Tropicamide administration

Examination of the nonhuman primate requires sedation (Kuhlman et al., 1992). The highly mobile primate eye and their anxious nature when handled mandate a chemically restrained animal for an adequate examination. Human safety considerations also are a factor. Ketamine hydrochloride works well due to its safety and controllable duration. The time to onset of mydriasis following tropicamide administration must be balanced against the time to the animal s recovery from ketamine s sedative effect. A refinement is the addition of a water-based lubricant eye drop at the time of tropicamide administration. This helps protect the cornea from desiccation while the monkey is sedated and may also aid in achieving prompt and satisfactory dilation by increasing tropicamide residence time in the precorneal tear film. Working with a seasoned technical staff appropriately trained for ketamine injection, the examiner can evaluate many primates in a reasonable time. 

Administration of 0.1 mg tropicamide to both eyes of the rabbits produced an intense mydriatic effect, which began slowly to decline after 90 min, but was still very evident (c. 70% of the peak intensity) after 7 h. The results of tests in which the dapiprazole vehicles 1 (reference), 5 and 6 were applied to one of the dilated eyes are illustrated in Fig. 1, where the area corresponding to the reversion effect vs. time of each vehicle are outlined. In Fig. 1, the data are expressed as differences in pupillary diameter, A, between the DAP-treated and the dilated, contralateral eye,... 

Lowering of pupillary sphincter tonus and pupillary dilation by local administration of homatropine or tropicamide (mydriatics) allows observation of the ocular fundus. For diagnostic uses, only short-term pupillary dilation is needed. The effect of both agents subsides quickly in comparison with that of atropine (duration of several days). 

Further improvement was obtained by using the corresponding ester analogues of methscopolamine (e.g., 7), some of them proved more potent than the similar soft methatropine analogues [79]. The ethyl ester analogue was shorter acting than even tropicamide, and, consistent with the soft drug approach, the untreated eye did not show any mydriasis, as opposed to administration of methscopolamine. 

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