INTRAOCULAR FOREIGN BODIES

INTRAOCULAR FOREIGN BODIES

Risk factors of visual loss: 1)Mechanism of injury 2)Size of the IOFB 3) Location of the IOFB 4)Endophthalmitis 5) PVR

25% of patients who sustained IOFB injury had final visual acuities of less than 20/200

PREOPERATIVE PREPARATION

History Ophthalmic examination Appropriate neuroimaging Consideration of antimicrobials

HISTORY: Accurate history-taking with attention to

the mechanism of injury (e.g. knife wound, explosive device, shotgun blast)

OPHTHALMIC EXAMINATION: Visual Acuity Endophthalmitis Globe rupture Retinal detachment An afferent pupillary defect

NEUROIMAGING: CT SCAN B-scan ultrasonography Ultrasound biomicroscopy (UBM) X Ray MRI

PREOPERATIVE SYSTEMIC ANTIBIOTICS:

Gram-positive organisms - coagulase-negative staphylococci - streptococci Gram-negative Fungal organisms

Third-generation fluoroquinolone: - levofloxacin Fourth-generation fluoroquinolone: - moxifloxacin

OPERATIVE CONSIDERATIONS

Timing of surgery (delayed versus immediate)

The route and instruments used for IOFB extraction

The role of intraoperative antibiotics

Delayed versus immediate intraocular foreign body removal

The presence or absence of clinical endophthalmitis

The stability of the patient for an extended surgical procedure

The availability of well trained operating room personnel

Advantages to immediate IOFB removal: 1) A decrease in the risk of endophthalmitis 2) A decrease in the rate of PVR 3) A single procedure under anesthesia

with its attendant risks

Advantages to delayed IOFB removal: 1) Better integrity of the repaired laceration 2)Less severe anterior segment pathology

(e.G. Resolution of corneal edema, hyphema resorption)

3)The presence of a PVD 4)Resorption of some V.H

ROUTE OF IOFB EXTRACTION

Strategies for IOFB extraction at this point depend on the nature of the material and its size

intraocular magnet: Small (<1.0 mm) metallic ferromagnetic IOFBs

basket forceps: Medium-sized IOFBs (1.0–3.0 mm) Metallic Stone concrete

diamond-coated forceps: Larger IOFBs (3.0–5.0 mm) Glass fragments

POSTOPERATIVE CARE: endophthalmitis (5-7%) RD (6.3 to 36.8%) PVR ( 6.7 to 46% )

Inert foreign body: - Stone - Glass - Porcelain - Plastic - cilia

Reactive foreign body: - Zinc - Aluminum - Copper - iron

Zinc and aluminum: - Minimal inflammation - Encapsulated

SIDEROSIS Risk factors: - Content - Location

RPE cells Pars plana TM Corneal epithelium Lens epithelium Pupillary constrictor muscle

CLINICAL SIGNS: Nyctalopia ↓ VL Mydriasis Iris heterochromia Brown deposit beneath the ant. Lens

capsule cataract

Peripheral retinal pigmentation diffuse retinal pigmentation Optic disc atrophy POAG

Abnormal ERG Increased a-Wave and normal b-Wave Diminishing b-Wave

CHALCOSIS

IOFBs containing over 95% copper :

severe , rapidly progressive purulent endoph-thamitis

IOFBs containing between 85 and 95% copper:

visual loss→ deposition of copper in 1) descment΄s membrane 2) ant. Lens capsule 3) vit. Cavity 4)ILM

K-F ring Ant. Subcapsular sunflower cataract Greenish discoloration of the vitreous Greenish refractile deposits in the ILM

IOFBs containing less than 85 % copper usually produce no detectable change

CONCLUSIONS: IOFBs are common in open globe injuries

Clinicians must remain suspicious of a possible IOFB in any traumatized eye

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