Nontuberculous Mycobacterial Infection after Removal of the Exposed Hydroxyapatite

Dear Editor, Numerous complications are associated with hydroxyapatite orbital implants. Implant exposure, the most important complication, differs by study but occurs in approximately 2% to 10% of patients [1]. Nontuberculous mycobacteria (NTM) are generally free-living organisms that can also inhabit body surfaces or cause secretions without causing disease [2]. It is also known that these organisms can cause infection through wound entry. Reported herein is a case of abrupt NTM orbital cellulitis after removal of the exposed hydroxyapatite. A 43-year-old male presented with orbital implant exposure occurring about 1 year earlier. A culture was performed of a sample from the exposure site, but no growth was observed. The patient had undergone evisceration surgery with hydroxyapatite implantation 23 years earlier, due to trauma. Orbital implant removal surgery was initially recommended, but the patient refused. He changed his mind 1 year later and was admitted to the hospital with no sign of infection at the exposure site (Fig. 1A). Prophylactic antibiotic treatment was started, then removal of hydroxyapatite, enucleation with hydroxyapatite reimplantation, and a dermis-fat graft were performed. There were no sign of infection on the removed hydroxyapatite or the surrounding sclera. The removed material was sent to the Laboratory Department for Culture. The operation site was initially stable, although swelling and erythema were noted on postoperative day (POD) #2. Based on these findings, intravenous antibiotic treatment was changed, and 5% ceftazidime and 2.5% vancomycin eyedrops were added. Despite this treatment, the lesion continued to worsen with increased discharge and development into an erythematous lesion (Fig. 1B and 1C). NTM was observed in the culture on POD #7, for which intravenous antibiotics were changed to fourth-generation cephalosporin and vancomycin and polymerase chain reaction (PCR) examination was conducted to identify the subtype of NTM. The lesion continued to worsen, however, and reoperation, graft and hydroxyapatite removal, debridement, and wound irrigation with antibiotics were performed on POD #8. The removed Korean J Ophthalmol 2017;31(4):366-367 ht tps: / /doi.org /10.3341/k jo.2017.0022 Correspondence