Abstract
Abstract: :
Purpose: To characterize the profile of the normal human Retinal Nerve Fiber Layer (RNFL) using Optical Coherence Tomography (OCT). Methods: A consecutive group of participants from the Los Angeles Latino Eye Study (LALES)- a population based prevalence study of eye disease in Latinos- underwent a complete ophthalmologic examination and OCT. A peripapillary circular scan with the diameter of 3.43 mm was performed on each individual.The RNFL profile was qualitatively evaluated by two observers to determine whether the profile was a «double hump» pattern, a «triple hump» pattern,or indeterminate pattern. The two observers evaluated the profile masked to participant demographic and clinical information and to the other observers evaluation. A «hump» was defined as a discrete thickened zone of the RNFL at least seven degrees in width and separated from an adjacent «hump» by at least seven degrees. An eye was considered to have a specific profile if both observers agreed on the profile. Results: 100 eyes of 100 consecutive participants were studied. All participants had no evidence of ocular disease. The mean age of the participants was 51.4 years (range 40 to 77 ). The most common profile identified by the observers was a «triple hump» pattern (in 57 % of eyes)- a superior, superior nasal, and an inferior «hump».The «double hump» pattern (a superior and and inferior hump) was identified in only 7 % of eyes.There was no agreement between the observers or an indeterminate pattern was noted in 36 % of eyes. Conclusion: The most common profile of the human RNFL was the «triple hump» pattern and not the «double hump» pattern. This profile of the RNFL should be considered when evaluating the optic nerve for glaucoma and other optic neuropathies.
Keywords: 484 nerve fiber layer • 430 imaging/image analysis: clinical • 432 imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)