Scleritis incidence drops 34% in UK over 22 years, 'likely' due to improved IMID care
The incidence of scleritis declined by about a third in the United Kingdom between 1997 and 2018, according to data published in Arthritis & Rheumatology.
Researchers further wrote that scleritis had multiple, significant associations with as many as 19 infectious and immune‐mediated inflammatory diseases (I-IMIDs). The strongest of these associations were reported with granulomatosis with polyangiitis, Behçet’s Disease, Sjögren’s syndrome, rheumatoid arthritis, systemic lupus erythematosus, Crohn’s disease and sarcoidosis.
“It has been long-recognized that scleritis (especially if necrotizing) may portend worse survival prognosis in patients with certain I-IMIDs, including rheumatoid arthritis (RA),” Tasanee Braithwaite, DM, of King’s College London, U.K., and colleagues wrote. “A key challenge to advancing evidence-based management of scleritis is the paucity of population-based epidemiological data on incidence internationally, and absence of data on the strength of association with systemic I-IMIDs, and with other sight-threatening ocular inflammatory phenotypes (eg, uveitis and optic neuritis) with which scleritis and these I-IMIDs may be associated.”
“Robust epidemiological data would facilitate increased awareness of scleritis as a cause of ocular symptoms in patients with I-IMIDs, more tailored investigation and risk stratification, health system cost modelling and allocation of appropriate resources (medicines, infrastructure, equipment and staff) to meet current and future demand,” they added. “Our appreciation of the epidemiology of scleritis is currently informed by few studies.”
To estimate the trends in scleritis incidence and prevalence, and examine its associations with I-IMIDs, in the U.K., Braithwaite and colleagues conducted a retrospective, cross-sectional and population cohort study for the years 1997 to 2018. For this study, the researchers included 10,939,823 individuals — among whom were 2,946 incident scleritis cases — from The Health Improvement Network (THIN), a nationally‐representative primary care records database.
Braithwaite and colleagues also conducted a case-control and cohort study for the years 1995 to 2019, which included 3,005 incident scleritis cases and 12,020 control patients, matched by age, sex, region and Townsend Deprivation Index (TDI). The researchers adjusted Poisson, Logistic and Cox proportional hazard multivariable models based on age, sex, TDI, race, ethnicity, smoking, nation and BMI.
According to the researchers, scleritis incidence rates declined from 4.23 (95% CI, 2.16-6.31) per 100,000 person‐years to 2.79 (95% CI, 2.19-3.39) per 100,000 person‐years between 1997 and 2018. The prevalence in 2018 was 93.62 (95% CI, 90.17-97.07) per 100,000 people, or about 61,650 patients in the U.K.
“This trend is likely to reflect improvements in the management of systemic I-IMIDs,” the researchers wrote. “Over this period, there has been increasing availability of antimicrobial therapies and immunosuppressive therapies including biologics.”
Women (adjusted incidence rate ratio = 1.54; 95% CI, 1.43-1.66) as well as Black (aIRR = 1.52; 95% CI, 1.14‐2.01) and South Asian (aIRR = 1.5; 95% CI, 1.19‐1.9) individuals demonstrated a higher risk for incident scleritis, compared with those who were white. Patients aged 51 to 60 years were also at higher risk (peak aIRR = 4.95; 95% CI, 3.99‐6.14), compared with those aged 10 years and younger.
Further, compared to control individuals, patients with scleritis were twice as likely to have a prior I-IMIDs diagnosis (P < .001), and demonstrated a significantly increased risk for a subsequent I-IMIDs diagnosis. The strongest associations included granulomatosis with polyangiitis (GPA), Behçet’s disease and Sjögren’s syndrome.
“This study highlights how the use of routinely collected large-scale data offers unprecedented opportunity to advance understanding of the epidemiology of rare conditions and their associations,” Braithwaite and colleagues wrote. “Here we report declining U.K. scleritis burden over 22 years, and multiple significant associations with I-IMIDs which precede or follow scleritis diagnosis, providing guidance for health policy and clinical management.”
“Most strongly associated were GPA, Behçet’s Disease, Sjögren’s syndrome, RA, SLE, Crohn’s disease and sarcoidosis,” they added. “The interplay between ophthalmologically managed scleritis, and I-IMIDs managed by rheumatology and other specialties, highlights the need for multi-specialty care pathways for patients with this potentially blinding disease.”