Risk of Uveitis Among People With Psoriasis
JAMA Ophthalmology, May 2017
To better understand the relationship between uveitis and psoriatic arthritis, Chi et al. assessed the risk of incident uveitis among people with psoriasis. They found that patients with severe psoriasis and concurrent psoriatic arthritis had the greatest risk of uveitis.
This retrospective cohort study was conducted in Taiwan and included 147,954 people with mild or severe psoriasis (10,107 with concomitant psoriatic arthritis) and 147,954 nonpsoriatic controls. Patients were categorized by presence/absence of psoriatic arthritis as well as by disease severity. Patients with severe psoriasis were defined as those treated with systemic therapy and/or phototherapy; patients deemed to have mild psoriasis had not received either therapy.
The primary outcome measure was occurrence of incident uveitis. The incidence of uveitis per 100,000 person-years was calculated by dividing the number of people with incident uveitis by the number of person-years for each group. Kaplan-Meier analysis and the log-rank test were used to compare the risk of uveitis between groups. Cox proportional hazard models were used to estimate hazard ratios (HR). Because some ICD-9-CM codes may refer to subtypes of uveitis that are not considered associated with psoriasis or psoriatic arthritis, a sensitivity analysis was performed using more selective diagnosis codes.
Relative to the nonpsoriatic controls, patients with severe psoriasis plus psoriatic arthritis had the greatest risk of incident uveitis (adjusted HR, 2.40). The risk of uveitis also was higher for patients with severe psoriasis who did not have psoriatic arthritis and for patients with mild psoriasis plus psoriatic arthritis (adjusted HR, 1.42 for both groups). However, the risk was not higher among patients with mild psoriasis who did not have psoriatic arthritis (adjusted HR, 1.09). Results were confirmed by the sensitivity analysis.
The authors concluded that people with severe psoriasis and concurrent psoriatic arthritis have the greatest risk of uveitis. Findings of this study may serve as a guide for clinicians to stratify uveitis risk among patients with different inflammatory presentations of psoriatic disease. (Also see related commentary by John A. Gonzales, MD, et al. in the same issue.)
The original article can be found here.