Factors leading to high intraocular pressure in Intraocular Device-Associated Uveitis (IDAU): a retrospective nested case-control study from a tertiary uveitis cohort

Intraocular device-associated uveitis (IDAU) — which we propose as a more precise alternative to the traditional term “uveitis–glaucoma–hyphema (UGH) syndrome” — is a rare but potentially sight-threatening complication of intraocular device implantation. Elevated intraocular pressure (IOP) is a major driver of visual morbidity in IDAU, but the risk factors that predispose affected patients to IOP elevation remain poorly characterised. We aimed to describe the clinical spectrum of IDAU and to identify independent risk factors for elevated IOP in this population, using the Chulalongkorn University Uveitis Cohort (CU 2 C) database. This first nested case-control study within the Chulalongkorn University Uveitis Cohort (CU²C) enrolled 375 subjects followed at a tertiary uveitis clinic in Thailand over 8 years (August 2014–June 2022). Cases ( n = 30) were IDAU patients with elevated IOP (> 21 mmHg); controls ( n = 60) were IDAU patients with normal IOP, sampled at a 1:2 ratio from the same cohort. Univariate and multivariate logistic regression were used to calculate odds ratios (OR) and 95% confidence intervals (CI) for candidate risk factors. We retrospectively identified 90 subjects who developed IDAU. Following a one-to-two case–control ratio, 30 case subjects and 60 control subjects were included. Three factors were significantly associated with high intraocular pressure in IDAU. These included intraocular lens (IOL) malposition (AOR: 8.30, 95% CI 1.25 to 54.76), long eye (AOR: 8.08, 95% CI 1.18 to 55.16) and age (AOR: 1.18, 95% CI 1.07 to 1.31). There was no statistical evidence of effects of hypertension, ruptured posterior capsule, vitrectomized eye, transillumination iris defect (TID), pseudophacodonesis and single-piece IOL in sulcus on high IOP in IDAU. In this first nested case-control study of IDAU, IOL malposition, long axial length (> 25 mm), and older age were independently associated with elevated IOP. These findings should inform clinician awareness and post-operative monitoring strategies for high-risk IDAU patients.