MAR 04, 2011
This article reports two cases of toxic anterior segment syndrome (TASS) resulting from unidentified impurities in generic trypan blue that was administered intracamerally to improve visualization of the capsule. The cases were two of 10 patients who underwent phacoemulsification and IOL implantation on the same day with the same surgeon. The authors report that the generic trypan blue had been purchased by the hospital, but the surgeon did not know that it was a generic compounded solution. Based on the experience of these two cases, the authors conclude that ophthalmologists should be aware that any substance administered intraocularly can be a source of complications and should know the source of all material used in surgery.
On the first-day postoperative visit, the two patients presented with severe limbus-to-limbus corneal edema, severe inflammation, increased white blood cells and fibrin in the anterior chamber, hypopyon and decreased vision without pain, while the other patients had uneventful first day visits and postoperative courses. Since the surgical procedure and products had been the same in all 10 patients except for the trypan blue injection, an impurity in the trypan blue was suspected as the cause of TASS.
Histology of the corneal buttons from the two patients revealed foci of inflammatory response and complete loss of endothelial cells. Cell culture analysis showed that the generic trypan blue was approximately twice as toxic to the endothelium as a proprietary trypan blue.
The two patients underwent six months of intensive steroid treatment. However, the corneal edema persisted, and the patients developed endothelial and trabecular meshwork damage. Penetrating keratoplasty was performed in both patients. One patient subsequently developed a fixed dilated pupil, while both patients developed uncontrolled IOP with iris synechiae. Filtering procedures were performed in both eyes.
These two TASS cases demonstrate the severe nature of the sequelae of unsafe intraocular medication. The authors conclude that rigorous and well-defined cell culture toxicity testing protocols should be mandatory to ascertain the safety of all generic medications, as well as other medications, devices and solutions used intraocularly. Endothelial cell cultures are now readily available and should be used to ascertain the safety of all intraocular medications.