The Risk of Sympathetic Ophthalmia after Vitreoretinal Surgery.

Purpose: To investigate the clinical course and outcomes of sympathetic ophthalmia (SO) and correlate these with the nature of the inciting event and the number of vitreoretinal (VR) procedures undergone by patients.

Design: A retrospective case review.

Subjects: All patients diagnosed with SO who had been treated or monitored at a single center over a 15-year period.

Methods: A search of the electronic patient record system at Moorfields Eye Hospital, London, over a 15-year period (between January 2000 and December 2015) was carried out using the search terms "sympathetic," "ophthalmia," and "ophthalmitis." Sixty-one patients with available records were identified, and data were collected from their complete electronic and paper records.

Main Outcome Measures: The main outcome measures were best-corrected visual acuity at 1 year and at the end of follow-up and the number of VR surgical procedures preceding the diagnosis of SO. Data on patient age, sex, disease duration, ocular and systemic manifestations, ocular complications, retinal angiography, and treatment were also collected.

Results: There was a wide age range at presentation (2-84 years), and the length of follow-up ranged from 1 to 75 years. The first ocular event was trauma in 40 patients and surgery in 21 patients. Vitreoretinal surgery accounted for 13 of the 21 (62%) surgical first-event triggers. Twenty-three of 61 (38%) patients underwent VR surgery (1-7 operations) at some point before diagnosis. Surgical details were available for 15 patients, who had undergone a total of 25 VR procedures. Based on the surgical activity of the unit, the risk of developing SO after a single VR procedure was estimated to be 0.008%, rising to 6.67% with 7 procedures. A total of 23 (38%) patients experienced a decrease in acuity at the end of the follow-up period, vs. 9 (15%) patients experiencing an improvement and 18 (30%) remaining unchanged.

Conclusions: We feel that the most significant finding in this study is the calculated risk of SO development after a single VR procedure, which was significantly lower in our cohort than that previously reported in the literature. This was seen to rise exponentially with additional procedures.