Abstract
Purpose :
Different parameters exist to investigate structural components of the Nerve Fiber Layer (NFL), Ganglion Cell Layer (GCL), Optic Nerve (ON). The noted layers have an interlaced structural pattern. Artificial Intelligence is developing to aid in evaluation of glaucomatous states. We hypothesize that, morphological changes in the mapping of the angles from the main arteriolar branches from the Central Retinal Artery (CRA): superotemporal (ST), inferotemporal (IT), superonasal (SN), inferonasal (IN)--would be an indicator of lost layers in the demarcated zones from those angles.
Methods :
A review of Open Angle Glaucoma (OAG) color disc photos, as classified by clinical level of Mild (N=46), Moderate (N=46), Severe (N=46) were compared by Student T-test against normal patients (N=25). The comparisons were of the angles formed by: ST/IT, ST/SN, SN/IN, IT/IN. A protractor was used to enumerate the angle: the apex point at the central retinal artery with line mapping through the aspect of these arterioles.
Results :
The summary Table identifies the clearest distinctions between Normal/Severe forms of OAG in all angles demarcated, and overall the angle demarcated by the ST/IT to show increase in overall area, with resultant decrease in the delineated areas of ST/SN as an expansion of the ST/IT angle. There was statistical significance (S) in ST/IT for all glaucomatous categories. In the stated angles that were related to the Superior, Inferior, Nasal poles of the ON there was less of a correlate.
Conclusions :
The angular mappings of the main arteriolar branches of the CRA were helpful in identifying differences between different levels in glaucoma; the most significant being in the angle demarcated by ST/IT and somewhat related in ST/SN. With further enumeration and development, these angular measurements may be help to develop algorithms and AI evaluation protocols.
This is a 2020 ARVO Annual Meeting abstract.