Two 10-0 noabsorbable surgical (Prolene) sutures are used to preplace an iris loop and a loop around the intraocular lens eyelet. The loops are sutured together at the 9-o'clock position, and the intraocular lens is repositioned by anchoring the iris sutures at the 12-o'clock position. (The figures are drawn from the surgeon's perspective.)
Azar DT, Clamen LM. Iris Fixation of a Decentered Silicone Plate Haptic Intraocular LensDouble Knot Technique. Arch Ophthalmol. 1998;116(6):821-823. doi:10.1001/archopht.116.6.821
We describe a novel technique for fixating a decentered silicone plate haptic intraocular lens. In the absence of posterior capsular tear or zonular dehiscence, the superior eyelet of the silicone plate haptic intraocular lens is sutured to the iris at the 12-o'clock position using a double knot technique. Two 10-0 nonabsorbable surgical (Prolene) sutures used to preplace an iris loop and a loop around the intraocular lens eyelet are sutured together at the 9-o'clock position. The intraocular lens is repositioned by anchoring the iris sutures at the 12-o'clock position. This technique allows one to avoid an explantation of the lens and implantation of a new intraocular lens.
The extensive surgical manipulations that were necessary in the early days of cataract extraction and intraocular lens (IOL) implantation tended to weaken the integrity of the lens capsule, leading to frequent cases of decentration and tilt of the IOLs. Today, with the improved techniques of endocapsular phacoemulsification, there has been a dramatic decrease in the incidence of IOL decentration and tilt.1 However, one is still occasionally faced with the problem of a decentered lens and the resulting need to then decide whether to explant or reposition the lens.
Historically, decentered IOLs were often explanted, and new lenses were implanted. Thus, over the years, ophthalmic surgeons have devised innovative methods of securing secondary IOLs.2,3 Sometimes, however, one can avoid lens explantation. In 1976, McCannel4 first described a technique for securing a displaced IOL using an iris fixation suture. McCannel's dislocated lens was an iridocapsular Binkhorst lens, the haptic of which he secured to the iris.4 Since the publication of McCannel's article, many other ophthalmic surgeons have used this technique and/or described new methods for suturing to the iris or sclera decentered polymethyl methacrylate IOLs with haptics, but not decentered silicone plate IOLs.5- 7 To our knowledge, this is the first report of suturing a decentered 1-piece silicone plate haptic IOL to the iris.
A 61-year-old woman was seen at our clinic 3 months after a phacoemulsification cataract extraction and implantation of a silicone plate IOL in her right eye. Her visual acuity was 20/30-1 OD and she complained of a halo effect when moving her head sideways. On examination of the right eye, the edge of the IOL could be seen through the dilated pupil, confirming an inferotemporal IOL displacement when tilting her head to the right, and an inferonasal displacement when tilting her head to the left. The lens, initially intended to be implanted in the bag, was noted to be in the sulcus. There was no evidence of posterior capsular tear or zonular dehiscence. The capsular bag was collapsed. Fundus examination results were normal. The patient was observed for a period of 4 months; her symptoms persisted and findings from the eye examination remained unchanged. The risks and benefits of as well as the alternatives to surgery were discussed. Rather than perform a lens explantation, a novel approach of fixating the decentered lens to the iris using a double knot technique was attempted. At the 2- and 7-week postoperative follow-up visits, the patient was doing well, without complaints. Her visual acuity was 20/20-2 and 20/25 OD at 2 and at 7 weeks, respectively. The lens was well centered and did not show evidence of dislocation.
A limbal stab incision is made at the 9-o'clock position and viscoelastic material is injected into the anterior chamber (Figure 1, A). A curved needle attached to the 10-0 nonabsorbable surgical suture (Prolene CIF-4) is passed through the incision and into the anterior chamber. The needle is then looped through the iris, to exit at the limbus (Figure 1, B). A stab incision is made at the limbus at the 12-o'clock position and a hook is passed into the anterior chamber, grasping the suture to create a loop (Figure 1, C). A hook passed through the 9-o'clock position incision to the posterior chamber grasps the loop from under the iris and pulls the loop out at the 9-o'clock position (Figure 1, D). An IOL forceps is used to pull the plate lens through the pupil. Preferably using a straight needle attached to 10-0 suture, another one of the 10-0 nonabsorbable surgical sutures enters the eye at the 9-o'clock position, is carefully passed through the eyelet of the IOL, and is pushed out through the cornea close to the limbus at the 2-o'clock position. The needle is cut from the suture (Figure 1, E). Passing a hook through the limbus at the 9-o'clock position, a loop is created through the eyelet of the plate lens (Figure 1, F). Now, 2 loops of suture exit the eye at the 9-o'clock position: the loop attached to the IOL and the loop passing through the iris (Figure 1, G). The IOL is rotated toward the 9-o'clock position and the ends of the 2 loops are gently pulled. A knot is tied near the eyelet of the IOL such that the 2 loops are tied together. The suture ends are cut flush at the knot (Figure 1, H). The sutures at the 12-o'clock position are gently pulled so that the IOL slips back under the pupil and is repositioned properly. A knot is made to secure the IOL to the iris, and the ends are cut flush at the knot. No sutures are required at the limbal incision sites (Figure 1, I).
Silicone plate IOLs may be more difficult to manipulate within the eye during IOL fixation than other lenses because they lack the easily grasped open-loop haptics. Thus, many surgeons choose to explant dislocated plate silicone lenses and replace them with new IOLs.8- 10 Other authors11 have described good results using creative methods to retrieve posteriorly dislocated silicone plate IOLs and reposition them to rest in the ciliary sulcus.
The technique described herein may also apply to subluxated and dislocated silicone plate haptic IOLs, as these occur more commonly than the decentered IOLs. The technique is modified to allow fixation through the inferior and posterior haptic eyelets after a dislocated silicone plate haptic IOL is retrieved into the pupillary plane. The IOL is sutured at the 12-o'clock position as described in this report for silicone plate haptic IOL decentration. Another suture may be placed at the 6-o'clock position before the suture at the 12-o'clock position is tied.
While foldable silicone haptic IOLs measure 14 mm in diameter, the 1-piece, silicone plate IOLs have a diameter of only 10.5 mm. Thus, the plate lenses are more likely to oscillate and decenter inferiorly. Inferior decentration of silicone plate lenses often causes no visually noteworthy problems. However, this type of lens dislocation occasionally leads, as it did with our patient, to decreased visual acuity as well as to a disturbing halo effect on movement of the head. The continued movement and rubbing of the displaced lens on the uveal tissue may lead to secondary complications such as inflammation, glaucoma, pain, glare, and hemorrhage.8 Despite symptomatic improvement of halos and blurred vision, it is not clear whether iris fixation of the silicone plate haptic lens alters the rate of potential secondary complications. When a decentered lens is symptomatic, one is left with the options of explanting or repositioning the lens. In the absence of zonular dehiscence or capsular tear, our method for iris fixation of a decentered silicone plate haptic lens requires minimal intraocular manipulations and avoids the need for IOL explantation and reimplantation.
Accepted for publication February 11, 1998.
The authors wish to thank Laurel Lhowe for the illustration.
Reprints: Dimitri T. Azar, MD, Director, Cornea Service, Massachusetts Eye and Ear Infirmary, 243 Charles St, Boston, MA 02114-3096 (e-mail: firstname.lastname@example.org).