Use of trypan blue to assess lymphatic function following trabeculectomy

Importance: To illustrate the importance of lymphatic drainage in assessing trabeculectomy bleb function using intracameral trypan blue. Background: To study the lymphatic drainage of trabeculectomy blebs using trypan blue, correlate with bleb function and classify them accordingly. Design: Prospective cross-sectional study in a tertiary care centre. Participants: Thirteen glaucoma patients post-trabeculectomy were studied. Methods: Trypan blue was injected into the anterior chamber. Main Outcome Measures: 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. Results: 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). Conclusions and Relevance: 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.