Pupil size

We have developed another bench for the measurement of the contrast value. Contrast measurement have been carried out on the MMA fabricated by Texas Instrument, in order to establish the test procedure (Zamkotsian et al., 2002a Zamkotsian et al., 2003). We can address several parameters in our experiment, as the size of the source, its location with respect to the micro-elements, the wavelength, and the input and output pupil size. In order to measure the contrast, the micro-mirrors are tilted between the ON position (towards the spectrograph) or the OFF position (towards a light trap). Contrast exceeding 400 has been measured for a 10° ON/OFF angle. Effects of object position on the micro-mirrors and contrast reduction when the exit pupil size is increasing have also been revealed. 

If a series of related chemicals, say noradrenaline, adrenaline, methyladrenaline and isoprenaline, are studied on a range of test responses (e.g. blood pressure, heart rate, pupil size, intestinal motility, etc.) and retain exactly the same order of potency in each test system, then it is likely that there is only one type of receptor for all four of these catecholamines. On the other hand, if, as Ahlquist first found in the 1940s, these compounds give a distinct order of potency in some of the tests, but the reverse (or just a different) order in others, then there must be more than one type of receptor for these agonists. 

PAM chloride - 2-pralidoxime chloride. See oxime, parasympathetic nervous system -the part of the autonomic nervous system that decreases pupil size, heart rate, and blood pressure and increases functions, such as secretion of saliva, tears, and perspiration. 

The course of post-LSD pupillary changes, with respect to dosage schedule and intensity and duration of effects, is a valuable tool. Pupil size 3 hr after the initial dose responded to the second dose of LSD and was an obvious measure to track in acute tolerance studies in humans. Given the number of rat studies in which this would be useful to monitor, the problem lies in determining rat mydriasis (easy in other animals) while a computerized pupillometer (developed by Martin Adler at Temple University) was informally tried by us once with LSD, systematic studies have not been done. 

The beam of light from the pen light is played across the eyes of the animal, and changes in pupil size are noted. In the normal animal, the pupil should constrict when the beam is on it and then dilate back to normal when the light is removed. Note if there is no response by recording a minus sign in the blank... 

Pupil size and evaluation (in darkened room with controlled illumination)... 

Pupil sizes. Left eye exposed to di-/.voproptvl phosphorofluoi idate (0 008 2 min. exposure) (a) 3 hr. after exposure (6) 24 hr. after exposure. 

Hess, E. H. (1965). Attitude and pupil size. Scientific American, 212,46-54. 

All reflexes were abolished, and pupil size varied. All patients survived the first coma and became fully conscious however, one patient died in coma several days later due to extensive liver necrosis (Piersol et al. 1933). Mild cerebellar damage (instability of gait, intentional tremor) was observed in one patient, but reversed to normal in two weeks (Storms 1973). 

Physiological Measures BP, HR, T, R, Pupil Size (PS), neurological and mental status exams... 

Duration of observation (Table 6) for each subject was lengthy and required a total more than 300 subject days of testing, considering that each subject (in groups of 2-4 as a rule) occupied a test cubicle for an average of five days. Vital signs, including pupil size, heart rate, blood pressure and performance on NF and VITA, were measured at 1, 2, 3, 4, 6, 8, 10, 12, 16 and every four hours thereafter until recovery. The nurse entered full descriptions of behavior as often as possible. 

Pupil size shows only a modest increase, and takes 8 hours to peak (Fig. 49). This suggests that most of the enlargement of pupils is central in origin although, as indicated previously, there is some doubt as to the centrality of the mechanism. 

Pupil size increased rapidly to a maximum of about 7 mm at 6 hours (Fig. 52), and tended to persist longer than changes in both cognitive performance and heart rate. The probable dominance of the central component of pupillary dilation is reinforced by this observation. 

The 5 groups of agents used in therapy of primary open-angle glaucoma are listed in the table, which summarizes their mechanism of decreasing lOP, effects on pupil size and ciliary muscle and duration of action. 

H hstract. Until recently, all ocular photoreception was attributed to the rods and cones of the retina. However, studies on mice lacking rod and cone photoreceptors (rdjrdcl), has shown that these mice can still use their eyes to detect light to regulate their circadian rhythms, suppress pineal melatonin, modify locomotor activity and modulate pupil size. In addition, action spectra for some of these responses have characterized a novel opsin/vitamin A-based photopigment with a 480nm. Electrophysiological... 

Van Gelder I disagree. The measured pupillary response depends on the exact second that you measure the pupil size, because there is second-to-second variation in the pupil size that does produce somewhat of an error bar. 

Pupil size Accommodation i Constriction of radial muscle causing dilation (mydriasis) No innervation Contraction of circular muscle (miosis) Contraction of ciliary muscle producing accommodation for near vision... 

Glaucoma Timolol and other ocular P-blockers are used to treat glaucoma. Propranolol is effective in diminishing intraocular pressure in glaucoma. This occurs by decreasing the secretion of aqueous humor by ciliary epithelium. It neither affects the ability of eye to focus for near vision, nor changes pupil size. Used in chronic cases only. 

The antimuscarinic properties result in what are usually the most troublesome adverse effects dry mouth, blurred vision, constipation, and (mainly in older males) urinary hesitancy and retention. Pupil size, and hence risk of glaucoma, is determined by a balance between anticholinergic (mydriatic) and sympathomimetic (miotic) effects. 

When given intravenously to a morphine-treated subject, the antagonist completely and dramatically reverses the opioid effects within 1-3 minutes. In individuals who are acutely depressed by an overdose of an opioid, the antagonist effectively normalizes respiration, level of consciousness, pupil size, bowel activity, and awareness of pain. In dependent subjects who appear normal while taking opioids, naloxone or naltrexone almost instantaneously precipitates an abstinence syndrome. 

Physiological Basis of Pupil Size and the Light Reflex.128... 

PHYSIOLOGICAL BASIS OF PUPIL SIZE AND THE LIGHT REFLEX 7.2.1 Pupil Size... 

Pupil size can be estimated from direct observation. A variety of cards and scales are available whereby the experimenter compares the size of the pupil to standard patterns and scales. The simplest and most often used card is the Haab pupil gauge. This consists of a card with black circles graduated in size between 2 and 10 mm in 0.5-mm increments. The card is held on the temporal side of the eye out of the subject s vision (to reduce accommodation miosis). Pupil size can be determined to an accuracy of 0.2 mm. A disadvantage of this method is the inability to make measurements in the dark and the possibility that the subject s eyes will react to the test or its administration. 

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