Study of the tear film using electronic devices
Authorship
A.S.A.
Master´s Degree in Optometry
A.S.A.
Master´s Degree in Optometry
Defense date
07.04.2025 09:00
07.04.2025 09:00
Summary
Objective The main objective of this study was to analyze the impact of electronic device use on ocular health, assessing the repeatability of tear parameters such as tear meniscus height, noninvasive tear break-up time, and corneal staining, and investigating how common digital activities, such as watching videos and reading on screen, affect the tear film. Methods An experimental study was conducted with a between-session and within-session design. Twenty-four participants aged 18 to 25 years participated, completing two sessions separated by one week. In each session, participants underwent tear film measurements before and after performing a visual activity (video viewing or reading on a screen) for 20 minutes. Tests included measurement of tear meniscus height (TMH), noninvasive tear break-up time (NIKBUT), and the presence of corneal staining using the Keratograph 5M device. Data were analyzed using statistical tests to assess repeatability and the effect of the visual tasks on the parameters studied. Results The results showed limited repeatability in the TMH and NIKBUT parameters, with considerable dispersion in the differences between sessions. The proposed visual activities had no significant effect on most tear film parameters, with a single exception in the TMH after reading, where an increase in its volume was observed, possibly due to a reflex effect. Corneal staining remained unchanged throughout the experiment and was therefore not subject to comparative analysis. Conclusion The study shows that, in the short term, the use of electronic devices does not cause statistically significant changes in the main tear film parameters, although international literature continues to point to prolonged use of screens as a significant risk factor. Methodological limitations, such as the small sample size and lack of control for environmental variables, highlight the need for stronger experimental designs and continued research to better define risk thresholds and identify effective eye protection strategies.
Objective The main objective of this study was to analyze the impact of electronic device use on ocular health, assessing the repeatability of tear parameters such as tear meniscus height, noninvasive tear break-up time, and corneal staining, and investigating how common digital activities, such as watching videos and reading on screen, affect the tear film. Methods An experimental study was conducted with a between-session and within-session design. Twenty-four participants aged 18 to 25 years participated, completing two sessions separated by one week. In each session, participants underwent tear film measurements before and after performing a visual activity (video viewing or reading on a screen) for 20 minutes. Tests included measurement of tear meniscus height (TMH), noninvasive tear break-up time (NIKBUT), and the presence of corneal staining using the Keratograph 5M device. Data were analyzed using statistical tests to assess repeatability and the effect of the visual tasks on the parameters studied. Results The results showed limited repeatability in the TMH and NIKBUT parameters, with considerable dispersion in the differences between sessions. The proposed visual activities had no significant effect on most tear film parameters, with a single exception in the TMH after reading, where an increase in its volume was observed, possibly due to a reflex effect. Corneal staining remained unchanged throughout the experiment and was therefore not subject to comparative analysis. Conclusion The study shows that, in the short term, the use of electronic devices does not cause statistically significant changes in the main tear film parameters, although international literature continues to point to prolonged use of screens as a significant risk factor. Methodological limitations, such as the small sample size and lack of control for environmental variables, highlight the need for stronger experimental designs and continued research to better define risk thresholds and identify effective eye protection strategies.
Direction
GARCIA RESUA, CARLOS (Tutorships)
Sabucedo Villamarín, Belén (Co-tutorships)
GARCIA RESUA, CARLOS (Tutorships)
Sabucedo Villamarín, Belén (Co-tutorships)
Court
FANDIÑO FERNANDEZ, JOSÉ MARIA (Chairman)
GARCIA DOMINGUEZ, GONZALO (Secretary)
VARELA LEMA, MARIA LEONOR (Member)
FANDIÑO FERNANDEZ, JOSÉ MARIA (Chairman)
GARCIA DOMINGUEZ, GONZALO (Secretary)
VARELA LEMA, MARIA LEONOR (Member)
Comparative study of techniques to measure heterophoria.
Authorship
A.V.F.
Master´s Degree in Optometry
A.V.F.
Master´s Degree in Optometry
Defense date
07.04.2025 09:00
07.04.2025 09:00
Summary
This study focuses on the evaluation of three different methods to measure heterophoria: the Cover Test, the Modified Thorington Test and the Von Graefe test. Heterophoria is a latent ocular deviation that can affect binocular vision and the quality of life of individuals, so it is crucial to have accurate and reliable techniques for its measurement. The main objective of this work is to compare the effectiveness and repeatability of these three techniques in a sample of healthy subjects. For this purpose, a study was carried out with the participation of 24 volunteers, 6 of whom were men and 18 women, aged between 17 and 30 years. Measurements of near vision heterophoria were recorded using each of the aforementioned techniques. The study methodology included multiple measurements in sessions separated by a week, which allowed us to evaluate the consistency of the results obtained. The results of the statistical analysis revealed that there were no significant differences between the three heterophoria measurement techniques. However, it was observed that the Cover Test and the Modified Thorington Test showed a better concordance in their results, which suggests that these techniques could be more reliable for the assessment of heterophoria in comparison with the Von Graefe test. Based on these findings, the study concludes that, although the three techniques are valid for measuring heterophoria, it is advisable to carry out additional research with samples of the same age.
This study focuses on the evaluation of three different methods to measure heterophoria: the Cover Test, the Modified Thorington Test and the Von Graefe test. Heterophoria is a latent ocular deviation that can affect binocular vision and the quality of life of individuals, so it is crucial to have accurate and reliable techniques for its measurement. The main objective of this work is to compare the effectiveness and repeatability of these three techniques in a sample of healthy subjects. For this purpose, a study was carried out with the participation of 24 volunteers, 6 of whom were men and 18 women, aged between 17 and 30 years. Measurements of near vision heterophoria were recorded using each of the aforementioned techniques. The study methodology included multiple measurements in sessions separated by a week, which allowed us to evaluate the consistency of the results obtained. The results of the statistical analysis revealed that there were no significant differences between the three heterophoria measurement techniques. However, it was observed that the Cover Test and the Modified Thorington Test showed a better concordance in their results, which suggests that these techniques could be more reliable for the assessment of heterophoria in comparison with the Von Graefe test. Based on these findings, the study concludes that, although the three techniques are valid for measuring heterophoria, it is advisable to carry out additional research with samples of the same age.
Direction
GARCIA RESUA, CARLOS (Tutorships)
Nores Palmás, Noelia (Co-tutorships)
GARCIA RESUA, CARLOS (Tutorships)
Nores Palmás, Noelia (Co-tutorships)
Court
FANDIÑO FERNANDEZ, JOSÉ MARIA (Chairman)
GARCIA DOMINGUEZ, GONZALO (Secretary)
VARELA LEMA, MARIA LEONOR (Member)
FANDIÑO FERNANDEZ, JOSÉ MARIA (Chairman)
GARCIA DOMINGUEZ, GONZALO (Secretary)
VARELA LEMA, MARIA LEONOR (Member)