Irregular or ragged incision – due to poor blade quality, surgeon inexperience, deep-set eyes, or improper dissection of the tenon’s capsule at the site of the incision.

Button holing of the scleral tunnel – Ideally the plane of sclera tunnel dissection should be mid stromal. A superficial dissection can result in scleral buttonhole with the loss of self-sealing character. Thinner flap and button hole of the superficial scleral flap can also occur while making back-cuts. To prevent these complications, it is important to start scleral dissection at a right depth and keep blade in the same plane as well as parallel to sclera. However, in the event of buttonhole, surgeons can either start fresh dissection at a deeper plane or suture the wound at the end of the surgery.

Premature entry – If the plane of dissection is too deep, one can inadvertently enter into anterior chamber prior to the completion of dissection of the tunnel. This in turn results in loss of self-sealing character of the wound and wound leak. All such wounds must be carefully examined at the conclusion of the surgery. If the wound is not watertight, one must not hesitate to apply sutures.

Intraoperative bleeding – The MSICS surgery can get complicated by excessive intraoperative bleeding from the anterior perforating vessels or injury to uveal tissues. If not managed properly, it can also result into postoperative hyphema. It is, therefore, important to identify anterior perforating vessels and cauterize these at point of scleral entry. Similarly, one must ensure to avoid uveal tissue injury during wound construction. Excessive intraoperative bleeding can be managed by air tamponade.

Detachment of scleral spur – Inappropriate dissection of scleral tunnel can lead to a localized detachment of the scleral spur which in turn leads to wound gape, wound leak, and high surgically induced astigmatism.

Failure to deliver nucleus

Zonular dialysis

Tear in capsulorhexis with consequent extension

Posterior capsular dehiscence

Iris prolapse

Iridodialysis

Hyphema

Failed delivery

Posterior capsular tear: If the sheet glide or irrigating vectis is used to facilitate nucleus delivery, then sudden shallowing of anterior chamber can result in posterior capsular tear.

Endothelial injury: Difficult nucleus delivery can also result in endothelial injury and even DM detachment.

Injury to iris tissue: Can occur from repeated prolapse and reposition or handling of iris. In cases where the iris is flabby and liable to chaffing with repeated episodes of iris extrusion out of the wound, suturing the wound is a good treatment option.

Posterior capsular tear or zonular dialysis: This can occur from inadvertently capturing posterior capsule. Management strategies for posterior capsular tear are similar to any other form of extracapsular cataract extraction. It is important to avoid repeated collapse of anterior chamber to avoid extension of the rent and minimize vitreous loss. A good vitrectomy with automated vitrector is necessary. Intraocular lens management is also same as with any other cataract surgery including the selection of intraocular lens, site of placement, and type of fixation. One must ensure that the lens is stable at the end of surgery and the anterior chamber is free of any vitreous strands.

Incomplete cortical clean-up: Especially the cortical matter present near equator of the capsular bag. Less efficient aspiration system combined with fluid pressure of anterior chamber maintainer is responsible for this complication.

Descemet’s membrane (DM) detachment – Compared to phacoemulsification, DM detachment is a relatively more common complication of MSICS. This higher predisposition is due to a larger area of dissection at the main wound and multiple side ports. The detachment can occur at the site of the main wound or side ports including the one used for inserting anterior chamber maintainer. The use of blunt instruments is a potential risk factor for DM detachment. Inserting anterior chamber maintainer while keeping irrigation fluid on can also result in DM detachment. The size of DM detachment varies depending upon the surgical step, time of its identification, and subsequent interventions. If goes unrecognized, it will result in severe postoperative edema depending on the size and location of the detachment. If recognized early, avoiding anterior chamber entry from the affected site will help limit the detachment. To facilitate reattachment, one can fill anterior chamber with air or perfluoropropane gas(C3F8) [37, 38]. Our experience suggests that air descemetopexy is safer and as effective as using C3F8 gas [37, 38].

Corneal edema or striate keratopathy – The rates of endothelial cell loss between various techniques of extracapsular cataract extraction has been comparable [39, 40]. The incidence of postoperative corneal edema following MSICS surgery is no different than in phacoemulsification. However, one can encounter this complication in the following clinical scenarios: (a) preoperative compromised corneal endothelium (b) Excessive endothelial cell loss from poor wound, repeated iris prolapse or difficult nucleus delivery. Corneal edema characteristically is most severe in the immediate postoperative period and clears gradually over a period of time without any special interventions. However, if the degree of endothelial injury is severe, the edema might not clear completely requiring endothelial replacement for the restoration of vision [41].