Purpose: To investigate whether microsurgical excision of trabecular meshwork (TM) in an ex vivo pigmentary glaucoma model can normalize the hypertensive phenotype. Methods: Eight eyes of a porcine pigmentary glaucoma model underwent 90° of microsurgical TM excision with an aspirating dual-blade (Goniotome (G)). 24 hours later, an additional 90° of TM were removed. Anterior segments with sham surgeries served as the control (C). Outflow facility and intraocular pressure (IOP) were analyzed. Histology with hematoxylin and eosin (H&E) was obtained. Results: After the first 90° TM excision, IOP was significantly lower in G (10.23±2.39 mmHg, n=7) than C (20.04±1.97mmHg, n=8, P<0.01). Outflow facility in G (0.38±0.07 µl/min/mmHg) was higher than C (0.16±0.02 µl/min/mmHg, P<0.01). After the second 90° TM excision, IOP in G (6.46±0.81 mmHg, n=7) was significantly lower than C (20.25±1.66 mmHg, n=8, P<0.001), while the outflow facility in G (0.50±0.05 µl/min/mmHg, n=7) was higher than C (0.16±0.01 µl/min/mmHg, n=8, P<0.001). Compared to the first excision, excision of an additional 90° did not change of IOP (P=0.20) or outflow facility (P=0.17) further. Conclusion: Excision of 90° of TM in a pigmentary glaucoma model using an aspirating dual-blade decreased IOP and increased outflow facility. Translational Relevance: Microsurgical TM excision over 90° can effectively restore outflow in pigmentary glaucoma.
Sustainability of Intraocular Pressure Reduction of Travoprost Ophthalmic Solution in Subjects with Normal Tension Glaucoma
