Effect of Therapeutic Pars Plana Vitrectomy on Total Immunosuppression Load in Patients with Non-Infectious Uveitis.

Purpose: The anti-inflammatory effect of therapeutic pars plana vitrectomy (PPV) in the management of posterior segment uveitis is incompletely quantified. In this study, we evaluated the change in total immunosuppression load (TIL) following PPV for the eyes of patients with non-infectious uveitis.

Methods: Retrospective chart review of patients with non-infectious posterior segment uveitis on continuous anti-inflammatory therapy (systemic corticosteroids ± immunomodulatory therapy [IMT]) ±3 months, who received therapeutic PPV for non-resolving inflammation. The TIL scores were calculated by adding the total daily dose of prednisolone graded on a scale of 0-9, and of the IMT graded between 0 and 3, and calculating the mean values for the pre-operative and post-operative visits, respectively.

Results: Sixty-five eyes of 65 patients were included. Mean follow-up was 19.1 ± 14.6 months pre-operatively and 9.4 ± 7.1 months post-operatively. Mean TIL scores for the post-operative visits (2.6 ± 1.9) were significantly lower than the pre-operative (4.4 ± 1.7) visits (p < 0.001). Mean logMAR BCVA was four lines better 1 month post-operatively (0.5 ± 0.4) than the immediate pre-operative vision (0.9 ± 0.6, p < 0.001). On multivariate regression analyses, the reduction in mean TIL scores post-operatively was more with longer durations of pre-operative treatment (adjusted risk ratio [aRR] = -0.04, p = 0.04), while the improvement in one-month post-operative BCVA was more if pre-operative vitreous haze was ≥2+ (aRR = -0.25, p = 0.02). Post-operative adverse outcomes included new-onset cystoid macular edema (n = 6), raised intraocular pressure (n = 5), and intra-operative retinal break (n = 1). Eleven (16.9%) patients were off all immunosuppression during the final follow-up.

Conclusions: Therapeutic PPV allowed control of intraocular inflammation on less intensive systemic anti-inflammatory therapy. Post-operative adverse outcomes observed were manageable.