Abstract
Purpose:
To identify eyes that show worsening and diabetic retinopathy (DR) progression using non-invasive techniques.
Methods:
Three hundred seventy five (375) type-2 diabetic patients with mild NPDR (ETDRS levels 20 or 35) were included in a 1-year observational and prospective study to identify phenotypes of retinopathy progression. Patients were included in 19 clinical sites from the European Vision Institute Clinical Research Network (EVICR.net). The study started in September 2010 and conclusion is expected by May 2013. Four visits are scheduled at months 0, 3, 6 and 12 with the following examinations: color fundus photography (CFP), spectral domain optical coherence tomography (SD-OCT) and blood tests. ETDRS severity level in the first and last visits, and microaneurysm (MA) turnover (formation plus disappearance rates), using the RetmarkerDR®, are assessed by the Coimbra Ophthalmology Reading Centre (CORC). SD-OCT Cirrus and/or Spectralis are used to measure retinal thickness (RT), nerve fiber and ganglion cell layers. One eye per patient is selected by the Reading Centre as the Study Eye.
Results:
375 patients were included (65.4% males and 34.6% females) with ages ranging from 35 to 82 years. Mean BCVA was 84.8±6.6 ETDRS letters. Mean HbA1C was 7.8±4.2% and the systolic and diastolic blood pressure was respectively of 137.7±16.6 and 77.4±10.1 mmHg. Eyes/patients showed at baseline a mean number of MA of 3.6±5.2. The mean RT in the central subfield was 265.0±21.8 µm for Cirrus OCT and 278.4±26.6 µm for Spectralis OCT. Males showed a higher RT than females (p<0.05). A wide range of abnormal RT values is observed, from higher to lower RT values. Comparing the mean RT in the central subfield with normal RT values (mean±2SD), 8.6% of the eyes/patients showed a decreased RT, and 8.3% of the eyes/patients showed an increased RT.
Conclusions:
MA and RT at baseline showed a wide range of values indicating involvement of different components of the disease process, vascular and neuronal, in different patients.
Keywords: 688 retina •
499 diabetic retinopathy •
550 imaging/image analysis: clinical