Mastering Small Incision Cataract Surgery (SICS) lays a solid foundation for achieving sutureless cataract surgery in the majority of the cases. This article aims to bring forth some commonly committed errors in SICS.
Though a surgeon is not expected to choose a patient, but a beginner should avoid extremes of nuclear grade. A grade 3 nucleus with a 6mm external incision and >6mm capsulorrhexis, are the most comfortable to manage initially.
Only topical anesthesia!
Anesthesia is meant to make the patient comfortable and the choice depends on the patient’s cooperation, condition of the eye, and the surgeon’s expertise. Attempting topical anesthesia in an uncooperative patient, non-dilating pupil or a novice surgeon can result in disaster.
Use of blunt knives
The creation of a triplanar incision requires sharp knives. Blunt knives result in ragged wounds and premature entry due to the application of excessive pressure. A poorly constructed wound opens the door to the occurrence of all kinds of complications in the subsequent steps.
SICS involves the passage of the nucleus from its capsular bag into the anterior chamber through the capsular opening. Trying to prolapse a large nucleus through a small capsulorrhexis results in zonular dehiscence and even nuclear drop! The enlargement of capsulorrhexis, in such a situation, should be undertaken by giving tangential cuts, as radial cuts tend to extend to the periphery.
Multiple layers of hydrodelineation should be avoided in a soft cataract, as it makes cortical wash cumbersome and increases the chances of the capsular tear. However, the posterior polar cataract is an exception, where hydrodissection should not be performed.
Nuclear prolapse out of the bag
With an adequately sized capsular opening, a single wave of fluid during hydrodissection pushes a portion of the nucleus into the anterior chamber. The remaining nucleus can be cartwheeled out using a Sinskey’s hook. At times, while trying to rotate the nucleus out of the bag, if the force is applied radially, the zonules may get damaged. Also, the nucleus may keep rotating in the bag in an extremely hypotonous eye. Use of Sinskey’s hook as a crow- bar will help in lifting the pole of the nucleus in such a case.
Nucleus in the anterior chamber:
Endothelial touch by the anterior surface of the nucleus results in postoperative corneal edema. This may especially occur in large brown nuclei, leaky wounds or instrument manipulation within the chamber. Repeated injection of viscoelastic creates a protective layer on the endothelial surface and prevents this complication.
The size of incision
The size of incision in SICS depends on the grade of the nucleus and the technique of nuclear delivery. The incision has three parts namely the external incision, the tunnel and the internal incision. Trying to engage a large nucleus in a small internal incision leads to non- progress of nucleus, prolonged handling resulting in endothelial decompensation. In such a situation, after filling the anterior chamber with viscoelastics, the internal incision should be enlarged by introducing the keratome knife and cutting sideways.
Irrigating microvectis is commonly used for delivery of nucleus by placing it’s concave surface below the nucleus. Accidental entrapment of iris between the Vectis and the posterior surface of the nucleus results in inferior iridodialysis. Therefore, placement of Vectis should be checked prior to its withdrawal outwards. The superior iris may prolapse into the wound when the nucleus moves towards the external wound. The iris should be reposited, viscoelastic injected followed by re-engagement of nucleus into the tunnel.
Sutureless or safe wound?
Leaving an unstable wound unsutured can lead to anterior chamber collapse, endothelial decompensation, iris prolapse and even endophthalmitis! Also, large wounds, even if stable, result in against the wound drift and induce astigmatism. Therefore, after side port hydration, if the situation demands, the wound should be sutured.