COHERENCE EXPLAINED HOW TO

The nomenclature for the middle two bands has much less supportive evidence. This band is typically thinner and fainter than the others. 29,30,36 The innermost band has been attributed to the external limiting membrane (ELM). There is discordance between different authors regarding which anatomic structure correlates with each band. Outside the central fovea, commercially available SD-OCT instruments typically resolve four bands in the outer retina. 35 The retinal vessels may sometimes be seen on OCT images as circular hyperreflective structures located in the inner retina, with a vertical shadow or reduced reflectivity extending into deeper layers. A recent study demonstrated that the incidence of the light beam could affect the appearance of Henle fiber layer by OCT, resulting in a thin hyperreflective layer corresponding to the photoreceptor synapses or a thicker hyperreflective layer corresponding to photoreceptor axonal extensions enveloped by the outer cytoplasm of Müller cells ( Fig. Within the retina, the retinal nerve fiber layer and the plexiform layers (both inner and outer) are seen as hyperreflective while the ganglion cell layer and the nuclear layers (both inner and outer) are relatively hyporeflective. In some patients, the posterior hyaloid can be seen above the ILM as a hyperreflective layer. The first detected layer in most OCT scans is the ILM that appears as a hyperreflective layer at the vitreoretinal interface. 2,30Īlthough the interpretation of features of the retina, which can be defined for our purpose to span from the ILM to the outer segments of the photoreceptors appears to correlate well with histology, the OCT features of the outer retina are less well understood and remain a topic of discussion ( Fig. Therefore, one-to-one correspondence of histology with OCT images cannot be expected. The angle of incidence of the light, motion artifacts, speckled noise, and image contrast can affect the axial resolution of the retinal imaging. 30 When light travels through the retinal tissue it can be reflected, scattered, or absorbed, and this creates the multilayered pattern of the retina. 29 However, care must be taken when making assumptions about these correlations because histologic sections require fixation and exogenous staining to produce contrast within tissue, and this can introduce artifacts, while OCT relies on intrinsic differences in tissue optical properties to produce image contrast. With the increase in the axial resolution of the new SD-OCT instruments (5–8 µm) and the ultrahigh-resolution OCT (2 µm), it has become possible to correlate OCT images accurately with histologic features of the retina. The OCT image closely approximates the histologic appearance of the macula and, for this reason, it has been referred to as an in vivo optical biopsy. Schachat MD, in Ryan's Retina, 2018 Normal Macular Anatomy See how brilliantly Russell has connected the ideas of philosophy and politics, by moving from a general to a specific topic, with sentences connecting one to another, creating coherence.Andrew P. Philosophy, as pursued in the universities of the Western democratic world, is, at least in intention, part of the pursuit of knowledge, aiming at the same kind of detachment as is sought in science …” Like the word “religion,” it has one sense when used to describe certain features of historical cultures, and another when used to denote a study or an attitude of mind which is considered desirable in the present day. “The word “philosophy” is one of which the meaning is by no means fixed. Example #4: Unpopular Essays (by Bertrand Russell) The entire paragraph is an example of coherent speech.

COHERENCE EXPLAINED HOW TO

Through the speech of the Old Major, Orwell starts the passage about the miserable nature of the life of animals on the animal farm, and then he inspires them to think about how to safeguard their interests on the farm. The life of an animal is misery and slavery: that is the plain truth.” “No animal in England knows the meaning of happiness or leisure after he is a year old.

We are born, we are given just so much food as will keep the breath in our bodies, and those of us who are capable of it are forced to work to the last atom of our strength …

“Now, comrades, what is the nature of this life of ours? Let us face it: our lives are miserable, laborious, and short.

Coherence explained