Intraoberver repeatability of macula meaurement by confocal canning laer tomography

Purpoe To ae the repeatability of macula meaurement provided by the Heidelberg Retina Tomograph II (HRT II) in normal ubject, patient with diabetic macular edema (DME), and patient with choroidal neovacularization (CNV). Deign Propective, obervational cae. Method etting: Intitutional-baed tudy. patient population: Ten normal eye, 14 eye with DME, and 14 eye with CNV. obervational procedure: Three can within a ingle day. An additional three can of each of the 10 normal eye on a different day. main outcome meaure: Bland and Altman analyi for a 0.25 mm, 0.50 mm, and 0.75 mm radiu circle. Reult Variability and repeatability of the meaurement were not related to circle ize for either group of patient. Coefficient of variability value of the normal group and a 0.50-mm radiu circle were 17%, 5.7%, and 6.1% for mean urface height, ignal width, and edema index, repectively. The correponding value were 15.6%, 10%, and 10% for the DME group, and 10.5%, 7.4%, and 8.5% for the CNV group. The 95% confidence interval of the difference between ingle obervation acro day of the normal group wa ±106 μm, ±80 μm, and ±0.10 for mean urface height, ignal width, and edema index, repectively. When three can were combined, the correponding value were ±61.5 μm, ±46.7 μm, and ±0.06. Concluion The repeatability and variability of meaurement of normal ubject, patient with DME, and patient with CNV were determined. Difference between the three group exit and are important for diagnoing a pathologic condition or meauring the effect of variou treatment.