The development of capsular tension rings (CTRs) has allowed cataract surgeons to extend the limits of phacoemulsification and in-the-bag placement of intraocular lenses (IOLs). In cases of profound zonular dialysis, the Cionni modified CTR (Figure 1) allows scleral fixation through 1 or 2 eyelets.
Currently described techniques for preplacing sutures for scleral fixation of the Cionni modified CTR use needles passed through the original phaco incision. This requires placing the primary incision along the axis of zonular dialysis or enlarging and/or distorting the wound to achieve proper positioning.1 Furthermore, these techniques result in blind passes under the iris to only approximate ciliary sulcus fixation.
We describe an external closed-system technique for preplacing sutures in the ciliary sulcus for the Cionni modified CTR under topical anesthesia.
A 14-year-old boy with Marfan's syndrome presented with a superiorly subluxated lens in his left eye, resulting in diplopia. Best corrected visual acuity (BCVA) was 20/50 and intraocular pressure (IOP), 14 mm Hg. The inferior zonules appeared stretched, with an apparent absence of zonules in the inferonasal quadrant without vitreous prolapse (Figure 2). After the risks and investigative nature of the surgery were explained, informed consent was obtained.
Under anesthesia comprising bupivacaine 0.75% and lidocaine gel 2% topically with intracameral nonpreserved lidocaine 1%, 2 paracentesis incisions were made inferiorly. Sodium hyaluronate 3.0%-chondroitin sulfate 4.0% (Viscoat®) was placed in the anterior chamber and over the area of zonular dialysis. After a 2.8 mm phaco incision was made in temporal clear cornea, a partial continuous curvilinear capsulorhexis (CCC) was created with a sharp cystotome. Two nylon iris retractors (Alcon) were positioned on the capsulorhexis edge and used for retraction and to place the lens more centrally (Figure 3).
A Utrata capsulorhexis forceps was used to complete the CCC, and hydrodissection was performed in a cortical cleaving fashion. Under low flow and vacuum, the irrigation/aspiration handpiece was used to remove the nucleus and cortex. Viscoat was then placed over the area of zonular dialysis to tamponade vitreous, and sodium hyaluronate 1.0% (Provisc®) was used to fill the anterior chamber, pushing the capsular bag posteriorly.
A localized conjunctival peritomy was made in the area of zonular dehiscence, and a 1.0 mm paracentesis was created 180 degrees away. A 0.5 inch 27 gauge needle bent at the hub on a Viscoat syringe was used to pierce the globe perpendicular to sclera at the ciliary sulcus, 1.0 mm posterior to the surgical limbus in the area of the dialysis. Once the eye was entered, the needle was rotated so it was parallel to the iris plane and advanced to the midpupillary space in a bevel-up position.
One end of a double-armed 10-0 polypropylene (Prolene®) suture on 2 long straight needles (Ethicon STC-6) was passed through the paracentesis 180 degrees from the area of dehiscence, keeping it anterior to the capsular bag. It was captured through the barrel of the 27 gauge needle, which was then retracted through the scleral puncture site, resulting in the suture passing through the paracentesis and across the ciliary sulcus (Figure 4).
The process was repeated, reintroducing the 27 gauge needle 1.0 mm meridionally adjacent to the initial scleral entrance. The other needle end of the double-armed 10-0 polypropylene suture was passed through the paracentesis and captured through the 27 gauge needle and was again retracted out of the eye (Figure 5).
Both ends of the double-armed 10-0 polypropylene suture were then pulled so the suture loop was brought into the eye through the paracentesis. A Kuglen hook was used to draw it out through the phaco incision (Figure 6). The loop was cut with Vannas scissors. The single-eyelet Cionni modified CTR (model 1L, Morcher GmbH) was brought onto the field. One end of the cut loop was passed through the eyelet and tied to the other cut end, keeping the suture anterior to the CTR (Figure 7). The knot was then rotated through the eye and out through sclera. The CTR was inserted in the capsular bag. The eyelet was positioned anterior to the capsulorhexis and dialed to the area of zonular dialysis (Figure 8).
A foldable acrylic posterior chamber (PC) IOL was inserted in the capsular bag, and the 2 iris retractors were removed from the eye. The 2 ends of the 10-0 polypropylene suture were pulled to provide adequate tension for centration of the capsular bag and IOL. One end of the polypropylene suture was cut short, and the suture ends were tied to each other in a 3-1-1-1-1 fashion (Figure 9). The suture was cut on the knot and rotated into the sclera. The overlying conjunctiva was closed at the limbus using a 10-0 polyglactin 910 (Vicryl®) suture.
The viscoelastic material was removed from the anterior chamber with the vitreous cutter, and acetylcholine chloride (Miochol®) was instilled. The phaco incision was then closed with an overlapping 10-0 polyglactin 910 suture.
On the first postoperative day, the patient's uncorrected visual acuity was 20/50 and the PC IOL appeared to be well centered. There was a 1+ anterior chamber cellular reaction with no corneal edema and no evidence of vitreous prolapsed anteriorly. The IOP was 8 mm Hg. At the 6 month follow-up, BCVA was 20/25 and IOP, 12 mm Hg. The IOL was well centered without pseudophakodonesis or evidence of pigment dispersion.
In the past, patients with significant zonular dialysis required intracapsular cataract extraction with placement of an anterior chamber IOL or a sutured PC IOL. With the introduction of the endocapsular tension ring, in-the-bag placement of a foldable PC IOL is possible and results in excellent centration.
However, in cases with profound zonular dialysis, the capsular bag may remain decentered or loose despite adequate expansion of the CTR. Furthermore, long-term progressive zonular weakening in eyes with pseudoexfoliation may result in significant pseudophakodonesis and late dislocation of an in-the-bag PC IOL.2,3
Although one can attempt to suture a standard CTR through the capsular bag, this may tear the capsule, dislocating the IOL. The Cionni modified CTR, which contains an angled hook extending off the ring with an eyelet to pass a suture through, is a safe method to achieve secure scleral fixation without violating the capsular bag.1 The CTR consists of an open, flexible, poly(methyl methacrylate) filament and eyelet.
Scleral sutures may be placed before or after insertion of the CTR. Placing the sutures after insertion is technically difficult and may result in tearing of the capsular bag or disruption of existing zonules as the inserted CTR will expand the bag toward the ciliary sulcus. Existing techniques preplace the suture needles through the incision in an open fashion, under the iris, and through the sclera to approximate the ciliary sulcus.1
The principles of our technique are similar to those described by Lewis4 for suturing PC IOLs in the ciliary sulcus using an ab externo approach.
Our ab externo technique has numerous advantages. As no blind needle passes under the iris are required, fixation is achieved at the exact scleral position for ciliary sulcus placement as identified externally. To achieve true sulcus fixation, we advocate entering the eye perpendicularly, 1.0 mm posterior to the surgical limbus in the vertical meridians and 0.5 mm in the horizontal meridians as reported by Duffey and coauthors5 in an anatomic study. This is important as incorrect placement of the CTR may result in iris damage, hemorrhage, or postoperative iris chafing. The procedure is safely performed under a closed system with no need to enlarge or distort the phaco incision to pass the suture needles to achieve proper position. Furthermore, no specialized equipment or intraocular needle drivers are required, and only one knot is used to support the CTR. If desired, a scleral flap or groove may be made to place the polypropylene suture within.
This technique can be performed using topical anesthesia, which allows for patient-assisted eye positioning to aid in the procedure. This technique has been used with 16 patients thus far with ideal intraoperative conditions, rapid recovery, and excellent postoperative results.
In cases of profound diffuse zonular weakness in which a double-eyelet Cionni modified CTR (model 2L, Morcher GmbH) is needed, this technique may be modified by passing both arms of a 10-0 polypropylene suture on a straight needle through the ciliary sulcus (as opposed to a paracentesis as described above) 180 degrees from the insertion of the sulcus-positioned 27 gauge needle. When the suture is hooked through the main incision and cut, there will be 4 cut ends—2 for each eyelet—to fixate to the sulcus 180 degrees apart.
We believe that this ab externo technique is a safe and effective method for scleral fixation of Cionni modified CTRs.
1. Cionni RJ, Osher RH. Management of profound zonular dialysis or weakness with a new endocapsular ring designed for scleral fixation. J Cataract Refract Surg 1998; 24:1299-1306
2. Nishi O, Nishi K, Sakanishi K, Yamada Y. Explantation of endocapsular posterior chamber lens after spontaneous posterior dislocation. J Cataract Refract Surg 1996; 22:272-275
3. Fischel JD, Wishart MS. Spontaneous complete dislocation of the lens in pseudoexfoliation syndrome. Eur J Implant Refract Surg 1995; 7:31-33
4. Lewis JS. Ab externo sulcus fixation. Ophthalmic Surg 1991; 22:692-695
5. Duffey RJ, Holland EJ, Agapitos PJ, Lindstrom RL. Anatomic study of transsclerally sutured intraocular lens implantation. Am J Ophthalmol 1989; 108:300-309