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.
Acute zonal occult outer retinopathy (AZOOR) is an acquired retinal diseases. The majority of patients who develop AZOOR are women characterized by an acute onset of visual blurred and scotoma with photopsias. The fundus examination is often normal or appeared mild abnormal. The RPE atrophy of fundus is similar with white syndrome. Although FFA and ICGA features are either unremarkable or unrelated to AZOOR, there are still important in differential diagnosis. The characteristic abnormalities appearance of FAF (complicated and varied), OCT (regional anomaly of ellipsoid zone), visual field (visual field defect) and ERG (decreased amplitude and prolonged latency of rod reaction, maximum reaction, cone reaction and scintillation reaction) are considered critical examinations to the diagnosis of AZOOR. Although there is no effective therapy for AZOOR, it has some self-limitation.
ObjectiveTo investigate the change of subfoveal choroidal thickness (SFCT) and the relationship between SFCT and the severity of the diabetic retinopathy using enhanced depth imaging optical coherence tomography (EDI-OCT). MethodsA total of 164 eyes (93 patients) of type 2 diabetes mellitus (DM) were included in this study. The patients included 34 males and 59 females, with an average age of (59.3±5.6) years, with an average diabetes duration of (5.11±4.64) years. The patients were divided into 4 groups according to international classification standards of DR, including non-diabetic retinopathy (NDR) group (64 eyes), mild non-proliferative diabetic retinopathy (NPDR) group (33 eyes), moderate NPDR group (37 eyes), and severe NPDR group (30 eyes). The control group included 25 normal subjects (42 eyes). All patients underwent visual acuity, intraocular pressure, slit lamp microscope, indirect ophthalmoscope, A/B-type ultrasound scan, frequency domain optical coherence tomography (SD-OCT) examination, as well as fasting blood glucose and mean arterial blood pressure measurement. The mean axial length was (23.04±0.78) mm, mean fasting blood glucose was (8.88±2.59) mmol/L, mean arterial pressure was (100.44±9.63) mmHg. SFCT of all eyes were measured by EDI-OCT. The relationship between SFCT and the severity of the diabetic retinopathy, DM duration, fasting blood glucose, the mean arterial pressure, axial length was analyzed by one-way ANOVA. ResultsThe mean SFCT was (224.24±42.10) μm in DM group and (276.77±48.07) μm in normal control group, the difference was statistically significant (F=23.86, P < 0.05). The mean SFCT was also statistically significant between all DM groups (P < 0.05). There were negative linear correlation between SFCT of all patients and the severity of retinal lesions (r=-0.555, P=0.000), and between SFCT and DM duration (r=-0.332, P < 0.05). But SFCT was independent of fasting plasma glucose (r=-0.123, P > 0.05), mean arterial pressure (r=-0.116, P > 0.05), and axial length (r=-0.018, P > 0.05). ConclusionsSFCT in DM eyes is thinner than that in normal controls. SFCT is different in the NDR, mild NPDR, moderate NPDR, severe NPDR patient. Severe DR patients have much thinner SFCT.
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 image features of high myopia with retinoschisis by spectraldomain optical coherence tomography (SD-OCT). Methods The clinical data of eight patients (eight eyes) of high myopia with retinoschisis were retrospective analyzed. All patients were diagnosed by SD-OCT (Topcon 3D-OCT 1000), had no macular holes and underwent vitrectomy including internal limiting membrane (ILM) peeling and gas tamponade. All patients also underwent visual acuity, refraction, premirror fundus examination and A/B mode ultrasound examination. Visual acuity and SD-OCT were followed up at one, three and six months after surgery. Before surgery, premirror fundus examination revealed shallow foveal detachment in 3/8 eyes, posterior scleral staphyloma in 7/8 eyes. SD-OCT showed concave arc stripes in 7/8 eyes, and outer retinoschisis in 8/8 eyes, middle or inner retinoschisis in 5/8 eyes and foveal detachment in 5/8 eyes. Results Six months after surgery, posterior retinoschisis disappeared in six eyes, foveal detachment still presented in one eye and parafoveal hole occurred in one eye. The corrected visual acuity improved from the 0.15 to 0.8 in one eye which had a restored continuous inner segment/outer segmen (IS/OS) line by SD-OCT. The corrected visual acuity improved from 0.01 to 0.1 in one eye, from 0.05 to 0.15 in one eye, not changed in five eyes. There was no continuous IS/OS line in those patients by SD-OCT. Conclusions SD-OCT shows a variety of morphological features of myopic retinoschisis which could be cured anatomically and functionally by vitrectomy combined ILM peeling. The continuity of IS/OS layer from SD-OCT could help to interpret the vision recovery after the operation.
Objective To observe the imaging features of ultra-wide field short wave fundus autofluorescence (SW-FAF) in eyes with multiple evanescent white dot syndrome (MEWDS), and analysis the correspondence to conventional images. Methods It was a retrospective case series study. Thirteen patients (14 eyes) diagnosed with MEWDS were enrolled. There were 12 females and 1 male, aged from 22 to 57 years, mean age was 34.5 years. All the eyes underwent fundus color photography, optical coherence tomography (OCT) and ultra-wide field autofluorescence (FAF). Simultaneous fundus fluorescein angiography (FFA) and indocyanine green angiography (ICGA) were performed in 6 eyes. The characteristic changes of SW-FAF in studied eyes were observed and compared with the images of FFA and ICGA. All the eyes were followed up every 1 to 2 weeks, with an average of 16.7 weeks. The characteristic images of SW-FAF and corresponding OCT were studied during follow up. Results MEWDS presented with numerous multiple hyper-autofluorescent spots, sized from 50-500 μm, with a vague boundary in ultra-wide field SW-FAF. These spots located mainly at the peripapillary area and the posterior pole with a confluent pattern. The lesions extended to the mid-peripheral retina as well and became more scattered. The distribution of the hyper-autofluorescent lesions in SW-FAF corresponded roughly to that of the greyish-white spots seen in color photograph and the hyper-fluorescent spots detected by FFA. It was consistent with the distribution of hypo-fluorescent spots in late-phase ICGA as well. But the number of the spot showed in FAF is much more than that in FFA, and slightly less than that in ICGA. The OCT scans through the hyper-autofluorescent lesions in SW-FAF showed impairment of outer retina. After the recovery, the hyper-autofluorescent spots disappeared with the outer retina structure repaired completely. Conclusions MEWDS presented with numerous multiple hyper-autofluorescent spots which located mainly at the peripapillary area in ultra-wide field SW-FAF. The distribution of the hyper-autofluorescent lesions in SW-FAF corresponded roughly to color photograph, FFA and ICGA in late-phase. The OCT scans through the hyper-autofluorescent lesions in SW-FAF showed impairment of outer retina.
Peripapillary intrachoroidal cavitation (PICC) is a common pathological change observed in high myopia. The exact pathogenesis of PICC is still unclear. Expansion and mechanical stretching of the peripapillary sclera, breakage and defect in the retina near the border of the myopic conus and communication between intrachoroidal cavity and the vitreous space may be important segments during the development of PICC. Color fundus photography shows a localized and well-circumscribed peripapillary lesion with yellow-orange colour, often accompanied by fundus changes, such as myopic conus excavation, optic disc tilting and inferotemporal retinal vein bending at the transition from the PICC to the myopic conus. However, the PICC lesion is not easy to be recognized in the fundus photography. Fluorescein angiography shows early hypofluorescence and later progressively staining in the lesion. Indocyanine green angiography shows hypofluorescence throughout the examination. Optical coherence tomography (OCT) is vital in diagnosing PICC. Hyporeflective cavities inside the choroid, sometimes communicating with the vitreous chamber, can be observed in OCT images. OCT angiography indicates lower vessel density or even absence of choriocapillary network inside or around PICC lesions.
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.
ObjectiveTo observe the changes in choroidal thickness in type 2 diabetes patients with diabetic retinopathy (DR). MethodsA total of 227 eyes from 150 type 2 diabetes patients were enrolled in this study. The patients included 67 males (89 eyes) and 83 females (138 eyes). The mean age was (65.6±8.0) years, and the mean diabetes duration was (12.4±6.5) years. All the patients were examined for best corrected visual acuity (BCVA), diopter, slit lamp ophthalmoscopy, indirect ophthalmoscopy and spectral domain optical coherence tomography (SD-OCT) examination. The patients were divided into non-DR (NDR group, 99 eyes), non-proliferative DR (PDR) without macular edema (ME) group (NPDR/ME-group, 64 eyes), non-PDR with ME group (NPDR/ME+ group, 5 eyes), PDR without ME group (PDR/ME-group, 25 eyes), PDR with ME group (PDR/ME+ group, 5 eyes) according to the Early Treatment Diabetic Retinopathy Study. The ones having a history of pan-retinal photocoagulation (PRP) were classified as PRP-DR. Age-matched normal subjects were enrolled as the control group. Sub-foveal choroidal thickness (SFCT) was measured by SD-OCT with enhanced depth imaging (EDI). ResultsMean SFCT was (310.2±54.8), (251.1±81.4), (262.5±83.2), (286.2±76.8) and (327.4±83.1) μm respectively in control, NDR, NPDR/ME-, PDR/ME-and PRP-DR groups. Mean SFCT decreased significantly in NDR and NPDR/ME-group (t=2.754, 2.140; P < 0.05). Mean SFCT in PDR/ME-group was thicker than that in NDR (t=-2.114, P < 0.05). Mean SFCT in PRP-DR group was thicker than that in PDR/ME-group (U=271.500, P < 0.05). ConclusionSFCT decreased during the early course of diabetics and increased significantly as the severity worsened from NDR to PDR, and increased in the early duration after PRP treatment.
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.