phaco basics procedure

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PHACO BASICS: PROCEDURE Dr.Kaivan Shah Dr.Smita Praveen: 

PHACO BASICS: PROCEDURE Dr.Kaivan Shah Dr.Smita Praveen

1.Incision & Wound construction: 

1.Incision & Wound construction Be clear about: a) Anatomy of surgical limbus:3 borders & 2 zones b) Astigmatic neutral funnel: mouth 3-3.5 mm at limbus & flares out as moves posterior 3 shapes: Frown, smile & straight c) Self sealing valve mechanism: inner corneal lip should be 1.75 mm all along & should be smooth, not ragged

Types:: 

Types: Main Port : 2 types 1. Scleral incision : should be square, self sealing, 1/3 to 1/2 thickness(300-500micron) adv. : less chances of endophthalmitis disadv. : not possible under topical & temporal section,more bleeding,difficult instrumentation 2. Clear Corneal incision : superior or temporal depending on keratometry reading Temporal better b’coz, less induced astigmatism less pooling of fluid in deep set eyes Tunnel interferes less with visibility as HD>VD by 1 mm

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Types: uni,bi and tiplanar, hinged Adv. : done under topical, no bleeding, ease of instrumentation Disadv.: more chances of endophthalmitis Limbal approach is good compromise between two. Side port : Site - 2-3 clock hours from main port 180 deg apart, corneal not Scleral Size - 1.5*1.5mm

2. CCC:: 

2. CCC: Prerequisite for phaco as intact CCC strengthens capsule withstand IOP fluctuations,allows post.chamber phaco Ideal size : 5-6mm,should cover o.25mm of IOL circumferentially Needs : firm eyeball, well-formed A/C with flat ant.capsule, moderate to good dilatation, red fundal reflex Physics : ripping & shearing forces Site : main port- easy maneuverability, more leakage side port- stable A/C, difficult to stabilize eye

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Method : needle/cystitome Vs forceps Forceps CCC : ( Utratta ) Adv : good grip on flap, easy to change direction Useful in fibrotic, atrophic capsule, in intumescent cataracts with high I/L pressure for posterior CCC Disadv: wound leak & corneal distortion Dye assisted : use of trypan blue in mat.cat.

3. Hydroprocedures:: 

3. Hydroprocedures: Aim: convert lens in 3 parts: 1.capsule with cortex, 2.epinucleus, 3.endonucleus Adv: facilitates rotation, epinuclear plate gives cushion during phaco & protect PC & reduce energy, enables prolapse of small nucleus out of rhexis margin in CSZ instruments:2cc syr,26-30G cannula,27G ideal

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2 components: 1. Hydrodissection : separation of lens from capsule by fluid wave. Remove visco first to avoid inadvertent increase in IOP Do it from main port, tenting of margin Inject beyond 2-3mm of margin Watch for : fluid wave, loss of glow, pop up nucleus Compression hydro dissection Careful in: small/large CCC, post.polar

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2. Hydrodelineation : create smallest possible nucleus & thickest epinuclear plate Watch for Golden ring Always do rotation of nucleus after completion of hydroprocedures. Difficult rotation causes: incomplete hydro, adhesions with capsule, dialysis of bag, soft cataract

4.PHACOEMULSIFICATION:: 

4.PHACOEMULSIFICATION: Aim : remove central core nucleus with minimum phacoenergy by diff.techniques Understand posterior curvature of lens & hardness of nucleus Instruments : phaco tip & chopper Before starting phaco fill A/C with visco & remove ant.epinuclear plate & cortex Different techniques used: “stop & chop”,”divide & conquer”,”phaco chop”

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Different steps used: trenching, splitting of nucleus & phaco aspiration. Depending upon step, phaco parameters are modified. 1. Trenching : first step in stop-chop & divide-conquer method, width 2 tip diameters, length up to ring, depth 2-3 tip deep(glow should be seen) Settings: low flow, low/nil vacuum, high power 2. Splitting : with 2 instruments Push method / pull method

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3. Chopping : piece of nucleus after splitting are aspirated by this technique Settings: medium flow,high vacuum, medium energy Control over footpedal & familiarity with machine sounds of utmost importance Method: bury tip in nucleus with short burst energy, hold with vacuum & aspirate it with intermittent use of energy Careful while aspirating last piece Chattering & Surge occurs while this step Horizontal chop Vs Vertical Chop

5.Epinucleus Removal:: 

5.Epinucleus Removal: 3 parts: anterior, equatorial & posterior Instruments: Phaco tip & iris repositor settings: high flow,medium vacuum,low power Method: “flip & chip” Catch equatorial part with vacuum,pull in CSZ & aspirate with small burst of energy Keep Repositor below tip to prevent catching PC Hydro.can be done to separate it from capsule

6.Cortex Aspiration: 

6.Cortex Aspiration Includes removal of cortex & PC polishing Important to prevent PCO & uveitis Cortical removal : 1.Coaxial I/A system : tip is straight/angulated(45/90 degree) Aspiration orifice in front of tip-o.2 to 0.7m Tip covered by silicone sleeve 2.Bimanual I/A system : 1 irrigation(2 holes) & 1 aspiration cannula Method: catch beneath CCC pull towards centre & aspirate in CSZ

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Parameters: high flow & vacuum Capsule polishing : to reduce PCO formation Very low vacuum & flow High magnification with focus on PC Stretch PC by filling A/C with visco,no folds in PC should be present Instruments: sand blasted aspiration cannula/rounded iris repositor Beginners don’t try

7. IOL insertion : 

7. IOL insertion Visco filled eye & adequate wound size Nonfoldable IOL: with 2 forceps with/without dialer Foldable IOL: holder-folder method & injector method Ensure in the bag placement

8.Visco Wash: 

8.Visco Wash Visomet washed with I/A mode Ensure all viscomet is washed to prevent postop glaucoma Tap over centre of IOL to release visco trapped in the bag

9.Wound Closure: 

9.Wound Closure Adequate hydrate wound Check water tightness of wound If necessary air can be put Take suture if in doubt about integrity/corneal wound burn in c/o corneal tunnel

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Thank you