Low Tension Glaucoma
Watch Lecture: https://youtu.be/MIdPeHWzwV4
Low Tension Glaucoma: More common in Japanese Associated with vasospastic disorders (migraine and Raynaud phenomenon), Autoimmune disorders, Sleep Apnea, Systemic hypotension, Coagulopathies Clinical Features: NFL heme (see image) Focal deep and central HVF defects are more common but typical ”POAG like” HVFs still predominate Consider avoiding timolol due to decreased blood flow (LoGTS)
Collaborative Normal Tension Glaucoma Study (CNTGS) 1998: Lowering IOP by 30% reduced VF progression after 5 years compared to untreated controls (35% vs 12%). Excluded use of beta blockers and adrenergic agents due to cross over effect. Laser and surgery allowed. Less treatment effect if baseline NFL heme present. Treatment benefit overall was absent until influence of cataract on VF was accounted for (more prevalent cataracts in treatment arm. NFL heme was used as an enrollment criteria but not as a clinical endpoint. IOP upper limit was 24mmHg!
Differential Diagnosis of LTG: Congenital anomalies (coloboma, pits) Physiologic cupping ONH Drusen Compressive ON lesions AION/PION Toxic/Nutritional optic neuropathies POAG with IOP spike outside clinic hours