Validation of objective measurement of vitreous inflammation using Spectral Domain Optical Coherence Tomography

Abstract

 

Purpose

 

To validate a proposed method for objective measurement of vitreous inflammation using a different Spectral Domain Optical Coherence Tomography (SD-OCT) device (Cirrus HD-OCT, Carl Zeiss Meditec, Dublin, CA) in a larger cohort of patients.

 

Methods

 

Observational, single-center cohort study. 56 uveitis eyes (56 patients) seen in a single tertiary referral uveitis unit (Institut Clinic d'Oftalmologia, ICOF, Hospital Clinic, Barcelona) were included in the study. Clinical data collected included visual acuity, diagnosis, phakic status and activity of uveitis as per standardized criteria (anterior chamber cell score and vitreous haze score, VHS). SD-OCT images captured at the same time than the clinical examination were analyzed using custom software, which provided absolute measurements of vitreous signal intensity which was then compared with that of the retinal pigment epithelium to generate an optical density ratio with arbitrary units (VIT/RPE-Relative intensity), as previously described elsewhere.

 

Results

 

The VIT/RPE-Relative intensity was significantly higher in eyes with vitritis (0.37±0.4) than eyes with no vitritis (0.34±0.1, p<0.001), as well as in eyes with active uveitis (0.38±0.4) than eyes with quiescent uveitis (0.34±0.1, p<0.001). The VIT/RPE-Relative intensity showed a significant positive correlation with VHS (r=0.587, p<0.001). Significant differences were also observed between the different VHS groups with regards to the VIT/RPE-Relative intensity (p<0.001).

 

Conclusions

 

The results of this study support the previously proposed method for objective measurement of vitreous inflammation using SD-OCT, and achieves similar outcomes analyzing images captured with a different SD-OCT device in a larger cohort of patients. These findings suggest that the VIT/RPE-Relative intensity determination may be employed in future clinical trials as an objective, quantitative disease activity endpoint.  

 

Box and whisker plot illustrating vitreous signal intensity/retinal pigment epithelium relative intensity measurements using SD-OCT and their relationship with different vitreous haze scores determined by clinical examination. Horizontal lines within each box represent medians, whereas the end of the boxes are the upper and lower quartiles.