This patient presents with a decade long history of very poor vision out of one eye. While there is no recollection of trauma, the pre-operative consultation reveals clues that suggest a prior blunt force injury. The patient now desires cataract surgery and we have to formulate and execute a procedural plan to ensure success. While phacoemulsification with ultrasonic energy is usually our preferred option, in this case MSICS (manual shelved incision cataract surgery) could be more favorable.
Pre-Operative Consultation
The patient has 20/25 vision from the right eye which has a mild degree of nuclear and cortical cataract development. The left eye is only able to perceive a strong light stimulus and there is a totally opaque cataract. While there are whitish streaks of cortical opacity in the cataract, the nucleus is very brunescent and dark in color, hinting at its very dense nature (figure 1). On closer inspection there is an area of extensive zonular loss with a gap seen between the iris and the anterior lens capsule of the cataract spanning about three clock hours or 90 degrees. There is slight phacodonesis but otherwise the rest of the anterior segment appears unremarkable.
Without a video through the dense cataract of the left eye, ultrasound is used to image the posterior segment and measure the axial length. To ensure proper calibration and accurate axial length measurement, an ultrasound axial length of the right eye is also performed by the same operator and it matches the previously obtained optical coherence biometry axial length of this eye. This gives a higher degree of certainty in having an accurate ultrasound axial length for this left eye with the dense brunescent cataract.
Surgical Technique
A retrobulbar block was used for anesthesia to keep the patient comfortable during this extended procedure which took 38 minutes. Equal parts of 2% lidocaine and 0.75% bupivacaine mixed for a total of 4 milliliters which was delivered into the muscle cone. The patient was draped in preparation for making a superior incision for the cataract surgery. The first step was to create a paracentesis and inject a small aliquot of triamcinolone into the anterior chamber to check for vitreous. While no vitreous prolapse was present initially, the zonular gap was confirmed as the triamcinolone particles drifted through that area and into the vitreous cavity.
Dispersive viscoelastic was used to plug the zonular gap and a small amount of trypan blue dye was painted on to the anterior lens capsule. The cystotome was used to puncture the anterior lens capsule and start the capsulorhexis, which proceeded without issues. It was also used to assess the nucleus which was found to be extremely dense. In a case like this, performing MSICS (manual shelved incision cataract surgery) to extract the nucleus whole would be safer than using excessive phaco energy in an attempt to break up the nucleus.
A superior MSICS incision at half-scleral depth was performed, keeping a long tunnel shelf and a trapezoid shape where the internal opening of the incision was a bit wider than the external opening. The nucleus was brought out of the capsular bag using hydro-dissection and placed on top of the iris. An opposite paracentesis incision was made to allow a second instrument to help push the nucleus out of the incision (figure 2). The nucleus was very dense and so brunescent that it was a dark as coffee. It also had a large anterior-posterior dimension of greater than 5 mm.
Bimanual irrigation and aspiration was used to remove the lens cortex and the capsular bag was then inflated with viscoelastic. A capsular tension ring was placed in the capsular bag to give support to the area of zonular loss (figure 3). After securing the capsule, triamcinolone was used to check for any vitreous strands. One small area of vitreous prolapse was identified and removed with the 23g bimanual vitrectomy instruments.
For the IOL choice, we have options which include placing the IOL into the capsular bag or into the ciliary sulcus. For optimal long term stability, a three-piece monofocal IOL was used with the haptics in the sulcus and the optic captured behind the capsulorhexis. By placing the haptics 90 degrees away from the area of zonular loss and by capturing the optic, we can provide a stable, strong, and safe place for the IOL for decades to come. The MSICS incision was sutured with 10-0 nylon to ensure a water-tight closure. The conjunctival was closed with 8-0 Vicryl to have a second layer of coverage and protection. The eye was medicated, patched, and shielded overnight.
Post-Operative Course
The patient is recovering nicely from the procedure with a clear cornea with light Descemet’s folds, moderate anterior chamber inflammation, and a well-positioned IOL (figure 4). The 10-0 nylon sutures are intended to be left in place while the 8-0 Vicryl sutures will slowly break-down and fall out over the next few weeks.
The MSICS procedure is a very valuable technique, particularly for very dense, brunescent cataracts. An added bonus is we can achieve efficient removal of the entire nucleus without risking lens fragments falling through areas of zonular loss. This is a technique that is performed widely across the world but is still very uncommon in the USA. I certainly encourage my American colleagues to learn the MSICS procedure so that tough cases like this can be conquered and we can deliver great vision to our patients.
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