Optical coherence tomography angiography (OCTA) is a new and non-invasive imaging technique that is able to detect blood flow signal in the retina and the choroid within seconds. OCTA is different from the traditional angiography methods. The major advantages of OCTA are that it can observe blood flow signal in different layers of the retina and the choroid without injecting any dye, provide blood flow information that traditional angiography cannot provide, and enrich pathophysiological knowledge of the retinal and choroidal vascular diseases., which help us to make an accurate diagnosis and efficient evaluation of these diseases. However there is a large upgrade potential either on OCTA technique itself or on clinical application of OCTA. We need to fully understand the advantage and disadvantage, and differences of OCTA and traditional angiography. We also need to know how to interpret the result of OCTA. With that we could make a fast diagnosis in a non-invasive way and improve our knowledge of the retinal and choroidal vascular diseases.
ObjectiveTo observe the clinical characterisitics of choroidal excavation in the macula. MethodsA total of 22 patients (22 eyes) with choroidal excavation diagnosed by spectral domain high definition optical coherence tomography (HD-OCT) were enrolled in this study. The patients included 12 males (54.50%) and 57 females (45.50%). The age was ranged from 21 to 82 years old, with an average of (41.44±13.17) years. All the patients were affected unilaterally, including 9 right eyes and 13 left eyes. The corrected vision, slit lamp microscope with preset lens, fundus photography, HD-OCT and fluorescence fundus angiography (FFA)were measured for all patients. The clinical characterisitics and concomitant diseases were observed. Seventeen eyes were followed for a period between 3 to 12 months. The lesions change were evaluated by HD-OCT. ResultsThere were 18 eyes (81.8%) with symptoms of micropsia and metamorphopsia, 4 eyes (18.2%) without symptoms. The corrected vision was ranged from 0.3 to 1.2, 12 eyes (54.54%) with moderate or high myopia. Fundus examination presents yellowish-white exudation in 12 eyes (54.54%), yellowish-white exudation accompanied with hemorrhage in 9 eyes (40.91%), grayish yellow reflex halo in 1 eye (4.55%). HD-OCT showed that the retinal pigment epithelium (RPE) layer was involved in the excavation, and the photoreceptor outer segment and pigment junction (OPR) layer was disappeared in all eyes. The external limiting membrane and the photoreceptor inner segment/outer segment junction layer were preserved in 13 eyes (59.09%) and disappeared in 9 eyes (40.91%). There were 10 eyes (18.18%) with a single lesion, 4 eyes (18.18%) with idiopathic choroidal neovascularization, 4 eyes (18.18%) with punctate inner choroidopathy, 1 eye (4.55%) with polypoidal choroidal vasculopathy, 1 eye (4.55%) with macular preretinal menbrance, 1 eye (4.55%) with central serous chorioretinopathy. FFA showed hypofluorescence in early phase, hyperfluorescence in late phase, without obvious leakage. There was no noticeable changes in size and morphological changes in the follow-up period. ConclusionsChoroidal excavation in the macula occurs mostly in middle-aged people with myopia. It can be associated with many fundus diseases. The excavation is located in RPE layer, and OPR layer disappeared. Choroidal excavation in the macula develops slowly.
ObjectiveTo observe the characteristics of optical coherence tomography (OCT) angiography (OCTA) in retinal vein occlusion (RVO). MethodsProspective and observational study. Clinical examination of 81 consecutive patients (86 eyes) diagnosed with RVO were included in the study, in which the branch retinal vein occlusion in 47 eyes, central retinal vein occlusion in 39 eyes. Forty-five patients were male and 36 patients were female. Aged from 28 to 76 years old, the mean age was (55.36±10.01) years old. Comprehensive optical and imaging examination were performed, including fundus photography, fundus fluorescein angiography (FFA), spectral domain OCT, en face OCT and OCTA. The retinal blood flow imaging scan mode and the optic disc blood flow imaging scan mode were performed, the scanning region in the macular area were 3 mm×3 mm, 6 mm×6 mm, 8 mm×8 mm respectively, around the optic disc were 3 mm×3 mm and 4.5 mm×4.5 mm. Each region scans 2 times. The characteristics of foveal avascular zone change, macular edema, non-perfusion and optical disc edema in OCTA and their corresponding FFA and en face OCT were observed. ResultsBy OCTA, 67 eyes (77.9%) for foveal avascular zone change, 23 eyes (26.7%) for macular edema, 40 eyes (46.5%) for non-perfusion, and 33 eyes (38.4%) for optical disc edema can be detected. The foveal avascular zone change can be indentified as the tranformation, destruction and even vanish of the arch in superfacial layer of retinal macular area, acompanied with the dilatation and thickening of capillary vessels, the occlusion and expanding of capillary vessels arounded the foveal avascular zone in the deep layer of macular area. Those performances were more clear than FFA. The main expression of macular edema was low signal and was not as clear as en face OCT. The tortuosity and expansion of retinal vessels, density decreasing and even occlusion or abnormal traffic branch of capillary vessels can be observed in non-perfusion. These observations were similar to FFA. However, pieces of highly signal identical with non-perfusion area can be detected in chroid capillary. The representation of optical disc edema was the brush-like expanding of capillary vessels aroud optical disc. ConclusionsOCTA can help for observing the abnormal changing of capillary vessels in foveal avascular zone and macular edema, non-perfusion and optical disc edema. Foveal avascular zone change showed occlusion and expanding of capillary vessels around the foveal avascular zone in the deep layer of macular area. Macular edema showed the weak signal. Non-perfusion showed tortuosity and expansion of retinal vessels, density decreasing and even occlusion or abnormal traffic branch of capillary vessels. Optical disc edema showed brush-like expanding of capillary vessels around optical disc.
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.
ObjectiveTo observe the preliminary application of intraoperative optical coherence tomography (iOCT) in vitreous retinal surgery and the influencing factors of the imaging quality. MethodsA retrospective case study. A total of 132 subjects were chosen in June 2015 and April 2016 in our hospital. All the subjects were taken vitreous retinal surgery and iOCT scanning. The patients included 46 males and 86 females, with an average age of 61.7 years. 111 cases had macular diseases and 21 cases had vitreous hemorrhage. Cases are divided into high myopia and non-high myopia group according to ocular axial length (AL), 28 eyes in high myopia group (AL≥26 mm),104 eyes in non-high myopia (AL<26 mm).The scanning time, image quality and eye conditions were observed during the operation. The discordance between surgeon microscope visualization of the pathology and the findings of the iOCT and the postoperative adverse reactions were also observed. ResultsThe iOCT images were identified in 124 of 132 subjects, while were not identified in 8 eyes. For the macular area morphology change, iOCT tips and surgeon judgment rate was inconsistent in 22 eyes (16.7%). For the operation guidance value, change the operation rate of 12/132,accounted for 9.1%. The iOCT imaging quality of high myopia groups was lower than the non-high myopia groups (χ2=17.13, P=0.001). Corneal edema and operation time were considered as influencing factors on the quality of the imaging in the non-high myopia groups (r=3.75, 6.18; P=0.049, 0.013). There were no complications such as endophthalmitis. ConclusionsThe surgeon can observe morphological changes in the macular area through iOCT which is difficult to be observed by operating microscope and selected reasonable operation method during the surgery. High myopia, corneal edema and operation time affect the image quality.
Objective To observe the choroidal thickness of patients with chronic central serous chorioretinopathy (CSC) in affected eyes and unaffected fellow eyes.Methods Forty-five chronic CSC patients diagnosed by fundus pre-set lens, fundus fluorescein angiography (FFA) and indocyanine green angiography were enrolled in this study. The patients included 36 males and nine females, with a mean age of (46.18plusmn;8.20) years, with a mean duration of (16.34plusmn;7.23) months. Thirty-six patients were affected unilaterally and nine patients affected bilaterally. The patients were divided into affected eyes group (group A, 51 eyes) and unaffected fellow eyes group (group B,39 eyes). Fifty age-, sex- and diopter- matched normal subjects (50 eyes) were enrolled in this study as control group (group C). Enhanced depth imaging (EDI) choroidal scans were obtained in all eyes by using spectral-domain optical coherence tomography. Subfoveal choroidal thickness (SFCT) and choroidal thickness at 3 mm nasal (NCT3 mm), temporal (TCT3 mm), superior (SCT3 mm), inferior (ICT3 mm) to the fovea were measured.Results The mean SFCT of group A, B and C were (436.76plusmn;87.01), (394.71plusmn;61.63), (294.86plusmn;75.30) mu;m respectively. The mean SFCT of group A and B were thicker than group C, the difference was significant among three groups (F=44.791,P＜0.001). There were difference between group A, B, C in NCT3 mm, TCT3 mm, SCT3 mm and ICT3 mm (F=15.816, 22.823, 15.147, 11.527;P＜0.001). The mean SFCT in affected eyes of unilateral patients was (416.34plusmn;79.44) mu;m, which was thicker than that in unaffected fellow eyes (t=2.897, P=0.007). Conclusion Choroidal thickness increased significantly in affected eyes and unaffected fellow eyes in patients with chronic CSC.
ObjectiveTo observe the foveal contour characteristic of idiopathic epiretinal membrane (iERM). MethodsA total of 53 eyes in 52 patients with iERM who underwent pars plana vitrectomy with epiretinal membrane and inner limiting membrane peeling were enrolled in this retrospective study. All eyes received the examination of optical coherence tomography (OCT) and minimum resolution angle in logarithmic (logMAR) best corrected visual acuity (BCVA). Foveal contour grading was according to the ratio of central macular thickness (CMT) to the thickness of the retina 1 mm away on OCT line scan: Grade 0, depressed; Grade 1, flat; Grade 2, elevated. Baseline foveal contour grade was as follows: 28 eyes with Grade 1 (Group 1), and 25 eyes with Grade 2 (Group 2). The mean logMAR BCVA was 0.40±0.26 in Group 1, and 0.60±0.27 in Group 2 respectively. The mean CMT was (433.52±133.05) μm and (571.70±85.40) μm respectively. The logMAR BCVA and CMT both demonstrated significant difference between the two groups (t=-2.825, -4.512; P<0.05). OCT images and BCVA at 1, 3 months after surgery were collected and analyzed. The change in foveal contour, BCVA and CMT were evaluated. The relationship between surgical outcome and different preoperative grading was analyzed. ResultsFoveal contour grade at 3 months after surgery was as follows: 15 eyes with Grade 0, 21 eyes with Grade 1, and 17 eyes with Grade 2, demonstrating significant difference compared with baseline (Z=-3.588, P<0.05). In Group 1, there were 12 eyes with Grade 0, 10 eyes with Grade 1, and 6 eyes with Grade 2 postoperatively. In Group 2, there were 3 eyes with Grade 0, 11 eyes with Grade 1, and 11 eyes with Grade 2 postoperatively. The postoperative foveal contour grade was significantly different between the two groups (Z=-2.466, P<0.05). The logMAR BCVA at 1, 3 months after surgery both improved significantly compared with baseline (P<0.05) in Group 1 (t=-3.226, -5.439) and Group 2 (t=-4.137,-5.919). The logMAR BCVA at 1, 3 months after surgery demonstrated significant difference between the two groups (t=-2.231, -2.291; P<0.05). The CMT decreased significantly at 1, 3 months after surgery in Group 1 (t=-2.674, -4.090) and Group 2 (t=-9.663, -9.865) compared with baseline (P<0.05). The CMT at 1, 3 months after surgery demonstrated significant difference between the two groups (t=-2.825, -3.003; P<0.05). The improvement of logMAR BCVA 3 months after surgery was negatively correlated (P<0.05) with preoperative logMAR BCVA (r=-0.758) and preoperative CMT (r=-0.359). ConclusionIn iERM eyes, flat foveal contour had better surgical prognosis than elevated ones.
Objective To observe the optical coherence tomography (OCT) features of Best vitelliform macular dystrophy (BVMD) at different stages.Methods Twenty-eight BVMD patients (56 eyes) were enrolled in this study. All the patients were examined for visual acuity, slit-lamp microscopy, direct ophthalmoscope, fundus photography, electrooculogram, fundus fluorescein angiography (FFA) and OCT. Fifty-six eyes were classified into stage 0 (eight eyes)、Ⅰ (two eyes)、Ⅱ(10 eyes)、Ⅱa （12 eyes）、Ⅲ (six eyes) 、Ⅳa (six eyes)、Ⅳb (five eyes) and Ⅳc (seven eyes) accordingly. The OCT features of BVMD at different stages were observed.Results The OCT results showed that the macular area was normal in eyes of stage 0; disturbance of retinal pigment epithelium (RPE) and subretinal hyporeflective area were found in eyes of stage I; the location of the yellowish material between RPE and the inner segment and outer segment (IS/OS) with normal appearance in RPE and IS/OS interface were found in eyes of stage Ⅱ. In all the other progressing stages from Ⅱa、Ⅲ and Ⅳ, the vitelliform material appeared as a thicker highly reflective lesion located between the outer nuclear layer and RPE layer, usually accompanied by optical hyporeflective lesion. Images of stage Ⅳc were in similar appearance besides edema of retina. OCT images of Ⅳb stage were demonstrated atrophy of retinal layer and IS/OS loss with fibrosis. Conclusions OCT demonstrated the location of the yellowish material between RPE and IS/OS. Optical hyporeflective lesion between the outer nuclear layer and RPE layer accompanied thicker highly reflected lesion might be the characteristic image in stages II a to IV of BVMD.
Objective To observe the spectral domain optical coherence tomography (SD-OCT) features of acute Vogt-Koyanagi-Harada (VKH) eyes before and after treatment.Methods Twenty-eight patients (56 eyes) with acute VKH diagnosed by slitlamp microscopy, B mode ultrasound and fundus fluorescein angiography (FFA) were enrolled in this study. All the patients were treated with steroid after diagnosis. SD-OCT was performed in all the patients before and after treatment. The follow-up was ranged from 12 to 32 weeks with a mean of (21.30plusmn;8.53) weeks. The foveal retinal detachment height, inner and outer segments (IS/OS) of photoreceptors, and the changes in retinal structure within the vascular arcades before and after treatment were comparatively analyzed. Results OCT examination results showed that before treatment, all eyes had retinal neural epithelial detachment. The average neural epithelial detachment height in the fovea was (635.44plusmn;340.04) mu;m. Forty-three eyes (76.8%) had different types of subretinal exudates; 41 eyes (73.2%) had b granular reflection in the subretinal space. Twenty-two eyes (39.3%) had paraforveal outer nuclear layer (ONL) thickening with finger-like protrusions attached with membrane-like structure. Thirty-three eyes (58.9%) had wavy lines of the retinal pigment epithelium (RPE). After the treatment, these exudates dissolved within one week and RPE line became straight. The retina reattached after (2.33plusmn;0.82) weeks. In most patients external limiting membrane and IS/OS became intact after (5.01plusmn;6.71) weeks and (11.40plusmn;7.89) weeks respectively. However, at the end of follow-up, 46 eyes (82.1%) still had focal areas of IS/OS defect and 11 eyes (19.6%) had focal ONL thinning. Conclusions Before the treatment, the OCT features of acute VKH are serous retinal detachment at fovea, different types of subretinal exudates and wavy RPE. After the treatment, the OCT features of acute VKH are exudates dissolving, straight RPE line and early recovery of external limiting membrane.