Abstract
Purpose: :
The goal of this study is to help define the average medial canthal tendon distraction lengths in asymptomatic individuals and to compare the distraction distance between sex, race and age.
Methods: :
This is a prospective study measuring the medial canthal tendon distraction in asymptomatic individuals. Included in the study were any white or black patient presenting for an eye exam to the Detroit Medical Center between the ages of 18 and 99. Patients excluded from the study were patients with an ectropion on exam or with clinical findings of corneal staining. Patients that presented with complaints of epiphora or ocular irritation were also excluded from the study. Patients selected for the study were placed in an exam chair with their head firmly placed on the headrest for stabilization. A metric ruler was placed parallel to the lower lid so that the 0.0 millimeters (mm) mark was aligned with the inferior punctum. The lower lid was displaced laterally with maximum tension and the reading of the punctum placement was recorded in millimeters. The patient’s age, race and sex was also recorded at this time. Statistical analysis was then performed on the data points. Race and sex was analyzed using an unpaired t-test. Age was analyzed using an ANOVA analysis stratifying the groups into age rages of: 20-40, 40-60 and >60.
Results: :
140 eyes were studied. There were 86 black, 54 white, 72 male and 68 female eyes. The patient age range was from 21 to 83 years. When comparing the lateral distraction between race in (mm) the mean distraction was 2.645 in blacks and 2.972 in whites giving a mean difference of .327 and a statistically significant p-value of .0021. When comparing the lateral distraction between sex in mm the mean distraction was 2.728 in females and 2.813 in females giving a mean difference of .085 and a p-value of .4208. Using ANOVA analysis comparing distraction in mm between age groups the mean distraction was 2.367 in the 20-40 year age group, 2.764 in the 40-60 age group and 3.193 in the over 60 age group giving a p-value of <.0001 indicating statistical significance.
Conclusions: :
The average distraction among all tested individuals was 2.77 mm; 2.645 for blacks and 2.972 for whites. There was no statistical significance in the lateral distraction between sexes, however, there was a significant difference between race and age. This anatomical variance study may be useful for clinicians who are deciding the best-fit surgical technique for repairing an ectropion.
Keywords: eyelid • anatomy