Diabetic Neuropathy: Function-Structure of Corneal Nerves to Assess Injury-Repair
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 44
- 试验地点
- 2
- 主要终点
- Cornea Sensitivity
研究概览
简要总结
Peripheral neuropathy affects about 50% of the diabetic population and there is no treatment other than good blood glucose control, which is ineffective in subjects with type 2 diabetes. Part of the problem for the lack of an effective treatment is the inability to detect peripheral neuropathy in its early stage. The hypotheses to be addressed in the first phase of this study is that changes in cornea sensitivity (blinking and squinting) following addition of a hyperosmotic solution will provide a novel screening tool for early diagnosis of peripheral neuropathy. For the second phase of the study the investigators will examine the effect of fish oil treatment of diabetic subjects with neuropathy on corneal nerve density and sensitivity. Corneal nerves are the most highly innervated part of the human body with great sensitivity. The first phase will use this property and determine whether sensitivity is lost in diabetic patients with neuropathy. Preclinical studies have supported this hypothesis and now this will be tested in human subjects. Preclinical studies have also shown that treating diabetic rodents with fish oil improves nerve regeneration and outcome measures of peripheral in diabetic rodents. In the second phase the investigators will perform preliminary studies in human subjects with diabetic neuropathy and determine whether treating them with fish oil increases corneal nerve density and sensitivity.
详细描述
Recruitment has been suspended because of the COVID-19 crisis and the Iowa City VA is just beginning to have face to face appointments.
The hypotheses to be studied in the following specific aims is that changes in cornea sensitivity to a hyperosmotic solution will provide a novel screening tool for early diagnosis of diabetic peripheral neuropathy. The investigators also propose that clinical feasibility studies will demonstrate that treatment with fish oil will improve outcome measures of diabetic peripheral neuropathy.
Specific aims:
- Determine if the reflex squinting and blinking response to the application of a hyperosmotic solution to the cornea is impaired in patients with type 2 diabetes with or without peripheral neuropathy.
a. Determine whether changes in corneal sensitivity correlate with loss of cornea nerves in the sub-epithelial layer of the cornea and symptom scores for PN. 2. Determine if treating human subjects with type 2 diabetic peripheral neuropathy with an oral fish oil supplement increases circulating levels of resolvin D1, restores cornea sensitivity to a hyperosmotic eye drop challenge and improves corneal nerve density and symptom scores for peripheral neuropathy.
研究设计
- 研究类型
- Interventional
- 分配方式
- Non Randomized
- 干预模型
- Single Group
- 主要目的
- Basic Science
- 盲法
- None
入排标准
- 年龄范围
- 50 Years 至 75 Years（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •Type 2 diabetes patients diagnosed based on the opinion of an Endocrinologist (Dr. Correia), the absence of a history of ketoacidosis, and a C-peptide > 0.8 ng/ml
- •At least 5 year known duration of diabetes.
- •HbA1c < 9.0%
- •None or mild to moderate peripheral neuropathy based on medical record, Michigan Neuropathy Screening Instrument including response to monofilament test, ankle reflex test, vibration perception threshold examination using a 128 Hz tuning fork as well as hot and cold sensation evaluation
排除标准
- •Any neurologic, muscular, genetic, or other condition known to affect nerve or muscle function
- •Electrolyte abnormalities, untreated hypothyroidism, abnormalities in calcium, phosphate, or magnesium concentrations, or any other metabolic disturbance affecting neural function
- •Cigarette smoking in the past year
- •Peripheral vascular, cardiac, pulmonary, or any other disorder affecting blood or tissue oxygenation
- •Risk of bleeding disorder or on medication known to increase risk of bleeding
- •History for use of aspirin
- •Any other medical or psychological condition judged to limit compliance with the protocol or interpretation of results
- •History of diabetic foot ulcer
- •LDL > 100 mg/100ml, HDL < 30 mg/100ml, Triglyceride > 400 mg/100ml.* 10) BP < 140 systolic and 80 diastolic
- •Insulin use to manage diabetes 200 units
- •History of taking fish oil supplements
- •The investigators are limiting subject population to those over 50 thus pregnancy should not be an issue nonetheless females who are pregnant, looking to become pregnant or are breast feeding will be excluded (* After overnight fast of 8-12 h; Average of three determinations in the sitting position after at least 5 minutes rest.)
结局指标
主要结局
Cornea Sensitivity
时间窗: Examination of the response to saline and Muro 128 is preformed once in each patient immediately following their consent or if they request at a later more convenient time.
Cornea sensitivity to a isotonic and hyperosmotic solution is evaluated as the amount of time the eyelid is closed over a period of 150 seconds following application of first isotonic saline (0.9% NaCl) followed by Muro 128 (5% NaCl solution) after a 5 minute recovery/washout period. The evaluation is done from analyzing the recordings of each event using a multi-camera video platform. The results are reported for response to saline (baseline) and Muro (stimulant) solutions as a ratio of the time the eyelids are closed vs. open over the 150 second period of the recording.
次要结局
- Change in Corneal Sensation Threshold Using Cochet Bonnet Filament(Done once to determine whether there is a difference between control and diabetes subjects with peripheral neuropathy)
- Michigan Neuropathy Screening Instrument(Done once as part of the determination to the subjects peripheral neuropathy.)
- Sensitivity to 10 g Monofilament Test(Done once as a determination of the presence of peripheral neuropathy)
- Presence of Vibratory Sensation of the Great Toe(Done once as a determination of the presence of peripheral neuropathy)
- Presence of Reflex(Done once as a determination of the presence of peripheral neuropathy)
- Visual Acuity(Done once to determine the subjects visual ability)
- Questionnaires for Corneal Sensitivity(Done once to determine extent of common eye disease such as dry eye)
- Determination of Tibial Nerve Conduction Velocity(Done once as a determination of the presence of peripheral neuropathy)