Abstract
Purpose: :
In the analysis of nerve fiber layer (NFL) thickness around optic disc of normal eyes using circular optical coherence tomographic (OCT) scans, the NFL profile exhibits a double–hump pattern with peaks over the superotemporal and inferotemporal sectors. The relationship of these humps to the retinal vessels was investigated.
Methods: :
Thirty–four normal eyes (9 men and 10 women, 17 right eyes and 17 left eyes) were examined using optical coherence tomography (OCT, circular scan around optic disc, diameter: 3.4 mm and 5.4 mm, 512 A–scans/scan), and red–free and color fundus photographs. The acoustic shadow of the retinal vessels were carefully identified using the red–free and color fundus photographs, and the relationship of the NFL humps and retinal vessels was investigated. At the same time, NFL thickness profile of the circular scan around optic disc was delineated as a circular profile and overlapped on the fundus photograph by custom–made software, and the relationship between the hump and retinal vessels was investigated.
Results: :
Results: The location of all detected humps was consistent with the location of retinal artery, adjoining artery and vein, or retinal vein. The locations of the superotemporal hump coincided with a retinal artery in 21 eyes, retinal artery and vein in 12 eyes, and retinal vein in 1 eye. The location of an inferotemporal hump coincided with a retinal artery in 22 eyes, retinal artery and vein in 9 eyes, and retinal vein in 3 eyes. Superonasal and inferonasal humps were detected in 17 and 7 eyes, respectively. The location of the superonasal humps coincided with a retinal artery in 11 eyes and retinal artery and vein in 6 eyes. The location of the inferonasal humps coincided with a retinal artery in 4 eyes, retinal artery and vein in 2 eyes, and a retinal vein in 1 eye. The location of humps were significantly consistent with that of retinal artery than vein (P <0.05).
Conclusions: :
The location of NFL hump was consistent with location of retinal vessels, especially retinal artery. The development of NFL and retinal vessels was concluded to be closely related.
Keywords: nerve fiber layer • retinal development • imaging/image analysis: clinical