Automated analysis of vitreous inflammation using spectral-domain optical coherence tomography

Purpose: To develop an automated method for quantifying vitreous signal intensity on optical coherence tomography (OCT), with particular application for use in the assessment of vitreous inflammation. Methods: This retrospective, observational case-control series comprised 30 patients (30 eyes), with vitreous haze secondary to intermediate, posterior, or panuveitis; 12 patients (12 eyes) with uveitis without evidence of vitreous haze; and 18 patients (18 eyes) without intraocular inflammation or vitreoretinal disease. The presence and severity of vitreous haze was classified according to the National Eye Institute system; other inflammatory indices and clinical parameters were also documented. Spectral-domain OCT images were analyzed using custom VITreous ANalysis software (termed ‘VITAN’), which is fully automated and avoids the need for manual segmentation. Results: VITAN performed accurate segmentation in all scans. Automated measurements of the vitreous:retinal pigment epithelium (RPE) signal ratio showed a moderate correlation with clinical vitreous haze scores (r = 0.585, P < 0.001), comparable to that reported using manual segmentation in our previous study (r = 0.566, P = 0.0001). The novel parameter of vitreous:RPE textural ratio showed a marginally stronger correlation (r = 0.604, P < 0.001) with clinical vitreous haze scores than the Vitreous:RPE signal ratio. Conclusions: The custom OCT image analysis software (VITAN) allows rapid and automated measurement of vitreous parameters, that is comparable to our previously reported vitreous:RPE index, and correlates with clinically measured disease activity. Such OCT-based indices may provide the much needed objective markers of vitreous activity, which may be used in both clinical assessment, and as outcome measures in clinical trials for intermediate, posterior, and panuveitis. Translational Relevance: We describe a rapid automated method for quantifying vitreous signal intensity on optical coherence tomography (OCT) and show that this correlates with clinical assessment of vitreous inflammation. Such OCT-based indices may provide the much needed objective markers of vitreous activity, which may be used both in routine clinical assessment, and as outcome measures in clinical trials for intermediate, posterior, and panuveitis.