To illustrate the importance of lymphatic drainage in assessing trabeculectomy bleb function using intracameral trypan blue. To study the lymphatic drainage of trabeculectomy blebs using trypan blue, correlate with bleb function and classify them accordingly. Prospective cross-sectional study in a tertiary care centre. Thirteen glaucoma patients post-trabeculectomy were studied. Trypan blue was injected into the anterior chamber. The duration taken for dye to stain a drainage bleb or lymphatics is recorded. The extent of the lymphatic structures were measured in clock hours. Intraocular pressure (IOP) prior to surgery was recorded. Eight post-trabeculectomy subjects with dye stained lymphatic vessels had lower IOP (12.6 mmHg, P = .013) compared to the five with no lymphatic vessel staining (mean IOP 23.6 mmHg). Lymphatic extent was inversely related to IOP (P = .021). Eyes with lymphatic connections to drainage blebs had lower IOP and reduced requirement for topical medications. The extent of lymphatic connection to drainage blebs is related to lower IOP.