The American Society of Cataract and Refractive Surgery (ASCRS) and the American Academy of Ophthalmology are aware of 2 separate outbreaks of acute retinal toxicity after intravitreal injections of compounded triamcinolone–moxifloxacin. The outbreaks occurred at 2 Dallas surgery centers following cataract surgeries performed in February 2017. Both centers obtained the drug formulation from the same Dallas compounding pharmacy, Guardian Pharmacy Services.

There are two companies that go by the name Guardian Pharmacy Services, and they are unrelated. The Dallas–based Guardian Pharmacy Services is not affiliated with the national long–term care Guardian Pharmacy Services headquartered in Atlanta.

The affected patients presented with variable, but frequently severe vision loss, and OCT abnormalities of the ellipsoid layer of the macula. We are referring to this complication as toxic posterior segment syndrome (TPSS). Thus far, 50 patients have been identified. However, unrecognized or unreported cases might exist from other compounding pharmacies.

Imprimis Pharmaceuticals Inc., has patented a triamcinolone–moxifloxacin formulation with the trademarked name Tri–Moxi for use at the end of cataract surgery. According to the company, no cases of TPSS have been reported in association with its proprietary Tri–Moxi compounded product. Because Tri–Moxi is a proprietary product, other compounding pharmacies (such as Guardian) must devise their own methodology to compound their version of triamcinolone–moxifloxacin. Thus, the Dallas compounding pharmacy in question may have used a formulation protocol that is also in use at other compounding facilities.

Until more conclusive information is known, ophthalmologists should exercise caution and due diligence when obtaining intravitreal triamcinolone–moxifloxacin from a new compounding source and carefully monitor patients.

Investigations into the etiology and clinical course of these TPSS cases are ongoing.