Session Title: Vascular Diseases & Anterior/posterior segment surgery
Session Date/Time: Sunday 29/09/2013 | 11:00-13:00
Paper Time: 11:16
Venue: Hall 3 (Level 0)
First Author: I.Lains PORTUGAL
Co Author(s): J. Figueira C. Farinha A. Baltar M. Costa
To analyze, with spectral domain optical coherence tomography (SD-OCT), the submacular choroidal thickness (CT) of diabetic retinopathy (DR) patients in different stages of disease and to compare it with healthy controls.
Department of Ophthalmology, Centro Hospitalar e Universitário de Coimbra, Coimbra, Portugal. Associação para a Investigação Biomédica e Inovação em Luz e Imagem, Coimbra, Portugal. Espaço Médico de Coimbra, Coimbra, Portugal. Faculty of Medicine, University of Coimbra, Portugal. Instituto de Retina de Lisboa, Lisboa, Portugal.
Cross-sectional study, developed in 4 ophthalmology centers. Thirty-two healthy controls (56 eyes) and 35 diabetic patients (70 eyes), with bilateral DR in the same stage, were recruited. According to DR stage, patients were classified in 3 groups: mild nonproliferative DR without maculopathy (NPDR, n=10); nonproliferative DR and history of treated diabetic macular edema (DME) (NPDR+DME, n=11); treated proliferative DR (PDR, n=14). Images were acquired with enhanced depth imaging protocol for SD-OCT (Heidelberg Engineering-Germany). The line of retinal pigment epithelium/Bruch membrane complex and the line of scleral/choroid interface were marked manually in the 5 central B-scans (subfoveal, 2 immediately upper and 2 immediately lower), by two independent observers blinded to the diagnosis, using MATLAB software (The Mathworks, Natick, MA, USA). In the centrofoveal B-scan, CT was determined automatically, in regular intervals of 500 µm. The mean and standard deviation of all the CT values included in a circumference of 1mm diameter centered in the fovea was also determined – central choroidal thickness (CCT).
Controls had mean age (51.2±6.6) lower than patients (61.1±10.1), so a linear regression was performed, allowing an adequate comparison between the study groups. NPDR+DME patients showed a significant reduction on CCT compared with normal values inferred to their age (249.7±71.6 µm versus 279.2±41.7 µm, p=0.04). In the centrofoveal B-scan, CT was significantly reduced in 6 of the 13 performed measurements (p<0.05). PDR patients showed similar results: CCT was significantly thinner (280.7±79.4 µm) than the normal inferred values (320.0±42.0 µm, p=0.02) and CT was also reduced in 5 of the 13 centrofoveal B-scan locations, including the subfoveal (p=0.03). In NPDR group, no significant differences were found in none of the CT measurements. Considering patients groups, no correlation was verified between the CCT and the retinal thickness in the corresponding area. A negative correlation was found in healthy controls (R=-0.47; p<0.001).
The submacular CT is reduced in the advanced stages of DR, namely in DME and PDR. This study introduces a new choroidal measure - the CCT –, that is clinically relevant as it represents a mean of all the determinations performed in the central macular area, instead of single evaluations in isolated points.