Korean researchers based in Seoul believe that eye care practitioners should consider age and optic disc morphology when predicting visual field (VF) progression in untreated normal tension glaucoma (NTG) patients who also have myopia. Their recent study found that patients with both conditions seem to have a slow progression rate even without glaucoma medications.

The study analyzed 97 patients with NTG and myopia who did not use IOP-lowering medications until glaucomatous VF progression was confirmed. The researchers investigated the natural course of NTG with myopia with a minimum three years follow-up and evaluated whether or not optic nerve head (ONH) morphology was associated with progression in the untreated patients.

Of the untreated NTG eyes with myopia, only 32 showed progression during the observation period: 10.3% at 36 months and 24.8% at 60 months.

When researchers analyzed the results based on age and disc tilt direction, they found those aged 50 or younger and those with a disc tilt direction less than 45° were more likely to experience progression. The study found an association between progression and the presence of disc hemorrhage, more temporally tilted disc and parapapillary atrophy.

The findings suggest that progression occurs less and the overall progression rate is relatively slower in NTG eyes with myopia compared with NTG eyes without myopia. The researchers believe that, in NTG with myopia, increasing stress around the ONH with axial growth at a young age may play a more important role than aging itself for glaucomatous VF progression. However, they find it difficult to conclude that glaucomatous defects in the myopic eyes are associated with myopic change solely on the basis of lack of progression.

Han JC, Han SH, Park Y, et al. Clinical course and risk factors for visual field progression in normal-tension glaucoma with myopia without glaucoma medications. Am J Ophthalmol. September 5, 2019. [Epub ahead of print].