Dropless cataract surgery-a combination of anti-infective and anti-inflammatory drugs injected transzonularly or through the pars plana for deposit into the vitreous-reduces the need for topical postoperative drops.
Take-home message: Dropless cataract surgery-a combination of anti-infective and anti-inflammatory drugs injected transzonularly or through the pars plana for deposit into the vitreous-reduces the need for topical postoperative drops.
By Lynda Charters; Reviewed by Robert J. Weinstock, MD
Tampa, FL-The newly available concept of dropless cataract surgery may be an alternative for both patients and physicians, said Robert J. Weinstock, MD.
“The limited early experience is showing some promise and some benefits regarding the patient, practice, and financial burdens,” said Dr. Weinstock, associate clinical professor, Department of Ophthalmology, University of South Florida, Tampa.
Patients who undergo cataract surgery generally follow the current standard of care-i.e., instillation of a number of topical medications for 4 to 8 weeks postoperatively, including an antibiotic, steroid, and nonsteroidal anti-inflammatory drug.
“This creates a tremendous burden on patients and practices alike when patients are required to follow an intensive eye drop regimen after cataract surgery,” Dr. Weinstock explained.
The length of the postoperative regimen is further complicated by the different daily dosing regimens of various medications, which can cause confusion for patients because of age and physical and mental handicaps.
“Patient compliance is one of the biggest issues we face in our practice,” Dr. Weinstock said. “It can be very challenging for many patients to remember to use their drops and some have physical challenges using the small bottles.”
In addition, as costs of medications continue to spiral, patients are refusing to pay those costs and insurance companies are not footing the bill, necessitating the switch to generic medications. Time spent by staff on helping patients with medication problems, as well as patient education, also increases exponentially.
“Uncertainty still remains after all this effort regarding whether or not patients are getting the correct drops into their eyes,” he said.
The ideal scenario would be elimination of the postoperative drop regimen altogether, he noted.
A couple of time- and sustained-release options are being studied to ease postoperative burden after cataract surgery. One such option is a punctal plug with time-release medication. A second approach is a time-released medication, dexamethasone intravitreal implant (Ozurdex, Allergan). However, that product is approved for chronic uveitis but not for cataract surgery.
Another potential route is intracameral injections. The concept behind intracameral injections, according to Dr. Weinstock, is well proven and may be a beneficial avenue to explore to decrease the number of drops for patients. Additionally, the approach has been used routinely for decades by many surgeons worldwide during cataract surgery. In some areas of the world, intracameral injections after cataract surgery are the standard of care.
Historically, vancomycin has been used for intracameral injection into the anterior chamber and more recently, gatifloxacin and moxifloxacin. Intravitreal injections for cataract surgery have not been used widely and have historically been outside of cataract surgeons’ comfort zones.
With the goal of relieving the postoperative drop regimen challenge, two proprietary intravitreal antibiotic steroid combinations have been developed, both from Imprimis Pharmaceuticals. One formulation (Tri-Moxi) combines triamcinolone acetonide and moxifloxacin hydrochloride, whereas the other (Tri-Moxi-Vanc) contains triamcinolone acetonide, moxifloxacin hydrochloride, and vancomycin.
These drugs have been shown to be safe and efficacious when used independently in the eye, Dr. Weinstock noted.
These formulations are proprietary combinations of medications that come in a vial. Triamcinolone injections have been problematic because the drug is thick and tends to clog needles, but the company has developed a solution that is easy to inject at the end of surgery into the vitreous where it remains and is absorbed slowly.
One method of injection is by the transzonular technique, in which a cannula is put between the iris and the anterior capsule, and the medication is delivered into the vitreous cavity. A second method is by pars plana injection into the vitreous through the sclera.
A few surgeons, such as Jeffrey Liegner, MD, of Sparta, NJ, have used the transzonular approach in thousands of cataract cases and have reported good long-term results, Dr. Weinstock recounted.
However, the method is not without some disadvantages. About 10% to 15% of patients need treatment with drops to address mild breakthrough inflammation 1 or 2 weeks after surgery that did not resolve after the intravitreal injection.
“In the vast majority of cases, surgeons are reporting that patients do not need drops after cataract surgery,” he said.
Floaters are noticed in about 20% of patients on the first day after surgery that resolve after a few days and a small percentage of patients are steroid responders in whom IOP can increase.
All in all, “the transzonular and/or intravitreal approach has been well received by both the patients and practices,” Dr. Weinstock concluded. “There are less patient compliance issues and fewer callbacks from pharmacies.”
Robert J. Weinstock, MD
This article was adapted from Dr. Weinstock’s presentation during the 2015 meeting of the American Society of Cataract and Refractive Surgery. Dr. Weinstock has no financial interest in the subject matter.