Magnetic Intraocular Foreign Bodies Research Articles

Magnetized forceps for intraocular foreign body removal: which one is suitable?

Magnetic intraocular foreign bodies can be removed with magnetized disposable forceps. Aim of this study is to compare the forceps magnetizability of different size, form and manufacturer. The forceps were magnetized using an established procedure. The inducible magnetic flux density was measured at the tip of the forceps. The mass that can be lifted with the magnetized forceps was then tested using steel balls in BSS solution. The weight of the metal parts of the forceps was measured. The magnetic flux density that could be induced, the weight of the steel balls that could be lifted and the mass of stainless steel used in the forceps were as follows: Alcon end-grasping 23G: 7.12 mT, 87.43mg, 1191mg; Alcon end-grasping 25G: 6.43 mT, 87.43mg, 1189mg; Alcon serrated: 4.39 mT, 63.78mg, 1284mg; Alcon serrated 23G: 3.62 mT, 13.74mg, 1200mg; Alcon serrated 25G: 2.4 mT, 13.74mg, 1195mg; DORC end-grasping 23G: 5.52 mT, 32.54mg, 153mg; Synergetics end-grasping 23G: 4.35 mT, 16.37mg, 193mg; Vitreq BV end-grasping 23G: 2.65 mT, none, 88mg. The magnetizability of a disposable microforceps seems to depend on the mass of steel at the tip of the forceps. The structure of the iron lattice could have an even greater influence. Not every disposable forceps can be sufficiently magnetized for this technique.

Intraocular Foreign Bodies: Clinical Characteristics and Prognostic Factors Influencing Visual Outcome and Globe Survival in 373 Eyes.

Aim To describe epidemiologic and clinical characteristics and prognostic factors influencing visual outcome after intraocular foreign bodies (IOFBs) injury. Methods Medical records of 370 patients (373 eyes) with IOFBs were reviewed to identify the factors influencing visual acuity by univariate and multivariate analyses. Results The majority of patients (97.0%) were men, with a mean age of 38.1 years. The most common cause of ocular injury was hammering (52.6%); magnetic IOFBs occurred in 84.7% of these cases. Factors associated with poor visual outcome (defined as <1.3 logMAR) included the following: age ≥50 years (P=0.046); worse presenting visual acuity (P < 0.001); complications of retinal breaks (P=0.006) and endophthalmitis (P=0.032); vitrectomy (P=0.035); and intraocular C3F8 gas tamponade (P=0.038). Excellent visual outcome (defined as ≥0.5 logMAR) was associated with age <50 years (P=0.003); better presenting visual acuity (PVA) (P < 0.001); wound length <4 mm (P=0.005); absence of vitreous hemorrhage (P=0.026) and retinal breaks (P < 0.001); nonvitrectomy surgery (P=0.043); and use of balanced saline (P=0.029). Conclusions Multiple prognostic factors were identified that may predict visual outcome and globe survival after IOFBs injury. Age, initial presenting visual acuity, wound length, complications (vitreous hemorrhage, retinal breaks, and endophthalmitis), surgical approach, and intraocular tamponade were significant predictors of visual outcome.

Investigation on the surgical approaches of magnetic intraocular foreign body extraction with 25 G pars plana vitrectomy

Objective To investigate the efficacy of different surgical approaches of magnetic intraocular foreign body extraction with 25G high-speed vitrectomy (25G HS-PPV). Methods Clinical data of 25 eyes of 25 patients were retrospectively analyzed. They had undergone extraction of magnetic intraocular foreign body with 25G HS-PPV from January 2012 to June 2013.Each patient was followed up for a period of 6 to 24 months, and the follow up period was 6 months or more after silicone oil removal for patients with silicone oil tamponade. Preoperative visual acuity, postoperative uncorrected visual acuity, postoperative best corrected visual acuity, intraocular pressure (IOP) and complication were observed. Results The magnetic intraocular foreign bodies were successfully extracted in all patients. Postoperative visual acuity maintained the same or improved compared with preoperative visual acuity.No iatrogenic complication occurred. Conclusion Choosing proper surgical approach and technique in 25G high-speed pars plana vitrectomy, magnetic intraocular foreign body could be successfully extracted with less iatrogenic complications. It is a microinvasive, safe and efficient method for magnetic intraocular foreign body extraction. Key words: Foreign body, intraocular; Vitrectomy, 25 gauge, high-speed, microinvasive

A safe method for removal of posterior segment magnetic intraocular foreign bodies

PurposeThe aim of the study was to evaluate the efficacy of our technique in achieving safe and atraumatic removal of posterior segment magnetic intraocular foreign bodies (IOFBs).Patients and methodsA prospective study was carried out at the Ophthalmology Department, Zagazig University Hospitals (Zagazig, Egypt). The study included 22 eyes of 22 patients with posterior segment magnetic IOFBs. Eight patients had already undergone primary surgical repair before. Traumatic cataract was treated using conventional surgical techniques. Our technique of IOFB removal involved pars plana vitrectomy; IOFB is then grasped using basket forceps and while the IOFB is removed through the sclerotomy an external earth magnet is used to prevent its slippage from the forceps and falling down onto the retina or optic disc.ResultsIn the 22 patients, the IOFB did not fall down into the vitreous cavity. In eight of the 22 patients, the IOFB had slipped from the basket forceps during its removal through the sclerotomy, but it was kept at the sclerotomy site by the effect of the magnet. We had to enlarge the sclerotomy in six of these patients. The IOFB was then regrasped by the forceps and safely removed.ConclusionOur technique is very effective in achieving safe and atraumatic removal of posterior segment magnetic IOFBs.

Innovative use of a magnetized pick for removal of an intraocular foreign body with 25-gauge transconjunctival sutureless vitrectomy.

Since being introduced in 2002, 25-gauge transconjunctival sutureless vitrectomy techniques continue to gain popularity among vitreoretinal surgeons and are being used in the management of increasingly complex surgical patients. In this report, we report a patient in whom a magnetized 25-gauge intraocular pick was used to facilitate removal of a metallic intraocular foreign body with 25-gauge transconjunctival sutureless vitrectomy without enlarging a sclerotomy wound. The magnetized 25-gauge intraocular pick allowed for removal of the intraocular foreign body through a posterior capsulorhexis and a standard cataract wound. "In the bag" placement of the posterior chamber intraocular lens resulted in a perfectly reconstructed pseudophakic anterior segment. The authors suggest that a magnetized 25-gauge pick may be a useful adjunct in the management of selected patients with a magnetic intraocular foreign body.

A study on the ways of treatment of magnetic intraocular foreign bodies located on retina surface with clear media

目的 探讨屈光间质透明的视网膜表面磁性异物的摘出方法.方法对异物周围视网膜先进行激光光凝,光凝后1～3天视网膜水肿减轻后做睫状体平坦部切口用磁铁吸出眼内异物,部分病例眼内注入膨胀气体以顶压异物着床处视网膜.结果23例(23眼)均一次将异物摘出.术后视网膜在位20眼(86.96%),发生视网膜脱离3眼(13.04%),经玻璃体视网膜手术后视网膜复位.术后视力不变或提高18眼(78.26%),下降2行以上5眼(21.74%).结论对于屈光间质透明的视网膜表面磁性异物先行激光光凝,再经睫状体平坦部切口摘出异物是较好的治疗方法之一。

Management of posterior segment foreign bodies and long-term results.

The management of 158 posterior segment intraocular foreign bodies (IOFB) was retrospectively analyzed: transscleral magnet extraction via the pars plana was used for 40 magnetic IOFB, transscleral extraction via the IOFB bed for 35 magnetic and 4 non-magnetic IOFB, pars plana vitrectomy (PPV) for 44 magnetic and 32 non-magnetic IOFB, and open-sky vitrectomy for 3 non-magnetic IOFB. Final visual acuity of 0.02 and better was achieved in 104 out of 119 magnetic IOFB (87%) and 24 out of 39 non-magnetic IOFB (62%), and final visual acuity 0.05 and better in 79 magnetic IOFB (66%) and 17 non-magnetic IOFB (44%). Transscleral extraction via the IOFB bed under ophthalmoscopic control and IOFB removal by PPV proved to be the operations of choice for an increasing number of IOFB. For magnetic IOFB, these techniques yielded better final functional results than transscleral magnet extraction via the pars plana. Final visual acuity did not depend on the interval between injury and IOFB removal, and with regard to the risk of endophthalmitis, IOFB need not be considered an absolute indication for immediate intervention. IOFB size up to 5 mm2 and initial visual acuity of 0.5 and better were significant positive factors for both magnetic and non-magnetic IOFB.

CONTROVERSIES IN THE MANAGEMENT OF POSTERIOR SEGMENT OCULAR TRAUMA

Despite steady advances in surgical instrumentation and technique, ocular trauma continues to be a leading cause of visual loss in the United States. Almost half of the patients with posterior penetrating injuries are left with severe visual impairment. Controversy persists over the optimal management of the injured eye, including the proper use of prophylactic antibiotics, prophylactic cryopexy, and prophylactic scleral buckling. The role and timing of vitrectomy surgery in severe ocular trauma also remain topics of considerable debate, as does the role of vitrectomy in the management of magnetic intraocular foreign bodies. Each of these issues is discussed, with particular emphasis on conflicting views presented in the relevant literature.

A new retractable micromagnet for intraocular foreign body removal.

We have developed a new, self-contained, small-gauge, permanent, rare-earth magnet for use in conjunction with pars plana vitrectomy in the treatment of selected magnetic intraocular foreign bodies. This magnet allows controlled grasping and releasing of the foreign body by the surgeon, thus increasing surgical control in magnetic intraocular foreign body removal.

Magnetized Instrument Removal of Foreign Body Through the Pars Plana

SUMMARY We describe a new, safe technique for removing posteriorly located magnetic intraocular foreign bodies. The technique consists of magnetizing an intraocular instrument by placing an electromagnet against the extraocular portion. After a vitrectomy, the magnetized instrument lifts the foreign body anteriorly in a controlled fashion, and removes the object through the pars plana. Its use is illustrated in two case reports.

Removal of nonmagnetic and magnetic intraocular foreign bodies with constant visualization.

A method of removing intraocular foreign bodies, magnetic or nonmagnetic, that are invisible to ordinary viewing procedures is presented. Intraocular foreign bodies are associated with media which is opaque from the blood and debris of trauma. Early removal of nonmagnetic particles usually is impossible, while localization of magnetic foreign bodies changes with movement of the patient or the eyeball, causing wrong magnet application and additional intraocular damage. All of this is resolved by placing the inside of the eye on a "television screen" where the foreign body and the forceps are seen constantly in a two dimensional aspect, allowing removal of the object with minimal trauma.

Contactless detection of magnetic and nonmagnetic intraocular foreign bodies

Contactless detection of magnetic and nonmagnetic intraocular foreign bodies

Practical characteristics of ophthalmic magnets.

Failure to extract a magnetic intraocular foreign body is often due to a misunderstanding of the pulling force of a magnet, which is not its field strength in gauss, but rather the product of the field times the field gradient. New equipment allows this pulling force to be plotted and the strength of different pole-tip shapes to be determined.

Magnetic vs nonmagnetic intraocular foreign bodies. An ultrasonic determination.

An ultrasonic method for preoperative differentiation of the nonmagnetic from the magnetic intraocular foreign body has been described. This method is useful when the intraocular object cannot be seen ophthalmoscopically.

The Posterior Approach for the Removal of Magnetic Intraocular Foreign Bodies

The Posterior Approach for the Removal of Magnetic Intraocular Foreign Bodies

Concerning Magnetic Intraocular Foreign Bodies and their Removal

The author describes the operative procedures he has found most effective in thirty years' experience. The anterior route is preferred as it involves no scleral incision which may lead to separation of the retina. From the Massachusett's Eye and Ear Infirmary. Read before the New England Ophthalmological Society, November 17, 1931. The author describes the operative procedures he has found most effective in thirty years' experience. The anterior route is preferred as it involves no scleral incision which may lead to separation of the retina. From the Massachusett's Eye and Ear Infirmary. Read before the New England Ophthalmological Society, November 17, 1931.

UNRECOGNIZED MAGNETIC INTRA-OCULAR FOREIGN BODIES AND THEIR LEGAL ASPECTS

Two recent legal decisions relative to unrecognized magnetic intraocular foreign bodies clearly define the degree to which improvement in medical knowledge and skill creates a corresponding responsibility and legal liability. In the case of Kosal v. Boyce, 201 N. W. 757, decided by the Supreme Court of Wisconsin in 1925,1the plaintiff-patient was struck in the eye by part of a steel spring. The defendant-physician, who specialized in diseases of the eye, ear, nose and throat, treated the injury. According to the record, this physician examined the eye by the use of the ophthalmoscope, direct illumination and oblique focal rays, but failed to discover any foreign body in the eye. Several months later another physician, with the aid of roentgenograms, discovered a piece of steel in the eye. The plaintiff brought suit, and the lower court awarded him damages to the extent of $2,000. The Supreme Court of