OCT-assessed vitreous inflammation in uveitis patients treated with intravitreal dexamethasone implants

Abstract

Purpose : Vitreous haze is an established biomarker of intraocular inflammation in uveitis patients. However, its use for clinical trials is limited by inter-rater variability. A recently developed optical coherence tomography (OCT)-based algorithm quantifying vitreous inflammation (Montesano G et al., 2018) may overcome these limitations and was shown to be associated with clinical disease activity ratings. We used this algorithm to assess change in vitreous inflammation following intravitreal dexamethasone (DEX) implant over at least 12 months and compare it to clinical ratings.

Methods : Retrospective clinical and OCT data (Spectralis; Heidelberg Engineering Inc) were collated. The inflammation score (INS) was obtained using the available automated OCT-based algorithm. Data were compared in a pre-post analysis using a random effects model and correlation coefficients.

Results : Patients with cystoid macular edema in intermediate uveitis (n = 14), posterior uveitis (n = 60), panuveitis (n = 10) or anterior uveitis (n = 3) resulting in a total of n=87 eyes of 73 uveitis patients treated with intravitreal DEX implants were available for analysis. The INS changed from 0.134 at baseline to 0.070 at last follow up (p = 0.0158). Patients received an average of 2.3 ± 2.3 injections (range: 1 – 14 injections). The overall INS correlated significantly with the clinical ratings of anterior vitreous cells. In all patients, the INS at baseline did not correlate significantly with the INS at final follow-up (FU), number of injections, visual acuity at last FU or visual acuity change. However, in only intermediate and panuveitis patients, we found a considerable positive correlation between initial INS and number of injections (r = 0.40, 95% CI 0.01 – 0.69).

Conclusions : We found OCT-assessed vitreous inflammation to decrease following intravitreal dexamethasone implants. The inflammation score was associated with clinical parameters and predictive of the number of future injections. The OCT-based vitreous haze score is a potentially relevant biomarker for long-term follow-up in uveitis patients as well as for future clinical trials. Further research should assess its relationship with structural and functional parameters.

This is a 2020 ARVO Annual Meeting abstract.