To describe a cohort of patients with pars planitis followed at a single tertiary care institution, determine the frequency of multiple sclerosis and/or optic neuritis in patients with this disorder, and calculate gene frequencies of human leukocyte antigen (HLA) class II alleles in these patients.
Design
Fifty-three patients with the diagnosis of pars planitis underwent clinical record review or telephone interview for follow-up or both; 32 of these underwent phlebotomy for analysis of HLA class II alleles.
Main outcome measures
Outcomes included visual acuity, occurrence of multiple sclerosis and/or optic neuritis, and HLA class II gene frequencies.
Results
With a mean follow-up of 2 years, approximately 90% of patients maintained a visual acuity better than 20/40 in at least one eye. The most frequently encountered ophthalmic complications included cystoid macular edema, cataract, and epiretinal membrane formation. Of 37 patients with pars planitis who had medical or neurologic follow-up evaluations, 6 (16.2%) developed multiple sclerosis. The HLA-DR15 allele, coding for one of the two HLA-DR2 subtypes, was associated with pars planitis (odds ratio = 2.86, 95% confidence interval = 1.42–5.78, P = 0.004).
Conclusions
A common immunogenetic predisposition to multiple sclerosis and pars planitis may be associated with the HLA-DR15 allele. This association may represent genetic linkage to the HLA-DR locus or a role for the HLA-DR15 gene product in the pathogenesis of both of these diseases.
Supported by an unrestricted grant from the Research to Prevent Blindness Foundation and grant EY 01765 from the National Eye Institute, National Institutes of Health.