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 preliminary application of intraoperative optical coherence tomography (iOCT) in vitreous retinal surgery and the influencing factors of the imaging quality. MethodsA retrospective case study. A total of 132 subjects were chosen in June 2015 and April 2016 in our hospital. All the subjects were taken vitreous retinal surgery and iOCT scanning. The patients included 46 males and 86 females, with an average age of 61.7 years. 111 cases had macular diseases and 21 cases had vitreous hemorrhage. Cases are divided into high myopia and non-high myopia group according to ocular axial length (AL), 28 eyes in high myopia group (AL≥26 mm),104 eyes in non-high myopia (AL<26 mm).The scanning time, image quality and eye conditions were observed during the operation. The discordance between surgeon microscope visualization of the pathology and the findings of the iOCT and the postoperative adverse reactions were also observed. ResultsThe iOCT images were identified in 124 of 132 subjects, while were not identified in 8 eyes. For the macular area morphology change, iOCT tips and surgeon judgment rate was inconsistent in 22 eyes (16.7%). For the operation guidance value, change the operation rate of 12/132,accounted for 9.1%. The iOCT imaging quality of high myopia groups was lower than the non-high myopia groups (χ2=17.13, P=0.001). Corneal edema and operation time were considered as influencing factors on the quality of the imaging in the non-high myopia groups (r=3.75, 6.18; P=0.049, 0.013). There were no complications such as endophthalmitis. ConclusionsThe surgeon can observe morphological changes in the macular area through iOCT which is difficult to be observed by operating microscope and selected reasonable operation method during the surgery. High myopia, corneal edema and operation time affect the image quality.
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.
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.
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.