To perform this task well, they had to realise and accept the need to move their discs away from their intended goal before moving them closer.In all three tests Dr Smith found that low-power participants made 2-5% morerrorsrs than their high-power counterparts.
For each retinal photograph, a trained grader, masked to participants' identities, applied the program to measure retinal microvascular geometric parameters within a concentric zone between the optic disc margin and two optic disc diameters away from the optic disc margin.
The measured area was standardized and defined within the region between 0.5 and 2.0 disc diameters away from the disc margin, and all visible vessels coursing through the specified zone were measured (Fig. 1).
The grader allowed the software to detect the center of the optic disc and divided the region into three subzones (A, B, and C) surrounding the optic disc, each zone corresponding to 0.5, 1.0, and 2.0 optic disc diameters away from the optic disc margin, respectively.
Measurements were based on all vessels crossing through a prespecified and standardized area from 0.5 to 2 disc diameters away from the optic disc margin.
Because of this relatively large size of observable retinal vessel, diameter measurements using fundus photography are limited to 0.5 to 1.5 disc diameters away from the optic disc margin [ 18].
In brief, diameters of the largest six arterioles and venules passing through the circular zone between one-half and one disc diameter away from the optic disc margin were summarized as the central retinal arteriolar equivalent and central retinal venular equivalent using the Parr-Hubbard formula further modified by Knudtson and colleagues (15).
However, because of the way redundancy is used in the data on the disc and the way the data are distributed along the spiral track, cleaning a disc area away from a scratch can improve data recovery; a number of smaller defects distributed along the track can be as bad or worse than one larger defect.
Laser-coagulations were performed 4 5 disc diameters away from the papillae with an Argon laser (532 nm, 400 mW, 50 ms and 50 μm).
Store your disc(s) away from where your laptop is stored.
