CAKE and PIE magazines’ Daily Congress News on the Anterior and Posterior Segments
Lessons on Manual SICS, From India to the World by Tan Sher Lynn
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anual small incision cataract surgery (MSICS or manual SICS) is a low-cost, small-incision form of extracapsular cataract extraction chiefly employed in the developing world as it provides the advantage of selfsealing sutureless wound. Speaking on the importance of MSICS in today’s world at the 37th World Ophthalmology Congress (WOC2020 Virtual®), Dr. Parikshit Gogate of Dr. Gogate’s Eye Clinic, India, noted that MSICS and phacoemulsification (phaco) are the two most common kinds of cataract surgery done in the world which can help patients achieve excellent vision without spectacles.
MSICS versus phaco Dr. Gogate and his team did a meta-analysis comparing MSICS and phacoemulsification using the DerSimonian-Laird method by looking at 70 to 80 studies. “We found no difference between phaco and SICS on best corrected and unaided visual acuity at the 6/18 and 6/60 cut-offs, though phaco gives better unaided vision at 6/9 visual acuity cut-off. There was no difference for endothelial cell loss or intraoperative and postoperative complications score. SICS was safer for beginner surgeons, while astigmatism is less in phaco,” the investigators reported. “Phaco and SICS are comparable and each has its own merits. Nevertheless, SICS is easier and can give better outcome than phaco in patients with very hard cataracts, very old patients with poor endothelial cell counts, post keratoplasty patients, or patients with uveitic cataracts or subluxations,” concluded Dr. Gogate. According to Dr. Debashis Bhattacharya, founder of the Disha Eye Hospitals in India, wound construction is the mainstay in SICS. He explained about external incisions, frown incision,
Chevron incision and a straight incision with a back-cut. He noted that incisional length is designed based on nuclear size and hardness. “The cataract is not only wide but thick and the scleral pockets are like pleats in the trousers to accommodate the thickness. It is safer to have a bigger incision and stitches if required, than to give a smaller incision that can cause tissue damage,” he advised. “The advantage of SICS is even though we have a very hard cataract nucleus, we are still able to remove it safely through a good incision. The incision is always a delicate balancing between safe sutureless wound closure and astigmatism, versus the facilitation of nucleus delivery,” explained Dr. Bhattacharya.
Modified instruments and incisions Meanwhile, Dr. Amulya Sahu, chairman of Sahu Eye Hospital, India, shared his experience with 2mm topoguided MSICS which he made possible through the modification and innovation of various instruments, thus contributing to emmetropia, postoperative correction in astigmatic error and quick postoperative recovery. These modified instruments included the single jet cannula with a small blunt tip at the front to help remove the lens from the posterior capsule and bring it to the anterior chamber, the vectis with a hanging surface at the front to hold and retrieve the lens, the modified Visco cannula, modified Simco cannula and revolving axis marker. Presenting on the topic of Astigmatismfree MSICS by Wound Modulation, Dr. Jagannath Boramani from Surya Netralaya, India, noted that literature review shows that in phacoemulsification and MSICS, different lengths, locations (superior, superotemporal or temporal) and shapes of the incision can cause different degrees of surgically induced astigmatism (SIA).
Having studied different types of scleral incision, Dr. Boramani found that the shorter the length of a straight incision is, the lesser the SIA. “Make the incision slightly curved, and the incision is further reduced. If you have a perfect U shape incision, there is almost no astigmatism. With meticulous tunnel engineering, it is possible to wipe out or at least minimize the stigma of astigmatism,” he shared.
Software matters Talking about software-assisted SICS, Dr. Rajeev Raut, chairman of the Life Science Research Trust, India, said that the principle is to deform the cornea before incision in order to get a spherical cornea after incision. “The software asks for preoperative corneal curvatures, corneal thickness, white-towhite diameter and intraocular pressure. It calculates how much to deform the cornea to achieve optimum postoperative shape. “Postoperative assessment found that corneal thickness values were consistent with earlier published reports on outcomes after SICS. Visual outcomes at the end of two months in 30 cases showed that 27 out of 30 patients could see TV and mobile phones without glasses. Subjective happiness was high.” Dr. Raut concluded that using an online algorithm based software to achieve the desired pre-incision shape makes the technique reproducible. “Infinite possibilities to study and improve the algorithm by artificial intelligence ensures continuous betterment of results. Low cost and friendly serverbased software maybe also be attractive to surgeons,” he said. Last but not least, Dr. M.S. Ravindra from Karthik Netralaya, India, shared surgery videos to help practitioners aspiring to explore phacosection, which according to him, is a safe cataract surgery which yields excellent results. “Performed under topical anesthesia, it harnesses the surgeon’s skills and uses less equipment. Fine manual control of fluidics makes surgery safer. The control on SIA is tunable and endothelial loss is at the lowest. Challenging cataract presentations can be comfortably handled with less risks,” explained Dr. Ravindra.
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