Dr. Ajay Kumar Singh, S13226
In the era of advanced phacoemulsification surgery, Manual Small Incision Cataract Surgery (MSICS) still remains as an efficient and cost-effective alternative. The most critical step in MICS is tunnel construction, which has to be carefully planned depending on surgical technique, grade of cataract and pre-existing astigmatism. The scleral tunnel has six aspects- size, shape, location, depth, width, internal lip. The incision of the tunnel may be constructed in various patterns, e.g. Smile, Straight, Frown, Blumenthal side cuts and Chevron ‘V’ incision. The MSICS incision can neutralize, decrease or increase the pre-existing astigmatism. In the process of healing, the meridian along which the wound is centered progressively flattens. Large incisions cause more SIA (surgically induced astigmatism). More the distance from the limbus, less is the SIA. Other factors affecting final SIA are tension of suture material, depth and length of suture bites, and postoperative steroid dosage.