Changes in Visual Acuity in Patients Receiving Upper Cervical Specific Chiropractic Care
Robert Kessinger, D.C., Dessy Boneva, D.C.
Journal of Vertebral Subluxation Research ~ Volume 2 ~ Number 1 ~ Pages 1-7
The present study was conducted to investigate the relationship between Upper Cervical Specific chiropractic care and changes in visual acuity. The population under study represented sixty seven subjects who had not previously experienced chiropractic care. They ranged in age from 9 to 79 years, averaging 46.4 ± 17.0.The subject group consisted of 37 females (48.7 ± 18.9 years) and 30 males (43.5 ±15.7 years). They were evaluated for each eye, before and six weeks after receiving chiropractic care, relative to their ability to accurately identify letters in a standard Snellen Chart. The chart contained 11 rows in which a different number of letters of varying sizes were displayed. Scores, for the population as a whole, were reported as the mean and standard deviation of the absolute number missed in each row before and after care, and further expressed as a percent increase or decrease, pre/post chiropractic care, for each row as “percent change in distance visual acuity,” (%DVA). Findings from this initial study suggest that observed changes were not a function of gender. Thus, the population as a whole demonstrated statistically significant improvement in the right eye (paired two-tailed t-test, p < 0.05) in distance visual acuity (%DVA) at distances associated with less than “typical” normal vision (20/50, 20/40, 20/25),”typical” normal vision (20/20), and better than “typical” normal vision (20/16). Significant improvements were also shown for the left eye at the same distance acuity levels, as well as at the levels of 20/125, 20/80, and 20/60. Regression analysis (p < 0.05) of scores before chiropractic care revealed a positive correlation between increasing age and number of letters incorrectly identified at the levels of 20/20 and 20/16 for both the right and left eyes. Regression analysis performed on scores after chiropractic care revealed the same relationship for the left eye as before care. However, after care, this relationship was only apparent at the 20/16 level in the right eye. Thus, evaluation of these data show improvements in % DVA following Upper Cervical Specific chiropractic care, at distances “typically” associated with less than normal, normal, and better than normal vision, with no correlation between upper cervical vertebral “listing.” Improvement in the left eye was evident at greater extremes of low vision than in the right eye. However, age related differences in the number of incorrectly identified letters, associated “typically” with normal and better than normal vision, showed apparent improvement in normal vision in the right eye following care. Possible implications and explanations for these findings are discussed.
Key Words: Upper cervical chiropractic care, vertebral subluxation, visual acuity