Abstract:
To study the influence of age, gender and iris colour on the corneal sensitivity threshold.
Eyes of 50 subjects of both sexes (24 males, 26 females) and ages between 23 and 71 years (mean: 44.9±1.4) were explored using the CRCRT–Belmonte esthesiometer. Mechanical and chemical threshold of the cornea were determined using the method of levels.
Mechanical and chemical thresholds increased with age; differences became significant in people over 50 years old. Female subjects had lower mean thresholds. Lower mean thresholds were also observed in blue eyes subjects (see the table, * p<0.05 t–test or Mann–Whitney test).
Multiple regression analysis showed that corneal mechanical threshold depends significantly on the age of the subject while the chemical threshold depend significantly on the three factors studied: gender, and iris colour. Corneal sensitivity decreases with age and is influenced by iris colour and gender, with blue eyes women being the more sensible to irritant stimuli. Normal ranges of mechanical and chemical sensitivity threshold values of the cornea can be predicted according to age, gender and iris colour of the subject. That would help to evaluate changes of corneal sensitivity in various pathological conditions.
Keywords: innervation: sensation • aging