T2 magnetic resonance assay and detection of ocular candidiasis
Mikkilineni S, Komati R, Shah N, and Gao H. T2 magnetic resonance assay and detection of ocular candidiasis. Invest Ophthalmol Vis Sci 2019; 60(9).
Invest Ophthalmol Vis Sci
Purpose : T2 magnetic resonance (T2MR) assay for diagnosis of candidemia is a new nanodiagnostic approach to detect amplified DNA of candida species from whole blood specimens without the need for prior isolation. This assay only takes a few hours, compared to days for traditional fungal blood culture, and it has reported sensitivity of 89% to 98%. However, no studies have investigated whether T2MR is superior to traditional cultures in detecting ocular candidemia complications, namely infectious chorioretinitis and endophthalmitis. We performed a retrospective clinical study to examine sensitivity of T2MR for ocular candidiasis. Methods : All inpatient ophthalmology consultations for ocular candidiasis at Henry Ford Hospital, an urban tertiary-care academic hospital, between August 2015 and December 2017 were reviewed. Clinical and microbiology data were collected from inpatient records. Patients were diagnosed with 'definite ocular involvement' if dilated exam revealed evidence of chorioretinitis or endophthalmitis. 'Suspicious for chorioretinitis' was defined as lesions initially thought to be candida but later determined to be other pathology. Results : Of 164 patients included in our study, 99 (60%) were T2MR positive while 120 (73%) were blood culture positive. Ophthalmologic exam found 22 patients (13%) had definite ocular candida infections, a higher rate than other reports using blood culture for diagnosis. Of these, 20 patients had chorioretinitis and 2 had endophthalmitis. Eleven patients (7%) were suspicious for chorioretinitis; and 131 patients (80%) with no evidence of ocular involvement. One case required immediate intravitreal injection. This case was diagnosed by blood culture as T2MR was not properly collected. Only one other patient developed endophthalmitis during admission and underwent intravitreal injection. This patient had positive T2MR and blood cultures. Sensitivity of T2MR was 75% for those with definite chorioretinitis as compared to 64% for blood cultures. However, there were no statistically significant differences between the two tests among the three categories. Conclusions : Our results indicate that T2MR assay may be more sensitive than blood cultures for detecting ocular complications of candidemia. T2MR is a useful tool in management of candidemia as it is much faster than blood cultures which allows for earlier ophthalmologic examination and intervention on patients with ocular candida infections.