Pupil diameter

However this technology has also some limitation. For example, pupil diameter is an overall parameter and for a 100 m primary telescope, the internal pupil diameter cannot be reduced below 1 m. According to the maximal size of the wafers (8 inches), a deformable mirror based on MOEMS technology cannot be build into one piece. New AO architectures are under investigation to avoid this limitation (Zamkotsian and Dohlen, 2001). 

Visual Pupil diameter Pupil diameter to dark/light stimuli Rat Redfern et al.196... 

Effects of topical scopolamine drops on pupil diameter (mm) and accommodation (diopters) in the normal human eye. One drop of 0.5% solution of drug was applied at zero time, and a second drop was administered at 30 minutes (arrows). The responses of 42 eyes were averaged. Note the extremely slow recovery. 

Figure 7.1 Pupil diameter before (A) and after a light stimulus (S). Constriction (B) and dilation (D) velocities are determined from a least square fit of the slope. Amplitude of constriction (C) represents the maximal difference in diameter before and after the flash.

Lowenfeld12 identified the components of the fight reflex that were controlled by parasympathetic and sympathetic innervation of the smooth muscles controlling pupil diameter. They concluded that the parasympathetic nervous system must be intact to observe the light reflex the sympathetic nervous system influences the shape of the reflex. For example, in the absence of sympathetic innervation, the constriction velocity is increased and the dilation velocity is decreased. Conversely, in situations of increased sympathetic tone, the constriction is sluggish and incomplete, and the pupil slowly returns to its baseline size. The effects of abused drugs on these and other components of the light reflex were studied in the experiment described below. 

Figure 7.2 After high doses of the experimental drugs, changes (from baseline) in initial (p re stimulus) pupil diameter, constriction velocity, and constriction amplitude varied as a function of the drug condition and time.

Drug Dose Pupil Diameter Constriction Amplitude Constriction Velocity Dilation Velocity... 

Both indoleamine (e.g., lysergic acid diethylamide, LSD psilocybin) and phenethylamine hallucinogens (e.g., mescaline) increased pupil diameter.26 There have been no systematic studies of the effects of these drugs on dynamic measures of the light reflex. Phencyclidine (PCP) does not cause marked changes in pupil size or light reflex. However, subjects intoxicated with PCP often show horizontal and vertical nystagmus.26... 

Jasinski, D.R. and Martin, W.R., Evaluation of a new photographic method for assessing pupil diameters, Clin. Pharmacol. Then, 8, 271, 1967. 

Myosis 3 levels based on mean pupil diameter measured in treated and control animals (1 unit =1/30 mm) + decrease > 10 units ++ decrease > 20 units +++ decrease > 30 units... 

Others (respiration, fear, reactivity to touch) are scored in 2 directions. Finally, certain parameters (rectal temperature, pupil diameter) are measured quantitatively. 

Aktas et al. [141] showed an increased permeation of pilocarpine nitrate com-plexed with hydroxy-propyl-P-cyclodextrin using isolated rabbit cornea. They found a significant reduction in the pupil diameter compared to a simple aqueous solution... 

The pharmacokinetic profile of intranasal diamorphine has been studied in adults. Diamorphine is rapidly absorbed as a dry powder and has similar pharmacokinetic properties to intramuscular diamorphine, with similar physiological responses (for example reduced pupil diameter, respiration, and temperature) and behavioral measures (for example euphoria, sedation, and dysphoria). 

Adapted from NRC (2003) with permission by the National Academy of Sciences, courtesy of the National Academies Press, Washington DC Mild miosis defined by Johns (1952) as decrease of 1 to 2 mm in pupil diameter reversible within 24 h. 

When evaluating data from the Harvey (1952) study, Johns (1952) reported on the occurrence of miosis in exposed individuals. Regression analysis of 150 observations, including 55 controls, indicated that the concentration at which a 50% decrease in pupil diameter would be attained was approximately 4.1 mg-min/m, with 90% confidence limits of about 2.7 and 5.7 mg-min/m. Johns (1952) defined mild miosis as a decrease of 1 to 2 mm in pupil diameter, which usually disappeared within 24 h. While mild miosis as defined above was observed in some subjects at the lowest Ct tested (Ct = 1.0 mg-min/m ), other subjects exhibited mean maximal pupil decreases of < 1 mm, indicating attainment of a response threshold at this level of exposure. Untreated controls exhibited a pupil diameter decrease of >0.33 mm Johns (1952) attributed this difference to observer bias and pointed out that there was still a relative difference between the control group and the exposed groups. 

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