Repeated pseudoendophthalmitis after combined photodynamic therapy and intravitreal triamcinolone

Abstract

Dear Editor: Pseudoendophthalmitis, or sterile endophthalmitis, is a possible complication secondary to intravitreal triamcinolone acetonide (IVTA). This clinical entity has been described as the presence of inflammation in the anterior chamber and vitreous opacity that may mimic infectious endophthalmitis. Usually, patients do not refer pain or photophobia, and the signs seem to solve without specific therapy [5, 6]. However, little is known regarding pathophysiology of this phenomenon. A 58-year-old woman with myopic subfoveal choroidal neovascularization was offered combined photodynamic therapy (PDT) and IVTA (Trigon Depot, Bristol-Myers Squib, Anagni Frosinone, Italy). The patient was treated in the context of a pilot study approved by the Bioethics Committee of the University of Santiago de Compostela [3]. Signed informed consent was obtained in accordance with the local legislation. Her initial best corrected visual acuity (BCVA) was equivalent to 20/80 [+2] letters. The IVTA was administered 3 days after PDT. Two days after the intravitreal injection the BCVA decreased to 20/800 in the absence of pain, photophobia or hyperemia. In the anterior chamber it was possible to observe +4 cells and +3 flare, whereas the vitreous had severe opacity. Pseudoendophthalmitis was suspected and treatment with topical dexamethasone was given. No cultures were taken and a close follow-up was done. Over the following 24 h a decrease in vitreous haze and a progressive improvement of visual acuity were observed. One week and 1 month after the injection, BCVAwas equivalent to 20/50 [+2] letters and 20/ 40 [+4] letters respectively. After 6 months of follow-up, BCVA dropped down to 20/80 [+ 2] letters and a reactivation of the lesion was observed on fluorescein angiography. Due to the initial improvement in visual acuity and the inactivity of the lesion for 6 months, a second combined treatment was administered. After the second intravitreal injection, BCVA decreased to 20/160 during the first 24 h and to 20/ 400 over the next 48 h. The clinical characteristics were similar to those observed during the first episode and no specific therapy was given. From the third day the vitreous opacity began to decrease and after a week it was completely solved. BCVA 1 month later was equivalent to 20/30 [−3] letters. Because of repeated pseudoendophthalmitis episodes after IVTA injection, allergy tests were performed. Prick tests with Trigon Depot diluted 1/1 and 1/10, carboxymethylcellulose 1/10 and 1/100, and polysorbate 80 1/10 and 1/100 were all negatives. A parenteral provocation test with Trigon Depot did not reveal any early or late reaction. The etiology of pseudoendophthalmitis secondary to IVTA remains uncertain. Possible contamination of the vial with bacterial endotoxins and dispersion of the steroid crystals have been proposed [1, 4, 5]. An inflammatory reaction to the vehicle cannot be ruled out; therefore, the Graefe’s Arch Clin Exp Ophthalmol (2007) 245:1403–1404 DOI 10.1007/s00417-007-0592-7