Prospective Study of the Diagnostic Accuracy of the In Vivo Laser Scanning Confocal Microscopy for Ocular Demodicosis.

Abstract

We sought to determine the diagnostic accuracy of in vivo confocal microscopy (IVCM) for ocular demodicosis. Reliability and validity analysis. This was a single-center study of consecutive patients presenting to Zhongnan Hospital of Wuhan University, Hubei, China, between February 2017 and February 2018 with blepharitis. After examination, the blepharitis was scanned by IVCM. The regrading of the shuffled image set was performed by grader 1 (experienced) and grader 2 (inexperienced). The regrading of the shuffled image set was performed by 2 graders 3 weeks later. Eyelash samples were collected for light microscopy. The main outcome measures were sensitivity, specificity, and positive and negative predictive values of IVCM compared with those of positive light microscopy under 2 definitions. Sensitivities and specificities for multiple graders were pooled and 95% confidence intervals (CIs) were calculated. Sensitivity of IVCM grader 1 and grader 2 based on the definition of "light microscopy-positive demodex" was 100% (95% CI 94.84-100%) and 98.8% (95% CI 93.02-99.94%), respectively. Sensitivity of IVCM grader 1, grader 2, and light microscopy to the definition of "definite diagnosis demodex" definition was 100% (95% CI 97.02-100%), 93.63% (95% CI 88.28-96.73%), and 56.69% (95% CI 48.55-64.49%). IVCM is better than traditional methods in detecting the number and sensitivity of demodex, and it is both highly sensitive and specific when performed by an experienced operator.