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.
ObjectiveTo investigate the effects of intravitreous injection of conbercept for macular edema secondary to retina1vein occlusion(RVO) during 6 months period. MethodsA retrospective clinical study. 34 patients (34 eyes) were included in this study,who were diagnosed with macular edema due to retinal vein occlusion by ophthalmologic examination, fundus photography, optical coherence tomography (OCT), fundus fluorescein angiography and other methods. The best corrected visual acuity (BCVA) was examined using the international standard visual acuity chart, and the results were converted to the logMAR visual acuity. The average logMAR BCVA was 0.90±0.68, and the mean macular central retinal thickness (CMT) was (672.27±227.51) μm before treatment. All subjects received intravitreal injection of 0.5 mg conbercept (0.05 ml) at the first visit. Injections were repeated based on the visual acuity changes and the OCT findings. 34 eyes received 69 times of injection, the average number of injections was 2.03±1.03. BCVA, OCT were examined before and after treatment using the same method. BCVA and CMT changes, drugs and treatments associated cardiac and cerebral vascular accident, intraocular pressure elevation, retinal tears, retinal detachment, endophthalmitis and other complications after treatment were observed. Linear correlation analysis was used to analyze the correlation between prognosis BCVA and baseline BCVA, correlation between prognosis BCVA and baseline CMT, and also correlation between BCVA and CMT at different time points before and after treatment. ResultsAt 1 week and 1, 2,3, 6 months after treatment, the average logMAR BCVA was 0.65±0.61, 0.56±0.61, 0.46±0.55, 0.56±0.71, 0.44±0.48 respectively. During 1, 2, 3, 6 months after treatment, the mean logMAR BCVA were improved with statistically significant difference (Z=34.029, 47.294, 41.338, 43.603;P < 0.05), while 1 week after treatment showed no obvious improvement (Z=21.941,P > 0.05). At 1 week and 1, 2, 3, 6 months after treatment, the average CMT was (285.89±96.69), (256.65±143.39), (278.68±156.92), (290.11±188.17), (217.15±48.04) μm respectively. At 1 week and 1,2,3,6 months after treatment, the mean CMT were all decreased with statistically significant difference (Z=68.500, 98.735, 93.235, 91.132, 109.162; P < 0.05). There was a positive correlation between the prognosis visual acuity and preoperative visual acuity (r=0.682,P < 0.05). However,there was no correlation between the prognosis vision and the degree of macular edema before treatment (r=0.078,P > 0.05). Before and 3, 6 months after treatment, BCVA was negatively correlated with CMT (r=0.491, 0.416, 0.386; P < 0.05), while there was no correlation in other time points (r=0.145, 0.217, 0.177; P > 0.05). Systemic adverse reactions and persistent intraocular pressure elevation, iatrogenic cataract, retinal detachment, retinal tear, endophthalmitis and ocular complications were never found in the follow-up period. ConclusionIntravitreal conbercept is a safe and effective approach for RVO,which can significantly improve visual acuity and reduce CMT.
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.
ObjectiveTo evaluate the spectral domain optical coherence tomography (SD-OCT) characteristics of polypoidal choroidal vasculopathy (PCV) and its correlation with the visual acuity after photodynamic therapy (PDT) combined with intravitreal ranibizumab. MethodsTwenty-six eyes of 26 patients with PCV diagnosed by indocyanine green angiography (ICGA) were enrolled in this study. All the patients were examined for best corrected visual acuity (BCVA), slit lamp microscope, SD-OCT, fundus fluorescein angiography (FFA) and ICGA before and 1, 3 months after treatment. The mean baseline BCVA was (31.46±16.87) letters, mean central retinal thickness (CRT) was (581.19±309.05) μm, and mean subfoveal choroidal thickness (SFCT) was (248.92±95.45) μm. Patients were divided into 2 groups according to the final visual improvement after 6 month of treatment: GR or sensitive Group (17 eyes) and PR or non-sensitive Group (9 eyes). GR group included 12 males and 5 females, with a mean age of (65.24±7.03) years, a mean CRT of (619.06±335.07) μm and a mean SFCT of (271.24±106.61) μm. There were 4 eyes with subretinal hemorrhage (SRH), 2 eyes with interface retinal fluid (IRF), 13 eyes with subretinal fluids (SRF) and 15 eyes with pigment epithelial detachment (PED). PR group included 8 males and 1female, with a mean age of (64.00±7.02) years, a mean CRT of (509.67±255.21) μm and a mean SFCT of (271.24±106.61) μm. There were 6 eyes with subretinal hemorrhage (SRH), 5 eyes with interface retinal fluid (IRF), 6 eyes with subretinal fluids (SRF) and 8 eyes with pigment epithelial detachment (PED). The difference of sex, age, CRT and SFCT between these two groups was not significant (P>0.05). The relationship of baseline SD-OCT and post-treatment BCVA was analyzed. ResultsOn 1, 2, 3, 6 months after treatment, the BCVA were (38.46±19.81), (40.04±20.80), (42.96±21.63), (43.77±20.91) letters respectively. On 6 months after treatment, the mean CRT in GR and PR group were (360.71±276.54), (341.44±193.68) μm respectively (P>0.05). 64.71% (11/17) eyes in GR group and 22.22% (2/9) eyes in PR group had a SFCT thicker than 263μm. The difference was statistical significant between two groups [odds ratio (OR):0.052, 95% confidence interval (CI):0.005-0.533; P=0.013]. Logistic regression analysis showed that existence of IRF (OR=9.375, 95% CI: 1.299-67.645; P=0.026) or SRH (OR=6.500, 95% CI: 1.094-38.633; P=0.040) at baseline was negative prognostic factor to treatment. ConclusionThick SFCT is a protective factor, however, existence of IRF or SRH at baseline is negative prognostic factor of final visual improvement.
ObjectiveTo determine the retinal nerve fiber layer thickness (RNFLT) of chronic progressive external ophthalmoplegia (CPEO) and kearns-sayre syndrome (KSS) patients using spectral-domain optical coherence tomography (SD-OCT) and to analyze the potential influence factors for RNFLT of these patients. Methods18 CPEO and 4 KSS (CPEO with retinitis pigmentosa and cardiac block) patients, all were muscle biopsy confirmed, were included in this study. There were 7 males and 15 females, the average age was (29.09±13.40) years, the average onset age was (16.4±10.7) years and the average disease duration was (11.30±7.30) years. All the patients underwent SD-OCT examination for the left eye, the peripapillary RNFL thickness was measured using the Spectralis 3.45 mm circle scan protocol. 8 quadrants were scanned including superior temporal (ST), temporal upper (TU), temporal lower (TL), inferior temporal (IT), inferior nasal (IN), nasal lower (NL), nasal upper (NU) and superior nasal (SN). The relationship between RNFLT and onset time, disease duration was analyzed by Pearson correlation analysis. ResultsThe average RNFLT of ST, TU, TL, IT, IN, NL, NU, SN in the 22 patients were (136.3±24.1), (85.4±25.7), (68.2±11.7), (128.2±28.7), (127.3±29.5), (66.7±16.8), (70.1±17.6) μm, respectively. The circumferential average RNFLT was (101.5±14.4) μm. There was no significant difference between the KSS group and CPEO group (P>0.05). The decrease of the circumferential RNFLT had no relationship with the onset age (r=-0.306, P=0.11), but a negative relationship with the disease course (r=-0.518, P=0.03). There were negative relationships between the disease course and RNFLT of 4 nasal quadrants (IN:r=-0.555, P=0.01, NL: r=-0.630, P=0.00, NU: r=-0.559, P=0.01, SN: r=-0.557, P=0.01). ConclusionThere is no difference in RNFLT of patients with CPEO and KSS. There is a negative relation between RNFLT (especially RNFLT of 4 nasal quadrants) and disease course.
ObjectiveTo observe the imaging features of branching vascular network (BVN) in polypoidal choroidal vasculopathy (PCV). MethodsEighty PCV patients (90 eyes) were enrolled in this study. The patients included 58 males and 22 females. The age was ranged from 49 to 85 years, with a mean age of 61.4 years. All the patients were examined for fundus photography, fundus fluorescein angiography (FFA), indocyanine green angiography (ICGA) and optical coherence tomography (OCT). The fibrovascular retinal pigment epithelium detachment (PED) was defined as a well-demarcated subretinal heterogeneous plaque with increasing fluorescence on FFA. The late lichenoid hyperfluorescent plaque was defined as a well-demarcated lichenoid hyperfluorescent plaque on late phase ICGA. The double-layer sign on OCT was defined as a wide range of shallow PED from Bruch membrane. ResultsBVN were found on early ICGA in 76 eyes among the 90 eyes (84.4%). Among these 76 eyes, 18 eyes (23.7%) demonstrated the subretinal reddish-orange branches corresponding to BVN. Fifty-six eyes (73.7%) demonstrated all or part of the BVN on early FFA. Three eyes (3.9%) demonstrated branching transmitted fluorescence corresponding to BVN throughout the FFA. Seventy-three eyes (96.1%) were manifested by occult choroidal vascularization on FFA, and 21 eyes (27.6%) of them were fibrovascular PED. Among the 76 eyes with BVN, all BVN appeared earlier than polypoidal lesions on ICGA. Polypoidal lesions located on the terminal of BVN in 62 eyes (81.6%). Sixty-nine eyes (90.8%) on ICGA demonstrated the late lichenoid hyperfluorescent plaque, whose area was equal to or greater than the area of BVN shown on early ICGA. Seventy-two eyes (94.7%) had the double-layer sign. Among these 72 eyes, 15 eyes (20.8%) had lumen-like structure within the double-layer sign. Sixty-five eyes (90.3%) had punctate and linear hyper-reflectance within the double-layer sign. Two eyes (2.8%) demonstrated a hyporeflective short segment and a gap of Bruch membrane on OCT corresponding to the origin of the BVN. Sixty-three eyes (87.5%) had an area of double-layer sign that matched the area of late lichenoid hyperfluorescent plaque on ICGA. ConclusionsBVN in PCV can be noted as reddish-orange branches on fundus examination. Most of the BVN are shown as early branching transmitted fluorescence but collectively an occult choroidal vascularization on FFA, as lichenoid hyperfluorescent plaque on late ICGA, and as double-layer sign on OCT whose area matches late lichenoid hyperfluorescent plaque.