Olfactory Function Assessment of Blind Subjects Using the Sniffin' Sticks Test

In recent years, a growing number of studies have focused on the olfactory abilities of blind individuals as well as their tactile and auditory senses. In this study, we aimed to investigate possible alterations in the sense of smell in early- and late-blind subjects as compared with sighted controls, using a Sniffin' Sticks test battery.

Prospective clinical study.

Tertiary referral center.

A total of 66 subjects were included in the study. The subjects were divided into 2 groups: blind subjects-who were then subgrouped as subjects with congenital blindness (n = 17) and those with acquired blindness (n = 16)-and sighted subjects (n = 33). We compared both congenitally and acquired blind subjects with sighted counterparts using the Sniffin' Sticks test for odor threshold, odor discrimination, odor identification, and total odor scores.

The blind subjects were more successful than their sighted counterparts in odor discrimination and odor threshold tasks. There was no statistically significant difference between the blind participants and the sighted individuals in terms of odor identification value. Another important finding was that the difference between individuals with congenital blindness and those with acquired blindness was not significant in any of the parameters.

This finding may suggest that odor discrimination and odor threshold in blind people were superior to those of controls. There was no difference in any of the results of tasks among congenital and acquired blind subjects.