posterior capsular rupture & vitrectomy farid karimian m.d 2002
DESCRIPTION
Posterior Capsular Rupture & Vitrectomy Farid Karimian M.D 2002. 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 - PowerPoint PPT PresentationTRANSCRIPT
Posterior Capsular RupturePosterior Capsular Rupture
& &
Vitrectomy Vitrectomy
Farid Karimian M.D 2002Farid Karimian M.D 2002
Capsular Anatomy 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
Signs of Capsule RuptureSigns 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
Predisposing Factors for Predisposing Factors for Capsular RuptureCapsular 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
Predisposing Factors…cont.(1)Predisposing Factors…cont.(1)
Long and short axial length eyes deep or shallow AC
Pseudoexfoliation, weak zonules, poor dilation
Brunescent or black cataractDense asteroid hyalosis
Predisposing Factors… cont.(2)Predisposing Factors… cont.(2)
Posterior polar cataracts (esp. calcified):
- cataract to post capsule adhesion,
- posterior capsule thiningInexperienced surgeonsPoor visualization (eg. Microscope
problems)
Predisposing Factors… cont.(3)Predisposing Factors… cont.(3)
Demented, disoriented, anxious, and addict patients: inadvertant movement
Equipment malfunctionPre-existing trauma unseen
capsular or zonular damageSmall pupils
When the Posterior Capsule When the Posterior Capsule is Torn?is Torn?
Terminal stages of phaco for emulsification of last pieces of endonucleus
During posterior capsule polishingDuring I/AHydrodissection, IOL insertion: less
common
Developing a Surgical PlanDeveloping 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)
Posterior Capsular Rupture Posterior Capsular Rupture During Nucleus EmulsificationDuring 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
Conversion to ECCEConversion 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
Continued Continued PhacoemulsificationPhacoemulsification
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 not create multiple fragments
The Pseudo-posterior Capsule:The Pseudo-posterior Capsule: Sheet’s glide after viscoelastic Sheet’s glide after viscoelastic
injection under nucleusinjection 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
Principles of managing an open Principles of managing an open posterior capsuleposterior 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
Principles of managing an Principles of managing an open posterior capsule…(cont)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
1- Do not mix… cont.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
2- Do not stretch the slinky2- 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
Posterior Assisted LevitationPosterior 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)
Specific Clinical SituationsSpecific Clinical SituationsPosterior 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
Specific Clinical Situations Specific Clinical Situations cont…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
2- During Sculpting2- 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
2- During Sculpting…cont.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
3- During Rotation of the Nucleus3- 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
4- During Emulsification4- During EmulsificationCauses:
- 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
5- During Cortical Aspiration5- During Cortical AspirationCauses:
• 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!
6- During or After IOL Implantation6- 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
During or After IOL During or After IOL Implantation… cont.(1)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
Vitrectomy Following Vitreous Loss: Vitrectomy Following Vitreous Loss: PrinciplesPrinciples
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
Vitrectomy with Coaxial InfusionVitrectomy with Coaxial Infusion- Special tip to-reduce no. of entrances- Easily placed through phaco incision - It fails, because stretches the slinky1. The coaxial infusion strikes posterior capsule rupture sizeMore vitreous comes forward2. Coaxial cannula reaching the body of vitreous
hydration of vitreousIncrease vitreous volume Forward movement3. Flow moves the vitreous around wiggling and
shaking vitreous flush it forward
Recommendation: Don’t use coaxial infusion cannula
Two-handed (port) VitrectomyTwo-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
Postoperative CarePostoperative 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