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Quantification of Oculomotor Responses and Accommodation Through Instrumentation and Analysis Toolboxes
Published on: March 3, 2023
Abstracts from the 2024 European Association for Vision and Eye Research Congress, 3-5 November 2024, Valencia
Aida Ramón-Campillo1, Inmaculada Bueno-Gimeno1, Javier Gené-Morales2,3
1Optics, Optometry and Vision Sciences, University of Valencia, Burjassot, Spain.
Aims/Purpose:
This study aims to assess whether changes in intraocular pressure (IOP) occur after a blood draw and quantify these changes' magnitude in a group of patients over 60 years old.
Methods:
We analysed data from the right eye of 54 subjects, with a mean ( SD) age of 68 4 years. The measurements were conducted in the morning while fasting. First of all, subjects rested in a seated position for 5 minutes to equalise baseline conditions. IOP was then measured using the iCare rebound tonometer (IC100, iCare Oy, Finland) and the mean value obtained from 6 measurements was recorded. After 10 minutes, subjects underwent the blood draw. Five minutes after the blood draw, the subject sat back in the chair for the second IOP measurement, conducting the same procedures for both measurements. Pre- and post-drawing IOP values were compared with Wilcoxon signed rang test, for related samples.
Results:
The analysis showed that IOP decreased after extraction, with a mean ( SD) of 14.09 3.18 mmHg pre-extraction and a mean ( SD) of 13.33 2.90 mmHg post-extraction. Grouping the sample into age groups, no statistically significant differences were found in the 60-64 age group (n = 11; p = 0.35) and the 75-79 age group (n = 5; p = 0.68). A trend towards significance was found in the 70-74 age group (n = 18; p = 0.06) and statistically significant differences in the 65-69 age group (n = 20; p = 0.04). Grouping the sample according to their IOP values (using to the sample IOP median) no statistical differences were found when IOP values were between 8 and 15 mmHg (n = 38; p = 0.57) and statistically significant differences were found in the group with IOP between 16 and 28 mmHg (n = 16; p = 0.001).
Conclusions:
It was found that IOP decrease after a blood draw, tending to decrease more in subjects aged 65 to 74 years and remains unchanged in the other age groups. Additionally, higher baseline IOP levels lead to greater changes post-extraction. These results may be related to reflex effects of the autonomic nervous system, activating a vagal reflex, which may induce a decrease in IOP. Future studies are required to analyse the various influencing factors.
