Pro vs. con of transzonular injection of antibiotics, steroids at time of cataract surgery

Issue: August 25, 2016

ByCynthia Matossian, MD, FACS

ByAudrey Talley Rostov, MD

Endophthalmitis prophylaxis has always been a concern around cataract surgery. Unfortunately, patient compliance with postoperative drops may be a contributor to this dreaded infection. This month, Cynthia Matossian, MD, FACS, and Audrey Talley Rostov, MD, discuss two techniques for endophthalmitis prophylaxis, transzonular and intracameral instillation of antibiotics during cataract surgery. We hope you enjoy the discussion.

Kenneth A. Beckman, MD, FACS
OSN CEDARS/ASPENS Debates Editor

Transzonular approach

Compliance with prescribed medication regimens by most patients is a big problem. In fact, according to a recent anonymous survey among the CEDARS/ASPENS membership, 83.3% agreed that compliance with topical medications in the postoperative period poses issues for cataract patients.

As a result, many eye surgeons and pharmaceutical companies are trying hard to come up with alternative drug delivery methods or devices. One such approach by Imprimis, coined “dropless surgery,” is the use of a proprietary antibiotic and steroid mixture transzonularly during cataract surgery to eliminate or decrease the need for topical medications postoperatively. Thirty-two percent of the survey participants had tried this method, and 61% had not yet evaluated it. Some of the reasons provided for not having tried this transzonular approach to date included that they were in the process of currently evaluating this approach, saw no benefit because the patients still needed an NSAID topically, or may reserve this approach for patients who cannot afford topical medications or have physical impairments that make drop instillation a challenge.

Imprimis has two formulations available: triamcinolone with moxifloxacin, abbreviated as TriMoxi, and triamcinolone and moxifloxacin with vancomycin, abbreviated as TriMoxiVanc. The preference among the survey participants showed 70% for TriMoxi and 30% for TriMoxiVanc.

Just like any new technique, there is a learning curve for the transzonular delivery of this mixture into the anterior vitreous after IOL implantation but before irrigation-aspiration is started. Of the surgeons who use this approach, 15% said the learning curve was difficult, 31% moderately difficult and 39% easy. Several cannulas have been specifically designed to facilitate this step.

The many advantages of the transzonular approach over traditional postoperative topical drop administration include:

Elimination of medication compliance issues.
Lower cost for patients compared with buying prescribed medication bottles.
Fewer pharmacy calls to the office tying up technician time and office lines.
Decreased staff time requirements to address pre-certifications for branded medications.
Easier for patients who have issues with manual dexterity, tremors, or other manual or neurological comorbidities that hinder drop instillation.
Easier for patients who have dementia, Alzheimer’s or other entities that render them forgetful.

I have been using this approach in select patients for more than a year. I find the technique easy to perform with the 27-gauge Rycroft cannula. I inform patients about floaters ahead of time and let them know that this technique may not eliminate all postoperative drops but will certainly decrease the number. My patients love it, my staff is very happy to not be inundated with pharmacy calls, and the family members, spouses or caregivers of the patients are elated not to have a confusing medication grid to follow for each eye.

For more information:
Cynthia Matossian, MD, FACS, is the founder of Matossian Eye Associates, with offices in Doylestown, PA, Hopewell, NJ, and Hamilton, NJ. She can be reached at email: cmatossian@matossianeye.com.

Disclosure: Matossian reports she is neither a speaker nor a consultant to Imprimis but she is involved in a clinical study using the TriMoxi and TriMoxiVanc products.

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Intracameral approach

Endophthalmitis is one of the most dreaded complications of cataract surgery. Antibiotic prophylaxis for the prevention of postoperative endophthalmitis has included topical and intracameral delivery systems. The landmark 2007 ESCRS study established intracameral cefuroxime to decrease the rate of postoperative endophthalmitis, and subsequent European and U.S. studies have confirmed these findings. The largest U.S. prospective study in Northern California in 2013 demonstrated a 22-fold decrease in postoperative endophthalmitis. Of note, only intracameral antibiotics have demonstrated this statistically significant decrease in endophthalmitis rates. Topical antibiotics have not been shown to have statistical significance when it comes to endophthalmitis prevention.

As such, there has been increasing interest in intracameral delivery of antibiotics at the time of cataract surgery. In addition, patient compliance with postoperative medication regimens remains an additional concern. A recent CEDARS/ASPENS survey revealed that 83% of respondents agreed that compliance with postoperative medications is an issue for patients.

Antibiotic delivery at the time of cataract surgery can be done as an intracameral injection in the anterior chamber or as a transzonular injection. Drug delivery can include antibiotic alone or in combination with a steroid. Intracameral antibiotics such as cefuroxime and moxifloxacin can be obtained by compounding pharmacies. A combination of moxifloxacin/dexamethasone for intracameral injection into the anterior chamber is made by Ocular Science. Transzonular antibiotic/steroid combinations manufactured by Imprimis include a combination of triamcinolone and moxifloxacin (TriMoxi) and triamcinolone/moxifloxacin/vancomycin (TriMoxiVanc).

In a recent CEDARS/ASPENS survey, 38% of respondents currently perform intracameral (other than transzonular) injections at the end of cataract surgery. Thirty-two percent of respondents have tried transzonular approach, yet a number of respondents have discontinued the transzonular approach due to:

Concerns about floaters in the immediate postoperative period.
Higher possibility of intraoperative complications.
A reduced “wow” factor on postoperative day 1.
Concerns about the cost to the ASC.
Concerns about hemorrhagic occlusive retinal vasculitis.

In addition, 46% of respondents rated the transzonular injection learning curve to be moderately difficult to difficult. Of the members that perform transzonular injections, 85% do not recommend them in cases of accommodating IOLs and 60% did not recommend this approach with toric IOLs.

There are many advantages of intracameral (other than transzonular) injection of antibiotics (or antibiotic steroid combination) at the time of cataract surgery.

These include:

Evidence-based medicine for postoperative endophthalmitis prevention.
Decreased need for or elimination of postoperative topical medications such as antibiotics and steroids.
Decreased expense for patients’ postoperative medications.
Easy to perform.
Can be safely used with any IOLs.
Preserve “wow” factor on postoperative day 1.
No increase in floaters.
No additional concerns about increasing intraoperative complications because zonules are not disrupted.

I currently use intracameral cefuroxime or intracameral moxifloxacin at the conclusion of cataract surgery. I no longer use intracameral vancomycin due to recent reports and concerns about hemorrhagic occlusive retinal vasculitis. I have discontinued the use of postoperative antibiotic drops and am currently evaluating a new formulation of moxifloxacin/dexamethasone for intracameral injection to further decrease the postoperative drop regimen with antibiotics and steroids, except in select cases.

For more information:
Audrey Talley Rostov, MD, can be reached at Northwest Eye Surgeons, 10330 Meridian Ave. N., Suite 370, Seattle, WA 98133; email: atalleyrostov@nweyes.com.

Disclosure: Talley Rostov reports financial disclosures with Allergan, Bausch + Lomb Surgical, Shire and Ocular Therapeutix.