Related Experiment Videos
Influence of viewing distance on vertical strabismus
Michael H Gräf1, Daniela Rost, Ralph Becker
1Department of Strabismology and Neuroophthalmology, University of Giessen, Friedrichstrasse 18, 35385 Giessen, Germany. michael.h.graef@augen.med.uni-giessen.de
Summary
Vertical strabismus, a common eye alignment disorder, can change with viewing distance. Surgery can effectively reduce this deviation, improving visual outcomes for patients.
Area of Science:
- Ophthalmology
- Strabismology
- Binocular Vision
Background:
- Vertical strabismus is a condition where the eyes misalign vertically.
- Viewing distance can influence the manifestation of vertical strabismus.
- This study investigates the impact of viewing distance on vertical deviations in 19 patients.
Purpose of the Study:
- To analyze how viewing distance affects vertical strabismus.
- To evaluate the efficacy of eye muscle surgery in correcting vertical deviations.
- To explore potential management strategies for vertical strabismus.
Main Methods:
- Vertical deviation angles were measured using the alternate prism and cover test at 5 meters and 0.3 meters.
- Measurements at 0.3 meters included assessments with and without a 3.0 D addition to corrected refraction.
- Fifteen patients underwent eye muscle surgery and were re-examined after 3 months.
Main Results:
- Vertical deviation varied from 0 to 16 degrees at distance and showed significant changes at near fixation.
- Post-surgery, vertical deviation for distance fixation was reduced, with a median of 2 degrees.
- The difference between distance and near fixation deviations also decreased significantly after surgery.
Conclusions:
- Vertical strabismus can be influenced by convergence and accommodation, often presenting as incomitant deviation.
- Eye muscle surgery is an effective treatment for reducing baseline vertical deviation.
- Bifocal glasses may be beneficial for managing vertical accommodative vergence.