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.
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 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.
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 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 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.
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 choroidal thickness and its relationship with age and refraction status in Chinese population. Methods 180 healthy volunteers (360 eyes) were enrolled in this study. Based on the age, the volunteers were divided into A (20-29 years old), B (30-39 year old), C (40-49 years old), D (50-59 year old), E (60-69 year old), and F (70-85 year old) group, with 33, 31, 29, 30, 31, 26 volunteers respectively. And the volunteers were divided into ＜60 years old group with 123 volunteers and ge; 60 years old group with 57 volunteers. Enhanced depth imaging (EDI) choroidal scans were obtained in all eyes by using spectraldomain optical coherence tomography. Subfoveal choroidal thickness (CT) and CT at 1 mm/3 mm temporal, nasal, superior, inferior to the fovea (S 1 mm, I1 mm, T1 mm, N 1 mm, S, I3 mm, T3 mm, N3 mm) were measured. The differences of CT between different quadrants, genders, eyes and ages were comparatively analyzed. The correlations between age, refraction status and CT in the volunteers of ＜60 years old and ge; 60 years old group were analyzed. Results The subfoveal CT was (262.78plusmn;84.38) mu;m. The differences were significant between subfoveal CT and all the quadrants CT (P＜0.05) except for S1 mm and T1 mm (P＞0.05 ). There was no difference between genders or eyes in subfoveal CT (P＞0.05 ). There was no difference between A, B, C, D group in subfoveal CT (P＞0.05 ). The subfoveal CT of E and F group were thinner than A, B, C, D group (P＜0.05). In the ＜60 years old group, there was a positive correlation between refraction status and CT (r=0.147,P＜0.05); but no correlation between age and CT (r=－0.055, P＞0.05 ). In the ge; 60 years old group, there was a significant negative correlation between CT and age (r=－0.543, P＜0.05), but no correlation between refraction status and CT (r=-0.008, P＞0.05). Conclusions The average subfoveal CT in Chinese population was (262.78plusmn;84.38) mu;m. The refraction status is the main influence factors in subjects ＜60 years old, while the age is the main influence factors in subjects ge;60 years old.
The abnormalities of retinal vessels such as retinal arteriolar narrowing, arteriovenous nicking, micro-aneurysms, retinal hemorrhages, and cotton wool spot are closely related to systemic diseases including hypertension, diabetes mellitus, cardiovascular disorders, stroke and renal diseases. The modern retinal vessels examination technology has features of quick noninvasive, quantitative standardized and intelligent analysis. Taking advantage of these to fully discover the retinal vascular abnormalities and get deeper understanding of the relationship between its' mechanism and systemic vascular diseases is not only helpful to better diagnose and treat retinal vascular diseases, but also contributes to predicting the risk and prognosis of systemic diseases. We suggest emphasizing on the study of correlation between retinal vascular abnormalities and systemic vascular diseases using modern retinal vessels examination technology. It will provide the preventive clue of diseases of circulatory system by finding out the retinopathy. Meanwhile, correctly treating systemic diseases would get a better prognosis of the retinopathy. They exist side by side and play a part together for providing a better prognosis, which would be a new direction for the doctors and scientists in the new era.