Abstract
Purpose :
Rubella virus (RV) is implicated in Fuchs heterochromic iridocyclitis (FHC), but RV is also detected in other forms of uveitis including intermediate uveitis. Vitreous cell infiltration of unknown etiology is possibly caused by intraocular lymphoma or infectious agents especially when it resists to steroid treatment, and vitreous biopsy is needed in such cases. This study aims at investigating the positivity of RV in the vitreous of steroid-resistant intermediate uveitis of unknown etiology.
Methods :
Thirty eyes of 30 patients (male ratio = 56%, mean age = 61 y.o.) who underwent diagnostic vitrectomy, and were measured for Goldmann-Witmer coefficient (GWC) of RV were involved in this study. GWC was calculated by measuring immunoglobulin G (IgG) and RV-specific IgG in the vitreous fluid and serum that were taken at the same day, and the calculated GWC equal to or more than 2 was defined to be positive in this study. Data regarding patients' demographics, ocular manifestations, final diagnosis, and biopsy results including, cytology, flow cytometry, Ig heavy chain rearrangement, measurement of interleukin (IL)-10/IL-6, comprehensive polymerase chain reaction for various infectious agents, and GWC of RV were retrospectively collected from the medical records. The Mann-Whitney U test was performed for statistical analysis.
Results :
The final diagnosis of the 30 patients included 7 patients with intraocular lymphoma (23%) diagnosed by the biopsy, and 2 patients with sarcoidosis and one with ocular tuberculosis diagnosed by systemic investigations and exclusion by biopsy. None of these 10 patients was positive for RV by GWC. Twenty patients were not classified into specific uveitis diagnosis either by biopsy or systemic investigations, except that RV was positive in 8 (40%) of these 20 patients. RV-positive group was younger than RV-negative group (mean age = 34 y.o. vs 77 y.o., P=0.0005), and male ratio was higher in RV-positive group (88% vs 45%).
Conclusions :
Certain rate of RV-positive patients is present in steroid-resistant intermediate uveitis especially in young male, implicating its pathology in cellular infiltration in the vitreous even when heterochromia is absent. Detection of RV should be considered when vitreous biopsy is performed for steroid-resistant intermediate uveitis.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.