Diabetic Retinopathy Classification: ETDRS 7-fields vs Widefield Imaging (Clarus 500 and Optos California)
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 发起方
- 入组人数
- 81
- 试验地点
- 1
- 主要终点
- ETDRS severity level according to the Early Treatment Diabetic Retinopathy Study - Diabetic Retinopathy Severity Scale (ETDRS-DRSS).
研究概览
简要总结
The goal of this observational study is to analyse and compare Diabetic Retinopathy severity level using 30º ETDRS 7-fields and Wide-field Imaging techniques using Clarus 500 (Carl Zeiss Meditech Inc., Dublin, USA) and Optos (Optos, Dunfermline, UK) in diabetic patients with mild to moderate diabetic retinopathy. The main questions it aims to answer are:
- To compare the Clarus 500TM wide-field imaging technique with the ETDRS 7-fields method in the assessment of DR severity level using the ETDRS DRSS.2. To compare the two wide-field imaging techniques (Clarus 500TM vs OptosTM) in the assessment of DR severity level using the ETDRS DRSS.3. To evaluate the peripheral area imaged by the wide-field Clarus 500TM and OptosTM to characterize DR lesions distribution (predominantly observed within or outside the ETDRS 7-fields) and severity (according to the ETDRS standard photos).4. To determine the relevance and frequency of DR PPL, located outside the ETDRS 7-fields area, and to explore PPL occurrence in different DR severity levels.
Participants will undergo a non-invasive ophthalmological examination, which includes BCVA, 7-fields CFP and UWF FP to assess ETDRS DRSS level.
详细描述
Diabetic Retinopathy (DR) remains a significant cause of blindness in working-age populations across the world. The gold-standard method for assessing its severity is the modified Airlie House classification developed for the Early Treatment Diabetic Retinopathy Study (ETDRS), still used by clinical trials for developing of DR therapeutic and management guidelines.
ETDRS Diabetic Retinopathy Severity Score (DRSS) is based on the identification of DR lesions on colour fundus photography's (CFP) obtained in different locations of the retina. The photography acquisition protocol consists in acquiring seven stereoscopic pairs of overlapping 30° fields images of the ocular fundus to map out the macula and mid-peripheral retina. Photographers and fundus camera systems usually need training and certification by external reading centres to guarantee proper images quality and fields definition in a process that can be challenging with a considerable learning curve. Patient collaboration to follow a fixation point in different locations and withstand intense flashes of light, a good dilation of eye pupil and the difficulty to obtain well focused images in peripherical gaze positions are some of the main difficulties for obtaining gradable images using this 7-fields acquisition protocol.
On the other side, the grading process of ETDRS 7-fields images can be extremely labour-intensive and strongly dependent on the quality of the images, presence of artifacts and the definition of the peripherical fields, requiring well-trained people to identify and recognise features that can be very subtle or easily get unnoticed.
Moreover, the retinal area documented with the ETDRS 7-fields protocol represents approximately only 35% of the retina surface. Substantial diabetic retinal pathology can exist in the retinal periphery located outside this area which is being emphasized by advanced retinal imaging technology. Predominantly Peripheral Lesions (PPL) like the presence of venous beading, new-vessels, haemorrhages and microaneurysms in the extreme periphery have been correlated with peripheral non-perfusion, neurodegenerative changes and consequent increase of DR progression.
Recent instrumentation like OptosTM (Optos, Dunfermline, UK) or Clarus 500TM (Carl Zeiss Meditech Inc., Dublin, USA) allow wide-field acquisitions that document up to 90% of the retina surface in just one or two images decreasing patients tiredness and discomfort and overcoming most of the quality and fields definition issues described above.
研究设计
- 研究类型
- Observational
- 观察模型
- Cohort
- 时间视角
- Prospective
入排标准
- 年龄范围
- 35 Years 至 80 Years（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •DM type 2 according to 1985 World Health Organization (WHO) criteria
- •Age between 35 and 80 years
- •BCVA ≥ 75 letters (20 /32)
- •Refraction with a spherical equivalent less than 5 Diopters
- •NPDR levels 35 and 43-47 (based on the ETDRS criteria - 7 fields CFP)
排除标准
- •Cataract or other eye disease that may interfere with fundus examinations
- •Other retinal vascular disease than DR
- •Refractive errors > to + or - 5 Diopters
- •Pupil diameter of less than 5 mm
- •Poor quality images due to artifacts, movements, or media opacities
结局指标
主要结局
ETDRS severity level according to the Early Treatment Diabetic Retinopathy Study - Diabetic Retinopathy Severity Scale (ETDRS-DRSS).
时间窗: 12 months
Compare DR severity level between the ETDRS 7-fields imaging and the wide-field imaging techniques: Clarus 500TM and OptosTM. The ETDRS - DRSS goes from level 10 - no presence of DR to level 75 - Severe proliferative DR
One or more than 2-steps change on ETDRS - DRSS severity level
时间窗: 12 months
Compare ETDRS -DRSS between the two imaging techniques and evaluate the presence of 1 step or more than 2 steps difference between ETDRS 7-fields imaging and the wide-field imaging techniques: Clarus 500TM and OptosTM
Peripheral DR lesions characterization
时间窗: 12 months
Investigate the peripheral area and analyze the presence, distribution, and severity of peripheral DR lesions, in wide-field images: Clarus 500TM and OptosTM. Presence and distribution of lesions in the periphery will be evaluated as 1) Not observed; 2) predominantly observed outside ETDRS fields; 3) Uniformly distributed within and outside ETDRS fields. 4) Ungradable. Severity of the peripheral lesions will be evaluated using the same ETDRS-DRSS scale described above and will vary between level 35 and level 65. Also, it will then be compared with the ETDRS 7-field area and graded as less, equivalent or greater than the observed inside ETDRS 7-fields area.
次要结局
- Correlate and analysed DR findings in each imaging technique with disease severity(12 months)
- Evaluation of Images quality in each imaging modality.(12 months)
- Evaluation of Patients satisfaction about each imagining modality.(12 months)