Microincision Cataract Surgery

1.8 mm Incisional Surgery

Pawel Klonowski; Robert Rejdak; Jorge L Alió


Expert Rev Ophthalmol. 2013;8(4):375-391. 

In This Article

Abstract and Introduction


Microincision cataract surgery (MICS) is an approach to cataract surgery through incision less than 1.8 mm with the purpose of reducing surgical invasiveness, improving at the same time surgical outcomes. The main confirmed advantages of MICS are the control and avoidance of surgically induced corneal astigmatism and the decrease of postoperative corneal aberrations. MICS has been demonstrated to be minimally traumatic surgery, providing better postoperative outcomes than standard small incision phacoemulsification. High degree of surgical innovation, use of advanced phacoemulsification surgical platforms with pressurized fluidic control and new surgical instrumentation, allow doing very sophisticated cataract surgery. MICS favors the use of fluidics, reducing the use of phacoemulsification power. Bimanuality provides opportunity to do manipulation in anterior chamber area easily and much more comfortably than with standard coaxial technique. Today, surgery is performed through 1 mm incision. The use of the modern MICS intraocular lens (IOL) requires incisions of 1.8 mm. The increased availability of MICS IOLs allows to select the best IOL as per the demand of the patient. Long-term stability of the MICS outcomes and wide range of surgical capacity makes MICS the most modern and adequate approach to minimally invasive cataract surgery.


Cataract surgery has experienced a large transformation during the last decades. This transformation has been in response to increased refractive requirements of patients and ophthalmic surgeons. New technology has allowed for unlimited development of the surgery technique and surgery tools. Refractive results of the surgery and new intraocular lens (IOL) technology has gained popularity among patients wanting to remove opaque lens. The need to improve surgical outcomes has led to further development of the surgery technique.

The driving force of cataract surgery development was incision size reduction. The trend to diminish incision size contributed to the development of the phacoemulsification machine, lasers and surgical tools. This evolution of eye surgery had led to development of bimanual cataract surgery with incision size lower than 1.8 mm. Separated irrigation and aspiration approved to use fluidics as a powerful tool and in this way use less phaco energy during each surgery. The reduction of the energy allowed diminishing the aggressiveness of the cataract surgery and improved surgical outcomes.

Microincision cataract surgery (MICS) was described first time by one of the authors named Jorge Alió in 2002 in Spain, as a new concept of cataract surgery based on bimanuality, new tools, fluidics and new concept of surgery technique.[1] Agarwal et al. and Tsuneoka et al. described in parallel this surgical approach to cataract surgery with other denominations such as Phaconit or bimanual phacoemulsification-aspiration.[2–6]

Nowadays, standard incision size in bimanual MICS (Bi-MICS) is 1.5 mm. The surgery is done with the proper set of tools, the efficient phaco machine and the appropriate surgical technique. The use of pressurized inflow of fluid is obligatory for MICS. We use precise irrigating choppers and I/A handpeaces which are dedicated to this size of the incision. Limitation of the MICS is based on the IOL technology. Until now we have only few IOLs meeting 1.5 mm MICS requirements. The surgical technique allows us to do MICS with sub 1.0 mm incision with new tool project.

Changes also occurred in coaxial phacoemulsification. The width of the phaco tip and the sleeve was reduced to 1.8 mm. Coaxial MICS (Co-MICS) belongs to the family of MICS. It does not have all the advantages of bimanual surgery but this technique allows implanting MICS lenses through the 1.8 mm incision.

MICS has gained popularity among surgeons. MICS surgery is well described in literature and large numbers of articles evaluating this novel surgical method are available. Many surgeons describe MICS as a favorable technique because this is not only the novel surgical technique but it has many advantages not available for standard coaxial or micro-coaxial phaco technique.[7] The future trends in cataract surgery will focus on bimanual cataract surgery.

The advantages of Bi-MICS surgery technique over the previous techniques are as follows:

  • Smaller incision

    • low impact on corneal biomechanics[8–10]

    • less surgically induced astigmatism (SIA)[11,12]

    • better postoperative corneal optical quality[13]

    • reduce the risk of endophthalmitis

    • lower risk of iris prolapse during the surgery

  • The separation of irrigation and aspiration

    • unlimited possibility of the fluid stream managing[5]

    • improves efficiency of the fluid managing system

    • improves access to nuclear fragments[14]

    • energy savings technique[12,15–17]

  • The flexibility of the two incisions

    • bilateral access to nuclear fragments[18]

    • better access to the anterior chamber[14,18]

    • easier capsulorhexis and hydrodissection

  • The small size of the instruments;

    • allows better intraocular view

    • The separate irrigation steam

    • may be used to protect the posterior capsule[19]

    • maintain stable AC during whole surgery.[20]

In the authors' opinion, the only limitation of this surgery is time-consuming learning curves. Each transition needs to be supported by well-based knowledge and practice. This is the reason why many surgeons in Europe are switching to MICS technique. So far, 16% of the European MICS cataract surgeons have replaced their older technique with MICS. Bi-MICS is different from coaxial phacoemulsification. Learning curves is crucial to become MICS surgeon.