign bodies.
Loose intraocular foreign bodies can cause trauma to the corneal endothelium, angle structures, and even the posterior lens capsule intraoperatively if contact with a vibrating phacoemulsification needle pushes them posteriorly at high velocity. Stable retained metallic intraocular foreign bodies can cause chronic recalcitrant postoperative inflammation that can lead to cystoid macular edema and macular epiretinal membrane formation.8 Furthermore, there is a theoretical risk for siderosis bulbi caused by ionizable iron, which is present in some alloys used to fabricate second instruments. To evaluate this, we contacted Bausch & Lomb, Rhein-Tec, and American Surgical Instruments Corp. Bausch & Lomb reported trace amounts of iron in the steel/titanium alloy used to fabricate Rosen choppers (personal communication, R. Khanna, October 2009). Rhein Medical, Inc. (personal communication, J. Bee, October 2009) and American Surgical Instruments Corp. (personal communication, S. Ghotavadekar) reported no use of iron in the fabrication of their choppers. Siderosis bulbi can result chronic iron deposition in corneal stroma, iris, lens, and retina, leading to iris heterochromia, uveitis, secondary glaucoma, and retinal degeneration.
Computed tomography and UBM can be helpful in localizing intraocular foreign bodies that cannot be visualized clinically, as is the case with intraocular foreign bodies in the ciliary sulcus. Although intraocular foreign bodies in this location can remain stable, our case shows that even those that appear stable may dislodge in the late postoperative course. A loose intraocular foreign body can be asymptomatic at first but then traumatize various intraocular structures including, but not limited to, the corneal endothelium. We therefore recommend strong consideration of removal of metallic intraocular foreign bodies after cataract surgery.
Intraoperative gonioscopy and a micrograsping forceps enabled removal of the retained intraocular foreign body in the angle in this case. Should the intraocular foreign body have remained or moved into the ciliary sulcus, endoscopic-guided removal would be our preferred approach.
As a general rule, if the intraocular foreign body is easily accessible, removal is the best option. When the intraocular foreign body is difficult to visualize or access, despite apparent stability and inertness, we recommend strong consideration of removal. In some cases, this may necessitate referral to a vitreoretinal surgeon or a center equipped with endoscopic equipment.
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