Sensitivity and specificity of the iVue iWellnessExam™ in detecting retinal and optic nerve disorders

Abstract

Background

The purpose of this study was to assess the specificity and sensitivity of the iWellnessExam™ screening protocol available on iVue^® spectral domain optical coherence tomography (SD-OCT), in a cohort of confirmed normal subjects and subjects with confirmed disease.

Methods

In total, 126 of 132 confirmed normal subjects and 101 of 107 subjects with confirmed disease were included for analysis. Of the patients with confirmed disease, 67 had retinal disease, 50 had optic nerve disease, and 16 had both retinal and optic nerve pathology. All subjects were screened on the iWellnessExam protocol. Screen shots of the OD, OS, and OU comparison data were obtained and deidentified for reviewer analysis. Based on these data alone, each subject was sorted by a well trained eye care clinician into one of four categories (1, normal; 2, retinal disease; 3, optic nerve disease; 4, retinal and optic nerve disease).

Results

Of the confirmed normal subjects, 125 of 126 were correctly identified as normal (specificity 99%). Retinal and/or optic nerve disease was correctly detected in 97 of 101 patients with confirmed disease (category 2, 3, 4), retinal pathology was correctly detected in 64 of 67 patients with retinal disease (category 2, 4), and optic nerve pathology was properly detected in 45 of 50 patients with optic nerve disease (category 3, 4), with a sensitivity of 96%, 95.5%, and 90%, respectively.

Conclusion

The iWellnessExam offers the health care provider an excellent method for identifying eyes at risk using very reliable technology. High specificity and sensitivity was obtained when reviewed by a well trained eye care clinician. It would be valuable to repeat the study with a novice and/or student clinician reviewing the same data set to ascertain interobserver variability, as well as the impact of clinical experience on accurate referral, based on the screening data.

Keywords:

• epidemiology
• ganglion cell complex
• glaucoma
• macula
• nonglaucomatous optic neuropathy
• screening
• spectral domain optical coherence tomography

Acknowledgments

The authors would like to acknowledge Tamara St Preux for assistance in data acquisition.

Disclosure

JS lectures for Optovue Inc, but has no financial interest in the company. None of the other authors have any relevant disclosures. The two iVue systems used in the study were on loan to JS from Optovue Inc.