Abstract
Purpose: :
To determine the structural–functional correlation between retinal nerve fiber layer thickness and optic nerve function (automated visual threshold perimetry) in adults with optic nerve hypoplasia.
Methods: :
23 patients were studied with a diagnosis of optic nerve hypoplasia based on disc appearance (fundus photography) and who also had retinal nerve fiber layer (RNFL) and optic disc analysis by optical coherence tomography (OCT) as well as visual field testing (HVF n=14, GVF n=19).
Results: :
A significant correlation was found between RNFL thickness and disc area (correlation coefficient R=0.51, p<0.001), RNFL thickness and vertical neuroretinal rim volume (R=0.50, p<0.001), and between disc and cup area (R=0.429, p=0.004). A significant linear and non–linear relationship between RNFL and average visual field threshold was also found (linear R=0.425, p=0.038, non–linear R=0.53, p=0.053). Two eyes had significantly more visual field loss than would be predicted from their RNFL thickness. Qualitatively, there was a very good correlation between nerve fiber layer sectoral analysis and the area of the corresponding visual field defect.
Conclusions: :
Optic nerve hypoplasia shows significant relationships between disc morphology as measured by optical coherence tomography and RNFL thickness. Segmentally thinned RNFL from developmental causes correlates well with the location of visual field defect.
Keywords: neuro-ophthalmology: optic nerve • nerve fiber layer • visual fields