A case-control study of visual acuity in onychocryptosis.
BACKGROUND
There are many theories surrounding the etiology of ingrown toenails (IGTN). Few factors have been formally assessed, but it is widely accepted that a poor nail cutting technique has a causative role.


OBJECTIVE
To investigate the hypothesis that decreased visual acuity may lead to inadequate nail cutting and the formation of IGTN.


METHODS
A prospective case-control study was performed. Near and distance visual acuity were tested on a population with IGTN (n = 19) and compared with that of an age- and sex-matched control cohort (n = 24) who underwent epidermal cyst excision in the same tertiary referral center. Comparisons of visual acuity were made between groups by Mann-Whitney U-test. Differences were taken to be significant if P < 0.05. Institutional Review Board approval was sought and granted.


RESULTS
No significant difference in visual acuity (near or distance) was demonstrated between patients with IGTN and the control group (P = 0.33).


CONCLUSIONS
Visual acuity does not appear to play a significant role in the development of IGTN.
Hogan
Aisling M
AM
St. Vincent's University Hospital, Adelaide & Meath Hospital, incorporating the National Children's Hospital, Dublin, Ireland.
Broe
David
D
Stunnell
Helen
H
Bobart
Andra
A
Ridgway
Paul F
PF
D000203:Activities of Daily Living; D000293:Adolescent; D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D005139:Eyeglasses; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009263:Nails, Ingrown / Q000209:etiology*; D011446:Prospective Studies; D012648:Self Care; D015354:Vision, Low / Q000150:complications*; D014792:Visual Acuity; D055815:Young Adult