Diabetes mellitus has been associated with ocular surface damage and exacerbates dry eye disease (DED) pathology. To investigate clinical and inflammatory changes in the ocular surface of insulin-independent type II diabetic patients. This cross-sectional control study will recruit 200 Type 2 diabetic patients and 200 age- and sex-matched subjects without DM.
Diabetes mellitus (DM) is a developing global health challenge due to the multiple complications associated with long-term hyperglycemia. Although diabetic retinopathy is the most prevalent and well-known ophthalmic consequence, diabetes also causes clinically significant effects on the ocular surface. Among the ocular surface diseases, dry eye disease (DED) is the most common. Multiple mechanisms, such as ocular surface and lacrimal gland inflammation, neurotrophic deficiency, and meibomian gland dysfunction (MGD), play significant roles. A loss of tear film homeostasis characterizes DED. DM is one of the risk factors for DED; 47% of DM patients suffer from ocular surface damage due to negative alterations to the tear film, corneal thickness, corneal epithelium, corneal nerve, and corneal endothelium. It has been suggested that one or more of the following initial events may lead to alterations described in the tear film and ocular surface of patients with DM: a) chronic hyperglycemia, b) corneal nerve damage, and c) impairment on insulin action. Previous studies have explored the association between DM and ocular surface dysfunction. However, ocular surface and tear film parameters in diabetic patients are lacking in the Chinese population. Moreover, corneal nerve damage and ocular surface inflammation have not been systematically evaluated. Our study aimed to investigate clinical and inflammatory changes in the ocular surface of insulin-independent type II diabetic patients in a Chinese population.
Study Type
OBSERVATIONAL
Enrollment
80
He Eye Hospital
Shenyang, Liaoning, China
RECRUITINGMMP-9
MMP-9 was measured using an immunochromatography assay by collecting 1ul tear samples from the lateral canthus using a capillary tear collector. To assess the concentration of MMP-9 in the tear samples, a commercial reagent card (S05B, Seinda Biomedical Corporation, Guangdong, China) based on colloidal gold and immunochromatographic analysis was utilized. 1ul tear sample was placed in the sampling hole on the reagent card, followed by three drops of diluent in the dilution hole. The reagent card was loaded into the proprietary analyzer, and 15 minutes later, the MMP-9 concentration was measured
Time frame: Baseline
Non-invasive tear break-up time
Changes in non-invasive initial tear film breaking time will be assessed using the Keratograph 5M (Oculus, Germany) topographer. Three sequentially readings will be captured, and the median value will be included in the final analysis. The median value will be recorded.
Time frame: Baseline
Conjunctival hyperemia (RS score)
Conjunctival hyperemia (RS score) will be assessed by keratograph image (Oculus, Germany) of 1156\*873 pixels, redness score (RS) (accurate to 0.1 U) was displayed on the computer screen
Time frame: Baseline
Quality of meibum grade
Meibum quality will be assessed under a slit-lamp: Five meibomian gland in the middle parts of the eyelid will be assessed using a scale of 0 to 3 for each gland (0 represented clear meibum; 1 represented cloudy meibum; 2 represented cloudy and granular meibum; and 3 represented thick, toothpaste like consistency meibum).
Time frame: Baseline
Expressibility of meibum grade
Meibum expressibility will be assessed under a slit-lamp: Eight meibomian glands in the middle part will be evaluated on a scale of 0 to 3 (0 denoted that all glands expressible; 1 denoted that 3 to 4 glands expressible; 2 denoted those 1 to 2 glands expressible; and 3 denoted that no glands were expressible). The overall score was computed using the mean scores of these eight glands.
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Time frame: Baseline
Conjunctivocorneal epithelial staining grade
Conjunctivocorneal epithelial staining will be assessed under a slit-lamp: Conjunctivocorneal epithelial staining will be assess corneal and conjunctival epithelium damage. Double vital staining approach with two microliters of a preservative-free solution containing 1% lissamine green and 1% sodium fluorescein will be instilled in the conjunctival sac. The eye will be sectioned into three equal pieces (temporal conjunctiva, cornea, and nasal conjunctiva). Each region receives a maximum staining score of three points and a minimum of zero points. The combined scores from all three parts were then recorded on a scale ranging from 0 (normal) to 9 (severe)
Time frame: Baseline
Tear Film Lipid Layer
Tear Film Lipid Layer interferometry will be assessed using DR-1 (Kowa, Nagoya, Japan).
Time frame: Baseline
OSDI Score
Chinese translated, and validated OSDI (Allergan Inc, Irvine, USA) version will beused to assess and quantify DE symptom. The 12 items of the questionnaire can be tabulated into a score that ranges from 0 (no symptoms) to 100 (severe symptoms) points
Time frame: Baseline
Tear meniscus height (TMH)
Non-invasive first tear film breakup time using the Keratograph 5M (Oculus, Germany) topographer will be measured three times consecutively and the median value was recorded
Time frame: Baseline
Corneal nerves and immune/inflammatory cells change
HRT III RCM, (Heidelberg Engineering GmbH, Dossenheim, Germany) will be used to record corneal nerves and immune/inflammatory cells change.
Time frame: Baseline
Retinal morphology
A scanning laser ophthalmoscope (TRC-NW300, Topcon, Tokyo, Japan) will be used to examine and record the retinal morphology, and deep learning software will be used to analyze the vascular changes of the subjects.
Time frame: Baseline
Central corneal sensitivity
Central corneal sensitivity will be measured using a Cochet-Bonnet esthesiometer (Luneau Technology Operations, France), which stimulates the cornea with a nylon monofilament. The stiffness of the filament is adjusted by altering the length (0-6cm) of the filament with a slider on the side of the pen
Time frame: Baseline
Corneal endothelium
Corneal endothelium of all patients will be photographed by contactless specular microscopy (SM) device (EM-4000; Tomey Corporation, Japan) by the same observer. The unit of cell density was evaluated as mm2
Time frame: Baseline
Thermal imaging: Ocular surface temperature (OST)
All measurements were taken in the same room with controlled temperature and humidity. Prior to ocular thermography or other tests, participants were acclimatized to the room for 20 minutes. Morgan and colleagues described the following criteria for recording OST: The patients were instructed to blink normally, close their eyes for 3 seconds, and the first image was captured soon after the eyelids opened. The temperature was taken in the central cornea, which was defined as a circular area 4 mm in diameter in the middle of the cornea
Time frame: Baseline