Automated standardized pupillometry with optical method for purposes of clinical practice and research.

The aim of the current study was the introduction and standardization of two experimental conditions for dynamic pupillometry. Pupillometry is a method that can provide valuable data concerning the functioning of the autonomous nervous system. The system for recording the pupil reaction was developed in the Laboratory of Clinical Neurophysiology of the 1st Department of Neurology of Aristotle University of Thessaloniki, in co-operation with the Laboratory of Fluid Mechanics of the Aristotle University of Thessaloniki. This system is fully automated. It includes an infra-red video camera, which has the capacity to record in complete darkness, and an SLE (clinical photic stimulator) lamp. A software application automatically performed all the procedures. During the first experiment, one flash was administered. During the second experiment, a series of 25 flashes (1 Hz frequency) was administered. Fifty physically and mentally healthy subjects aged 23-48 years took part in the study. Means, standard deviations and ranges for all variables characterizing normal subjects during both experimental conditions are reported. Test/re-test results and comparisons of the two eyes are also reported. The combined use of these two experimental conditions in dynamic pupillometry may be a very useful tool in medical research. There are already reports on the usefulness of pupillometry in the research of various diseases, including depression and Alzheimer's disease. It is expected that it will also be a valuable research tool in the study of diabetes, alcoholism, myasthenia gravis, cancer, multiple sclerosis, etc.

Changes in pupil reaction to light in Alzheimer's disease patients: a preliminary report.

The aim of this preliminary study was to compare the pupil reaction to light in Alzheimer's disease (AD) patients before and after treatment and in normal controls. Ten AD patients diagnosed according to DSM-IV and NINCDS-ADRDA criteria (five medication-free and five under anticholinesterase treatment) and five age- and gender-matched controls took part in the study. Drug-free patients and all control subjects were free of any medication for at least four weeks. An optical method was used to assess the pupil reaction to a single flash. Medication-free AD patients manifested shorter latency and lower amplitude of maximum response to light in comparison to controls. These findings are in agreement with the presence of a cholinergic deficit in AD patients. Pharmacological treatment with donepezil, which is an anticholinesterase agent partially improves this deficit. The results of this preliminary investigation suggest that dynamic pupillometry could be a useful adjunct to assist the diagnosis of early AD, and the differential diagnosis between different types of dementia. AD patients seem to manifest a specific pattern of pupil reaction to light, and some characteristics of this pattern are detectable even in patients receiving anticholinesterase medication. However, this is only a preliminary report and further research is mandatory.