SURGICAL PEARLS

Dropless Cataract Surgery

Better for the patient, better for the surgeon

BY JAMES C. LODEN, MD

The technology surrounding cataract surgery is impressive by any measure, and our techniques continue to be refined and improved. However, appropriate delivery of antibiotic and steroid drops continue to be not only a huge hassle, but also an important indicator of success that is out of our control. I started using transzonular injections of an antibiotic and steroid formulation for my cataract patients almost 1 year ago, and I wouldn’t go back to the old way.

Expense, Efficiency, Efficacy

The first impetus for investigating transzonular delivery of antibiotics and steroids for our patients was the amount of expense they were incurring with cataract surgery. While some patients have insurance that covers a large percentage of their medication costs, others have little to no coverage. The prices for generic post-operative drops have increased dramatically over the last year, and name-brand drops often cost patients somewhere in the vicinity of $350 out of pocket, which is more than the net amount a surgeon earns for performing the surgery. It’s not surprising that some patients delay surgery for the second eye because they can’t afford the drops.

In addition, there’s great inconsistency in what the pharmacist dispenses to the patient. If we allow generic drugs, the patient may receive any generic antibiotic or steroid ophthalmic drop. If we indicate that no substitutions should be made, substitutions are often still made. In a high volume practice, these changes create a good deal of chaos. The average number of cataract surgeries in our multi-partner practice is more than 100 a week. If each patient generates just one extra call from the pharmacy or patient to clarify medications, that requires nearly a full-time position just to respond to questions.

TriMoxi can be injected into the anterior vitreous with a transzonular approach during cataract surgery, eliminating or reducing the need for post-operative antibiotic and steroid drops.
IMAGE IS COURTESY OF AHAD MAHOOTCHI, MD

Another motivating factor is looking at the endophthalmitis rate with cataract surgery in the United States and comparing those rates to the rates in the United States and Europe where intracameral antibiotics are used. The rate of post-cataract endophthalmitis in the U.S. is around 1 in 500 (0.265%).¹ Part of this may be attributed to lack of compliance. We know from studies with glaucoma patients that even those who intend to use their drops often do so improperly.² A simple conversation with your cataract patients will reveal that many aren’t using the drops at the intervals indicated, which minimizes absorption.

A long-term study in the United Kingdom evaluated the use of intracameral vancomycin and found that the incidence of endophthalmitis prior to the introduction of intracameral antibiotic prophylaxis was 0.3%, which dropped to 0.008% after the introduction of intracameral antibiotics.³ This dramatic drop in risk was the greatest impetus for our practice to look seriously at the intraoperative delivery of antibiotics. Fortunately, our decision coincided with the availability of compounded Tri-Moxi (triamcinolone acetonide and moxifloxacin hydrochloride; Imprimis Pharmaceuticals), which is administered transzonularly during ocular surgery.

Clinical Pearls

Tri-Moxi is injected into the anterior vitreous with a transzonular approach at the time of cataract surgery. The first step is to ensure that the anterior chamber is filled with viscoelastic; trying to inject the compound under an air bubble or with balanced saline solution isn’t a consistent way to perform the injection. I prefer a cohesive viscoelastic and advise that you separate it, injecting a small amount between the anterior capsule and the iris in addition to filling the anterior chamber. This helps create a space so the cannula can be inserted more easily.

The cannula itself must be sufficiently long to reach under the iris to the equator of the lens capsule, and still have enough range to dive posteriorly through the zonules. A fine, 27- or 30-gauge cannula is best, as a thicker cannula with a larger distal tip will encounter greater resistance sliding through the zonules. If the anterior capsule is distorting and bending outward with traction on it, that’s an indication that the cannula is pressing into the equator of the capsule rather than passing through the zonules. This means the cannula needs to be placed further out in the periphery before dialing posterior.

It’s important to be aggressive with this maneuver. You can’t be timid when placing the cannula. Once a surgeon learns the anatomy and is confident with the feel of the positioning, the maneuver will be very comfortable. However, all surgeons should acknowledge that early on, while developing their delivery technique, they will miss on occasion and the Tri-Moxi will end up in the anterior chamber. When this happens, I simply withdraw the cannula, draw up 0.20 cc of Tri-Moxi, replace the viscoelastic if necessary, and inject the additional 0.20 cc. On the occasions that I see the medication in the vitreous, but also see that some was expelled into the anterior chamber, I will redraw 0.10 cc and re-inject to make sure the patient receives the full 0.20 cc dose to prevent breakthrough inflammation.

Special Cases

While Tri-Moxi is excellent for the majority of patients, there are certain cases where I personally don’t use it. Patients who are glaucoma suspects or known steroid responders aren’t offered dropless cataract surgery. Also, I’ve found it to be less effective in cases where pupil stretches were needed and there is increased inflammation. In addition, if I’m performing arcuate incisions, I supplement Tri-Moxi with a topical generic antibiotic of choice for 3 days post-operatively to prevent keratitis.⁴

Breakthrough inflammation may be noted in diabetic patients, highly pigmented African-Americans, and patients where pupil stretch maneuvers have caused a reduction of the blood-aqueous barrier.

I also generally elect to forgo Tri-Moxi in cases where I’m implanting a toric IOL. Perfect positioning is essential with toric IOLs, and once I have the lens in the desired location, I prefer not to enter the anterior chamber again and risk rotation. In addition, I cannot re-verify position with the ORA intraoperative aberrometer (WaveTec Vision), because as the Tri-Moxi spreads into the vitreous, it distorts the image. In these cases, I’ve found it easier to give intracameral Vigamox (moxifloxacin HCI 0.5%) and subtenon kenalog, 0.7 cc, in the inferior nasal quadrant.⁵

Administrative Handling

We offer all eligible patients the option of a dropless cataract surgery. For those already selecting a premium cataract procedure, the cost is included. For all standard cataract surgery procedures, patients who opt to undergo dropless surgery pay a fee of $125. This is charged through the clinic and the clinic delivers the product to the ambulatory surgical center (ASC), so it’s not part of the global ASC bill. Patients sign an agreement at the clinic that Tri-Moxi is an off-label, compounded formulation, and they assume any risk. They’re also informed that approximately 5% of patients may still need drops at some point to control breakthrough inflammation.

Patients are highly educated about what to expect following surgery. They’re told they’ll have slightly blurrier vision the first 3 days after surgery, and may have visual floaters from days 3 to 7 post surgery. We have found that patching the eye for the first 24 hours gets patients past the intense period of cloudy vision and minimizes complaints.

Overall Benefits

The benefits of delivering a transzonular antibiotic and steroid formulation are numerous, for the patient, the physician and the staff. It reduces cost and hassle for the patients, and is particularly appreciated by the families of older patients. Questions and concerns regarding drops consume a huge amount of staff time in a busy cataract clinic, and almost all of that can be avoided with the dropless option. Perhaps most important, there is a nearly 10-fold reduction in the risk of endophthalmitis. Using dropless therapy is definitely one of the greatest changes to my cataract procedure. ■

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