Cochet and Bonnet's corneal perception meter

The corneal sensation test is to prove whether the corneal ulcer area and the non-ulcer area are different in perception, or to prove whether the trigeminal nerve function is reduced or paralyzed, and should be used for corneal sensation examination. Have the patient take a sitting position straight ahead, or turn the eyeball in all directions to be inspected, and touch the cornea vertically with a 0.11 mm diameter nylon thread until the line is bent to the just-observable curvature (approximately 5° deflection) So far, first test with a nylon thread of up to 60 mm, if there is no feeling, then use a length test that shortens 5 mm, and so on, until the patient feels wired contact. Basic Information Specialist Category: Ophthalmic Examination Category: Other Inspections Applicable gender: whether men and women apply fasting: not fasting Tips: Do not touch your eyes with your hands before checking. Normal value It is normal for the difference between perception and ignorance to be no more than 5 mm. If 30 mm is unconscious, the 15 mm initial perception is a decrease in perception. You can try the center of the cornea first, then try the peripheral part or other parts. Clinical significance Abnormal results Dendritic keratitis is one of the most common local causes of corneal dysfunction, and herpes zoster is one of the causes of corneal dysfunction. Patients with corneal ulcers who need to be examined. Precautions Taboo before inspection: Do not touch the eyes with your hands. Requirements for inspection: The nylon thread should not be too moist. Inspection process Have the patient take a sitting position straight ahead, or turn the eyeball in all directions to be inspected, and touch the cornea vertically with a 0.11 mm diameter nylon thread until the line is bent to the just-observable curvature (approximately 5° deflection) So far, first test with a nylon thread of up to 60 mm, if there is no feeling, then use a length test that shortens 5 mm, and so on, until the patient feels wired contact. Not suitable for the crowd Inappropriate crowd: not a patient with keratitis.