Penetrating Ocular Trauma

Ocular Trauma, Penetrating Ocular Trauma, Eye Trauma, Ocular Injury

1. PENETRATING TRAUMA Dr. Om Patel

2. Ocular Trauma Preventable cause of blindness in all age groups Penetrating injuries 3 times m ore common in men 50% aged 15-34 years

3. Injury Closed globe Open globe Contusion Lamellar laceration Laceration Rupture Penetrating IOFB Perforating

4. Term Definition Remarks Eye wall Sclera and cornea Restricted to rigid ocular structure Closed globe Eyewall does not have full thickness wound Caused by partial- thickness sharp force (lamellar laceration), blunt force (contusion) and superficial foreign body Open globe Eyewall has a full thickness wound Cornea and /or sclera sustain a through and through injury BIRMINGHAM EYE TRAUMA TERMINOLOGY (BETT)

5. Term Definition Remarks Rupture Full thickness wound caused by a blunt object, due to raised intraocular pressure( inside – out) Eyewall gives way under blunt force at its weakest point, which may or may not be at the impact site Laceration Full thickness corneal and /or scleral wound caused by a sharp object (outside- in mechanism) The wound (globe opening) occurs at the site of impact. Penetrating injuries Single full thickness wound of the eyewall usually caused by a sharp object No exit wound has occurred.

6. Term Definition Remarks Intraocular FB The retained foreign object causes a single entrance wound Technically a penetrating injury, but grouped separately because of different clinical implications ( treatment,prognosis ) Perforating injury Two full thickness wounds (entrance and exit) of the eyewall usually caused by a sharp object or missile The two wounds are caused by the same agent Lamellar laceration Closed globe injury of eyewall or conjunctiva usually caused by a sharp object or blunt trauma; the wound occurs at the impact site Partial thickness defect of bulbar conjunctiva or eyewall

7. Term Definition Remarks Contusion Closed globe injury resulting from a blunt object, injury can occur at the site of impact or at a distant site of impact or at a distant site secondary to changes in globe configuration or momentary intraocular pressure elevation No full thickness eyewall injury

8. Ocular Trauma C lassification S ystem Unambiguous definition for each term Common international language of ocular trauma terminology : improving accuracy in both clinical practice and research Limited to mechanical injuries of the globe

9. Ocular Trauma Classification System Type: Open – Globe Closed - Globe A. Rupture A. Contusion B . Penetrating B. Lamellar laceration C . IOFB C. Superficial foreign body D . Perforating D. Mixed E . Mixed E. N/A

10. Ocular Trauma Classification System Grade (Visual Acuity) A.  6/12 B. < 6/12 to 6/60 C. < 6/60 to 1/60 D. < 1/60 to Light perception E. No Light Perception

11. Pupil A . Positive, RAPD in injured eye B . Negative, no RAPD in injured eye Zone I . Cornea and Limbus II . Limbus to 5mm Posterior into Sclera III . Posterior to 5mm from the Limbus 5mm from limbus

12. Penetrating Injury Single full thickness wound of the eyewall , usually caused by a sharp object No exit wound occurs

13. Modes of injury 1. Trauma by sharp and pointed instruments- Needles, knives, nails, arrows, pens, pencils, glass pieces etc. 2. Trauma by foreign bodies travelling at very high speed- bullet injuries, iron foreign bodies

14. Effects of penetrating injury Mechanical effects of the trauma Introduction of infection Post –traumatic iridocyclitis Sympathetic ophthalmitis Risk factors- Delay in primary repair Ruptured lens capsule Dirty wound

15. Evaluation Initial Evaluation Non Ocular injury kept in mind Vital signs BP Pulse Respiratory Rate Mental status , unconsciousness Any obvious bone or soft tissue injury

16. External Examination Scalp, face and periorbital soft tissue must be palpated for subcutaneous FB ,step deformities Ocular adnexa Lid laceration , lid periorbital edema, any obvious FB protruding Visual acuity Pupil Extraocular Motility

17. Ophthalmologic Evaluation Detailed description of mechanism and circumstances of injury Sharp/blunt object Size of object RTA , factory setting, playing, E xact time of injury Place of injury Prior ocular history (ophthalmic surgery/prior trauma) Pre injury vision Any ocular medication Examine the non involved eye

18. Slit Lamp Examination Conjunctiva Foreign Bodies Hemorrhagic Chemosis Conjunctival laceration Cornea Epithelial Defect Corneal Laceration (length, depth, width) Sclera Scleral laceration/ Rupture

19. Anterior Chamber Cells, fibrin, FB in AC Depth of AC Iris and Angle Iris prolapse/ plugging the wound Sphincter tear Iridodialysis Iridodonesis Cyclodialysis Crystalline Lens Phacodonesis Subluxation Dislocation Rupture of Anterior / Posterior Capsule Intralenticular FB

20. IOP Contraindicated in open globe injury Posterior Segment examination Vitreous haemorrhage Retinal detachment Retinal dialysis Retinal tear Posterior vitreous detachment Choroidal rupture Optic nerve trauma IOFB

21. DIAGNOSTIC IMAGING X-Ray orbit AP Lateral USG CT scan Cultures should be sent, in case the wound is infected • wound margin • devitalized excised tissue • IOFB

22. Patient with a serious injury Evaluate patient and eye Management options Counsel, discuss management options with patient/ family Design Management Plan M anagement strategy for patients with serious ocular trauma

23. Design Management Plan Reconstruct in one or more surgical sessions as appropriate Appropriate medical therapy and close follow-up; watch fellow eye ; continue counselling

24. Surgical Repair Best to perform reconstructive surgery as early as possible Delay can occur Medical condition Last food ingestion Availability of GA

25. Preoperative management Shield/rigid eye cover placed to protect the globe Pad should not be placed Systemic antibiotic should be started Anti tetanus toxoid NPO

26. Surgical preparation Topical medication Not to be given Minimal touch technique Antiseptic solution should be kept away from ocular surface irrigated only with saline Drapes should be applied gently without any pressure

27. Principles of Repair of corneal wounds PRIMARY- A water tight closure of the globe Restoration of structural integrity

28. SECONDARY- Restoration of normal anatomy Avoidance of uveal tissue and vitreous incarceration in the wound Remove necrotic tissue debris Removal of disrupted lens Removal of foreign bodies Iatrogenic damage should be avoided Effort should be made to protect visual axis

29. Sutures A rea of compression is equal to the length of the sutures therefore lesser number of longer sutures are used in the repair of the wound .

30. Longer sutures especially near to the visual axis lead to greater tissue distortion and therefore more of astigmatism

31. Longer sutures put away from the visual axis Corneal periphery closed with long, tight sutures Corneal centre closed with shorter, more widely spaced minimally compressive tissue bites Perpendicular to the lacerations Single interrupted sutures Equal depth of suturing on both sides

32. Management of prolapsed tissue If lens or vitreous extrudes through the wound the tissue should be excised at the corneal surface. If Iris , retina, or uveal tissue is extruded it should be gently reposited either with smooth instrument or with viscoelastic. Excision of uveal tissue -- tissue appear necrotic or extruded for more than 24 hrs .

33. Corneoscleral Laceration with Iris I ncarceration A cleanly incised wound where iris is adhering to the posterior margins of the wound and formed AC can be managed easily by putting sutures and sweeping the iris. Fluid, blood or clots are thoroughly irrigated with BSS. Any foreign body is to be checked and removed.

34. Iris tissue which is devitalized, macerated, feathery or depigmented should be removed. Prolapsed tissue for more than 24 hours should be removed. Iris which is healthy can even be reposited even after 24 hours.

35. In a case of combined corneo scleral laceration, the first suture should be placed at the limbus . Then the corneal wound and lastly the scleral wound anterior to posterior

36. Monofilament 10-0 nylon thread on a spatula needle is used. 90 % of the depth of corneal tissue should be taken during suturing . Sutures should be a bit tighter. AC is to kept formed during suturing with repeated air injection.

37. Laceration with lens incarceration Primary lens removal if injured lens capsule and opaque lens Lens surgery deferred until eye has recovered from the initial effect of primary surgical repair. ECCE should be preferred. Secondary IOL implantation. ICCE if total anterior dislocation followed by thorough anterior vitrectomy .

38. Laceration with vitreous loss/ incarceration Complete vitreous removal from AC by anterior vitrectomy . Pupil should be circular, round with no peaking.

39. Scleral injury The extent of laceration or injury is not clearly visible usually as scleral laceration begins anteriorly and ends posteriorly to an unknown end. Overlying conjunctiva, episclera , Tenon’s capsule make the determination of extent and location more difficult.

40. Scleral tear repair Start anteriorly dissecting the episclera away from the scleral wound and identify exact plane of dissection and identify the edges of laceration Unlike corneal laceration scleral laceration should be closed in a “close as you go” manner

41. Limited anterior dissection , exposure of small portion of defect followed by suturing , then proceed posteriorly Closure should be done as posteriorly as possible without exerting excess distortion or torque on the globe

42. Wounds too posterior to close without the threat of intraocular tissue loss should be left to heal on their own. Due to slow healing of the sclera and for structural support, non-absorbable sutures ( 8-0 Mersilk ) should be used for large defects. For smaller wounds, absorbable sutures ( eg , 8-0 Vicryl ) are appropriate.

43. Haemostasis should be meticulous so that edges can be identified If laceration is underneath the muscle, the muscle can be disinserted . Laceration is repaired and the muscle is resutured .

44. Post-operative management Broad spectrum antibiotic eye drops Topical corticosteroid eye drops Cycloplegic Antiglaucoma medication In case of infected wounds, fortified eye drops ( cephazolin 5%, tobramycin 1.3 %) Systemic antibiotics are to be continued

45. Penetrating Posterior S egment T rauma Scleral perforations include single, double and multiple perforations accompanied by retained IOFB Open globe injuries can have single, double or multiple lacerations. 75% of the ocular penetrating wounds are anterior to the ora serrata Examination is difficult due to associated hyphema , cataract & VH

46. USG – extremely useful in identifying RD, IOFB, posterior exit wound, posterior extension of anterior scleral laceration and choroidal haemorrhages

47. Sequence of E vents Vitreous incarceration &VH  generate contractile forceTRD

48. Contractile forces involved in vitreous body after penetrating injury. (circumferential & tangential)

49. Aims of surgery To remove disorganised tissue and debris Reposit and repair viable tissue such as iris or retina Repair a wound or rupture to give a watertight closure Restore the anatomy of the anterior and posterior segments to prevent incarceration Delayed removal of posteriorly impacted foreign body gives a better result than early intervention

50. Vitrectomy Indications : Non clearing VH VH with retinal detachment IOFB Endophthalmitis Posterior perforations Giant retinal tears Macular holes Sympathetic endophthalmitis

51. Indications for posterior segment intervention(IOFB) Question of infection The primary and secondary mechanical consequences (VH, PVR) Threat of chemical damage Lacerated open globe injury – IOFB should be considered

52. Facts If history suspicious - presume IOFB is present 1/5 th do not experience pain, vision may be good Warning signs – hemorrhage over sclera, localized corneal edema, non-surgical hole in the iris

53. Facts Scleral indentation not advised until entry wound closed first USG is very effective method for presence and location of FB False negative - possible if the object is small, wooden, or of veg. matter Gas bubbles can lead to false positive results B-scan tends to over estimate the size of IOFB

54. CT-scan replaced plain X-ray as mainstay of IOFB diagnostics Sensitivity upto 65% for FB volume < 0.06mm³ and 100% for larger than 0.06mm³ MRI – very sensitive , its use limited because of the threat of movement of magnetic objects

55. Fact In the vitrectomy era – accurate pre-op. intraocular localization of FB is less important If IOFB not found during surgery ‘hiding place’ is behind iris inferiorly, In the peripheral vitreous Under the retina Usually in the pool of blood or in the angle

56. Management Clean and close the entry wound if non self sealing Remove the hyphema and or lens if visualization is poor Perform PPV, remove post hyaloid face carefully, Locate the IOFB and determine its size comparing to vitrectomy pole Completely separate and free the FB from surrounding area

57. Prepare scleral extraction site, usually extend pars plana incision Consider L-shaped incision if linear incision is too long Approach FB using intraocular magnet or forceps. Remove fibreoptic probe & use toothed forceps and gape the scleral wound to remove the FB

58. Timing of surgery…usually fibrous proliferation does not start prior to 10 days.. safe period is 7-10 days after trauma

59. Timing F irst 24-48 hrs only primary closure. Avoids bleeding, disturbed visibility, & increased complications 7-10 days- Less tissue edema, less possible haemorrhage , & PVD may have occur. less fibrous proliferation. IOFB- operate as early as possible.

60. Prognostic factors Good visual prognosis (6/18 or better) expected in- 1. Presenting acuity after injury of 6/60 or better 2. Wound location anterior to pars plana 3. Wound length of 10 mm or less 4. A sharp mechanism of injury It is seen that wounds longer than 20 mm, which extend posterior to the equator, will lead to poor final vision and subsequent enucleation in majority.