Corneal Impression Membrane (CIM) Sampling for Microbial Keratitis Diagnosis
试验速览
- 阶段
- 2 期
- 状态
- 尚未招募
- 入组人数
- 70
- 试验地点
- 1
- 主要终点
- To demonstrate at least 65% sensitivity of CIM in detecting fungal organisms, thereby proving a non-inferiority of CIM to conventional corneal scraping method.
研究概览
简要总结
Microbial keratitis remains a challenge to diagnose, with gold-standard culture often positive in <60% of cases. Moreover, smear microscopy positivity rates also suffer from low sensitivity. These poor outcomes are often attributed to very low pathogen levels within the collected samples, which are routinely collected by sharp instruments, such as a blade or needle.
Since May 2017, Corneal Impression Membranes (CIMs) have replaced these sharp instruments as the gold-standard, sampling tool at St Pauls Eye Hospital in Liverpool, UK, and are now being more broadly adopted across major corneal departments in the UK. In Liverpool, it has been shown through both experimental and clinical studies that the CIMs reliably provide better microbiological diagnostic rates than a sharp instrument and/or a swab for bacterial keratitis (in Liverpool, culture positivity increased from 19.4% for scraped samples to 65.2% for samples collected by CIM (total 3099 corneal samples))1. The use of the CIM also results in a better patient experience compared to obtaining samples using a sharp instrument. In addition, it provides the opportunity to expand its usage among ophthalmic technicians in primary care centres.
Till date CIMs have not been evaluated in the Indian context, and the performance of CIMs in improving fungal culture positivity rates is not known, due to low fungal burden in the UK (<1% of the samples evaluated in Liverpool).
Hypothesis: CIMs will be non-inferior to conventional microbial keratitis sampling with a sharp instrument (current gold-standard) when evaluated by broth and solid culture.
Aim: To evaluate CIMs in comparison to conventional scrapes for microbiological reporting from infectious keratitis patients (fungal suspicion). The Primary comparison will be to culture. The Secondary output will be to compare to smear microscopy.
Objectives:
1. To compare the culture positivity rate between conventional (Scraping) method and CIM
2. To compare the smear positivity rate between conventional (Scraping) method and CIM
3. To evaluate the efficacy of CIMs with respect to fungal keratitis
Type of study:
Prospective PILOT study for evaluation of an alternative sample collection method for microbial keratitis sampling
研究设计
- 研究类型
- Interventional
- 分配方式
- Na
- 盲法
- None
入排标准
- 年龄范围
- 18.00 Year(s) 至 75.00 Year(s)（—）
- 性别
- All
入选标准
- •Suspicion of Fungal Keratitis and Undergoing routine corneal scraping for diagnostic purposes.
排除标准
- •Suspected Viral, Acanthamoeba, Mixed Keratitis cases Microbial Keratitis in both eyes Perforated ulcer Small ulcer of less than 3 mm.
结局指标
主要结局
To demonstrate at least 65% sensitivity of CIM in detecting fungal organisms, thereby proving a non-inferiority of CIM to conventional corneal scraping method.
时间窗: The microbiology positivity will be checked at Day 1, 3 days, 1 week and 2 weeks.
To demonstrate that CIM collected specimens can be used for immediate identification of organisms by smear microscopy.
时间窗: The microbiology positivity will be checked at Day 1, 3 days, 1 week and 2 weeks.
次要结局
未报告次要终点
研究者
Josephine Christy
Aravind Eye Hospital