Recurrent nontuberculous mycobacterial endophthalmitis: a diagnostic conundrum

Abstract

ObjectiveTo report a case of recurrent nontuberculous mycobacterial endophthalmitis in the context of neurotrophic keratopathy secondary to herpes zoster ophthalmicus that had an atypical presentation and complex course, and highlights the challenges of causative organism identification and therapeutic interventions in this condition.MethodsA retrospective chart review was conducted to determine the visual outcomes of the patient.ResultsA 68-year-old pseudophakic male with long-standing neurotrophic keratopathy and perforated descemetocele managed with cyanoacrylate glue and a contact bandage lens in the left eye, began experiencing recurrent episodes of endophthalmitis after undergoing a penetrating keratoplasty. Several therapeutic procedures including an anterior chamber washout, two pars plana vitrectomies, explantation of the posterior chamber intraocular lens and capsular bag, and multiple intravitreal antimicrobial injections, were performed to which he has ultimately responded favorably, with no signs of infection to date and stable visual acuity. The causative organism of his recurrent infections was initially identified as Mycobacterium abscessus through biochemical testing and 16S ribosomal ribonucleic acid gene sequencing; however, repeat polymerase chain reaction (PCR) and sequencing of the 65 kDa heat shock protein (hsp65) gene for experimental purposes confirmed the accurate identification of the organism to be Mycobacterium chelonae. Given the greater reliability of PCR and sequencing of the hsp65 gene over traditional biochemical tests and culture techniques, M. chelonae was likely the infectious agent all along, and the organism was originally misidentified on the basis of less accurate tests.ConclusionRecurrent atypical mycobacterial endophthalmitis requires expedient identification and management to prevent poor visual outcomes. Standard biochemical testing can identify the causative organism but is limited by the inability to distinguish between nontuberculous species reliably. We recommend the use of PCR in conjunction with sequencing of the hsp65 gene for reliable differentiation of M. chelonae and M. abscessus in atypical mycobacterial ocular infections. Minimum inhibitory concentration antibiotic susceptibility tests on cultured strains are the best guide to antibiotic selection, given the rapidly rising resistance to antimicrobials in atypical mycobacterial species.

Nontuberculous Mycobacterial Ocular Infections: A Systematic Review of the Literature

“…Clare and Mitchell reported a case of iris root abscess and necrotizing sclerokeratitis in an immunocompetent woman with no apparent risk factors [ 177 ]. Sclerokeratitis was seen after cataract surgery in 4 eyes [ 40 , 123 ], and keratitis leading to endophthalmitis was also seen in 6 eyes after cataract surgery [ 157 , 158 , 161 ] and 2 eyes after penetrating keratoplasty (PKP) [ 133 , 156 ]. In one case of an elderly lady with dry eyes, punctal plug insertion caused secondary upper lid canaliculitis and keratitis [ 29 ].…”

“…Isolates grown on culture media can be speciated by genotypic and molecular techniques as they allow for a rapid identification of NTM. In our review it is evident that there is increasing utilization of PCR and PCR probes/hybridization to accurately and rapidly identify specific NTM species [ 54 , 61 , 87 , 121 , 130 , 144 , 145 , 151 , 154 – 156 , 178 ]. Another genotypic method that was frequently employed is the PCR restriction endonuclease analysis [ 35 , 45 , 165 ].…”

Nontuberculous mycobacterial endophthalmitis: case series and review of literature

“…This presentation led to early vitrectomy resulting in a successful treatment. From literature review, there were only 11 eyes that showed final BCVA of 6/60 or better [ 7 , 21 , 30 , 32 , 37 , 41 , 43 , 47 , 52 ]. Stewart et al reported a case of M. abscessus endophthalmitis with a full visual recovery [ 50 ].…”

Development of the neurotrophic keratopathy questionnaire: qualitative research

“…Additional searches in PROQOLID and clincialtrials.gov were conducted to identify PROs used in NK or other eye disease clinical trial programs. Symptoms and signs reported in the literature review related to NK included: redness, discomfort, inflammation, decreased corneal sensation, dryness, decreased tear production, reduced visual acuity, and irregular blinking (if bilateral disease) [1,3,19,20]; however, some patients are asymptomatic [8,19]. Although several existing PROs for eye disease were identified, [21][22][23][24][25][26] a gap analysis of each tool's content showed that none of them adequately assessed the symptoms, signs, and impacts of patients with NK.…”