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Novel technique preserves capsular bag in cases of dangling crystalline lens
Anterior segment and microincision vitrectomy techniques are combined to enable in-the-bag placement of a foldable IOL.
A combined anterior and posterior surgical procedure may be considered a viable treatment option for patients with severe zonular dehiscence and a nearly luxated lens, according to a report.
The authors described a novel method of combining microincision pars plana vitrectomy, posterior levitation of the crystalline lens, phacoemulsification with sutured capsular tension rings and in-the-bag IOL placement.
“[The] dangling lens phacoemulsification technique allows preservation of the capsular bag, standard phacoemulsification and, ultimately, in-the-bag intraocular lens placement, which fully preserves the natural anatomy of the anterior segment in eyes with severe zonular dehiscence,” study author Okan Toygar, MD, told Ocular Surgery News. “Another advantage of this technique is that you can implant any desired IOL, including premium multifocal and toric IOLs, into the eye, which is not possible with pars plana lensectomy.”
The report was published in the Journal of Refractive Surgery. The surgeries were performed by Michael E. Snyder, MD, and Christopher D. Riemann, MD, at the Cincinnati Eye Institute.
Novel vs. conventional technique
Severely subluxated or completely luxated crystalline lenses are typically managed with pars plana lensectomy with or without secondary IOL placement, Toygar said.
“During this conventional technique, posterior phaco fragmentation liberates lens material into the vitreous cavity that may end up caught in the residual vitreous base where it is difficult to remove and may cause inflammatory complications,” he said. “The patient may be left aphakic and contact lens dependent or may receive an anterior chamber IOL, iris-fixated lens or a sutured posterior chamber IOL.”
Complications of these IOL placement techniques include peaked pupil, photophobia, iris capture of the IOL, iritis, pigment dispersion glaucoma, uveitis-glaucoma-hyphema syndrome, secondary IOL subluxation and cystoid macular edema.
“Additionally, IOL options for non-in-the-bag applications are limited in the U.S. There are currently no IOLs that are FDA approved for placement anywhere but within the capsular bag. Techniques for the off-label placement of posterior segment polymethyl methacrylate IOLs often require large wound sizes of up to 7 mm,” Toygar said.
The new technique involves a fairly short learning curve for experienced surgeons, Toygar said.
“If the anterior segment surgeon is experienced in the management of complicated cataract surgeries and IOL implantation techniques, the learning curve will not be so long. For the vitreoretinal surgeon, it is not so difficult to hold the lens in the retropupillary space, but core vitrectomy and 360° peripheral vitrectomy have to be performed very carefully to not damage the crystalline lens,” he said.
Vitrectomy and capsulorrhexis
Toygar and colleagues attempted a small-incision, capsule-sparing procedure to maximize small-incision safety in a patient with high axial myopia who had spontaneous loss of vision because of an unstable crystalline lens. If the capsule could not be preserved, surgeons devised a back-up plan of performing a pars plana lensectomy and secondary sutured posterior chamber IOL implantation.
A core vitrectomy and 360° peripheral vitrectomy were performed. A light pipe and soft tip cannula were used to rotate the dangling lens anteriorly and draw it into the retropupillary space.
The anterior segment surgeon created a 2.2-mm temporal limbal tunnel, and a 30-gauge needle was passed through the inferotemporal paracentesis to create another tunnel through the superonasal limbus. The anterior capsule was then pinched between the needle tips. One needle was used to penetrate the anterior capsule and create a small flap.
An iris retractor hook was inserted onto the margin of the rhexis to engage the capsular bag and provide countertraction for continuation of the capsulorrhexis and additional support for the lens and capsule in the retropupillary space.
The vitreoretinal surgeon placed two iris hooks opposite the remaining intact superior zonules and withdrew the soft tip cannula and the light pipe. Sequential insertion of the iris retractor hooks into the margin of the capsulorrhexis completed the capsulorrhexis. Hydrodissection was performed with four iris hooks supporting the crystalline lens.
Phaco and IOL insertion
Bimanual phacoemulsification was performed with the Constellation system (Alcon). A CV8 Gore-Tex suture, a modified capsular tension ring suture (Morcher) and a temporary 10-0 nylon suture were used to close the capsular bag structure.
The remaining cortical and epinuclear fragments were removed, and the posterior capsule was polished. An SN6AD1 8.50 D multifocal posterior chamber IOL (Alcon) was injected into the capsular bag.
A pair of sclerotomies into the ciliary sulcus were created superiorly, 180° away from the modified capsular tension ring suture fixation site. A capsular tension ring segment was placed into the superior capsular bag and suture fixated to the superior scleral wall.
The Gore-Tex knots were snugged to stabilize the capsular bag structure. The knots were tied, trimmed and rotated intraocularly. Plain 6-0 gut sutures were used to close Tenon’s fascia and conjunctiva. – by Matt Hasson
- Reference:
- Toygar O, et al. J Refract Surg. 2015;doi:10.3928/1081597X-20151111-10.
- For more information:
- Okan Toygar, MD, can be reached at Bahcesehir University Medical Park Göztepe Hospital, E-5 uzeri 23 Nisan sok. No:17. Merdivenkoy, Kadikoy, Istanbul, Turkey; email: otoygar@yahoo.com.
Disclosure: Toygar reports no relevant financial disclosures.