Scleral-sutured posterior chamber IOL fixation technique maximizes intraoperative centration

A girth hitch provides long-term four-point fixation and prevents IOL torque and tilt.

Issue: November 10, 2014

A novel scleral-sutured posterior chamber IOL implantation technique enables surgeons to control and maintain centration, according to a report.

Perspective from Amar Agarwal, MS, FRCS, FRCOphth

Michael E. Snyder

A girth hitch provides true four-point IOL fixation and helps the surgeon prevent IOL tilt, the study authors wrote in the Journal of Cataract and Refractive Surgery.

Many existing scleral-sutured IOL techniques lack long-term stability and control over centration and tilt, but this technique is easier to learn and offers more control than other scleral suturing methods, according to Michael E. Snyder, MD, the corresponding author.

“I think the learning curve is shorter, given that the sclerotomies are created in a controlled fashion externally, and keeping track of the suture loops is much easier when the manipulations in placing the sutures can be done without having the suture attached to the IOL during this process, since IOL movement, flipping or twisting near the operative site can tangle the suture loops, sometimes in non-obvious ways,” Snyder told Ocular Surgery News.

Paired openings in scleral wall

“This technique breaks each step of the procedure into discrete components, each of which has a quick learning curve in and of itself, and the steps can be combined in a modular way to master the overall procedure. The steps of this technique are also translatable to sutured capsular tension rings (Cionni), whether single or doubly fixated,” Snyder said.

The technique involves a side-port nasal paracentesis and centered conjunctival peritomy. Anterior vitrectomy is performed through a single-port pars plana cannula.

A temporal 7-mm scleral groove is carved posterior to the limbus and tunneled anteriorly into the margin of clear cornea. An anterior chamber maintainer is placed into the paracentesis, and the globe is pressurized.

A 15° blade is used to create two sets of 0.5-mm paired openings in the scleral wall, level with the ciliary sulcus. The openings in each pair are separated by 3 mm to 4 mm, and the sets are oriented 180° apart.

A needleless Gore-Tex expanded polytetrafluoroethylene CV-8 suture is placed in the anterior chamber through the main wound and retrieved with 25-gauge microforceps through one of the scleral openings. The other end of the suture is retrieved through the paired opening, with a suture loop exiting the eye through the main wound. The process is repeated with a second piece of suture at the opposite opening.

“All of the sutures are placed using microforceps, without making ‘blind pass’ needle sticks with sharp needles inside the eye, as is common with other ab interno techniques,” Snyder said.

Girth hitch, suturing

The proximal suture loop is folded over itself to create a girth hitch affixed to the trailing haptic of a CZ70BD PMMA IOL (Alcon). The IOL is oriented with the unattached haptic toward the wound. The fixation procedure is repeated with the distal suture loop and leading haptic of the IOL.

“By using the girth hitch, both arms of the suture loop pass above the haptic, eliminating the torque inherent in suture loops passed though the eyelets of a haptic, in which case one loop must be above while the other must be below,” Snyder said.

The IOL is guided into the ciliary sulcus, and the wound is secured with a running 10-0 nylon suture. The Gore-Tex sutures at one site are snugged, and a knot is tied over the more counterclockwise opening with a 2-1-1 configuration. The process is repeated at the opposing site and the other haptic. Both knots are trimmed and rotated inside the eye wall, and the IOL is rotated 1 to 2 clock hours clockwise at each location.

The surgeon can fine-tune IOL centration by sliding the external section of the Gore-Tex suture along the scleral surface until the Purkinje 1, 3 and 4 reflections are aligned.

“This provides an excellent adjustability to fine-tune to the pupil center. Also, having a wide span between the scleral openings at each site makes it easy to tie the knot external to the eye wall and then rotate the knot internal to the eye wall, while still controlling the final IOL position,” Snyder said. – by Matt Hasson

Reference:

Snyder ME, et al. J Cataract Refract Surg. 2014;doi:10.1016/j.jcrs.2014.08.022.

For more information:

Michael E. Snyder, MD, can be reached at Cincinnati Eye Institute, 1945 CEI Drive, Blue Ash, OH 45242; email: msnyder@cincinnatieye.com.
Disclosure: Snyder is a consultant to Alcon.

Perspective

Amar Agarwal, MS, FRCS, FRCOphth

The technique of modified scleral fixation of a posterior chamber IOL in eyes with aphakia mentioned by Dr. Snyder shows the innovative use of an expanded polytetrafluoroethylene suture in placing the IOL stably. The technique has been narrated adequately with good illustration. In sutured scleral-fixated IOLs, problems arise frequently due to the unstable positioning of the lenses in the long term. Pseudophakodonesis, or implant movement, in the long run is known to cause persistent inflammation in both the anterior and the posterior segments of the eye. The author, through his four-point fixation method of anchoring the haptic to the sclera by girth hitch, has provided equilibrium in the anchorage. Nevertheless, the tilt needs to be assessed objectively by optical coherence tomography or ultrasound biomicroscopy. Recent literature on glued IOLs has shown good functional outcomes in the long term with insignificant optic tilt. As far as the torque is concerned, the equidistant placement of the haptics and the symmetrical suture tension can reduce the tilt induced by torque effect. As the author rightly mentioned, the centration problems that can arise when the haptic is held via the eyelets may not be present here because they were stabilized by the haptic itself.

References:

Kumar DA, et al. J Cataract Refract Surg. 2013;doi:10.1016/j.jcrs.2013.01.039.
Kumar DA, et al. Ophthalmology. 2014;doi:10.1016/j.ophtha.2014.07.032.

Amar Agarwal, MS, FRCS, FRCOphth

OSN APAO Edition Board Member

Disclosures: Agarwal has no relevant financial disclosures.