Elevated intraocular pressure (IOP) is currently the sole modifiable risk factor for glaucoma, a leading cause of irreversible blindness worldwide. The trabecular meshwork (TMW) plays a pivotal role in regulating IOP by facilitating aqueous humour outflow. We performed single cell expression quantitative trait loci (eQTL) mapping in TMW cells collected from 74 people (45 males, 29 females) donors. Following isolation and culture with or without dexamethosone, a total of 316,799 singlet cells were captured and underwent RNA sequencing. Differential gene expression analysis revealed 63 upregulated (log2 fold change >3) and 17 downregulated (log2 fold change >3) genes following dexamethasone exposure. A total of 164,378 cis acting eSNPs and 6,178 eGenes were identified. The causal variants at several IOP and glaucoma-associated loci were definitively mapped using colocalization. Understanding the genetic underpinnings of IOP regulation through an improved understanding of the molecular pathways involved in TMW homeostasis will facilitate novel therapeutic development.