Late Posterior Migration of Glass Intraocular Foreign Bodies FREE

The treatment of intraocular foreign bodies (IOFBs) in the previtrectomyera was largely dependent on the source and composition of the material, associatedocular pathologic features, and intraocular location. With modern vitreoretinalsurgical techniques, however, most glass IOFBs are removed despite their inertnature. Occasionally, the surgical complexity involved in their extractionmust be weighed against the risks of leaving them in place. We describe 3patients with retained glass IOFBs in which initially stable or encapsulatedglass IOFBs subsequently migrated and induced further complications or visualsymptoms. There are rare reports of glass IOFBs located initially in the posteriorsegment, migrating anteriorly, and producing additional anterior segment decompensation,such as illustrated in case 3 below. However, cases 1 and 2 are most unusual,as late migration caused additional retinal pathologic conditions.

We followed up 3 patients from 2 institutions with retained glass IOFBsfor more than 6 months. The mechanism of injury, visual acuity, findings fromthe clinical examination, and fundus appearance were documented. Late migrationnecessitated surgical intervention in all 3 patients, although 1 patient refusedsurgery because of special circumstances.

A 23-year-old man was struck with a glass beer bottle during an altercationand sustained a penetrating open globe injury with multiple glass IOFBs inthe anterior and posterior segments of the left eye (Figure 1). The wound involved 7 mm of the cornea and an additional22 mm on the scleral surface. All anterior segment glass IOFBs were removed(the largest measuring 7 × 6 × 3 mm) and the wound was repaired.One additional fragment with largest dimension measuring approximately 1 cmremained on the inferior equatorial retinal surface. Owing to the risk ofadditional retinal injury with further glass IOFB manipulation, removal wasnot performed at the initial surgery.

Postoperatively, the glass IOFB became partially encapsulated and remainedimmobile on the inferior retinal surface. Retinal examination 3 months afterinjury revealed an immobile glass IOFB with some overlying gliosis (Figure 2). The patient obtained a visualacuity of 20/50 OS 10 months after the initial injury.

Twelve months after injury, the patient noted that, "I can see the glassmoving." Visual acuity was 20/60 OS. Ophthalmic examination revealed a mobileglass IOFB with a small underlying retinal laceration, moderate (3+) pigmentcells in the anterior vitreous, and numerous small preretinal opacities (Figure 3). Owing to the mobility of the glassfragment and the potential for further retinal damage, pars plana vitrectomy,pars plana lensectomy, and IOFB removal were performed (Figure 4). Three weeks after surgery, a new round retinal hole wasnoted in the region of the preretinal fibrosis. Argon green laser retinopexywas performed but 1 week later, 4 additional open holes were noted along witha large inferior retinal detachment and early proliferative vitreoretinopathy.The patient underwent pars plana vitrectomy, membrane peeling, further endolasertreatment, 16% perfluoropropane gas tamponade, and scleral buckling. Fiveweeks after this intervention, the patient's retina remained attached, althoughhe had anterior membranes and preretinal fibrosis. The patient was subsequentlylost to follow-up.

A 21-year-old man robbing a bank, leaped through a plateglass windowand sustained lacerations to his face and eye. Immediately after capture,ophthalmologic examination revealed a pars plana entry wound; a glass IOFB,estimated to be 4.5 × 1.5 × 1.5 mm, was found lodged on the surfaceof the peripheral retina of his right eye. The glass IOFB was not removedat the initial surgery because of poor posterior visualization and the riskof retinal injury during the glass IOFB manipulation. The anterior segmentwas not damaged. Other than vitreous hemorrhage, no additional pathologiccondition was found. The patient's visual acuity eventually returned to 20/20OD. Fundus examination of the peripheral retina revealed a large immobileglass IOFB with localized fibrosis around its base, where it was in appositionto the retina. The patient was sentenced to life in prison for the robberyand the killing of a guard, but was examined periodically in prison and theglass IOFB remained in place in its peripheral location. As no inflammationdeveloped and because the right eye was quiet and stable with 20/20 visualacuity, subsequent removal of the glass IOFB was not felt to be necessary.

On awakening in his cell 6 years after the crime, he noted double visionand beautiful "rainbows" in his right eye when he lay supine in his cell.He was examined in the prison and the glass IOFB had dislodged from its originallocation and was now resting on the fovea when the patient was in the supineposition (Figure 5). When sitting,the glass IOFB drifted inferiorly away from the macula and symptoms cleared.

Surgical removal of the glass IOFB through a pars plana vitrectomy wasrecommended and the risks of surgery were discussed. The inmate, however,insisted that if there were any complications whatsoever, he would see toit that his surgeon was killed. Further periodic follow-up was, therefore,offered under these unusual circumstances. The patient was seen again 6 monthslater with no change in his eye findings, but he was ultimately transferredto another high-security facility and was lost to follow-up.

A 21-year-old man who was a passenger involved in a motor vehicle collisionsustained a head injury with a severe scalp laceration and an open left globe.A glass IOFB lacerated the cornea and produced a cataract, necessitating cataractremoval and corneal wound repair. The vitreous was not removed, as the corneawas cloudy during the wound repair. Visual acuity 1 week after the procedurewas 20/400 OS from corneal edema. The fellow right eye was normal with uncorrected20/25 visual acuity.

On funduscopic examination, the retina was not injured, but a 4 ×4 × 3-mm rectangular piece of glass was present in the inferior vitreousjust posterior to the equator, as shown on computed tomography (Figure 6). It did not move with positioning and, after discussion,he decided to be examined periodically for possible fragment migration.

Visual acuity remained 20/400 OS, and the patient's condition was monitoredat monthly intervals for 6 months. However, almost 7 months after the injury,he was seen in the emergency department reporting pain and discomfort in theleft eye. The glass IOFB had migrated through the pupil into the anteriorchamber and was lodged inferiorly causing local corneal edema. Removal ofthe glass IOFB was performed through a keratotomy incision. The retina remainedunaffected, except for some localized fibrosis at the former site of the glassIOFB. A few weeks thereafter, the cornea was clear, and visual acuity witha contact lens improved to 20/25 OS.

Glass IOFBs can pose special challenges. They are often large relativeto the entry wound, and surgical removal can be challenging, particularlyif they are of a large cuboidal or irregular shape. Grasping the glass fragmentwith foreign body forceps is often difficult and sharp edges can cause retinalor lenticular injury during extrication. In some cases, the level of surgicalcomplexity required for extraction combined with their inert nature may dictatethat a glass IOFB be retained in the posterior segment.

One of the largest series of glass IOFBs is provided by Gopal et al,¹ in which they report on 51 eyes with glass IOFBs.In 8 eyes, glass pieces were left behind without any untoward events at anaverage of 31 months' follow-up. In none of these eyes was any late anterioror posterior segment complication encountered. The authors hypothesized thatpreretinal fibrosis encapsulates the glass IOFB and provides additional security.In this same study, Gopal et al encountered iatrogenic retinal breaks in 13eyes when attempts were made to remove the glass IOFB.

A review of the literature by Milkowski² revealsnumerous cases of retained glass IOFBs near the optic nerve, retina, vitreous,and lens where complications did not develop. This article also summarizesrare cases of migration of posterior IOFBs into the anterior chamber causingcataract, corneal edema, and iridocyclitis.² A1991 report by Saar et al³ describes theanterior migration of glass splinters from the vitreous to the anterior chambercausing corneal edema. They also stated in this article that the "migrationof intraocular glass is always from back forwards."^{3 (p189)} A similar case with anterior migration is presented herein ascase 3. However, late posterior segment migration as in cases 1 and 2, causingadditional retinal pathologic conditions or symptoms must be rare and, toour knowledge, have not been previously reported.

We describe 3 eyes with glass IOFBs that migrated after they were deemedstable with partial encapsulation or entrapment in the vitreous base. In 2cases, partially encapsulated glass IOFBs caused late posterior segment findingsincluding retinal laceration and obstruction of macular vision. Though thelate posterior migration of retained glass IOFB is considered rare, thesecases highlight the need for close follow-up in such cases. Early interventionwith glass IOFB removal must be weighed against the hazards of removal andthe necessity of close follow-up.

The authors have no relevant financial interest in this article.

This study was supported in part by funding from the American OphthalmologicalSociety–Herman Knapp Foundation, Cleveland, Ohio (Dr Ray).

We acknowledge the invaluable assistance of Magdalena Krzystolik, MD,in the preparation of the manuscript.

Corresponding author: John Loewenstein, MD, Retina Service, MassachusettsEye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School,243 Charles St, Boston, MA 02114 (e-mail: john_loewenstein@meei.harvard.edu).