A cluster of nontuberculous mycobacterial endophthalmitis (NTME) cases after cataract surgery: clinical features and treatment outcomes.

Purpose: To report the clinical features and treatment outcomes in a cluster of patients with endophthalmitis after cataract surgery caused by nontuberculous mycobacterium.
Patients and Methods: Retrospective chart review and noncomparative, consecutive case series. Nine consecutive cases of endophthalmitis, after cataract surgery in a local clinic, were referred to our hospital. The treatment outcomes and analysis of risk factors for infection are reported.
Results: The major symptoms at presentation were pain, redness, and decreased vision. Best-corrected visual acuity at presentation ranged from hand motion in two cases (22%), counting fingers at 30 cm in three cases (33%), 20/100 in two cases (20%), 20/63 in one case (11%), to 20/50 in one (11%) case. The mean duration between cataract surgery to presentation at our hospital was 16.7 days. Prompt intravitreal injections (IVI) of amikacin (0.4 mg/0.1 mL) and vancomycin (1 mg/0.1 mL), with topical moxifloxacin were administered initially. Pars plana vitrectomy with amikacin (10 mg/L) and vancomycin (20 mg/L) intravitreal irrigation, and intraocular lens removal were performed for all patients. Systemic antibiotics including amikacin and tigecycline were prescribed for 10 days, and clarithromycin was prescribed for at least 3 months. In all the nine cases, the culture results from either aqueous tapping or vitrectomy sample were positive for nontuberculous Mycobacterium: Mycobacterium abscessus/chelonae, which was compatible with iatrogenic clustered infection. At the last follow-up, three cases (33.3%) had best-corrected visual acuity of counting fingers at 30 cm, while the other six cases had no light perception. Two cases (22%) were enucleated and one case (11%) had phthisis bulbi.
Conclusion: Nontuberculous mycobacterium endophthalmitis (NTME) often induces chronic recurrent or persistent intraocular inflammation. Very poor outcomes despite aggressive antibiotic treatment and repeated surgical interventions are suggestive of the virulent nature of the organisms. Autoclave sterilization and perioperative disinfection may help in reducing iatrogenic clustered infection.