Quantifying vitreous inflammation in uveitis: an optical coherence tomography prospective study

Objective: To quantify vitreous inflammation in a uveitis cohort using optical coherence tomography and correlate findings to gold-standard Nussenblatt scores. Design: Prospective cohort study. Participants: 36 eyes from 19 patients primarily with pan uveitis. Methods: Study participants were scanned with optical coherence tomography and evaluated by 2 independent graders using open-source ImageJ software. Graders characterized the mean intensity of the vitreous in a 67 500-pixel box immediately above the internal limiting membrane and over the fovea and divided it by the mean intensity of the retinal pigment epithelial layer (RPE). The vitreous to retinal pigment epithelial layer ratio (VIT/RPE) ratios were correlated to Nussenblatt vitreous haze scores recorded by an independent uveitis specialist blinded to the graders' reads. Grader 1 measured intensity a second time after a 48-hour washout period, and the intraclass correlation coefficients (2,1) were calculated for intra- and intergrader reliability. Results: 21 (58.3%) eyes had a Nussenblatt score of 0, 9 (25.0%) had a score of 0.5, and the remaining 6 (16.7%) had a score ranging from 1 to 4. The r values for VIT/RPE intensity ratio regressed against Nussenblatt scores were 0.670, 0.672, and 0.660 for grader 1 read 1, grader 1 read 2, and grader 2 read 1, respectively (p < 0.001 for all linear correlations). The intragrader reliability was 0.999 (p < 0.001) and intergrader reliability was 1.000 (p < 0.001). Conclusion: The VIT/RPE intensity ratio is a clinically relevant measure that reliably captures inflammation in uveitis and correlates well with gold-standard Nussenblatt scores.