Vol 6 (2021): Continuous Publishing
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Published online: 2021-02-24

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The inter-eye difference in corneal sensitivity in patients with infectious ulcers as measured with the Cochet-Bonnet esthesiometer

Ancy Chakko12, Bilto Babu23, Satheesh Solomon T Selvin2
Ophthalmol J 2021;6:31-37.


Background: The purpose of this study was to quantify the inter-eye difference in corneal sensations in patients with infectious corneal ulcers using the Cochet-Bonnet esthesiometer (CBE).

Material and methods: Patients with unilateral corneal ulcers of at least 1.5 mm of the clear cornea in all quadrants meeting the study criteria were identified and enrolled. The clinical features with their etiologies were noted. The corneal sensations were measured with CBE in all four quadrants. Patients were further sub-categorized based on the surface area and the “time to heal” of the ulcers for further correlation and analysis.

Results: This was a cross-sectional study conducted at a tertiary care center. The study included 35 patients, with the majority (30 patients, 85.7%) diagnosed with fungal etiology. The average corneal sensations in the ulcer and the normal eyes were 52.29 mm and 57.36 mm, respectively. The inter-eye differences were 3.93 mm (p = 0.06) and 6.55 mm (p = 0.04) among patients with an average surface area of ≤ 10 mm2 and > 10 mm2, respectively. Patients who took up to 30 days and > 30 days to heal had inter-eye differences in a sensation of 0.71 mm (p = 0.04) and 6.14 mm (p = 0.05), respectively.

Conclusions: The mean corneal sensations in all quadrants were less significant in the infectious ulcer eyes than normal eyes. Infectious ulcers with a surface area of > 10 mm2 had greater inter-eye differences in their corneal sensitivities. Patients who took a longer "time to heal" of > 30 days showed a significant and greater inter-eye difference in their corneal sensitivities.

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