Normal Eyelid Sensation Distribution

After proper taken consent patients without previous eyelid surgery in the Oculoplastic clinic at Duke Eye Center and Duke Aesthetic Center will be enrolled to test the eyelid sensation distribution using the Cochet-Bonnet aesthesiometer. The aesthesiometer (Luneau ophthalmologie) with a 0.12mm diameter filament was chosen for its ease of use, sensitivity, and safety. This instrument contains a 6 cm long, retractable, flexible monofilament. For any given length, when applied perpendicularly to test surface, the filament will exert a precise pressure before visibly bending. The filament length inversely corresponds to the pressure exerted by the aesthesiometer.

Selection of eyelid laterality will be randomized on the same day of the study. Ipsilateral upper and lower eyelids will be divided in thirds (medial, central and lateral borders) including the margin (fig.2). The eyelid sensation will be tested on every third by applying the tip of the aesthesiometer filament perpendicular to the eyelid skin and tarsal plate until the filament bent slightly. The filament length will be set at 6 cm (longest length) and applied to the test site 3 times. This process will be repeated 3 times and if the patient verbally responded to the 3rd touch, the number 6 will be recorder.

If the patient responded less than 3 of the 3 times, the filament will be shortened by 0.5 cm and the test will be repeated. This process will be continued by shortening the filament 0.5 cm each time, until the patient feels the filament touch 3 of 3 times. This filament length number will be recorded as the touch reading for that time period.

The mean touch thresholds for the various test sites will be compared using a Freidman two-way analysis variant (ANOVA).