Objective To compare the macular imaging and measurements of patients with idiopathic epiretinal membranes (ERM) by stratus optical coherence tomography (OCT) and two different types of spectral-domain OCT. Methods Forty-six consecutive patients (46 eyes) diagnosed as idiopathic ERM in the period of August 2008 to October 2008 were enrolled in this study. The patients included 11 males and 35 females, with a mean age of (61.04plusmn;10.13) years. Twenty-one age- and sex- matched normal subjects (21 eyes) were enrolled in this study as control group. All the subjects underwent stratus OCT, cirrus OCT and 3D OCT-1000 examinations. The macular area was divided into three concentric circles which including central region with 1 mm diameter, inner area with ＞1 mm but le;3 mm diameter, and outer ring area with ＞3 mm but le;6 mm diameter. The inner area and outer ring area were divided into superior, nasal, inferior and temporal quadrants by two radioactive rays. The characteristics of OCT images and the quantitative measurements were compared among these three machines. The macular thickness of ERM group and control group was also compared. And the correlation of visual acuity and the macular thickness in idiopathic ERM patients was evaluated. Results The increased macular retinal thickness, disorder structure of inner retina, uneven surface and proliferative inner and outer plexiform layer were observed in ERM group by stratus and spectral-domain OCT. But the minor pathological changes on inner retina structure and internal surface proliferation could be observed more clearly by spectral-domain OCT than those by stratus OCT.The macular thicknesses of all the subjects measured by Cirrus OCT and 3D OCT-1000 were thicker than those measured by Stratus OCT (t=7.445-11.253,P=0.000). The correlations of measurements between three OCTs were good (r＞0.9). The flatted or disappeared fovea of ERM patient group was observed by all three OCTs. The macular thicknesses on different subfields of patients in ERM group were thicker than those in control group, especially in the 1-3 mm inner ring (t=2.477-10.139,P＜0.05). Moderate negative correlations were shown on the macular thickness and visual acuity in ERM group (r=-0.216-0.517). Conclusions Spectral domain OCT yields better visualization of the intraretinal layers than time domain OCT. The images in spectral domain OCT are more clear and fine compared to stratus OCT. Stratus OCT correlates with spectral domain OCT, but they are different, and cannot be replaced by each other.
Objective To compare difference of the cross-sectional pathological imaging and quantitative measurement of central serous chorioretinopathy (CSC) between time- and fourier-domain optical coherence tomography (OCT). Methods Consecutive 26 patients (26 eyes) with unilaterial CSC were subsumed. Bilateral eyes of all the patients underwent time- and fourier-domain OCT. Horizontal and vertical line scanning and radial six-line scanning protocols were used for timedomain OCT examination; horizontal and vertical high resolution five-line scanning and macular cube scanning protocols were used for fourier-domain OCT examination. The characteristics of OCT images, retinal segmentation and the quantitative measurement were compared between these two methods. Results Fourier-domain OCT could yield the three-dimensional images of surface of inner limiting membrane (ILM) and RPE. The band of external limiting membrane (ELM) of normal subjects and CSC patients, and the inner segment and outer segment (IS/OS) of normal subjects could be clearly shown by fourier-domain OCT. However, the band of IS/OS disappeared in 65.4% of the CSC patients. The outer boundary of retina was defined in front of the retinal pigmental epithelia (RPE) by fourier-domain OCT. The foveal thickness of normal subjects and CSC patients was (180.50plusmn;12.69) and (158.41plusmn;34.20) mu;m, respevtively. The height of detachment of neural epithelial layer was (245.84plusmn;154.61) mu;m measured by fourier-domain OCT. The band of IS/OS of normal subjects could be clearly shown by time-domain OCT. However, the band of IS/OS disappeared in 73.4% of the CSC patients, which showed no difference with fourier-domain OCT (Z=-0.108, P=0.914). The outer boundary of retina was defined in front of the IS/OS band by OCT. The foveal thickness of normal subjects was (141.16plusmn;12.75) mu;m, which was thinner than that measured by fourier-domain OCT (t=20.671，P=0.000). The foveal thickness and the height of detachment of neural epithelial layer was (146.40plusmn;36.28) mu;m and (240.32plusmn;156.82) mu;m measured by time-domain OCT, respectively, which showed no significant difference with which measured by fourier-domain OCT (t value was from 0.026 to 1.517, P value was from 0.144 to 0.980). Conclusions Fourier-domain OCT yields better visualization of intraretinal layers and more accurate definition of outer boundary of retina than time-domain OCT. Thus the measurements by fourier-domain OCT were more accurate. Moreover, three-dimensional images of CSC shown by fourier-domain OCT enable the comprehensive observation of pathological morphology and location.
Objective To observe the effects of local macular foveal photoreceptor defects on visual acuity.Methods Thirty-one patients (31 eyes) with photoreceptor defect in macular fovea (case group) diagnosed by spectral domain optical coherence tomography (SD-OCT) and 30 patients (30 eyes) age- and diopter- matched normal subjects (control group) were enrolled in this study. There were 22 eyes with full photoreceptor defects and 9 eyes with outer segment defects in case group. All subjects were examined for best corrected visual acuity (BCVA), slit-lamp microscopy, direct ophthalmoscope and SD-OCT. Independent sample t-test was used to compare central foveal thickness (CFT) between case group and control group. Difference of logMAR BCVA, CFT, maximum width and height of photoreceptor defects, defected area and residual retinal thickness in macular between patients with full photoreceptor defects and outer segment defects were also compared.Results The CFT of case group and control group were (225.32plusmn;19.70),(240.02plusmn;10.70) mu;m, the difference was not statistically significant (t=-1.96, P＞0.05). In full photoreceptor defects and outer segment defects patients, the mean logMAR BCVA were 0.22plusmn;0.31, 0.32plusmn;0.43; the mean CFT were (224.09plusmn;20.57), (228.33plusmn;18.17) mu;m; the maximum width of photoreceptor defects were (131.32plusmn;108.18), (143.22plusmn;66.93) mu;m; the mean defected area were (0.022plusmn;0.054), (0.019plusmn;0.019) mm2; the mean maximum height of photoreceptor defects were (77.41plusmn;6.62), (44.89plusmn;4.26) mu;m; the mean residual retinal thickness were (87.00plusmn;20.31), (128.33plusmn;23.54) mu;m respectively. There was no statistical significance between full photoreceptor defects and outer segment defects patients in the mean logMAR BCVA, CFT, maximum width of photoreceptor defects and defected area (t=-0.76, -0.538, -0.305, 0.166; P＞0.05), but there were significant difference in mean maximum width of photoreceptor defects and residual retinal thickness (t=12.72, -4.91;P＜0.05). Conclusions The local photoreceptor defects in macular fovea can lead to decrease of visual acuity. The wider the photoreceptor defects, the worse the visual acuity.