Abstract
Purpose: :
to compare the ability of optical coherence tomography (OCT) retinal nerve fiber layer and macular thickness measurements for detection of progressive axonal loss following acute traumatic optic neuropathy (TON) in a longitudinal study.
Methods: :
three patients with unilateral TON were evaluated sequentially after trauma. Macular and retinal nerve fiber layer (RNFL) thickness measurements were obtained using OCT weekly for five weeks and around the twelfth week after trauma.
Results: :
all patients showed progressive macular and RNFL thickness reduction. RNFL loss was apparent 2 weeks after trauma and became significant around 4 weeks and much more prominent 12 weeks after trauma. Macular thickness measurements showed reduction at 5 weeks that became significant only 12 weeks after trauma. When compared to the initial measurement macular thickness average reduction rate at the 12th week was 13.58% while peripapilary RNFL thickness average reduction rate was 59.31%.
Conclusions: :
RNFL thickness measurements show greater and faster retinal neural reduction when compared macular thickness measurements in traumatic optic neuropathy. Although both measurements reduce significantly after trauma and both can be used for quantification of axonal loss, macular thickness measurements reduction is much smaller when compared to RNFL thickness measurements.
Keywords: neuro-ophthalmology: optic nerve • optic nerve • trauma