Modified manual small incision cataract surgery technique for phacoemulsification-trained surgeons

Abstract

Purpose: To present the technique and outcomes of a modified manual small incision cataract surgery designed for the phacoemulsification surgeons who are learning to perform manual small incision cataract surgery.

Methods: This was a retrospective, single-centred, comparative study. We included all the patients who underwent the modified manual small incision cataract surgery for visually significant cataract at Singapore National Eye Centre. All surgeries were performed by either a senior phaco-trained surgeon (M.A.) who had performed more than 500 manual small incision cataract surgery or a junior phaco-trained surgeon (D.C.) who had performed around 500 phacoemulsification but never performed any manual small incision cataract surgery. The main modification of this technique lies in the creation of an additional phaco-like main wound at 90° to the scleral tunnel wound, with most surgical steps performed through this additional wound. The outcomes were analysed and compared between the senior and junior surgeons. The main outcome measures were visual outcome and major intraoperative complications such as posterior capsular rupture and zonular dialysis.

Results: A total of 132 cases were included; 102 (77.3%) and 30 (22.7%) cases were performed by the senior and junior surgeons, respectively. Pre-operatively, 85.6% eyes had best-corrected visual acuity of counting fingers or worse. Postoperatively, the visual outcome at 1 month was similar between the senior and junior surgeons, with 68.7% eyes achieving a best-corrected visual acuity of ⩾6/12 (p = 0.17). No posterior capsular rupture, zonular dialysis or endophthalmitis was observed during the study period.

Conclusions: This modified technique may serve as a useful transition technique for the phaco-trained surgeons to develop skills in manual small incision cataract surgery, with demonstrable good visual outcome and safety.

Keywords: cataract; cataract surgery; phacoemulsification; small incision cataract surgery.

Figure 1.

Various steps of the modified manual small incision cataract surgery (MSICS): (a) a scleral tunnel (6–7 mm in width) is being created, starting from 2 mm posterior to the limbus, and advanced anteriorly along the plane of sclera and mid-posterior corneal stroma until approximately 1 to 2 mm beyond the limbus without entering the anterior chamber. (b) A clear corneal tunnel is being created, at 90° from the scleral tunnel, using a keratome in a similar fashion to the routine phacoemulsification. (c) an anterior continuous curvilinear capsulorrhexis is being performed through the clear cornea tunnel (CCT). (d) The scleral tunnel wound is being further enlarged internally within the cornea so that the inner wound was larger than the outer wound (a ‘funnel-shaped’ wound). (e) After hydrodissection, viscodissection is performed to prolapse the nucleus out from the capsular bag into the anterior chamber and out through the scleral tunnel wound, with pressure exerted on the posterior scleral tunnel wound edge. (f) The nucleus is completely removed from the anterior chamber. Through the CCT, irrigation and aspiration of cortical matter (g), insertion of an intraocular lens (h), and removal of viscoelastic are performed (i).

Figure 2.

Intraoperative anterior segment optical coherence tomography showing the cross-section of the scleral tunnel wound, with an upwards, posterior-to-anterior morphology.