Research Information System
Thesis Type: Expertise In Medicine
Institution Of The Thesis: Gazi Üniversitesi, Tıp Fakültesi, Turkey
Approval Date: 2015
Student: NURİYE GÖKÇEN YALÇIN
Supervisor: ŞENGÜL ÖZDEK
Abstract:DME is the most common cause of visual deterioration in diabetic retinopathy. There is a lot of definition and classification about the types of DME. To determine the importance of DME characteristics is necessary for predicting vicual acuity and choosing appropriate treatment. We aimed to detemine these parameteres and to be defined DME via optic coherence tomography. We believe that CMD is a result of chronic oedema and may connected with unfavorable visual outcome. We aimed to definite CMD which had no clear definition in DME and to investigate its features. Our study was designed retrospectvely. OCT scans who was diagnosed DME and had been followed up in our department between November 2011 and March 2015 was scanned. Two hundred fifty nine eyes of 187 patients ( 92 female/ 95 male) were included to the study. The presence and localisation of hard exudates was determined from colour fundus photographs. The presence and intensity of macular ischemia, periferial ischemia and the type of the edema was evaluated from fundus flourescein angiography. OCT scans were evaluated in terms of parameteres such as cystiod macular edema, vitreomacular interface abnormalities, serous foveal detachment, presence of foveal contour, internal reflectivities of the cysts, disruption of the outer layer bands and presence of hyperreflective dots. The horizontal and vertical diameters of the biggest cyst in the area of 1000μm from the center of the fovea were measured for the definition of CMD. The analysis of ROC curve was made to define a cut-off value from these measurements. The groups of CMD were created with these values and features of CMD were put forward. The mean visual acuity was 0.5±0.02 LogMAR. The mean central foveal thickness was 474±131μm. The visual acuity was shown as decreasing with the presence and severity of the macular ischemia. Whereas the central foveal thickness was higher when there was macular ischemia. The presence and the severity of the peripheral ischemia had no effect on the visual acuity and the severity of the oedema. The focal leakage (36.3%) was the highest type of the oedema. The visual acuity was the worst (0.63±0.42 LogMAR) and the oedema was the highest(510 ± 135μm) in the diffuse leakage type. The macular ischemia and the disruption of the outer layer was seen most frequently (both of them, 48%) in the diffuse oedema. Cystic changes were observed almost in all cases (96.9%). The correlation between the central foveal thickness and visual acuity showed medium degree positive correlation (r=0,417). Vitreomacular interface abnormalities were found at a rate of 79.4%. These abnormalities was unrelated with the severity of DME but related with the visual acuity. The broad base VMT had the worst visual acuity (median 1.10 LogMAR) after than ERM had the second worse visual acuity(median 0.70 LogMAR). The visual acuity was showed no difference between the eyes which had subfoveal detachment and the eyes which had no detachment. Unlike visual acuity, the central foveal thickness was higher in the eyes which had SFD (555±127 μm) than in the eyes which had no detachment (454±124 μm). The visual acuity when the absence of foveal contour (0.58±0.4 LogMAR) was lower than groups of the protection of the contour and mild affected ones. There was no relationship between the internal reflectvity of the cyst and the visual acuity. The correlation between the horizontal, vertical diameters of the biggest cyst and visual acuity showed medium degree positive correlation (rs=0,349, r=0.419). The horizontal and vertical diameters of the biggest cyst was higher when there was macular ischemia, disrupton of outer retinal layer, loss of foveal contour and diffuse oedema. When the horizontal diameter was and above 450μm we defined this group as CMD. In this group the predictability of visual acuity as lower than 0.32 namely sensitivity was 58%. When the horizontal diameter was lower than 450 μm we defined this group as CME. In this group the predictability of visual acuity as and higher than 0.32 namely spescifity was 73%. Sensitivity was 62% and spescifity was 69% for the determined 300 μm value in the vertical diameter. According to this cut-off values CMD and CME groups were formed. Central foveal thickness, outer retinal layer disturbance, loss of foveal contour, macular ischemia, diffuse and mixed oedema was observed higher in the CMD groups than CME groups. The cystoid degeneration can be defined as when the horizontal diameter of the biggest cyst in the area of 1000μm from the center of the fovea was above 450μm, vertical diamater was above 300μm and together with the macular ischemia, the disruption of outer retinal layer, the loss of foveal contour and diffuse, mixed oedema. This definition can be a guide for professionals to predict the visual acuity and expectation of the treatment. In our study we determined the criterias related with the visual acuity and the severity of oedema needed when describing DME. These parameters are; 1. Macular ischemia, focal-diffuse oedema type in FFA 2. Central foveal thickness 3. Subfoveal detachment 4. ERM and VMT in vitreomacular interface abnormalities 128 5. Outer retinal layer (ELM /ISOS) disturbance 6. The presence of foveal contour 7. The horizontal and vertical diamaters of the biggest cyst We thought that there is no importance to classify DME except those parameters according to our datas.