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WOUND CLOSURE (VECTOR ANALYSIS) ECCE VERTICALLY APPLIED IOP AND TISSUE FORCES IN OPPOSITE DIRECTION PHACO HORIZONTALLY APPLIED SUTURE FORCE.

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Presentation on theme: "WOUND CLOSURE (VECTOR ANALYSIS) ECCE VERTICALLY APPLIED IOP AND TISSUE FORCES IN OPPOSITE DIRECTION PHACO HORIZONTALLY APPLIED SUTURE FORCE."— Presentation transcript:

1 WOUND CLOSURE (VECTOR ANALYSIS) ECCE VERTICALLY APPLIED IOP AND TISSUE FORCES IN OPPOSITE DIRECTION PHACO HORIZONTALLY APPLIED SUTURE FORCE

2 DYNAMICS OF SUTURELESS CATARACT INCISIONS THEORY Corneal flap mechanism THEORY Square incisional geometry

3 SQUARE INCISIONAL GEOMETRY EXTERNAL INCISION INTERNAL INCISION TUNNEL SIZE

4 astigmatically neutral funnel corneal astigmatism is directly proportional to the cube of the length of the incision inversely related to the distance from the limbus

5 SELF-SEALING WOUND DEPENDS ON The architecture of the wound Delicate handling of tissue edges Adequate intraocular pressure

6 PHACO INCISION GOALS INTRAOPERATIVELY POSTOPERATIVELY

7 INTRAOPERATIVE Allow Easy Entry Of The Phaco Needle Allow Ease Of Mobility Of The Phaco Needle Minimize Incision Leak Prevent Incision Burn.

8 POSTOPERATIVE Self Sealed Astigmatically Neutral Both In Short Term And Longterm

9 vital statistics of a phaco incision 1. Site (limbal or …) 2. Placement (time of incision!) 3. Style(mood of the incision!) 4. The length of the external incision 5. Length of the sclerocorneal tunnel 6. Depth of tunnel dissection 7. Size of initial opening for phacoemulsification 8. Size of incision for IOL insertion 9. Paracentesis opening

10 INSTRUMENTS REQUIRED FOR THE PHACO INCISIONS(sclera tunnel) A 15° freehand/preset depth (300 micron A 2.0 mm broad crescent blade A suitable breadth keratomewith a 90 degrees angle at the tip (bevel up) A 0.6 to 1.0 mm broad blade for the paracentesis A blunt tipped extender blade (bevel down) A caliper

11 TECHNIQUE OF MAKING A PHACO (Scleral Tunnel) INCISION Peritomy and cautery Grooving Tunnel dissection Stab incisions and AC viscoinjection AC entry

12 clear corneal incision (advantages) Well suited for topical anesthesia lesser risk of bleeding better accessibility better red reflex eliminates the conjunctival incision minimal or no effect on astigmatism

13 disadvantages of clear corneal incision technical difficulty lack of forehead support need to enlarge for use of nonfoldable IOLs difficulty in converting to a ECCE potential for greater endothelial cell loss.possible corneal thermal burns.higher incidence of endophthalmitis in some studies

14 Proposed incision for begginers (changing ECCE to phaco) limbal groove Straight or Parallel to limbus Biplanar Slightly wider than phaco tip

15 PARACENTESIS OPENING required for bimanual techniques Usually on the left side (30-90 degree) 0.6 to 1.0 mm in breadth simple stab or shelved

16 Clear Cornea Incision With initial partial thickness vertical incision Without an initial incision

17 ASTIGMATIC INDUCERS 1. Longer incision. 2. Corneal incision. 3. Limbus parallel incision. 4. Uniplanar incision. 5. Sutured incision

18 The caliper is set at 2.8 mm.

19 A light indentation on the peripheral corneal surface is created with the pointed ends 0f the caliper.

20 A 150-300-um-depth groove is created

21 A paracentesis incision is created with the diamond blade fully extended

22 An oblique entry is created as the blade not only driven through the corneal stroma to Descemet 's level. but also slices to the surgeon 's left. Notice the compression of tissue being created because ofthe relatively dull blade

23 Descemet's level is entered 1.75 mm from the epithelial level as the blade is swept to the left.

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