Evaluating high intraocular pressure criteria used to define failure in glaucoma surgery studies

Abstract

Purpose : To systematically review high intraocular pressure (IOP) cut-offs used as failure criteria in glaucoma surgical studies.

Methods : A systematic review (Prospero CRD42023460048) was conducted using MEDLINE searching for studies on glaucoma surgical techniques providing subconjunctival filtration, both ab externo (e.g., trabeculectomy, glaucoma drainage devices, deep sclerectomy, Preserflo MicroShunt, Express shunt) and ab interno (e.g., Xen Gel). Two independent reviewers selected studies to include and extracted high IOP cutoffs used as surgical failure criteria.

Results : Out of 2,503 identified studies, 277 met the eligibility criteria (Fig 1). A total of 147 different high IOP failure criteria were found (Fig 2). These included 46 variations of the 21 mmHg criterion, 45 of the 18 mmHg criterion, 32 of the 15 mmHg criterion, 9 of the 12 mmHg criterion, 12 based on percentage IOP reduction from preoperative values, and 3 on a target IOP. The median number of high IOP failure criteria used per study was 1 (interquartile range: 1-2). Overall, the 21 mmHg criterion was the most common (used in 186 studies [67.1%]), followed by 18 mmHg (115 studies [41.5%]), 15 mmHg (63 studies [22.7%]), percentage IOP reduction (17 studies [6.1%]), 12 mmHg (12 studies [4.3%]), and target IOP criteria (3 studies [1.1%]). For individual criteria, the most frequent ones were IOP>21 mmHg at any visit (61 studies [22.0%]), IOP>18 mmHg at any visit (28 studies [10.1%]), and IOP>21 mmHg or <20% IOP reduction in 2 consecutive visits after 3 months (26 studies [9.4%]).

Conclusions : The criteria for defining high IOP failure in glaucoma surgery are highly heterogeneous in the current literature. Further research is needed to assess how different definitions of high IOP affect surgical failure rates.

This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.