Pseudopapilledema (Fig. 13.6) is due to a narrow scleral canal. Because of the constriction, the nerve fibers are tightly compressed. The optic disk is elevated and the full circle of the margin obscured. The optic cup is absent, and the retinal vessels appear tortuous. There are no abnormal morphologic changes such as bleeding, nerve fiber edema, and hyperemia; visual acuity and visual field are normal. Pseudopapilledema can occur with hyperopia,
Fig. 13.5 Oblique entry of the optic nerve superiorly with an inferior crescent and inferior segmental ectasia of the fundus.
13.3 DisordersthatObscuretheMarginoftheOpticDisk 365
Fig. 13.6 Circular blurring of the margin of the optic disk with absence of the optic cup.
although it is encountered equally frequently in emmetropic or slightly myopic eyes.
Differential diagnosis: optic disk edema, optic disk drusen (see Table 13.1). 18.104.22.168 Myelinated Nerve Fibers
Normally retinal nerve fibers are not myelinated. However, myelinated areas occasionally occur in the retina (Fig. 13.7). They occur most frequently at the
— Myelinated nerve fibers. -
Fig. 13.7 Because they are myelinated, the nerve fibers appear whitish and striated and can simulate segmental blurring of the margin.
margin of the optic disk. Whitish and striated, they simulate segmental or circular blurring of the margin. Myelinated nerve fibers can also occur on the periphery of the retina. Because of their location in the innermost layer of the retina, they tend to obscure the retinal vessels. Myelinated nerve fibers normally cause no loss of function. Only extensive findings can lead to small sco-tomas.
Was this article helpful?
I ought to change, but I've attempted and failed. Does this seem familiar? Frequently, altering habits does seem insurmountable. A lot of us merely don't have enough motivation to alter our habits all of our foul habits in a way that would really affect our life. We hold them tight as we view them as rewards. But your habits determine your life. Discarding Negative Habits Methods That Will Help You Deconstruct The Bad Habits Holding You Back.