Abstract
Abstract: :
Purpose:Optical Coherence Tomography (OCT) has improved image output and analysis compared with its predecessors. The speed of OCT depends on the radial scanning acquisition protocol. We compared the accuracy of "fast" and "slow" protocols for the assessment of diabetic macula oedema prior to and following focal argon laser treatment. Methods:A series of diabetic patients listed for focal argon laser treatment were scanned using the Zeiss Stratus OCT 3. All patients underwent radial scans with both "slow" regular macular thickness map (series of six 6mm line scans) and "fast" macular thickness map (six 6mm line scans in one scan) protocols. The images were analysed with the retinal thickness/volume protocol, which produces average retinal thickness in nine sectors as defined by the Early Treatment Diabetic Retinopathy Study (ETDRS). The main outcome measures were statistically significant differences (paired t tests) in thickness/volume measures. Results:Seventy–six OCT images of treated and fellow eyes in 19 diabetic patients (mean age 62.2, range 41–79, 8 males) who underwent focal argon laser treatment were analysed. Treated eyes showed no difference in mean foveal thickness (343 ± 217 by "regular" and 341 ± 222 by "fast", p= 0.79) and mean total macular volume (8.90 ± 2.76 by "regular" and 8.96 ± 2.90 by "fast", p= 0.30) by the two protocols. There was also no difference in mean foveal thickness (215 ± 40 by "regular" and 215 ± 41 by "fast", p= 0.81) and for macula volume (7.42 ± 0.80 by "regular" and 7.44 ± 0.83 by "fast", p= 0.13) in untreated fellow eyes. There was no difference in "fast" vs "slow" scanning protocols in measuring retinal thickness in each of the ETDRS areas (p>0.05). There was also no difference in coefficients of variation in either group with "fast" or "slow" protocols. Conclusions:We found no clinically significant difference between the "fast" and "slow" acquisition protocols in assessing diabetic patients undergoing focal argon laser treatment.
Keywords: retina • imaging/image analysis: clinical • diabetic retinopathy