Abstract
Introduction: JIA is a group of heterogeneous diseases characterized by the presence of chronic arthritis develops before the 16th birthday after the exclusion of other causes of chronic arthritis. Uveitis is the most common extra-articular manifestation in JIA which has vision threatening complications. The well known risk factors for development of uveitis in JIA are 1) younger age at the development of JIA, 2) female sex, 3) short disease duration, 4) ANA positivity 5) RF negative disease 6) oligoarticular subtype. Since the disease is most of the times asymptomatic, regular screening by ophthalmologist is necessary for early diagnosis and treatment.(1-4) Objectives: The Rheumatology Clinic of Tripoli Children Hospital receives JIA cases from western and southern areas of Libya. Despite adherence to the guidelines for uveitis screening, low incidence of uveitis was noticed. We studied this population to find out the reason for this low prevalence. Methods: This case series study is performed by reviewing the medical records of the patients. Data regarding demographic characters, age at presentation and if MTX was received are collected, for those with uveitis if received before development of uveitis. Data was summarized by using percentages, mean and standard deviation where applicable. Chi square test was used to compare JIA with uveitis and a period ranged from 3 weeks to 12.5 years. Patients were included even if they were followed up for short period because tow has developed uveitis during this period. Results: The majority of cases are of the oligoarticular type and polyarticular seronegative type representing 28.3% and 27.7% of the cases respectively. Age at presentation ranged from 10 months to 15.5 years with mean 8 ± 4years. Females represented 67.1% of the cases and female predominance was noticed in all JIA types except ERA were males and females are nearly equal (male to female ratio 1:1.2) ANA positive cases represented 20% and rheumatoid factor positive cases represented 8.4% of total cases. Of the 155 cases 9 (5.8%) developed uveitis. There are also 6 cases of idiopathic uveitis still following up may develop JIA not included in the analysis. 2 of the uveitis cases were males and 7 were females. By comparing uveitis and non-uveitis cases sex was not found a significant factor (p value = 0.22).The period from JIA diagnosis to development of uveitis ranged from 0 (uveitis developed at diagnosis) to 6 years with average of 2 years. The mean age at JIA diagnosis in uveitis cases is 5.6 ± 2 years. This is significantly lower than non-uveitis cases (p value (0.042) 4 cases developed in the persistent oligoarticular subtype, 2 cases in the polyarticular seronegative subtype, 1 case in the extended oligoarticular subtype, and 1 case in Enthesitis related arthritis. All of the cases were rheumatoid factor negative and 5 of them were ANA positive. Comparing uveitis and non-uveitis cases ANA positivity was a significant factor in the development of uveitis (p value = 0.00) while rheumatoid factor result was not a significant factor (p value = 0.523) 6 of uveitis patients did not receive MTX as a treatment before the development of uveitis while 4 of them received MTX. By comparing uveitis and non-uveitis cases MTX did not significantly affect the development of uveitis (p value = 0.47) Conclusion: The incidence of uveitis is one of the lowest amung JIA cases and the factors found to be significant in the development of uveitis are age at presntation and ANA positivity