Date of Award
Master of Science in Vision Science
Christina M. Schnider
To evaluate differences in the overnight corneal swelling response between hydrogel toric and equivalent powered spherical contact lenses, 16 subjects participated in an overnight in-clinic test session. After 8-9 hours of sleep the mean percent central corneal swelling was 10.984% for the eyes wearing the toric lenses and 10.074% for the eyes wearing the spherical lenses. There was a statistically significant difference in the mean percent corneal swelling induced by the two groups (P < 0.05 one-tailed repeated measures paired t-test). Qualitative evaluations showed 25% more striae and epithelial punctate staining in the toric group as well. These findings suggest that there is a corneal health basis for prescribing equivalent powered spherical hydrogel contact lenses rather than toric lenses to low cylinder astigmatic patients.
Reimers, Loren Scott, "A comparison of overnight corneal swelling with hydrogel toric and equivalent powered spherical contact lenses" (1997). College of Optometry. 1214.