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 observe the characteristics of spectraldomain optical coherence tomography (SD-OCT) and fundus autofluorescence (FAF) in acute and chronic central serous chorioretinopathy (CSC).Methods Seven-three eyes of 67 patients with CSC diagnosed by slit-lamp microscopy, fundus photochromy, fundus fluorescein angiography (FFA) and indocyanine green angiography were enrolled in this study. All the patients were examined for FAF and SD-OCT. The patients were divided into acute CSC group (37 patients, 37 eyes) and chronic CSC group (30 patients,36 eyes) according to the clinical features and FFA images. According to the OCT feature in retinal detachment area, they were divided into three categories, which including intact, non-intact and atrophy outer segment, respectively. According to the FAF characteristics, they were divided into hyper-FAF, hypo-FAF and mixed type, respectively. The characteristics of SD-OCT and FAF of both acute and chronic CSC patients were evaluated and analyzed. Results In acute CSC group, 19 eyes (51.35%) were hypo-FAF, 18 eyes (48.65%) were hyper-FAF. In chronic CSC group, two eyes (5.56%) were hypo-FAF, 16 eyes (44.44%) were hyper-FAF, and 18 eyes (50.00%) were mixed type. There was significant difference between both groups (chi;2=31.872,P=0.000). The SD-OCT results showed that in acute group, 15 eyes (40.54%) were intact outer segment, 18 eyes (48.65%) were non-intact outer segment, and four eyes (10.81%) were atrophy outer segment. In chronic group, five eyes (13.89%) were intact outer segment, 17 eyes (47.22%) were non-intact outer segment, and 14 eyes (38.89%) were atrophy outer segment. There was significant difference between both groups (chi;2=10.572,P=0.005). Conclusions The FAF characteristics of acute and chronic CSC mainly manifests hypo-FAF and mixed type, respectively. The OCT characteristics of acute CSC mainly manifests intact outer segment and non-intact outer segment, but non-intact outer segment and atrophy outer segment in chronic CSC.
Idiopathic macular hole (IMH) refers to full thickness defects of retina in macular area with no clear reasons. The management of IMH includes vitrectomy combined with internal limiting membrane (ILM) peeling and pharmacological vitreolysis. But ILM peeling may damage the inner retina; novel techniques, such as inverted ILM flap technique and foveola non-peeling ILM surgery, autologous ILM transplantation had made the method of ILM peeling more diversified with less damage. Pharmacological vitreolysis targeting fibronectin and laminin is considered to work in a two-step mechanism, involving both vitreoretinal separation and vitreous liquefaction. Furthermore, IMH judgment and prognosis indicators like ellipsoid zone, macular hole index, hole formation factor, diameter hole index and tractional hole index based on spectral domain optical coherence tomography enriched the assessment of macular hole diameter, depth and shape. How to make full use of new interventions to reduce the incidence of macular hole and obtain a better visual acuity with closed holes is an important direction for future research.
Objective To observe the retinal and choroidal changes in morphology and thickness after photodynamic therapy(PDT) for idiopathic choroidal neovascularization(ICNV). Methods Sixteen eyes of 16 patients with ICNV were treated with verteporfin PDT. 16 eyes of 16 agematched normal subjects were observed for the purpose of comparison. The best corrected visual acuity(BCVA) was checked before and 1, 3 and 6 months after PDT treatment. Enhanced depth imaging optical coherence tomography (EDI-OCT) technique was used to measure central retinal thickness (CRT) and central choroidal thickness(CCT). The correlations between BCVA and CRT, CCT were analyzed by Pearson statistical anallyses. Results BCVA was improved at 1, 3 and 6 months after PDT, and the difference had statistical significance compared with that before treatment (F=3.08,P=0.030). There was edema in the retina at 1 month after PDT. CNV in 13 eyes became fibrotic at 3 months after PDT, and all became fibrotic at 6 months after PDT. The reflex of choroid correspond to CNV was weak at 1, 3 and 6 months after PDT. CRT decreased at 1, 3 and 6 months after PDT (F=8.946,P=0.000). The difference was statistically significant between the CRT of control group and that 1 months after PDT (P=0.001), but there was no statistically significant difference between the CRT of control group and that 3 and 6 months after PDT（P=0.128, 0.083）. The CCT group had no statistically significant difference before and 1, 3 and 6 months after PDT (F=1.674, P=0.170). The CCT group also had no statistically significant differences between the control group and 1, 3 and 6 months after PDT (P=0.186, 0.551, 0.98). The BCVA was inversely correlated with CRT and CCT, and the correlation had no statistical significance (r=－0.051,－0.164;P=0.739,0.283). Conclusions PDT may improve BCVA in ICNV. Retinal edema resolves, CRT decreases, but CCT had almost no changes after PDT.
Objective To observe the characteristics of fundus fluorescein angiography（FFA）and optical coherence tomography（OCT）in nonarteritic anterior ischemic optic neuropathy (NAION),and investigate its relation with visual acuity and course of disease.Methods The clinical data of 47 patients (47 eyes) with NAION were retrospectively analyzed. All the patiens had undergone visual acuity，fundus and visual field examination，meanwhile FFA and OCT were carried out at first visit. FFA and visual field were carried out by routine. OCT was carried out by line and circle shape scanning in macula and optic disc. Thirtyfive NAION patients were checked with OCT at half, one, two, three and six month after onset in respectively. Take the healthy fellow eyes of 36 NAION patiens as control group.The FFA,visual field,OCT characteristics and relation with visual acuity and course disease were comparatively analyzed.ResultsFFA showed that all the eyes appear as delayed filling of the optic disc in early stage and hyperfluorescence leakage of the optic disc in late stage，besides hyperfluorescence presented to macular area in 24 eyes. OCT showed that optic papilla swelling and physiological depression narrow or nearly disappearance, neuroepithelial layer thickening or neuroepithelial layer eminence and subretinal fluidity area opaca between optic disc and macula. There were 14 eyes with normal physiological depression and 22 eyes with small physiological depression or non physiological depression in control group. Half month after onset，the neuroepithelial layer thickness of macula fovea, the maximum thickness of neuroepithelial layer between optic disc and macula，and the average retinal nerve fiber layer（RNFL）thickness in NAION group were higher than those in the control group，the difference were statistically significant (F=6.51，26.12，75.49；P＜0.05).Two months after onset，the maximum thickness of neuroepithelial layer between optic disc and macula, the average RNFL thickness, and the RNFL thickness of temporal optic disc in NAION group were significant thinner, but the elevated height of the optic disc in NAION group were near those of the control group. Three months after onset，the average RNFL thickness and the RNFL thickness of temporal optic disc in NAION group decreased continually, they were lower than those of the control group, the difference were statistically significan（F=75.49，37.92；P＜0.05）.Visual field showed that inferior defect were found in 21 eyes (45%). With progress, the superior RNFL thickness obviously decreased, coincidence with appearance of visual field. It indicate that the superior optic atrophy serious. Visual acuity had significant negative correlation with the neuroepithelial layer thickness of macula fovea, the neuroepithelial layer maximum thickness between optic disc and macula, the average RNFL thickness, the RNFL thickness of temporal optic disc(r=-0.394,-0.424,-0.412,-0.464；P＜0.05).Conclusions FFA showes that hyperfluorescence leakage appearanced in part macula. OCT showes that RNFL becomes thinner as the disease duration increases. The results of OCT and visual field examinaion in the configuration of optic disc and changes of RNFL are accordant.
The improvement of diagnostic levels for fundus diseases depend on the advancements of fundus imaging technology. Different fundus imaging technologies allow doctors to inspect ocular fundus from different aspects such as morphological or functional changes of retina. As a basic fundus examination method, optical coherence tomography provides highresolution and crosssectional retinal images coupled with noninvasive advantages. Fully understanding of the advantages and disadvantages of each fundus imaging technique, appropriate choosing one or combining several imaging techniques, and optimizing diagnostic procedures for each fundus disease are crucial steps to improve our diagnostic levels of ocular fundus diseases.
Objective To observe the distribution of macular thickness and its relationship with axial length, gender, refraction status and race in six-year-old children. Methods 1543 six-year-old children from 34 schools in Sydney were randomly selected. The thickness of center macula（CM）, inner macula（IM）and outer macula（OM）were measured by optical coherence tomography（OCT）, the differences of macular thickness between different genders and races were comparatively analyzed. The axial length and refraction status of all children were measured by IOL Master and autorefractor RK-F1 respectively. Results The CM, IM and OM thickness of all those six-year-old children were normally distributed，on average they were 193.6, 264.3 and 236.9 mu;m respectively,the differences were statistically significant（t=0.40,0.08,0.20;P＜0.05）. The CM,IM and OM average thickness was 194.2,264.9,229.0 mu;m for boys and 189.3,262.5,231.5 mu;m for girls respectively. CM and IM thickness of boys were thicker than those in girls（t=0.15,0.11;P＜0.05）. The CM,IM and OM average thickness was 196.0,265.2,237.5 mu;m for White kids,186.0,262.3,236.5 mu;m for East Asia kids and 19.4,263.7,233.8 mu;m for Central East kids respectively. The CM and IM thickness of White and Central East children were significantly thicker than East Asia children (t=0.12,0.15;Plt;0.05）. There was no difference between these three races in OM thickness（t=0.16,P=0.6）. The IM and OM were thinner with longer axial length (Plt;0.05). The CM,IM and OM thickness was thicker with higher hyperopic degrees (Plt;0.05). Conclusions Macular thickness was normally distributed in six-year-old children and was significantly affected by gender, race, axial length and refraction status.
Objective To compare the axial length (AL) measured with IOLMaster and contact A-Scan in eyes with macular edema (ME) and to investigate the correlation between measurement difference and foveal thickness.Methods Sixty-seven ME eyes of 42 patients (ME group) and 40 healthy eyes of 30 participants (control group) were enrolled in this study. Foveal thickness was measured with 3D optical coherence topography (OCT)-1000. The AL was prospectively measured by IOLMaster and contact A-scan.The correlation between measurement difference and foveal thickness was analyzed by Pearson correlation analysis.Results Mean foveal thickness of ME eyes was (377.85plusmn;119.84) mu;m. Mean AL by IOLMaster and contact A-scan were (22.95plusmn;0.97) mm and (22.82plusmn;1.04) mm in ME group, and (23.21plusmn;1.08) mm and (23.17plusmn;1.15) mm in the control group respectively. The difference between two groups was statistically significant (t=-3.102,P=0.003). There was no correlation between measurement difference and foveal thickness in ME group (r=-0.097;P=0.447). Conclusions There is a difference of AL measurements using contact A-scan and IOLMaster in ME eyes. However, there was no correlation between measurement difference and the foveal thickness.
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.