Abstract
Abstract: :
Purpose: To quantitatively compare the clinical assessment of two retina specialists in identifying the area and position of retinal thickening in patients with progressing diabetic macular oedema (DMO). Methods:The sample comprised 22 patients with pre–treatable DMO (mean age 58.8yrs, SD 6.6yrs). Pre–treatable DMO was defined as thickening of the retina, less than 1 disc diameter in size, beyond a radius of 500µm from the fovea. Volunteers were assessed every 3 months. Two medical retina specialists (GS and MQ) independently mapped the extent of retinal thickening using non contact lens fundus biomicroscopy. The areas mapped by each specialist and the distance of the leading edge of oedema to the fovea was compared for each visit relative to baseline using Image J software. Results: The group mean total retinal area examined at visit 1 was 30.66mm2 (SD 2.19). The group mean area of DMO identified by the retina specialists at visit 1 was 5.27mm2 (SD 4.77) and 5.11mm2 (SD 4.11) for GS and MQ, respectively (p>0.05, two–tailed paired t–test). The group mean area of concordance (i.e. area(s) identified by both retina specialists as thickened) of DMO at visit 1 was 2.56mm2 (SD 3.59) and the group mean area of discordance (i.e. area(s) where the retina specialists failed to agree on the presence of retinal thickening) was 5.11mm2 (SD 4.03) (p=0.040, two–tailed paired t–test). When determining the distance of the leading edge of oedema to the fovea, the agreement between retina specialists was much improved. Conclusions:The degree of inter–examiner variability is high when identifying the area and position of DMO but low when identifying the distance of the leading edge of oedema to the fovea. The distance of the leading edge of oedema to the fovea (rather than the area of oedematous retina) is the main factor driving conversion from pre–treatable DMO to CSDMO and determining the decision to initiate treatment.
Keywords: diabetes • diabetes • diabetes