Vitreoretinal Surgery Without the Aid of an Ophthalmic Surgical Assistant

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RETINA SURGERY RETINA PEARLS eyetube.net Section Editors: Dean Eliott, MD; and Ingrid U. Scott, MD, MPH Vitreoretinal Surgery Without the Aid of an Ophthalmic Surgical Assistant

Strategies for performing independent surgery of the vitreous and retina.

By Yannek I. Leiderman, MD, PhD

In this issue of Retina Today, Yannek I. Leiderman, MD, PhD, discusses instruments and techniques that facilitate successful vitreoretinal surgery in the absence of a surgical assistant. We extend an invitation to readers to submit pearls for publication in Retina Today. Please send submissions for consideration to Dean Eliott, MD ([email protected]); or Ingrid U. Scott, MD, MPH ([email protected]). We look forward to hearing from you. — Dean Eliott, MD; and Ingrid U. Scott, MD, MPH

istorically, surgery of the vitreous and retina contact lens systems and noncontact visualization sys- has required a surgeon and an assistant skilled tems.3-5 My colleagues and I most commonly use either in the techniques and modalities of this highly the SDI-BIOM Wide Angle Panoramic Viewing System subspecialized discipline.1,2 Advances in vitreo- (Insight Instruments, Inc.) or the Resight Fundus Viewing Hretinal surgical instrumentation have introduced the system (Carl Zeiss Meditec). In addition to superior possibility of vitreoretinal surgery for most indications in optics, important features of both platforms include the absence of an assistant specifically trained to assist hands-free, surgeon-controlled focusing and automated with such procedures. or hands-free image inversion. The chief impediment to efficient independent surgery We perform macular surgery using either a dispos- has been the inability to perform peripheral vitrectomy able 36° field-of-view macular contact lens (SuperView with the aid of scleral depression, a mainstay of rheg- Tornambe Contact Lens, Insight Instruments, Inc.) or matogenous retinal detachment repair via pars plana the Resight macular lens (Carl Zeiss Meditec) noncon- vitrectomy. A number of strategies have been developed tact viewing system. One disadvantage of using a self- to overcome this and other technical challenges in “inde- retaining contact lens system is decentration; this may pendent” vitreoretinal surgery. This article describes my be minimized by the application of a matchhead-sized preferred technique together with practical advice to facil- or smaller quantity of viscoelastic agent to the concave itate the transition to independent vitreoretinal surgery. surface of the contact lens prior to initial lens placement. Application of the lens in this manner promotes adhe- BASIC TECHNIQUES sion and stability of the lens. Posterior Segment Visualization A variety of commercially available systems developed Trocar Placement for wide-angle viewing of the fundus are amenable to Several instruments have been developed to facilitate independent surgery, including self-retaining and sew-on independent accurate cannula insertion in microinci-

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sional vitrectomy surgery (MIVS), including devices that simultaneously stabilize the globe and allow displace- ment of the bulbar conjunctiva (eg, Dugel Entry Plate, Peregrine Surgical Ltd.) and trocar-cannula instruments incorporating calipers. I use valved cannulas (EdgePlus, Alcon Laboratories, Inc.) for independent surgery, as 2 independent instruments are necessary for the placement and removal of cannula plugs, which, in the absence of an assistant, can lead to unsafe intervals of low outflow resistance.

Peripheral Vitrectomy There are a number of commercially available instruments to facilitate independent peripheral vitrectomy with the aid of scleral depression, including extraocular transscleral light sources, operat- ing microscope-based transpupillary illumination (OFFISS, Topcon Medical Systems), and intraocular Figure 1. Surgical instrumentation for 25-gauge pars plana self-retaining illumination. The latter are now widely vitrectomy performed without the aid of an assistant. A used devices in vitreoretinal surgery, and designs limited conjunctival peritomy and 20/25-gauge sclerotomy include single- or twin-fiber sources that may be adapter (Alcon Laboratories, Inc.) are shown for removal of a inserted via instrument cannulae or de novo. I use the luxated crystalline lens via pars plana lensectomy and subse- Alcon 25-gauge Chandelier Illumination System, a quent anterior chamber intraocular lens insertion. A single- single-fiber endoilluminator that may be inserted via fiber endoilluminator is in place via the preexisting superona- a fourth MIVS cannula or via a preexisting cannula. sal instrument cannula to facilitate peripheral vitrectomy with One advantage of this system is that an additional the aid of scleral indentation. The semirigid portion of the (fourth) cannula need not be placed for peripheral illuminator cable is affixed to the surgical field in a gooseneck vitrectomy; the endoilluminator may be inserted via configuration; the axis of illumination can then be adjusted in any 1 of the existing 3 cannulae, and may then be the same fashion as that of a gooseneck desk lamp. reinserted in any other cannula to facilitate optimal intraoperative illumination. In the majority of cases, available on eyetube.net, illustrates independent the infusion need not be displaced, and adequate peripheral vitrectomy with the aid of scleral depression illumination is obtained by using 1 or both of the using a chandelier endoilluminator without the need superior instrument cannulae. Intraoperative adjust- for placing an additional instrument cannula. Glare ments to the endoilluminator orientation may be from a chandelier illuminator can be bothersome dur- necessary for optimal visualization. To facilitate ing fluid-air exchange, in which case the chandelier may simple and rapid reorientation of the endoillumina- be extinguished or replaced with a light pipe. tor, I fixate the semirigid portion of the cable in a gooseneck configuration (Figure 1); the axis of illu- Examination of the Peripheral Retina mination can then be adjusted in the same fashion I perform examination of the periphery with the as that of a gooseneck desk lamp. The surgical video, aid of scleral depression for 360° at the conclusion of “Independent Surgery of the Retina and Vitreous,” every vitreoretinal surgical procedure. Although there are data to suggest that the incidence of iatrogenic or watch it now ON eyetube.net occult retinal breaks is very low in the setting of MIVS, the rate is not zero. Moreover, the influence of chande- Independent Surgery of the Retina lier endoillumination or other factors during indepen- and Vitreous dent surgery is unknown with regard to new or missed By Yannek I. Leiderman, MD, PhD intraoperative retinal breaks. One time-tested approach is to perform scleral depression using a cryopexy probe direct link to video: so that any breaks or suspicious lesions can be treated http://eyetube.net/?v=smeem as they are noted. If a self-retaining endoillumination source has been used previously during the procedure,

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Figure 2. Peripheral fundus examination with the aid of scleral indentation revealing the nasal ora serrata. Independent examination is performed using a noncontact wide-angle visualization system with hands-free, surgeon-controlled focusing and illuminated curved endolaser probe to facilitate treatment of any lesions noted during the course of examination.

this may be used to facilitate simultaneous scleral- depressed peripheral examination and treatment of any lesions with endolaser. In the more common scenario, in which I am work- ing with a qualified assistant and have not used a chandelier, I often prefer to perform independent peripheral examination with treatment of any lesions via endolaser (Figures 2 and 3). A number of illumi- Figure 3. Focal endolaser retinopexy applied to the anterior nated endolasers conferring high-resolution intraocu- margin of a giant retinal tear in a phakic patient via illuminat- lar visualization are available in a variety of MIVS plat- ed curved endolaser probe with the aid of scleral indentation forms. Peripheral examination and laser application (A). Postoperative result demonstrating the posterior aspect can be performed using an illuminated curved endola- of the giant retinal tear (B). The retina is attached throughout. ser (see video, “Independent Surgery of the Retina and Vitreous”). This technique may also be used for the efflux of intraocular gases (a vent is included with peripheral scatter panretinal photocoagulation. It is most valved cannula systems). worth noting that some surgeons still prefer to exam- ine the retinal periphery via intraoperative binocular TECHNIQUES FOR COMPLEX PATHOLOGY indirect ophthalmoscopy, with treatment Combined Pars Plana Vitrectomy and Scleral Buckle of peripheral lesions via concomitant cryopexy or In the execution of combined vitrectomy-buckle laser indirect ophthalmoscopy6; this technique is surgery, most surgeons now use a solid silicone rubber worth noting in the event that the aforementioned encircling band. Most commonly I place a Type 41 or tools are unavailable. Type 42 encircling band approximated with a silicone rubber sleeve to support the vitreous base. Although it Air-Gas Exchange may be helpful for an ophthalmic assistant, such as the The prime considerations in air-gas exchange are scrub nurse, to manipulate the rectus bridle sutures, control of intraocular pressure via maintenance of resis- placing a relatively narrow band immediately posterior tance to outflow and minimizing the potential for iat- to the rectus muscle insertions is readily done; often, the rogenic injury. Although a 2-needle approach to air-gas band may be localized without the aid of an assistant. exchange offers excellent control of outflow resistance, it may be technically challenging during independent Anterior Dissection surgery. Using a valved-cannula system, I prefer to Thorough anterior dissection in the setting of anterior inject gas via a syringe connected to the silastic infusion proliferative vitreoretinopathy is often performed with tubing while passive egress occurs via an instrument simultaneous deep scleral indentation and vitrectomy cannula. Note that it is critical to place a bypass chan- via direct transpupillary visualization with the aid of nel (“vent”) in the valve of the egress cannula to allow (Continued on page 44)

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(Continued from page 34) external illumination provided by a skilled assistant. A skilled assistant may be indispensable in the execution of this surgical element. Nonetheless, some cases may be performed using chandelier endoillumination. In select cases, simultaneous self-retaining endoillumination as well as external illumination may be helpful, particularly with an inexperienced assistant.

CONCLUSIONS Commercially available vitrectomy platforms and ancillary tools allow safe and efficient surgery without the aid of an ophthalmic surgical assistant for a wide variety of pathologies affecting the posterior segment. As with any modification of surgical procedure or technique, early success depends upon judicious case selection, familiarity with new technologies and tools, and thorough pre- and intraoperative communication among the core ophthalmic surgical team members comprised of surgeon, scrub nurse, and circulator. Formal clinical studies are required to assess the thera- peutic effectiveness, safety, efficiency, and cost effectiveness of independent vitreoretinal surgery. n

Yannek I. Leiderman, MD, PhD, is a surgeon on the Retina Service of the Eye and Ear Infirmary and Director of the Vitreoretinal Microsurgery Laboratory at the University of Illinois at Chicago. Dr. Leiderman states that he has received research support from Alcon Laboratories, Inc. (laboratory equipment). He may be reached via email at [email protected]. Dean Eliott, MD, is Associate Director of the Retina Service, Massachusetts Eye and Ear Infirmary, Harvard Medical School, and is a Retina Today Editorial Board member. He may be reached by phone: +1 617 573-3736; fax: +1 617 573- 3698; or via email at [email protected]. Ingrid U. Scott, MD, MPH, is a Professor of Ophthalmology and Public Health Sciences, Penn State College of Medicine, Department of Ophthalmology, and is a Retina Today Editorial Board member. She may be reached by phone: +1 717 531 4662; fax: +1 717 531 8783; or via email at [email protected].

1. Abrams GW, Topping T, Machemer R. An improved method for practice vitrectomy. Arch Ophthalmol. 1978;96(3):521-525. 2. Benson WE. Positioning of the surgeon and assistant for pars plana vitrectomy. Ophthalmic Surg. 1984;15(3):247. 3. Chalam KV, Patel CC, Shah VA. Newly designed self-retaining contact lens for vitreous surgery. Am J Ophthalmol. 2003;135:544-546. 4. Chalam KV, Shah VA. Self-illuminated contact lens for peripheral vitreous surgery. Ophthalmic Surg Lasers Imaging. 2004;35:76-77. 5. Spitznas M. A binocular indirect ophthalmomicroscope (BIOM) for non-contact wide-angle vitreous surgery. Graefes Arch Clin Exp Ophthalmol. 1987;225(1):13-15. 6. Morris RE, Shere JL, Witherspoon CD, et al. Intraoperative retinal detachment prophylaxis in vitrectomy for retained cataract fragments. J Cataract Refract Surg. 2009;35:491-495.

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