November 2014

 

CATARACT

 

Dropless approach to cataract surgery expands


by Vanessa Caceres EyeWorld Contributing Writer

 
 

Use of the injectable formulation has helped improve staff workflow. Staff time at the office and ASC has been greatly reduced with shorter instructions and calls and fewer call backs to pharmacies. Ahad Mahootchi, MD

 
Injection of TriMoxi

Injection of TriMoxi

TriMoxi reflex TriMoxi reflex Source (all): M. Stewart Galloway, MD

Injectable formulation aims to boost medication compliance, decrease patient cost

Getting patients to comply with their post-cataract surgery drop regimen can be challenging, to say the leastand then patients balk at the out-of-pocket expenses associated with those drops.

One pharmaceutical company hopes to make the drop regimen a little simpler for both surgeons and patients.

Imprimis Pharmaceuticals (San Diego) has developed sterile and injectable proprietary compound formulations for ophthalmology that became available after the company launched its Go Dropless campaign in April 2014. One formulation, called TriMoxiVanc, combines triamcinolone, moxifloxacin, and vancomycin. A second formulation, called TriMoxi, contains only triamcinolone and moxifloxacin. In addition to cataract surgery, the formulations can be used with other intraocular procedures.

A study presenting some of the first data on the preservative-free injections reported that TriMoxi helped to prevent inflammation, cystoid macular edema (CME), and endophthalmitis after phacoemulsification. At the 2014 ASCRS•ASOA Symposium & Congress in Boston, M. Stewart Galloway, MD, Crossville, Tenn., presented his retrospective chart review of 1,575 eyes that had received TriMoxi instead of topical antibiotics and steroids. Dr. Galloway injected 0.3 mg of triamcinolone and 0.2 mg of moxifloxacin transzonularly into the anterior vitreous of patients undergoing cataract surgery. The injections occurred with the use of a 27-gauge cannula before removing viscoelastic material.

Follow-up evaluations took place at 4 to 7 hours, 3 to 4 weeks, and at 6 months.

The mean IOP was 21.8 mm Hg on the day of surgery and 14.5 mm Hg at 3 weeks. No patients required ocular hypotensives due to a steroid response, Dr. Galloway said.

There were no cases of endophthalmitis. Dr. Galloway defined CME as any patient with reduced postop visual acuity and any increase in cystoid macular thickness more than 220 μm regardless of the presence or absence of cystic change on OCT. The overall CME rate was 2% in the study overall, but only 1.5% in those without the risk factors of diabetes or epiretinal membranes.

The overall inflammation rate was 2.5% postoperatively, and those patients required the short-term addition of topical steroids. The inflammation rate was higher in patients with an epiretinal membrane and those who later developed CME. The injectable approach improved patient medication compliance and decreased postop care requirements. The injection did, however, require slightly more preoperative counseling and led to an increasing number of patients who had a foreign body sensation, which Dr. Galloway attributed to the lack of topical anti-inflammatory use at the wound. The additional counseling came from explaining to patients that they would experience a brief reduction in visual acuity after surgery and to let them know that they would see the medication appear as floaters for several days after surgery. Further presentations on the dropless approach will be presented at upcoming ophthalmology meetings.

The formulations from Imprimis are currently patent pending. Imprimis acquired the intellectual rights to the formulations in August of last year.

As of June 2014, the formulations were available in 29 states with a physicians prescription. The company has compounding pharmacy license applications pending in 10 additional states.

Practice implications

Far more often than we may think, patients do not take their medications in the way we prescribe them, said Kevin T. Scripture, MD, Richmond, Ind.

That is where Dr. Scripture thinks that going dropless will be quite useful. Dr. Scripture, who has used compounded drug formulations since May 2005 in more than 20,000 patients, said the only anomaly he must stress to patients is that they will see floaters or shadows of the medication for several days after surgery. Its in a spot in the eye that will cast shadows on the retina, he said. In very rare casesmaybe one in every 2,000bleeding will occur from the injection hitting the ciliary body, Dr. Scripture said. However, that has never caused long-term problems.

Although some surgeons may be concerned about an IOP increase, Dr. Scripture said this happens about as often as it would with the use of topical drops.

The only time Dr. Scripture will avoid the injection is if a patient has related medication allergies.

Pearls, praises, and concerns

Ahad Mahootchi, MD, Zephyrhills, Fla., said that using the injectable formulation in more than 500 patients since last year has been a process. I did get rid of the postop antibiotic drops from the start. Reducing or eliminating the steroid or nonsteroidal drops has been a slower process, he said. After several months of trial and error, he is down to one drop of NSAID a day.

In my early days with it, I tried leaving a little in the anterior chamber under the inferior irisnot necessary or desirable. I tried using the leftover drug subconjunctivally, which wasnt necessary. Now I just use the leftover drug on the cornea at the end of the case, he said.

He previously saw quiet eyes in most eyes on postop day 1 and at all visits after that point; now, half of the eyes are 20/25 or better on day 1. He has not seen inflammatory issues in the first 2 weeks; his patients have experienced floaters only in the first 24 hours.

Dr. Mahootchi has found it helpful to individualize what drops, if any, patients use, and he still recommends lubricant drops for the first few days after surgery. Use of the injectable formulation has helped improve staff workflow. Staff time at the office and ASC has been greatly reduced with shorter instructions and calls and fewer call backs to pharmacies, he said.

A pearl to consider is how one performs the injection, Dr. Mahootchi said. I use the same 30-gauge cannula for TriMoxiVanc that I use for intracameral anesthesia. I slide the cannula through the inferonasal zonules. I have checked with an endoscopic cyclophotocoagulation probe, and the zonules dont get damaged. Much of the drug sits 360 degrees around the ciliary processes, he said.

Steven G. Safran, MD, Lawrenceville, N.J., is intrigued by the formulation, although he has not yet tried it. Im interested in seeing how it plays out, he said. He has not had any endophthalmitis cases with his current approach, so he is not motivated to change his regimen. Still, he likes the idea of avoiding compliance headaches. One of his concerns would be contamination sometimes associated with compounded injectables, he added. Another would be any issue with the use of the Crystalens (Bausch + Lomb, Bridgewater, N.J.), where injecting the formulation into the vitreous at the end of the case could possibly cause an anterior vault.

Dr. Mahootchi sees a difference in patient results, based on the amount of steroid that reaches the vitreous. That seems to affect iritis flare-ups at 3 weeks out. I think you have to get at least 0.2 cc of the drug into the vitreous. There is more rebound iritis 3 weeks postop with 0.15 cc, so getting the volume up is important. An endoscopic study done informally by Dr. Mahootchi with the Crystalens has shown that the approach is not damaging zonules.

In the rare occasions that Dr. Mahootchi sees a capsular block at day 1, it will resolve spontaneously, or he will push the lens back off the anterior capsule in the office. The inflated vitreous probably pushed the lens forward, and a seal forms to the anterior capsule, he said.

The final refractive result is unaffected. I havent seen a vault since injecting more slowly and spending a few seconds at the end of the case to tap vaulting thin lenses back toward the posterior capsule.

Editors note: Drs. Galloway and Mahootchi have financial interests with Imprimis. Drs. Safran and Scripture have no financial interests related to their comments.

Contact information

Galloway: eyeguy@frontiernet.net
Mahootchi: am@seebetterflorida.com
Safran: safran12@comcast.net
Scripture: kscripture@wweyecenters.com

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