Small incision cataract surgery (SICS) is a prevalent technique in all the high volume centres of India as it is faster, gives excellent visual outcome and is much cheaper than phacoemulsification.
Tip no. 1. Do a thorough pre-operative assessment and try selecting ideal cases
- It is mandatory to perform a proper pre-operative assessment of the patient.
- Helps in preparing the surgeon to anticipate complications and plan the operation accordingly.
Tip No.2. Try to achieve adequate size, shape & couture of the incision
- We usually make a frown incision 6mm long and 2mm away from limbus with the help of a 15 number blade.
- Beginners however may start with a straight incision before transitioning to frown.
- The incision should be made within the astigmatic neutral funnel.
- To remain astigmatically neutral, incisions closer to the limbus need to be smaller and longer incisions may be constructed further from the limbus.
- The incision should be placed on the steep meridian according to the Keratometry. This flattens the cornea, thus one achieves least postoperative astigmatic outcome.
- The size of the incision can be increased or decreased depending on the hardness of the nucleus.
- The depth should be approximately 0.3 mm.
Tip No.3. Make tunnel with appropriate architecture & apt side pockets
- The tunnel should be extended forwards uniformly 1-2mm in the cornea and should be 1mm longer than the outer scleral incision on either side. This leads to a self-sealing wound.
- A crescent blade is used for making the tunnel. It should be a new sharp blade.
- Adequate depth is judged by visibility of the knife, the crescent should be just visible through the sclera. The heel of the crescent should be flat on the globe during dissection, ensuring uniform depth of the tunnel.
- On either side of the tunnel, scleral pockets are created. This helps to accommodate the nucleus during delivery.
- While making tunnel one should take care of remaining in the same plane as there are chances of buttonholing if you go superficial, or premature entry if one goes deeper.
- Entry into the chamber should be done by a fresh sharp 3.2 mm blade in one go. A blunt blade may cause Descemet’s detachment. A side-port should also be made.
Tip no.4. With good visualization, properly stained capsule & deep AC one can conquer capsulorhexis
- Superior rectus bridle suture is released to allow the globe to move to the primary position.
- Air is then injected in the chamber and trypan blue dye 0.1 - 0.2ml is injected beneath the bubble for smooth staining of the anterior capsule. The dye helps in good visualisation of the capsule.
- The trypan blue is washed out of the eye using balanced salt solution.
- Viscoelastic is injected in the anterior chamber to deepen the anterior chamber.
- A 6mm capsulorhexsis is made with the help of cystotome made by a 26 gauge needle or Utrata forceps. We prefer Utrata forceps.
- Beginners may make a side port to perform the capsulorrhexis for better control with cystotome.
Tip no.5. Try to achieve uniform inner lip for astigmatically neutral wound
- Once the capsulorhexis is completed, the tunnel is extended. For this the cuts should be made while the blade goes forward in several to and fro movement. But cutting force should be applied only when the blade advances forward. On coming back, there should be no cutting action.
Tip No.6. Always do adequate hydro procedures with atraumatic nucleus delivery
Hydrodissection and Nucleus Prolapse
- Hydrodissection is done by taking BSS fluid in 1ml syringe. A little fluid is injected beneath the anterior capsule at several points till one achieves rotation of the nucleus. Then larger volume is injected in a bolus beneath the anterior capsule. This lifts the nucleus and an edge of the nucleus is seen coming out of the rhexsis rim. This tilt of the nucleus out of the bag is very important as it helps in prolapsing the nucleus out of the bag. It can be achieved by rotating the nucleus by a visco-cannula or by a lens dialler.
- Beginners can start by doing a can-opener capsulotomy and implementing this manoeuvre as it is easier than doing the same with a rhexsis.
Tip No.7. Pull the vectis out with simultaneous traction with superior rectus and downward push of lower lip, for easy nucleus delivery
- The most important step is of delivering the nucleus out. Several techniques may be applied for this step.
- Blumenthal, Irrigating vectis, Visco-expression, and Phaco-fracture are commonly used.
- Most frequently we use irrigating vectis technique. The vectis should be strong and one must check the free flow of the fluid through this. Viscoelastic is pushed above the nucleus and beneath it so that the nucleus is well coated to prevent the touch of the bare nucleus on the undersurface of the corneal endothelium.
- The vectis then goes beneath the nucleus through the tunnel and then gently the nucleus is brought close to the tunnel and pulled out by a smooth movement of the vectis. It will come out in one go if the nucleus is soft, but may not if the nucleus is large and hard.
- One should not struggle too much at this step and should not try to forcefully pull out the nucleus vectis combo as it leads to touching on the undersurface of the cornea resulting in endothelial loss.
- The nucleus may get fractured at this point. Half of the nucleus is then easily delivered out along with the vectis and the remaining piece is rotated 90 degrees to make its long axis longitudinal. After this viscoexpression can be done.
Tip No.8. Maximal side port utilization allows deep AC and easier cortex wash.
Residual Cortex Aspiration
- It is done from both the main and the sideport by Simcoe cannula. A thorough aspiration of the cortical matter is done by keeping the chamber deep all the time by applying the low vacuum by adjusting the pull on the plunger of the syringe. This gives you a pristine cornea the next day.
Tip No.9. Deep Visco-Filled AC is the prerequisite for in the bag IOL implantation.
- A rigid IOL is implanted after filling the chamber with the viscoelastic. The lower pole IOL is tilted downwards while inserting so that lower haptic goes directly into the bag.
- Then the dialler assists in dialling the upper haptic of the IOL into the bag.
- These days we prefer IOL implantation under BSS by using an AC maintainer for keeping the chamber deep. It obviates the need of removing the viscoelastic from behind the IOL.
Tip No.10. Thorough viscowash and covering incision with conjunctiva is essential.
Viscoelastic Removal and Hydration of Side Port
- All the cortical debris and viscoelastic is then aspirated using the Simcoe cannula. Chamber is deepened by the BSS. Corneal hydration of the side port is done.
- Conjunctiva is then apposed gently by bipolar diathermy cautery. It should be done after drying the conjunctival surface.
- It is mandatory to check, that the conjunctiva covers the incision site. The conjunctiva heals within 24-48 hours, thus preventing any chances of outside fluid entry into the chamber, which prevents any chances of endophthalmitis.
- Antibiotic is just sprinkled on the surface of the conjunctiva. No intracameral or subconjunctival injection is given by us.
- Kamaljeet Singh. Small Incision Cataract Surgery: Manual Phaco. 2nd edition. Jaypee Brothers Medical Pub; 2010.
- Singh K, Misbah A, Saluja P, Singh AK. Review of manual small-incision cataract surgery. Indian J Ophthalmol 2017;65:1281-8.