This study aims to analyze the changes of corneal nerve morphology and function in contact lens-related dry eye(CLADE) patients and further discuss the role of corneal nerve in the genesis and development of CLADE.
33 daily disposable soft contact lens wearers with dry eye disease(DED), 33 DED without contact lens wear and 33 normal control subjects will be involved in study. One experienced ophthalmologist will evaluate the DED symptoms and signs, which include ocular surface disease index(OSDI), tear film breakup time(TBUT), Schirmer Ⅰ test, corneal fluorescein staining, lissamine green staining and meibomian gland dropout rate. After evaluating, corneal sensitivity are measured using a Cochet-Bonnet aesthesiometer. Corneal nerve morphology will be assessed in the right eye using in vivo confocal microscopy(IVCM). Fifteen to twenty minutes after IVCM, 20μL of basal tears will be collected from the inferior meniscus of each participant to test tear neuropeptides. Then investigators analyse the correlation of corneal nerve changes and DED symptoms and signs.
Study Type
OBSERVATIONAL
Enrollment
60
daily disposable soft contact lens
Peking University Third Hospital
Beijing, Beijing Municipality, China
sub-basal corneal nerve density
Sub-basal corneal nerve plexus image will be acquired using a laser scanning confocal microscope. Sub-basal nerve fiber density will be calculated from a manual trace of the length of all nerve fibers in each 1 mm2 image.
Time frame: baseline
sub-basal corneal nerve tortuosity
Sub-basal corneal nerve plexus image will be acquired using a laser scanning confocal microscope. Sub-basal nerve tortuosity will be assessed using a grading scale separately by two experienced ophthamologist.
Time frame: baseline
ocular surface disease index(OSDI)
OSDI is one of the most frequently used questionnaires for evaluation of DED. This includes 12 questions which measure the frequency of symptoms over the recent week, and the scores range from 0 to 100.
Time frame: baseline
Tear break-up time (TBUT)
TBUT is the time from normal blinking to the first appearance of a break in the tear film.
Time frame: baseline
Schirmer Ⅰ test (SⅠt)
The Schirmer I test is performed using sterile strips without anesthesia. The strips are placed in the lateral part of the inferior fornix of the eye for 5min and the extent of tear flow down was measured in millimeters.
Time frame: baseline
Corneal fluorescein staining
The degree of fluorescein staining of the cornea was evaluated using the National Eye Institute (NEI) scale of five corneal regions (central, superior, temporal, nasal, and inferior).
Time frame: baseline
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Lissamine green staning
To grade the temporal zone, the subject looks nasally; to grade the nasal zone the subject looks temporally. The upper and lower conjunctiva can also be graded.
Time frame: baseline
meibomian gland droupout rate
meibomian gland evaluation
Time frame: baseline
corneal sensitivity
Corneal sensitivity will be measured in the right eye only using the Cochet-Bonnet aesthesiometer and the ascending method of limits to determine the threshold of stimulus detection.
Time frame: baseline
the concentration of substance P
20μL of basal tears will be collected from the inferior meniscus of each subject to test substance P. Substance P levels will be quantified by competitive enzyme-linked immunosorbent assays.
Time frame: baseline
the concentration of CGRP
CGRP levels will be quantified by competitive enzyme-linked immunosorbent assays.
Time frame: baseline