Treatment options for the common eye conditions cataract and primary open angle glaucoma (POAG) differ: cataract requires surgery whereas POAG can be treated with eye drops, laser or surgery. Research has found that combining glaucoma and cataract surgery is a promising approach for some patients when these conditions coexist (Shah et al, 2025). But when is it right to combine surgical treatment for both?

The prevalence of cataract and glaucoma increases with age (NHS, 2025; Rotchford et al, 2020), making coexistence common in elderly patients. Referring patients with cataract and glaucoma to a glaucoma specialist for cataract surgery is considered increasingly important to ensure treatment efficiency and patients having all the information before making a decision. 

Cataract surgery (phacoemulsification) has been shown to lower intraocular pressure (IOP) modestly in most patients with POAG by an average reduction of approximately 2–4mmHg. In angle closure glaucoma, IOP reduction can be more significant because of deepening of the anterior chamber and opening of the anterior chamber angle once the enlarged crystalline lens has been replaced with a relatively thin intraocular lens implant.