Surgery: Manual Small Incision Cataract Surgery using Blumenthal Technique

Dr. Rishi Swarup: This video demonstrates the Blumenthal technique of manual small incision cataract surgery. A paracentesis is made at nine o’clock. Trypan blue stain is used to stain the anterior capsule, particularly in white cataracts. The dye is injected under an air bubble to protect the corneal endothelium. The air bubble can be removed with balanced salt solution or directly with viscoelastic.

A continuous curvilinear capsulorhexis, or CCC, is made using a bent 26 number needle cystitome through the sideport. In white cataracts, the rhexis may run peripherally, so the direction of pull of the flap must be centripetal. Repeated injection of viscoelastic should be done to deepen the anterior chamber if required. The rhexis must be well controlled by folding down the flap.

A fornix spaced conjunctival flap is made. Ensure that the Tenons is also reflected along with the conjunctiva. Vertically, expose four to five milliliters of sclera from the limbus. Gentle cautery can be done to prevent oozing of blood into the tunnel. Using a 15 degree knife or a 15 number blade, a 5.5 millimeter scleral incision is made horizontally, with two millimeter back cuts obliquely placed.

Once the incision is made, the groove is deepened. It is important to keep the field dry, as any fluid may alter the perception of depth. A crescent blade is introduced into the tunnel. The heel of the crescent blade must sit on the sclera. With gradual wiggling movement, the crescent blade enters into the cornea. The tunnel is then extended on either sides, using gradual circular movements, creating a dissection of eight to 8.5 millimeters adjacent to the limbus near the inner lip.

Subsequently, another paracentesis is made on the other side of the tunnel. The karatoma is carefully introduced into the dissected tunnel. A dimple is created at the end of the corneal dissection and an entry into the anterior chamber is made. As soon as an entry is made, the karatoma should be directed parallel to the iris to maintain the anterior chamber depth. The incision is extended on both sides until it reaches the limbus, creating an inner lip of eight to 8.5 millimeters. It is important to only dissect while moving the blade forward.
A Sinsky hook is used to engage, rotate, and gently dial out the nucleus. The hook should be placed underneath the rhexis, through the main wound. The nucleus is gently dialed out of the bag and through the pupil. At least 50% of the nucleus should be brought out into the anterior chamber, with the largest diameter of the nucleus crossing the pupil.

At this point, introduce a pair of forceps into the main wound. By opening the forceps and pressing the inner lip, the nucleus will get engaged in the tunnel. Continue to depress while giving counterpressure at six o’clock, using a toothed forceps. Once the nucleus is half out of the tunnel, any instrument like a hook can be used to dial out the remaining nucleus out of the tunnel.

The anterior chamber is refilled with viscoelastic and any remaining epinuclear remnants are removed. Cortex is aspirated using a Simcoe cannula, or as in this case, we use a bimanual irrigation/aspiration. Ultimately, a single port aspiration and easy maintainer can be used. A 360 degree gentle cortical aspiration should be done.

The anterior chamber is deepened using viscoelastic after a thorough irrigation/aspiration, and the capsular bag is also adequately filled. A rigid PMMA, or as in this case a foldable lens, can be implanted. It is imperative that the leading haptic is directly placed into the bag and the trailing haptic gently dialed into the bag. Once the intraocular lens is implanted into the bag, irrigation/aspiration should be done to remove all remnant viscoelestic from the bag and the anterior chamber.

The site ports are hydrated and wound integrity is checked. If the wound is good, there will be no leakages. The conjunctiva is then closed using a cautery. Always check the intraocular pressure and integrity of the eye at the end of the case.