Article Date: 1/1/2010

New Technology Brings Combined Procedures Into the Mainstream

New Technology Brings Combined Procedures Into the Mainstream

ROBERT A. SISK, MD ∙ TIMOTHY G. MURRAY, MD, MBA

Cataracts pose a significant challenge in the medical and surgical management of vitreoretinal diseases. Media opacities may limit biomicroscopic diagnostic imaging by reducing stereoscopic resolution of transparent pathology, such as intraretinal and subretinal fluid accumulation, retinoschisis, and pathologic changes of the vitreous. They further reduce the quality of optically dependent retinal diagnostic imaging, such as fluorescein angiography, indocyanine green angiography, autofluorescence imaging, and optical coherence tomography. From comparisons between third-generation OCT and spectral-domain images, it is clear that even subtle amounts of accumulated fluid can strongly influence the vitreoretinal surgeon's decision to treat or observe the patient.

PROBLEMS WITH PHACO AND VITRECTOMY

Intraoperatively, cataracts impair the operative window for the retinal surgeon and limit access to the peripheral retina and anterior vitreous. Inadvertent damage to the capsule during vitrectomy can require unplanned lensectomy, increase operative time and risk of corneal edema, supra-choroidal bleeding and retinal detachment. After vitrectomy, there is predictable worsening of lens opacities, particularly early feathering of the posterior capsule and late nuclear sclerosis. These complications further deteriorate the surgeon's view — which may already be hindered by corneal compromise, anterior chamber inflammation or tamponade — and limit visual recovery by spectacle correction.

Planned cataract extraction in the setting of retinal pathology can be addressed at three points: before, after or during vitreoretinal surgery. The former two options expose the patient to the risks of a second surgery and its anesthesia, prolonged visual recovery and additional physical, financial or occupational strain on the patient and caregivers.

Medically frail patients and their families may not be able to tolerate these hardships. Cataract removal following vitrectomy is associated with increased rates of capsular tears, vitreous loss, retinal tears and detachment, zonular compromise and intraocular lens dislocation, and loss of lens material posteriorly into the vitreous cavity. Typically, technological advances have enabled improvements in surgical approach and have been particularly relevant in the application of small-gauge vitreoretinal surgery and microincisional cataract management.

Robert A. Sisk, MD, and Timothy G. Murray, MD, MBA, both practice ophthalmology at the Bascom Palmer Eye Institute at the University of Miami in Florida. Neither author reports a financial interest in any products mentioned in this article. Dr. Sisk can be reached via e-mail at rsisk@med.miami.edu.

INTRASURGICAL CATARACT REMOVAL

Performing cataract removal at the time of vitreoretinal surgery offers several distinct advantages over separating the procedures. If vitreous loss or a dropped lens occurs, the surgical team is already prepared for posterior vitrectomy. Anterior vitrectomy without visualization of traction on the peripheral retina may increase the rate of retinal tears and vitreous prolapse via anteriorly directed traction toward the cutter through limbal incisions. The decision of whether and where to place an IOL can be made following the vitreoretinal procedure.

This decision is particularly important for vitreoretinal pathology that may prohibit placement of an IOL or require removal of the scaffold of the lens capsule (eg, anterior proliferative membranes). Posterior capsular opacification can be prevented by posterior capsulotomy during vitreous surgery, obviating risk of retinal tear by laser capsulotomy.

In general, retinal surgeons make every attempt to coordinate planned combined cataract extraction with a cataract surgeon. However, it may be more appropriate for the vitreoretinal surgeon to perform the entire procedure when vitreous loss is anticipated or when the capsule, corneal endothelium or zonular support are preoperatively compromised. This decision simplifies postop care for patients and their families and alleviates the logistical limitations of coordinating the schedules of multiple surgeons. Visually significant retinal diseases are a relative contraindication to refractive surgery and toric or multifocal IOLs, and this combined approach is not advocated for those candidates.

COMBINED PROCEDURES USING MIVS

Retinal surgeons face increasing volume demands to offset reduced reimbursement for surgical procedures. The paradigm has shifted from hospital-based surgery to ambulatory surgery centers to meet these increased demands. A wellrun ASC can decrease turnover time, increase operative efficiency and result in a reduction in the use of secondary machines to accomplish surgical goals. These changes have followed the widespread acceptance of microincisional vitrectomy surgery (MIVS). First-generation MIVS technology was criticized for increases in postoperative hypotony and endophthalmitis. Critics also argued that reduced fluidics efficiency during core vitrectomy offset time gains in opening and closing incisions.

These criticisms spurred significant engineering advances in vitrectomy technology, especially in the area of MIVS. Automated infusion priming and setup, radio frequency identification and automated gas filling improve operative efficiency by freeing surgical assistants to perform other duties. Integration of phaco, vitrectomy and laser into a single machine with a touch-screen interface allows rapid progression through surgical steps without unnecessary delays. Increased cut speed and improvements in tubing compliance allow for robust removal of core vitreous similar to 20-gauge performance. Duty-cycle control of the pneumatic cutter facilitates rapid vitreous removal while providing stability around delicate peripheral cortical vitreous and retina. Increased safety and reduction in operative complications improve overall efficiency by reducing the number of steps in the procedure.

Phacoemulsification technology on the newest-generation vitrectomy units is now similar to the latest dedicated phacoemulsification units. Improvements in tubing design, Venturi pump and torsional technology have been applied to the integrated anterior and posterior unit such that the surgeon does not compromise performance compared to using separate machines. These practical improvements facilitate rapid, efficient removal of the lens nucleus and cortex, and seamless transition to vitrectomy.

We utilized this combined approach of phaco and 23-gauge pars plana vitrectomy at Bascom Palmer Eye Institute for over 150 cases with complex vitreoretinal diseases appearing with visually significant cataracts. The indications were diverse and included vitreous hemorrhages, retinal detachments and macular diseases. Intraoperative complications were few and consisted mainly of capsular tears in patients with predisposing factors such as prior core vitrectomy, ocular radiation and zonular weakness. Vitrectomy was performed following phacoemulsification in all cases, and placement of trochars did not contribute to capsular tears or zonular instability. Postoperative hypotony was uncommon, and we experienced no cases of endophthalmitis. This unique approach minimizes recovery time, limits second-surgery complications, and potentially en hances both the rapidity and extent of final visual recovery.

CONCLUSION

Cataracts are common and frequently comorbid with vitreoretinal diseases. Combined phacoemulsification and vitrectomy can be safely and efficiently utilized to tackle complex vitreoretinal pathology. Advances in vitrectomy and phaco technology have been integrated into a single unit to facilitate rapid transition from anterior to posterior procedures. From our experience, intraoperative and postoperative complications do not occur with greater frequency than would be expected from each procedure alone. RP

Case Description

A 54-year-old male with a radiation-induced cataract from plaque radiotherapy and intravitreal triamcinolone acetonide for a retinal vasoproliferative tumor and exudative retinal detachment was treated with combined phacoemulsification and vitrectomy with membrane peeling and endolaser. Acuity improved from 20/60 preoperatively to 20/30 with resolution of macular, subretinal and intraretinal fluid. Our standard combined procedure is described below.

After a povidone-iodine preparation and sterile draping, 23-gauge trochars were inserted 3.5 mm posterior to the limbus in a 15° beveled fashion, and then directed perpendicularly towards the optic nerve. The superior 23-gauge ports were temporarily occluded and the infusion cannula was connected but kept off until the phacoemulsification portion of the procedure was completed. Clear corneal incisions were created and viscoelastic was injected. A 5-6 mm continuous curvilinear capsulor hexis was performed with Uttrata forceps. After hydrodissection and rotation, the nucleus was removed using the bimanual divide-and-conquer technique. The cortex was removed with automated aspiration, and the capsular bag was inflated with viscoelastic. The 3-mm corneal wound was enlarged with a crescent blade to 4 mm. An acrylic foldable IOL (Acrysof MA60AC or MA50BM) was preferentially placed in the capsular bag, but the ciliary sulcus was used when inadequate zonular or capsular support was present. Viscoelastic was left filling the anterior chamber. The corneal wound was closed with a single nylon suture. Vitrectomy was performed using the Advanced Visual Instruments 130° widefield viewing system. Single interrupted sutures of 7-0 Vicryl were placed for any leaking wound following removal of the cannulas.



Retinal Physician, Issue: January 2010