Transzonular intravitreal injection eases treatment burden after cataract surgery

Reviewed by Sydney L. Tyson, MD, MPH

Administration of a transzonular intravitreal injection of a compounded formulation of a steroid and two antibiotics was shown to have similar effects regarding infection and inflammation rates compared with the standard instillation of topical drugs after cataract surgery.

An added benefit was the elimination of concern regarding patient compliance with the postoperative regimen. This formulation might be considered as an alternative to patient instillation of topical drugs postoperatively to prevent infection, inflammation, and cystoid macular edema (CME).

The rationale behind this formulation, according to the study investigators, was “the design of [this formulation] as a single-use intraoperative prophylactic is thought to decrease both [the] patient and surgeon burden by alleviating the need for complicated postoperative eye drop regimens.”

A number of complications, although rare, always can develop after cataract surgery, including persistent inflammation, CME, and endophthalmitis, and prophylactic therapies are prescribed to drive the risk to the lowest levels possible.

However, as with all drugs, there are associated safety concerns with the prophylactic medications.

In addition, patient compliance is always an issue because of the drug costs, the number of drugs prescribed, the complexity of the regimen, as well as the patients’ instillation skills.

These problems, according to Sydney L. Tyson, MD, MPH, underscore the need for a prophylactic regimen that is easier, “ . . . one that reduces or eliminates the patient burden of postoperative eye drops while remaining as safe and effective” as the standard of postoperative care.

Intracameral injections have been tried to meet these needs and are indeed safe and effective, prevent postoperative inflammation, and do not significantly increase the IOP. However, this route of administration can facilitate access of the drugs to the posterior segment.

In contrast, intravitreal injections of drugs are advantageous in that they can result in high concentrations of drugs intraocularly  that persist in the eye for up to 3 months and reach most ocular tissues.

Retrospective study

Retrospective study

Dr. Tyson, who is attending surgeon, Cataract and Primary Eye Care Service, Wills Eye Hospital, Philadelphia, and colleagues, conducted a retrospective review of the medical records of patients who underwent cataract surgery and were treated with a preservative-free 0.2 ml intravitreal injection containing triamcinolone acetonide (15 mg/ml), moxifloxacin (1 mg/ml), and vancomycin (10 mg/ml) (TMV, Imprimis Pharmaceuticals) between November 2012 and December 2014.

A total of 923 patients (1,541 eyes) were included and received the transzonular injection of TMV into the anterior vitreous after an IOL was implanted following phacoemulsification and before the viscoelastic was removed. All patients underwent the standard phacoemulsification and IOL implantation at one ambulatory center in Vineland, NJ.

Dr. Tyson explained that the TMV formulation was injected slowly using a 30-gauge cannula through the zonules via the ciliary sulcus inferonasally and the correct placement was confirmed by the observing the presence of a white plume in the vitreous after injection. If the injection was inadequate, second and third injections were allowed.

Patients also were treated with one drop of prednisolone acetate (Pred Forte 1%, Allergan), one drop of a fluoroquinolone, and one drop of an ophthalmic antihypertensive drug after surgery. Patients were followed on day 1, between days 14 to 21, and day 90 postoperatively.

Investigators analyzed the changes in the best-corrected and uncorrected visual acuities over time; the development of CME, inflammation, and endophthalmitis; changes in the IOP over time, and any postoperative medications used.

Results

Results

Investigators published their findings in Current Opinion in Ophthalmology (2017;28:73-80).

Most eyes (96.3%) were treated with one injection of TMV intraoperatively; 56 (3.6%) eyes needed a second injection; and one (0.1%) needed a third injection. No major complications developed; seven (0.45%) needed to undergo an unplanned vitrectomy.

In addition, no zonular disruption, hyphema, vitreous hemorrhages, retinal tears of detachments developed. Isolated cases of iris prolapse developed as a result of overfilling of the chamber with the viscoelastic and four cases of spontaneously resolving ciliary body hemorrhage were reported by the authors.

No additional medications were needed postoperatively in almost 92% of eyes. Breakthrough inflammation developed in 9.2% of eyes, visually relevant CME in 2.0% of eyes, and clinically relevant IOP increases in 0.9%.

“The rates of infection and inflammation reported in this retrospective review of a transzonular injection of TMV for prophylaxis after cataract surgery appear similar to reported rates with alternative prophylactic therapies such as topical drops,” Dr. Tyson said. “The transzonular injection of TMV may have advantages in terms of patient compliance.”

This study showed that almost 92% of eyes did not need additional medication postoperatively following the prophylactic transzonular intravitreal injection of TMV.

Dr. Tyson said, “TMV is an advanced technology prophylactic drug that can potentially change the postoperative cataract care paradigm.”

Sydney L. Tyson, MD, MPH

E: sydtyson@comcast.net

Dr. Tyson is a consultant for Imprimis Pharmaceuticals.