Glaucomatous Optic Neuropathy's & Normal IOP

NTG: Can you spot the differences?...

There are four anatomic optic disc appearances (phenotypes) recognized in glaucomatous optic neuropathy. Focal ischemic, myopic glaucomatous, senile sclerotic, and generalized enlargement. Recognizing the differences can matter considering there are a variety of clinical features associated with each. The comparison of optic nerve microvasculature among these different phenotypes in normal-tension glaucoma (NTG) Individuals shows significant differences in vascular and structural characteristics, which can have significant impact on our management.

For example, it has been shown myopic glaucomatous optic disc phenotypes have notably lower vessel density and blood flow rates compared to a focal ischemic pathogenesis. Specifically, the average optic nerve head vessel density and peripapillary choroidal vessel density are significantly diminished in myopic phenotypes, suggesting these individuals may experience a higher risk of glaucomatous damage due to compromised vascular perfusion. And with focal ischemia, anatomic structural differences in capillary networks creates the potential for ischemic glaucomatous optic neuropathy. Of course, all phenotypes often correlate with distinct and predictable corresponding visual field loss.

This is a reminder for us regarding the importance of understanding optic disc phenotypes when evaluating our glaucoma patients, as it can guide us towards more personalized treatment approaches thereby improving long-term outcomes - particularly with NTG.

- JRM

Go to the article in BMC Ophthalmology HERE.