Intra ocular foreign body

1. Intra ocular foreign body • Dr alisalehi • Vitroretinal fellowship

2. Epidemiology • According to the United States Eye Injury Registry (USEIR), the surveillance arm of the American Society of Ocular Trauma (ASOT), the frequency in the United States is 16%.

3. Foreign bodies • Detection • Indirect is best method • CT next best, including plastic and glass • MRI better for organic • US supplements CT and gives info on retina • Plain films if no CT

4. The most common cause is hammering; the incidence over time shows a decrease at the workplace and an increase in the home.

5. International • The frequency greatly varies (up to 41%) worldwide, depending upon the population surveyed

6. Mortality/Morbidity • Most IOFBs cause internal damage, and most will come to rest in the posterior segment. Commonly injured structures include the cornea, the lens, and the retina

7. Sex • According to the USEIR, 93% of patients with IOFBs are male.

8. Physical • A complete examination of both eyes is necessary, including the visual acuity. • A corneal entry wound and a hole in the iris provide trajectory information. • The slit lamp is extremely useful in detailing all anterior segment pathologies.

9. The indirect ophthalmoscope through a dilated pupil may allow direct visualization of the IOFB, which gives the most useful information for the surgeon. • Gonioscopy and scleral depression are not recommended unless the entry wound has been surgically closed.

10. Causes • Hammeringand using power tools are the most important causes. Protective eyewear, if appropriate (of polycarbonate), prevents virtually all injuries

11. Imaging Studies • CT scans are the imaging study of choice for IOFBlocalization. • A consultation with the CT technician is helpful in selecting the optimal section so as to reduce the risk of a false-negative result.

12. Plain x-ray is useful if a metallic IOFB is present and a CT scan is unavailable. • MRI is generally not recommended for metallic IOFBs.

13. Ultrasound is a useful tool in localizing IOFBs, and its careful use is possible even if the globe is still open; alternatively, intraoperative use after wound closure can be attempted.

14. Other Tests • Electroretinographyis useful if a chronic IOFB is found and siderosis threatens or is present.

16. Medical Care • Systemicand topical antibiotic therapy may be started prior to the surgical intervention. • Topical corticosteroids are also important to minimize the inflammation. • A tetanus booster may also be appropriate.

17. Surgical Care • The timing of intervention is primarily determined by whether the risk of endophthalmitis is high. If the risk is high, immediate (emergency) surgery, for intraocular foreign body (IOFB) removal as well as vitrectomy if the IOFB is in the posterior segment, is indicated.

18. In most other cases, the surgeon has the option of deferring intervention for a few days to reduce the risk of intraoperative hemorrhage.

19. The wound, however, should be closed as soon as possible. • A study by Zhang et al examined 1421 eyes in 15 hospitals in China over 5 years and concluded that closing the primary wound within 24 hours, whether by repair or independent self-sealing, reduces the endophthalmitis risk.

20. If endophthalmitis occurs, it is present at the time of patient presentation in over 90% of the cases.

21. IOFBs in the anterior chamber are typically removed through a paracentesis (not through the original wound) performed at 90-180° from where the IOFB is located.

22. Viscoelastics should be used to reduce the risk of iatrogenic damage to the corneal endothelium and the lens.

23. An intralenticular IOFB does not necessarily cause cataract. • Unless there is a risk of siderosis or the loss to follow-up is high, the IOFB and the lens may be left in situ.

24. Otherwise, usually, the IOFB is extracted first, the lens is extracted second, and an intraocular lens (IOL) is implanted simultaneously.

25. The posterior hyaloid should always be removed, and any deep impact should be prophylactically treated. For the actual removal, the best tool to extract a ferrous A posterior segment IOFB requires a vitrectomy, unless the tissue damage is minimal. IOFB is a strong intraocular magnet. For nonmagnetic IOFBs, a proper forceps may be used.

26. External electromagnets should not be used since they do not allow controlled extraction. • Rarely, a scleral cut-down is used.

27. In early clinical tests, this procedure has proven to be very effective in the prevention of the development of both proliferative vitreoretinopathy(PVR) and radiating retinal folds

28. Medication Summary • The goal of pharmacotherapy is to reduce morbidity and to prevent complications, such as posterior synechia(pupillary dilation), inflammation (corticosteroids), and intraocular pressure (IOP) elevation.

29. Antibiotics • For use in every case (systemic and topical); intravitreal usually only if infection is present or the case is high risk. • Vancomycin(Vancocin, Vancoled, Lyphocin)

30. Ceftazidime (Ceptaz, Fortaz, Tazicef, Tazidime) First-line choice for intravitreal gram-negative coverage. Third-generation cephalosporin with broad-spectrum, gram-negative activity; lower efficacy against gram-positive organisms.

31. Their mechanism of action may involve an alteration of RNA and DNA metabolism or an intracellular accumulation of peroxide that is toxic to the fungal cell.

32. Amphotericin B (Amphocin, Fungizone) • Produced by a strain of Streptomycesnodosus; can be fungistatic or fungicidal. Binds to sterols, such as ergosterol, in the fungal cell membrane, causing intracellular components to leak with subsequent fungal cell death.

33. Siderosisbulbi • is a disease caused by a retained intraocular iron-containing foreign body (IOFB). • A history of ocular trauma combined with heterochromia,mydriasis, pigmentation of the anterior chamber structures and a reduced electroretinographicresponse all provide an inkling of the diagnosis.

34. Affected eyes can often present with a severe increase in intraocular pressure (IOP) (Talamo et al. 1985). • A precise radiological and/or echographic localization of the IOFB, ideally supported by histological analysis of a biological sample, are vital to the confirmation of the disease. All epithelial cells defected.

35. Siderosisbulbi • IRON tends to deposit in epithelial tissues • Iris - heterochromia, mid-dilated, poorly-reactive pupil • Lens - brown dots and cortical yellowing • Retina -pigmentary degeneration + vesseles sclerosis • ERG - flat within 100 days • Used to monitor

36. Chalcosis • <85% pure - chalcosis, • >85% - sterile endophthalmitis (acute) • Copper deposits in basement membranes • cornea - Kayser-Fleischer ring • Iris - sluggish, greenish hue • Lens capsule - sunflower cataract • Vireousopacification • ERG like siderosis • Improves if Cu removed

39. Visual outcome and complications after removal of posterior segment intraocular foreign bodies through pars plana approach • RESULTS: • Among the 50 patients, there were 45 (90%) males and 5 (10%) females. Average age of the patients was 31.52 +9.52 (ranging from 20 to 50) years. The pre-operatively visual acuity finger counting to perception of light was 78% cases. The best corrected final visual acuity was 6/6 in 1 (2%) patient, 6/9 in 5 (10%) patients, 6/12 in 5 (10%) patients,, • 6/18 in 3 (6%) patients, 6/24 and 6/36 in 4 (8%) patients each, 6/60 in 4 (8%) patients, finger counting in 8 (16%) patients, hand movement in 4 (8%) patients, projection of light in 9 (18%) patients and no projection of light in 3 (6%) patients. The postoperative complications were corneal opacity in 8 (16%) patients

40. anterior chamber inflammatory reaction in 6 (12%) patients, increased intraocular pressure in 1 (2%) patient, silicone oil in anterior chamber in 1 (2%) patient, macular scar in 7 (14%) patients, cystoid macular edema in 1 (2%) patient, endophthalmitis in 4 (8%) patients, retinal detachment in 11 (22%) patients and phthisis bulbi in 3 (6%) patients.

41. CONCLUSION: • Acceptable visual results were achieved after the removal of posterior segment intraocular foreign bodies by vitrectomy. However, multiple complications can be encountered which require meticulate postoperative care.

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