OVDs in Challenging Surgeries

Traumatic Cataract With Vitreous in the Anterior Chamber
Garry P. Condon, MD
A 62-year-old white male was hit in the eye with a fishing sinker 3 months before presenting to my office. In the OR, the eye had a fairly large area of iridodialysis nasally and superiorly as well as a fixed pupil of approximately 7 mm in an undilated state. Furthermore, a generous amount of vitreous extended around the equator of the lens and came out underneath the bridge of iris in the zone of iridodialysis (Figure 1).

VISCODISSECTION AND PLACEMENT OF A CAPSULAR TENSION RING
I placed iris hooks to keep the iris out of the way, and I used the most accessible OVD to viscodissect the cortex of the lens away from the capsular bag. In a traumatic case like this one, I tend to put a standard capsular tension ring (CTR) in the capsular bag before I start removing the nucleus. I do this for two reasons. First, if I can viscodissect the material away from the capsule, I can insert the CTR without trapping too much cortex. Second, a CTR will stabilize the nucleus, especially when I start removing soft cortical and soft nuclear material. Otherwise, the entire bag will roll forward with any amount of aspiration.

Once I had the CTR in the capsular bag and sufficient tension in the posterior capsule, I moved the two iris retractors forward so they were located centrally around the edge of the bag to support the anterior-posterior position of the bag-ring complex. The CTR provided so much stability that removing the nucleus was routine. In a traumatized eye, if there are at least 180º of normal zonules, a simple CTR will often provide more than enough stability and distribution of the stable zonular forces to the rest of the capsular bag so that I can implant the IOL in the bag without any suturing.

After cortical removal, before I extracted the phaco tip from the eye, I instilled more dispersive OVD to make sure the vitreous stayed away from the capsular bag. I repeated the injection each time I exited the eye. Then, I implanted a single-piece lens in the bag.

IRIS REPAIR
Rather than take the iris hooks out through the cornea and drag out what vitreous was wrapped around them, I released the silicone “doughnuts” on the hooks and took them out through the main incision. I then began to repair the iris. I inserted a few straight STC needles (Ethicon, Inc., Somerville, NJ) through the iris, including the torn distal edge, to anchor it as well as possible to the sclera (Figure 3). I also used a microforceps manufactured by MicroSurgical Technology (Redmond, WA) to hold the edge of the iris while I inserted the needles. When suturing an IOL or CTR, it is important to aim posteriorly to the original iris insertion. Attaching the torn edge of the iris too anteriorly will occlude the angle in that area. I will try to go through the anterior portion of the pars plana or the ciliary body so that any bunching up of the iris will be significantly behind the scleral spur.

VITREOUS EXTRACTION
Once the IOL was well centered and the iris anchored, I addressed the vitreous. I first used BSS (Alcon Laboratories, Inc.) to irrigate out the cohesive OVD, which mobilized the vitreous within the anterior chamber. I used Triescence (Alcon Laboratories, Inc.), a preservative-free triamcinalone diluted 1:4 with BSS, to easily stain the vitreous material in the anterior and peripheral posterior chambers. After placing an anterior chamber maintainer, I inserted a 20-guage vitrector through the pars plana, 3.5 mm posterior to the limbus. Without getting too close to the capsule, I retracted and removed the prolapsed vitreous with this posterior approach. I then switched to the vitrectomy I/Acut mode on the Infiniti Vision System (Alcon Laboratories, Inc.) to clear the anterior chamber of any residual vitreous strands and viscoelastic.

CONCLUSION
Postoperatively, the patient has regained uncorrected vision of 20/30. I prefer to delay repairing the mydriatic pupil until the iris dialysis has stabilized substantially and the capsule’s edge has thickened. The delay avoids my inadvertently tearing the capsule with the tip of a sharp needle in the presence of a freshly placed CTR, which can disastrously undo all that has been accomplished.

I prefer the ultimate versatility of the combination of a dispersive and cohesive OVD in these cases. I take advantage of the highly specific dispersive property of Viscoat, which resists removal and creates a durable barrier to prolapsed vitreous when there is active aspiration in close proximity. The ProVisc provides a workspace for the needle’s placement with exquisite visibility, and yet it is easy to remove without dragging the vitreous back into the game.

Garry P. Condon, MD, is an associate professor of ophthalmology at Drexel University College of Medicine in Pittsburgh. He is a speaker for Alcon Laboratories, Inc., but acknowledged no financial interest in the products or other companies mentioned herein. Dr. Condon may be reached at (412) 359-6298; garrycondon@gmail.com.

View the three-part series of this case and others from Drs. Condon and Snyder at http://eyetube.net/v.asp?ladeki.

Phacoemulsification With a Double-Sutured, Intraoperatively Modified Capsular Tension Ring in Microspherophakia
Michael E. Snyder, MD
This case involved a very small eye: a 10-mm white-to-white microspherophakic eye of a 37- year-old white male. The eye had a trabeculectomy flap superiorly and significant posterior synechiae and peripheral iridocorneal adhesions (Figure 1). I disregarded the adhesions because they had been there a long time, but I planned to break the synechiae to improve my visualization of the eye. I began the case by filling the anterior chamber with DisCoVisc and instilling Viscoat (Alcon Laboratories, Inc., Fort Worth, TX) in the periphery. I selected DisCoVisc to pressurize the anterior chamber because of its excellent cohesive properties and its ability to at least partially flatten the highly convex anterior surface of the cataractous lens. A flatter anterior capsule reduces the risk of a peripheral extension of the capsulorhexis. The Viscoat in the periphery provided a “blanket” of dispersive protection of the exposed hyaloid face; I was attempting to reduce the risk of vitreous prolapse through the sparse zonules. I chose to use iris hooks instead of a Malyugin ring (MicroSurgical Technology, Redmond, WA) to expand the pupil, because I anticipated needing to place the hooks around the edge of the capsular bag and iris margin to stent to the scleral wall at the limbus.

THE CAPSULORHEXIS
The lens moved as I began the capsulorhexis, so I used an iris hook to exert a little posterior pressure on the lens to hold it still. All the zonules were extremely weak; when the patient was upright, his lens subluxated inferiorly. I instilled trypan blue dye to help me visualize the capsulorhexis (especially with weak zonules, it is much easier to catch an errant tear quickly if the capsule is stained).

Because a microspherophakic lens is small in its horizontal dimensions but quite large in its axial dimensions, there is a much greater tendency for the capsulorhexis to tear peripherally. Therefore, I intentionally began the capsulorhexis a lot smaller than I wanted it, and it ended up the correct size. I added extra OVD (both cohesive and dispersive) to keep the anterior chamber pressurized and prevent vitreous from coming around the equator.

NUCLEAR EXTRACTION AND IOL IMPLANTATION
Because of the laxity of the zonules, I used an ophthalmic viscosurgical device (OVD) in the periphery and beyond the equator of the lens to coat and pressurize the anterior chamber during hydrodissection. Subsequently, I was able to aspirate the soft nucleus very smoothly, without significant ultrasonic power. As I removed the lens, I periodically instilled an OVD into the anterior chamber to keep the pressure there higher than in the vitreous cavity, and I instilled a dispersive OVD into the capsular bag’s periphery to relieve the zonules of as much stress as possible and to keep the bag inflated while I aspirated the lenticular material. This agent remained in the bag while I performed the aspiration, owing to its dispersive-retentive properties.

The trabeculectomy flap was not functional, so scleral fixation was not contraindicated. Next, I inserted a 2L double-fixated capsular tension ring (CTR; Morcher GmbH). I manually “shrank” the ring by bending it slightly centripedally in several areas along its circumference so it would better fit the size of the capsular bag. I threaded a 10–0 nylon suture through the leading eyelet element to provide some countertraction as I gently fed the CTR into the capsular bag (Figure 2). The scleral fixation suture was preloaded through the eyelet on the fixation element. I used a bimanual approach (ie, holding the CTR with a Kuglen hook in one hand and a Sinskey hook in the other), and I then dropped the trailing element of the ring into the capsular bag. I was able to affix both sides of the bag with scleral suture fixation using 8–0 Gore-Tex (off-label for ophthalmic use; W.L. Gore & Associates, Inc., Newark, DE) through a 25-guage needle to dock the suture ends for ab interno suture passage with an ab externo scleral wall opening (Figure 3). Then, I implanted a single-piece AcrySof IOL (Alcon Laboratories, Inc.) in the capsular bag. I strongly prefer the flexible haptics of a single-piece lens when working with a small capsulorhexis or an unstable zonular apparatus.

Before closing the eye, I removed the OVD, which exited the eye beautifully in one cohesive element despite the iris’ slight floppiness. Some dispersive OVD will inevitably remain in eyes with compromised zonules, since one cannot be overly aggressive in irrigating and aspirating this area. The smaller molecular weight of the chondroitin sulfate in DisCoVisc causes less of a rise in IOP than does retained hyaluronic acid.1 Intraocular carbochol (Miostat; Alcon Laboratories, Inc.) can further mitigate any potential increase in IOP during the early postoperative period.

Most of this patient’s problems were phacomorphic, and he did not have any presentation of glaucoma or elevated IOP postoperatively. He regained 20/20 to 20/25 vision and was pleased with his outcome.

Michael E. Snyder, MD, is on the faculty and board of directors at Cincinnati Eye Institute and is a volunteer assistant professor of ophthalmology at the University of Cincinnati. He is a speaker for Alcon Laboratories, Inc., and a consultant to HumanOptics/Dr. Schmidt Intraocularlinsen, but he acknowledged no financial interest in the products or other companies mentioned herein. Dr. Snyder may be reached at (513) 984- 5133; msnyder@cincinnatieye.com.

1. Embriano PJ. Postoperative pressures after phacoemulsification: sodium hyaluronate vs. sodium chondroitin sulfate-sodium hyaluronate. Ann Ophthalmol. 1989;21(3):85-88, 90.

View the full video of this case as well as others from Drs. Condon and Snyder at http://eyetube.net/v.asp?geclim.