Posterior Capsular Rupture & Vitrectomy Farid Karimian M.D 2002

1. Posterior Capsular Rupture & Vitrectomy Farid Karimian M.D 2002

2. Capsular Anatomy Elastic basement membrane, type IV collagen Thickness: • 2-4  at the posterior pole Thickest: 17-23  near the ant. & post equator Ant. Capsule  14  thickness increases with age Fragile posterior capsule: - Congenital post lenticonus, posterior polar cataract - Posterior subcapsular ( PSC): age- related, steroid

3. Signs of Capsule Rupture • Sudden, abrupt and dramatic posterior displacement of iris • Momentary pupillary dilatation • Nucleus “ fall away” from the phaco tip • Nucleus dose not follow toward the phaco tip NOTE: Any time suspected of ruptured posterior capsule modify surgical plan on that suspicion

4. Predisposing Factors for Capsular Rupture 1- Position of surgeon’s hand obscuring visibility 2- Irrigation fluid pooling 3- Torsion of the globe 4- Poor microscope illumination or alignment 5- Poor visibility secondary to pathology: dense arcus, ptryguim, band keratopathy, corneal scars, interstitial keratitis

5. Predisposing Factors…cont.(1) • Long and short axial length eyes deep or shallow AC • Pseudoexfoliation, weak zonules, poor dilation • Brunescent or black cataract • Dense asteroid hyalosis

6. Predisposing Factors… cont.(2) • Posterior polar cataracts (esp. calcified): - cataract to post capsule adhesion, - posterior capsule thining • Inexperienced surgeons • Poor visualization (eg. Microscope problems)

7. Predisposing Factors… cont.(3) • Demented, disoriented, anxious, and addict patients: inadvertant movement • Equipment malfunction • Pre-existing trauma unseen capsular or zonular damage • Small pupils

8. When the Posterior Capsule is Torn? • Terminal stages of phaco for emulsification of last pieces of endonucleus • During posterior capsule polishing • During I/A • Hydrodissection, IOL insertion: less common

9. Developing a Surgical Plan Posterior capsule tear suspicion  Alternate surgical plan  Goal to minimize prolonged or damaging Procedures damaging retina and/or cornea Planning  Timing (when in the procedure)  Location (where in posterior capsule) Size (small, medium, large, or extra large)

10. Posterior Capsular Rupture During Nucleus Emulsification Two main questions: 1. Is vitreous present in A/C? 2. Is Conversion to ECCE indicated? Conversion decision: 1. Hardness and size of nucleus 2. Size of pupil 3. Maintain adequate deep A/C 4. Ease of access to anterior segment 5. Level of surgical experience

11. Conversion to ECCE • Support the lens nucleus with a dispersive viscoelastic (injection underneath) • Extend peritomy and corneoscleral incision • Open the wound larger than expected • Use lens loop or manipulator • No limbal pressure  vitreous will be expelled

12. Continued Phacoemulsification • Inject viscoelastic below fragment • Protect the endothelium • Lower bottle height, vacuum and flow • Emulsify the nucleus in A/C in one piece • Use second instrument to feed phaco tip • Do notcreate multiple fragments

13. The Pseudo-posterior Capsule:Sheet’s glide after viscoelastic injection under nucleus Support nucleus fragments Prevent excess loss of vitreous Both ECCE and phaco can be done over Sheet’s glide Finally I/A and vitrectomy over glide

14. Principles of managing an open posterior capsule 1- Do not mix cataract with vitreous - Mixture of lens material will cause inflammation - Isolated cortex in the eye is absorbed with low reaction - Cortex- vitreous mixture  variable course  from tolerance to severe inflammation

15. Principles of managing an open posterior capsule…(cont) - Nucleus left in the eye  variable clinical outcome - Small nucleus fragment in A/C  inferior angle  endothelium rubbing  cell loss  Should be removed

16. 1- Do not mix… cont. • Nucleus fragments behind iris and above anterior capsule  fairly harmless • Nucleus fragments in vitreous  significant inflammation • Increased inflammation: - personal Physiology and response, - Central nucleus > peripheral chips • About 1/3 of cases with dropped nucleus chips develop uveitis and glaucoma

17. 2- Do not stretch the slinky Vitreous has natural elasticity  extending down to macula (not necessarily) -Tensions on anterior vitreous  exertion through entire vitreous body  pulling on the macula and vitreous base During phacoemulsification  small incisions plugged by instruments  If pressure A/C is kept sufficient Prevent vitreous prolapse  Forces remained in anterior vitreous  No transmission to macula or vitreous base

18. Posterior Assisted Levitation • When stabilization of nucleus is impossible • Distal zonular dehiscence  Distal pole of nucleus falling into the vitreous • Pars plana stab incision 3.5mm posterior to limbus • Site of incision  wherever zonular hinge occurs • Cyclodialysis spatula  lever the nucleus into the A/C • Removal by phaco or extracapsular approach (preferred)

19. Specific Clinical Situations Posterior capsule rupture and vitreous loss situations 1- During Capsulotomy and Hydrodissection -poorly directed anterior capsule  peripheral extension  Tear usually stops by zonule network High volume with rapid injection  extends radial tear into equator and back to posterior capsule

20. Specific Clinical Situations cont… • Small capsulorrhexis  phaco needle trauma • Sharp hydrodissection needle  radial tear formation • Presence of posterior polar cataract or post capsule defect • High MW viscoelastic injection under capsular  wound extension  nucleus delivery

21. 2- During Sculpting •Hard nucleus insufficient power- - blunt needle tip - low machine power settings - low power generation • Nudging nucleus toward 6 o’clock  pushing inferior capsule Pulling on superior zonules • Superior zonular dehiscence  whole nucleus moved down Failure of nucleus to return •Conversion into ECCE after anterior capsule relaxing incisions

22. 2- During Sculpting…cont. • Peripheral sculpting  capsular trauma • High vacuum sculpting  sudden emulsification of posterior nuclear plate and cortex  capsular rupture • Inferior capsulorrhexis rim trauma  posterior extension • Improper focusing on sculpting depth

23. 3- During Rotation of the Nucleus Causes: - inadequate hydrodissection (nucleus adhered to capsule)  shearing off zonules - Second instrument- capsule trauma - Unstable zonules e.g. pseudexfoliation  bimanual rotation • If shearing of zonules is complete  ICCE removal must be done • Zonular dehiscence - <90°  complete hydrodissection  PE - 90°- 270°  capsular tension ring  PE - >270°  ECCE with radial tears in anterior capsule or ICCE

24. 4- During Emulsification Causes: - Small capsulorrhexis and during division - Sudden flattened A/C and capsular bag - Uncontrolled surge during emulsification nucleus particle - Sharp ends of nuclear fragments Management: - Protection of remaining PC with viscoelastic - Sheet’s glide support of nucleus fragment- pushing back PC and vitreous - Emulsification of nucleus fragments over glide in A/C

25. 5- During Cortical Aspiration Causes: •Post capsule trauma by I&A tip: Flat AC, excess aspiration • Anterior capsule entrapment in aspiration port  traction • Inadequate hydrodissection Management: - Place dispersive viscoelastic over the vent - Embed I&A tip into the cortex  apply vacuum (not aspirating vitreous) - Stripping toward capsule tear - Lower infusion bottle  inflow,  turbulence - Vitrectomy tip can be used for cortical removal - Leave cortical material: if not too much!

26. 6- During or After IOL Implantation  More complicated than earlier phases  First: secure IOL to prevent sinking  Use viscoelastic to hold vitreous back  By clockwise rotation bring IOL into sulcus or AC  If capsulorrhexis is intact  sulcus fixation

27. During or After IOL Implantation… cont.(1) • Close the wound  to prevent flat AC, further endothelial damage • Bimanual vitrectomy over and under the IOL • Constrict pupil by intraocular miotic injection over IOL  check vitreous clearance • If no sufficient capsular support  transscleral fixation, or ACIOL

28. Vitrectomy Following Vitreous Loss: Principles • Keep AC as closed as possible: instruments, suture • Maintain IOP stable: keep foot pedal at stage I, use viscoelastics • Loss of anterior segment  forward displacement of vitreous • Vitrectomy setting: suction 60mmHg, cut: 360-400 cpm • Do vitrectomy adequately • Keep capsule rent as small as possible

29. Vitrectomy with Coaxial Infusion - Special tip to-reduce no. of entrances - Easily placed through phaco incision - It fails,because stretches the slinky 1. The coaxial infusion strikes posterior capsule   rupture size  More vitreous comes forward 2. Coaxial cannula reaching the body of vitreous  hydration of vitreous  Increase vitreous volume   Forward movement 3. Flow moves the vitreous around  wiggling and shaking vitreous  flush it forward Recommendation: Don’t use coaxial infusion cannula

30. Two-handed (port) Vitrectomy • Close the entrance wounds for vitrectomy tip  i.e. make a closed system • Procedure will be performed rapidly and conveniently • Perform small vitrectomy without irrigation • Prevent eye softening by repeated injection of viscoelastic  push vitreous back • Chamber-maintainer through side-port forms AC • Remove the vitreous to below the level of posterior capsule

31. Postoperative Care At conclusion of surgery: - Betamethasone 4mg (short-acting) - Antibiotic e.g. Gentamicin 20mg - Trimcinolone (kenalog) 20mg or Methyl- prednisolone 40mg (longer anti-inflammatory action) - Take care of IOP rise, endophthalmitis, and other complications of vitreous loss - Systemic steroid, prednisolone 1-1.5 mg/kg PO for 7-14 days