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.
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 observe the relationship between shallow optic cup，small disc and occurrence in patients with nonarteritic anterior ischemic optic neuropathy (NAION).Methods Ninetysix patients（96 diseased eyes）who accorded with the diagnosis criteria for NAION，with duration ge; three months and optic disc edema in paracmasis were selected. The fellow eyes of 96 NAION patients and 80 normal eyes were selected in our study. The horizontal and vertical disc and cup diameters，optic cup depth, and peripapillary retinal nerve fiber layer (RNFL) thickness were measured by quot;crossquot; and quot;ringquot; scan of optical coherence tomography (OCT，Humphrey 2000，German Carl Zeiss Company) inspection system. The cup depth were classified four grades by cup shape according to OCT images：GradeⅠ，bottom of optic cup above the anterior plane of peripapillary neuroepithelial layer（PNL）；GradeⅡ，bottom of optic cup above the plane of PNL；Grade Ⅲ，bottom of optic cup between the plane of PNL and choroidal pigment epithelium；Grade Ⅳ，bottom of optic cup under the plane of choroidal pigment epithelium connection. The grades of optic cup and value in three groups were statistically analyzed. The follow up ranged from six months to three years.Results The disc diameter in horizontal scanning of diseased eyes，fellow eyes and normal eyes were (1.29plusmn;0.19), (1.32plusmn;0.17), (1.40plusmn;0.15) mm，and diameters in vertical scanning were (1.52plusmn;0.14), (1.49plusmn;0.17), (1.60plusmn;0.22) mm, respectively. Compared the diseased eyes and fellow eyes with normal eyes，the difference were statistically significant in horizontal scanning (t=4.291,3.315; P＜0.05) and in vertical scanning (t=2.812, 3.654; P＜0.05). Compared the diseased eyes with fellow eyes，the difference of average diameter were not statistically significant in horizontal and vertical scanning (t=1.153,1.335; P＞0.05). Of the diseased eyes，GradeⅠoptic cup in 36 eyes（37.50），Grade Ⅱ-Ⅲoptic cup in 52 eyes（54.17%），Grade Ⅳoptic cup in eight eyes（8.33%），and GradeⅠ-Ⅲ optic cup in 88 eyes（91.67%）were found. Of the fellow eyes，GradeⅠoptic cup in 18 eyes（18.75%），Grade Ⅱ-Ⅲoptic cup in 69 eyes（71.88%），Grade Ⅳoptic cup in nine eyes（9.34%），and GradeⅠ-Ⅲ optic cup in 87 eyes（9066%）were found. Compared the average RNFL thickness of diseased eyes with the fellow eyes and normal eyes，the differences were statistically significant in temporal, upper, nasal, lower quadrant(t=12.862，10.147，15.046，8.180，12.859，9.562，12.174，8.632；P＜0.001). Compared the average RNFL thickness of the fellow eyes and normal eyes，the differences were not statistically significant in all quadrants（t=1.040，1.576，1.062，1.192；P＞0.05）. During the followup，eight eyes with recurrence which optic cup were GradeⅠand Ⅱin diseased eyes；44 eyes（45.8%）occurred NAION. Correlation analysis showed that there was negative correlation between incidence of fellow eye and optic cup depth(t=-0.757, P=0.000). Conclusion Optic cup and disk in NAION patients are smaller than that in the normal，the anatomical characteristics of shallow cup and small disc was one of the NAION pathogenesis.
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 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 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 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.
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 OCT characteristics of lamellar hole-associated epiretinal proliferation (LHEP).MethodsA retrospective case analysis. A total of 128 patients (133 eyes) with lamellar macular hole (LMH) and 202 patients (212 eyes) with full-thickness macular hole (FTMH) diagnosed by the examinations of spectral-domain OCT (SD-OCT) in Department of Ophthalmology, The Third People's Hospital of Chengdu from January 2013 to December 2016 were included in this study. Among 133 eyes with LMH, there were 53 eyes (39.8%) with LHEP and 80 eyes (60.2%) without LHEP. Among 212 eyes with FTMH, there were 12 eyes (5.7%) with LHEP and 200 eyes (94.3%) without LHEP. The mean age of LMH with or without LHEP patients were 70.88±10.98, 64.76±13.60 years old, respectively. The difference of mean age between LMH with or without LHEP patients was statistically significant (U=1521.5, P=0.006). The inner diameter, median diameter and base thickness of the LMH, the height, base diameter and minimum diameter of FTMH were measured by SD-OCT. The traction index (THI) and the macular hole index (MHI) were calculated. An independent sample t-test or rank-sum test was used to compare the inner diameter, median diameter, and base thickness of the LMH in patients with or without LHEP, and χ2 test was used to compare the injury rate of ellipsoid zone.ResultsOf the LMH patients with or without LHEP, the inner diameter were 611.15±209.83 and 521.70±198.05 μm, the median diameter were 961.22±571.09 and 497.01±172.30 μm, the base thickness were 99.83± 38.69 and 154.12±43.17 μm. The differences of the inner diameter, median diameter and the base thickness between LMH patients with or without LHEP were statistically significant (t=2.490, 5.747, －7.395; P=0.014, 0.000, 0.000). Among the 53 eyes with LHEP, There were 50 eyes (94.34%) were injured in ellipsoid zone among 53 eyes with LHEP, while 17 eyes (21.25%) were injured in ellipsoid zone among 80 eyes without LHEP. The injury rate of ellipsoid zone between LMH patients with or without LHEP was statistically significant (χ2=68.126, P=0.000). In 12 eyes of FTMH with LHEP, there were 10 eyes with THI＜1.0 and MHI＜0.5.ConclusionCompared with the LMH without LHEP, the LMH with LHEP has larger inner diameter and median diameter, thinner base and higher injury rate of ellipsoid zone.
With the renovations of modern retinal imaging modality, such as video ophthalmoscopy, fundus photography, fundus fluorescein angiograph and spectral domain optical coherence tomography, it is possible to get high resolution and reproducible in vivo imaging of retina from neonates to improve the diagnosis and treatment of pediatric retinal disease. Now we have a better tool to investigate the early development of human retina, the pathogenesis and progression of pediatric retinal diseases, and to monitor the treatment efficacy and prognosis of these diseases. To expand these technologies in the diagnosis and treatment of pediatric retinal disease, we need simple, safe, comprehensive and objective applications which can only be achieved through multi-disciplinary cooperation.