Friday, September 30, 2005

Chapter 3 - Old School

Old School Cataract Surgery Techniques


  1. intracapsular cataract extraction (ICCE) - lens with capsule removed [VIEW VIDEO]

  2. extracapsular cataract extraction (ECCE) - lens removed and much of lens capsule left in place. Can be done via two approaches: manual or planned ECCE done with expression of nucleus through large; or, phacoemulsification ultrasound device breaks up nucleus through small incision. [VIEW VIDEO]

  3. Pars plana lensectomy (PPLx) is an approach by retinal surgeons often at time of vitrectomy.

Comparison of Cataract Surgery Techniques


[CLICK ON TABLE FOR LARGER VIEW]

ICCE – [view video]
Indications: rarely indicated today - I have only done five cases. Unstable lenses with severe zonular laxity.
Be Careful: children, capsular rupture, high myopia, Marfans, vitreous present.
Pre-op: orbital massage or osmotic agents to reduce vitreous pressure.
Anesthesia: Retrobulbar and lid block. Rarely general anesthesia, e.g., claustrophobia, dementia, tremor.
Procedure:
  1. Superior bridle suture

  2. May need a scleral support ring in high myopes

  3. Peritomy of about 170 degrees

  4. Limbal incision of about 170 degrees chord length in the 11-12 mm range

  5. Safety sutures are preplaced - usually 7-O Vicryl

  6. Small peripheral iridotomy is placed

  7. Alpha-chymotrypsin was placed to degrade zonules (no longer available)

  8. Anterior surface of the lens is dried with a cellulose sponge

  9. Cryo probe is placed on mid-periphery of the lens and frozen

  10. Lens is removed with a side to side motion through incision

  11. Wound is closed with safety sutures

  12. Vitreous is attended to if needed

  13. Anterior chamber lens is placed

  14. Wound is closed with 10-O nylon

Planned ECCE (with nucleus expression) [VIEW VIDEO]

Indications: Still indicated today. Hard lenses with tentative corneal endothelium (weak indication).
Contraindications: poor zonular support.
Pre-op: consider orbital massage or osmotic agents to reduce vitreous pressure
Anesthesia: Retrobulbar and lid block, sub-tenon's block, or rarely general anesthesia, e.g., claustrophobia, dementia, tremor.
Procedure:
  1. Procedure Superior bridle suture

  2. Peritomy of about 170 degrees

  3. Initial limbal groove in sclera with a chord length in the 11mm range

  4. Initial entry into anterior chamber to allow capsulotomy (3 mm)

  5. Instill viscoelastic (see appendix 2)

  6. Remove anterior capsule (usually with can opener approach)

  7. Mobilize lens (physically with cystitome or with hydrodissection--be careful)

  8. Extend initial incision to full length of groove (with scissors or knife)

  9. Safety sutures are preplaced usually 7-O vicryl

  10. Lens removed with lens loop or with counter pressure technique

  11. Wound is closed with safety sutures

  12. Cortical material is removed using I/A device (either automated or manual)

  13. Instill ophthalmic viscoelastic device (OVD)

  14. Lens is placed in the posterior chamber

  15. Wound is closed with 10-O nylon

  16. OVD is removed



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