Peripapillary hyperreflective ovoid mass-like structures: multimodal imaging and associated diseases.

Growing evidence has demonstrated that peripapillary hyperreflective ovoid mass-like structures (PHOMS) are novel structures rather than a subtype of optic disc drusen. They correspond to the laterally bulging herniation of optic nerve fibers and are believed to be the marker of axoplasmic stasis. PHOMS present in a broad spectrum of diseases, including optic disc drusen, tilted disc syndrome, papilloedema, multiple sclerosis, non-arteritic anterior ischemic optic neuropathy, optic neuritis, Leber hereditary optic neuropathy, and so on. We focus on the multimodal imaging features, pathophysiological mechanisms of PHOMS, and their association with multiple diseases and healthy people in this review to deepen the ophthalmologists' understanding of PHOMS. Additionally, we provide some new directions for future research.

Assessment of retinal and choroidal microcirculation after unilateral recession-resection surgery for horizontal strabismus by swept-source optical coherence tomography angiography.

This study explored the possible hemodynamic changes of the retina and choroid after horizontal strabismus surgery using swept-source optical coherence tomography angiography (SS-OCTA). 32 eyes of 32 patients who underwent unilateral horizontal rectus muscle recession-resection surgery were included. SS-OCTA examinations were performed preoperatively and one week postoperatively. Several OCTA measurements were used, including vessel density (VD) of the superficial vascular complex (SVC), VD of the deep vascular complex (DVC), VD of the choriocapillaris (CC), choroidal vascular index (CVI) and choroidal thickness (CT). No significant change in VD of SVC, DVC, and CC was observed whereas CT increased significantly with CVI unchanged. Recession-resection surgery for horizontal strabismus seemed not to significantly influence the microcirculation of the retina and CC in the early postoperative period. However, choroidal thickening happened with a constant CVI probably due to the postoperative inflammation. Further studies are needed to investigate the long-term effects of unilateral recession-resection surgery for horizontal strabismus on the microcirculation of the retina and choroid.

Changes in retinal and choroidal blood flow after one or two horizontal rectus muscle surgeries by optical coherence tomography angiography.

PURPOSE: To evaluate the retinal and choroidal microvasculature after one or two horizontal rectus muscle surgeries in strabismus patients using swept-source optical coherence tomography angiography (SS-OCTA). METHODS: 30 eyes of 26 patients who underwent horizontal rectus muscle surgery were included in this study. Group A, A' and Group B , B' respectively consisted preoperative and postoperative measurements of patients who underwent one or two horizontal rectus muscle surgeries. We analyzed the vessel density (VD) of the superficial vascular complex (SVC), the deep vascular complex (DVC), the choriocapillary layer (CC), choroidal vascular index (CVI), choroidal thickness (T-Ch) and retinal nerve fiber layer thickness (T-RNFL) preoperatively, and one week postoperatively. RESULTS: Only in the nasal sector of the perifoveal zone, the VD in SVC demonstrated a significant increase in Group A' (p = 0.027). There was a statistically significant difference in the VD changes of SVC between Group A and Group B (p = 0.043). The VD in DVC did not change significantly in the whole macular compared with the preoperative. Moreover, in both Group A' and Group B', the VD in CC showed a reduction in a single sector of the parafoveal area (p < 0.05). Group A' have increased CVI in the nasal sector of the perifoveal region (p = 0.008). In addition, the T-Ch increase in the perifoveal region was more significant in Group B' than in Group A' (p < 0.05). Group A' showed statistically significant decreases in T-RNFL in the foveal and parafoveal regions (p < 0.05). CONCLUSION: This study revealed that the increase in choroidal thickness was more significant after two rectus muscle surgery. In addition, there were microvascular changes in sectional macular regions after strabismus surgery. OCTA is an excellent way to study the impact of strabismus surgery on the macular structure and blood flow.

We used SS-OCTA, which provided more objective and accurate measurements, to assess macular vessel density and thickness of retinal and choroid after one or two horizontal rectus muscle surgeries.

Role of artesunate in autoimmune diseases and signaling pathways.

Artesunate (ART) is a derivative of artemisinin. Compared with artemisinin, ART has excellent water solubility, high stability and oral bioavailability. In this review, the application of ART in classic autoimmune diseases such as rheumatoid arthritis, systemic lupus erythematosus and ulcerative colitis is summarized. ART exhibited similar or even better efficacy than other highly effective immunosuppressive agents, such as methotrexate and cyclophosphamide. In addition, ART exerts its pharmacological effects mainly by inhibiting the production of inflammatory factors, reactive oxygen species, autoantibodies and the migration of cells to reduce damage to tissues or organs. Moreover, ART widely affected the NF-κB, PI3K/Akt, JAK/STAT and MAPK pathways to exert pharmacological effects.

A medicine called artesunate (ART), which comes from a plant, is sometimes used to treat malaria. It was first introduced by Chinese scientist Tu Youyou, who won the Nobel Prize in medicine. Autoimmune diseases (ADs) occur when the body's immune system attacks its own cells. ART has shown promise in treating ADs. ART works as well as, or even better than, other normal medicines used for ADs. ART can act in many ways and could be a promising medicine for the treatment of ADs.

Time-dependent recurrence and resolution of pigment epithelial detachment in central serous chorioretinopathy.

BACKGROUND: Cortisol plays a role in the pathogenesis of central serous chorioretinopathy (CSC). CSC patients have abnormal time-dependent changes in cortisol levels. Here we report a rare case of a patient with central serous chorioretinopathy whose pigment epithelial detachment (PED) exhibited time-dependent recurrence and resolution. CASE PRESENTATION: A 47-year-old man presented in 2016 for vision loss in the left eye related to recurrent CSC. During follow-up, his PED was observed to resolve spontaneously while he was still in our clinic and recurred the next morning. Such time-dependent changes of the PED were observed in several next follow-ups without any intervention. After excluding possible external factors, the abnormal diurnal variation of cortisol was considered as the internal factor affecting PED. CONCLUSIONS: This is the first article that described the spontaneous time-dependent recurrence and resolution of PED without external interference, where endogenous cortisol may be responsible. Interventions against the abnormal cortisol level might be a potential treatment strategy for CSC. More research is urged to explore the impact of the diurnal change in cortisol levels on eyes with CSC.

The Roles of Carbon Trading System and Sustainable Energy Strategies in Reducing Carbon Emissions-An Empirical Study in China with Panel Data.

Carbon emission reduction is now a vital element in urban development. This study explores the effectiveness of the two emerging methods to reduce carbon emission, which are carbon emissions trading system (ETS) and sustainable energy strategy, in the process of urbanization. We review the policy in the past decades to demonstrate the development of these two streams of carbon emission reduction methods and empirically test the effectiveness of the two methods with panel data across 30 provinces in China from 2009 to 2019. The sustainable energy strategy is confirmed to be effective in reducing carbon emissions in the region, while the effectiveness of carbon emissions trading system varies. We find that (1) substituting fossil fuel with other sustainable energy resources can effectively reduce the carbon emission; (2) the rewards from carbon emissions trading is a good incentive for the enterprises to reduce the carbon emissions; however, it is more tempting in the provinces that have the carbon emissions trading system, although the trading can be conducted across the province boarder. Our findings indicate that the sustainable energy strategy is a good practice and worth expanding to the whole country. It can be difficult for some provinces to transform and adopt the sustainable energy strategy if the fossil fuel is the major source for economic production. It is important to avoid setting fossil fuel as the main source for economic production or household consumption in the urbanization process. Meanwhile the carbon emissions trading system is found to contribute to CO2 emissions reduction only within the province. Therefore, having more provinces piloting the ETS will help the CO2 emission reduction further.

PRIMARY MULTIPLE EVANESCENT WHITE DOT SYNDROME AND MULTIPLE EVANESCENT WHITE DOT SYNDROME SECONDARY TO MULTIFOCAL CHOROIDITIS/PUNCTATE INNER CHOROIDOPATHY: A Comparative Study.

PURPOSE: To present and compare the clinical features and multimodal imaging (MMI) findings of the primary form of multiple evanescent white dot syndrome (MEWDS) and MEWDS secondary to multifocal choroiditis/punctate inner choroidopathy (MFC/PIC). METHODS: A prospective case series. Thirty eyes of 30 MEWDS patients were included and divided into the primary MEWDS group and MEWDS secondary to MFC/PIC group. Demographic, epidemiologic, and clinical characteristics and MEWDS-related MMI findings of the two groups were compared. RESULTS: Seventeen eyes from 17 patients with primary MEWDS and 13 eyes from 13 patients with MEWDS secondary to MFC/PIC were evaluated. Patients with MEWDS secondary to MFC/PIC tended to have a higher degree of myopia than those with primary MEWDS. No other significant differences in demographic, epidemiologic, and clinical characteristics and MMI findings were found between the two groups. CONCLUSION: "MEWDS-like reaction" hypothesis seems to be correct for MEWDS secondary to MFC/PIC, and the authors highlight the importance of MMI examinations in MEWDS. Further research is needed to confirm whether the hypothesis is applicable to other forms of secondary MEWDS.

Promoting Molecular Exchange on Rare-Earth Oxycarbonate Surfaces to Catalyze the Water-Gas Shift Reaction.

It is highly desirable to fabricate an accessible catalyst surface that can efficiently activate reactants and desorb products to promote the local surface reaction equilibrium in heterogeneous catalysis. Herein, rare-earth oxycarbonates (Ln2O2CO3, where Ln = La and Sm), which have molecular-exchangeable (H2O and CO2) surface structures according to the ordered layered arrangement of Ln2O22+ and CO32- ions, are unearthed. On this basis, a series of Ln2O2CO3-supported Cu catalysts are prepared through the deposition precipitation method, which provides excellent catalytic activity and stability for the water-gas shift (WGS) reaction. Density functional theory calculations combined with systematic experimental characterizations verify that H2O spontaneously dissociates on the surface of Ln2O2CO3 to form hydroxyl by eliminating the carbonate through the release of CO2. This interchange efficiently promotes the WGS reaction equilibrium shift on the local surface and prevents the carbonate accumulation from hindering the active sites. The discovery of the unique layered structure provides a so-called "self-cleaning" active surface for the WGS reaction and opens new perspectives about the application of rare-earth oxycarbonate nanomaterials in C1 chemistry.

Retinal arterial macroaneurysm rupture by Valsalva maneuver: a case report and literature review.

BACKGROUND: Retinal artery macroaneurysms (RAMs) are focal dilations of the large retinal arteries. Most RAMs are asymptomatic, however, when hemorrhage or exudation caused by a RAM involves the macula, patients can experience marked vision loss. This article reported a rare case of a ruptured RAM due to the Valsalva maneuver in an elderly female with constipation and offered a review of the relevant literature. CASE PRESENTATION: A 78-year-old woman with several risk factors presented with multi-level retinal hemorrhages following a Valsalva maneuver during constipation. Due to the poor coagulation and heavy bleeding in this case, the blood broke through the internal limiting membrane and drained "on its own" into the vitreous cavity. First, we observed the patient and controlled for her risk factors. After the blood was completely drained into the vitreous cavity, the root cause of the bleeding was found to be a RAM rupture. After laser photocoagulation, the patient's vision recovered significantly and remained stable for a long time despite the presence of an epiretinal membrane and a lamellar macular hole. CONCLUSIONS: This is the first reported case of a RAM rupture by Valsalva maneuver during constipation. For multi-level hemorrhages caused by RAM, measures should be taken to drain out the sub-internal limiting membrane hemorrhage and simultaneously control for risk factors. After the RAM is exposed, laser photocoagulation can be performed.

Wide-field OCT-angiography assessment of choroidal thickness and choriocapillaris in eyes with central serous chorioretinopathy.

Purpose: To assess wide-field changes in choroidal thickness and choriocapillaris in eyes with central serous chorioretinopathy (CSC) compared with the fellow eyes and eyes from healthy individuals using wide-field swept-source (SS) OCT-Angiography (OCTA). Methods: A cross-sectional study in which 68 eyes from 34 individual patients affected by unilateral CSC and 32 eyes of 32 age- and sex-matched healthy subjects were evaluated. All subjects underwent wide-field SS-OCTA examination to quantify choroidal thickness and vascular density of the choriocapillaris. To assess the wide-field changes, we developed five 4-by-4 mm square regions located in the posterior pole and in the four quadrants of the peripheral retina (superotemporal, inferotemporal, superonasal, and inferonasal subfields, respectively). Results: The choroidal thickness of eyes with CSC was greater than that of the fellow eyes in the central and inferonasal subfields (p < 0.001 for the central subfield and p = 0.006 for the inferonasal subfield, respectively). Compared with the choroidal thickness of healthy eyes, that of patients with CSC were significantly greater in all the subfields (p < 0.05 for the fellow eyes and p < 0.05 for eyes with CSC, respectively). Compared with that of healthy eyes, the vascular density of choriocapillaris in eyes of patients with CSC were significantly greater in the central and superotemporal subfields (p < 0.05 for the fellow eyes and p < 0.05 for eyes with CSC, respectively). In the central region, the vascular density of choriocapillaris of the fellow eyes was greater than eyes with CSC (p = 0.023). Conclusion: CSC appears to be a bilateral disease with asymmetric manifestations. Local factors of the diseased eyes may play an important role in the development of CSC, during which dynamic and regional changes in the choriocapillaris may have happened. Wide-field swept-source OCTA provided a useful tool to study the pathogenesis of CSC.

Enhanced Visualization of Retinal Microvasculature via Deep Learning on OCTA Image Quality.

PURPOSE: To investigate the impact of denoising on the qualitative and quantitative parameters of optical coherence tomography angiography (OCTA) images of the optic nerve and macular area. METHODS: OCTA images of the optic nerve and macular area were obtained using a Canon-HS100 OCT device for 48 participants (48 eyes). Multiple image averaging (MIA) and denoising techniques were used to improve the quality of the OCTA images. The peak signal-to-noise ratio (PSNR) as an image quality parameter and vessel density (VD) as a quantitative parameter were obtained from single-scan, MIA, and denoised OCTA images. The parameters were compared, and the correlation was analyzed between different imaging protocols. RESULTS: In the optic nerve area, there were significant differences in the PSNR and VD in all measured regions between the three groups (P < 0.0001). The PSNR of the denoised group was significantly higher than that of the other two groups (P < 0.0001). The VD in the denoised group was significantly lower than that in the single-scan group in all measured regions (P < 0.0001). In the macular area, there were significant differences in the PSNR and VD in all measured regions among the three groups. The PSNR of the denoised group was significantly higher than that of the other two groups (P < 0.0001). The VD in the denoised group was significantly lower than that in the single-scan group in all measured regions. The VD around the optic nerve in the denoised group was correlated with that in the single-scan group (R = 0.9403, P < 0.0001), but the VD in the MIA group was not correlated with that in the single-scan group (R = 0.2505, P = 0.2076). The VD around the fovea in the denoised and MIA images was correlated with that in the single-scan group (R = 0.7377, P < 0.0001; R = 0.7005, P = 0.0004, respectively). CONCLUSION: Denoising could provide an easy and quick way to improve image quality parameters, such as PSNR. It shows great potential in improving the sensitivity of OCTA images as retinal disease markers.

Retina Vascular Perfusion Dynamics During Exercise With and Without Face Masks in Healthy Young Adults: An OCT Angiography Study.

Purpose: To determine possible impacts on retinal microvasculature in healthy young adults during exercise with a face mask, using optical coherence tomography angiography (OCTA). Methods: Twenty-three healthy participants (23 eyes, 17 women and 6 men) performed the incremental continuous running test (ICRT) with different masks. OCTA of the macula and optic nerve head were performed before and after ICRT to detect changes in retinal vessel density (VD). All participants were in groups A, B, and C (before ICRT) and groups A', B', and C' (after ICRT), which comprised data from volunteers without a mask, with a surgical mask, and with an N95 mask, respectively. Results: Before ICRT, group C showed significantly reduced VD in the superficial plexus (SP), except foveal VD, compared with group A (P < 0.05). After ICRT, groups B' and C' showed significantly shorter maximum running time, lower oxygen saturation, and lower perifoveal VD of SP compared with group A' (P < 0.05). Conclusions: Use of an N95 mask reduced VD in SP even under quiescent conditions, which might have clinical implications for protecting healthy workers and indoor manual labor workers from potential risks of retinal damage due to long-term mask use. Moreover, mask use while exercising might lead to attenuated exercise ability and lower VD in SP, which should be investigated in additional studies. Translational Relevance: Retina vascular perfusion dynamics could be monitored in vivo by OCTA, which would be valuable to study physiologic retinal blood flow redistribution and potential impacts on retinal vascular perfusion during exercise with face masks.

Retinal Microvascular Changes in Hypertensive Patients with Different Levels of Blood Pressure Control and without Hypertensive Retinopathy.

PURPOSE: To determine possible correlations between different levels of blood pressure (BP) control and retinal microvascular changes in the macula and optic nerve head, using coherence tomography angiography (OCTA) in hypertensive patients without hypertensive retinopathy. METHODS: This was an observational, cross-sectional study. Seventy-three patients and 40 healthy volunteers were included in this study. The patients and volunteers were divided into four groups and from each participant one eye was selected randomly: Group A comprised 32 hypertensive patients with intensive BP control; Group B comprised 26 hypertensive patients with standard BP control; Group C comprised 15 hypertensive patients with poor BP control; Group D comprised 40 control subjects. 6 × 6 mm macula scan and 4.5 × 4.5 mm optic nerve head scan were obtained using OCTA. RESULTS: In macula scans, most measured regions of retinal VD showed significant reduction in group C, compared to groups A, B, and D (all P < .05). Partial measured regions of retinal VD were significantly lower in group B than groups A and D (all P < .05). In ONH scans, RNFL thickness and inside disc capillary density were significantly thinner and lower in groups B and C than in group D (all P < .05). SBP was significantly correlated with RNFL thickness (R = 0.430, 95% CI -0.583 to -0.201, P ≤ 0.001). CONCLUSIONS: We demonstrated that the frequency of OCTA follow-up may improve detection of reduced retinal VD, thus avoiding further retinal damage in hypertensive patients; however, the clinical implications of this finding deserve further study. Moreover, further exploration is needed regarding the implication that reduced SBP may be beneficial for lowering the risk of glaucoma.

Correction to: Assessment of choriocapillary blood flow changes in response to half-dose photodynamic therapy in chronic central serous chorioretinopathy using optical coherence tomography angiography.

An amendment to this paper has been published and can be accessed via the original article.

Assessment of choriocapillary blood flow changes in response to half-dose photodynamic therapy in chronic central serous chorioretinopathy using optical coherence tomography angiography.

BACKGROUND: Optical coherence tomography angiography (OCTA) is a newly developed imaging quantitative technique for analysis of choriocapillaris (CC) flow changes, thereby exploring the pathological mechanism of chronic central serous chorioretinopathy (CCSC) and the therapeutic effects of photodynamic therapy (PDT). In this study, we sought to quantify the blood flow changes in CC of CCSC patients receiving half-dose PDT using OCTA. METHODS: A total of 28 affected eyes and 24 unaffected eyes of 26 CCSC patients receiving half-dose PDT, and 40 eyes of 20 healthy gender- and age-matched subjects were retrospectively enrolled in this study. The proportion of total areas of flow signal voids (FSV, %) in CC level of OCTA was assessed in both eyes of the CCSC patients at baseline and repeated in multiple sections at 1-week, 1-month, 3-month and 6-month intervals after PDT. In addition, the CC patterns in response to PDT at early stage and the subsequent morphologic changes were qualitatively documented using OCTA. RESULTS: For affected eyes, FSV at 6-m follow-up was significantly lower than that at 1-m follow-up (p = 0.036). When compared to normal control eyes, FSV in affected eyes was significantly higher at 1-m, 3-m and 6-m follow-up (p < 0.05 for all), and FSV in unaffected eyes was significantly higher at baseline, 1-w, 1-m and 3-m follow-up (p < 0.05 for all). Three CC patterns of early response to PDT were identified, including signs of recovery with more even flow signals, transient appearance of worse ischemia and secondary neovascularization within CC level. CONCLUSION: Abnormal CC flow attenuation remains in completely resolved eyes of CCSC patients treated with half-dose PDT.

Use of optical coherence tomography angiography for assessment of microvascular changes in the macula and optic nerve head in hypertensive patients without hypertensive retinopathy.

PURPOSE: To compare optical coherence tomography angiography (OCTA) screening parameters of the macula and optic nerve head (ONH) between healthy volunteers and chronic hypertensive patients without hypertensive retinopathy. METHODS: This was an observational, cross-sectional study. Fifty-seven chronic hypertensive patients without hypertensive retinopathy (22 men and 35 women) and 40 healthy volunteers (17 men and 23 women), ranging in age from 60 to 70 years, were included in this study. Patients and volunteers were divided into three groups and one eye was selected randomly from each participant. Group A comprised patients who had a history of hypertension for >10 years (n = 35); Group B comprised patients who had a history of hypertension for 5-10 years (n = 22); and Group C comprised 40 healthy volunteers who had no history of hypertension. A 3 × 3-mm macula scan and a 4.5 × 4.5-mm ONH scan were performed in each group by OCTA using prototype AngioVue software within the AngioVue device. Vessel density (VD), foveal avascular zone (FAZ) area, choriocapillaris flow area, ONH capillary density, retinal nerve fiber layer (RNFL) thickness, and demographic information were compared among the groups. RESULTS: Macula scans showed that superficial plexus VD was significantly lower in groups A and B than in group C (P < 0.05). In addition, FAZ area was significantly larger in group A than in group C (P < 0.05). Inner retinal layer thickness was significantly thinner in groups A and B than in group C (P < 0.05). In ONH scans, RNFL thickness was significantly thinner in group A than in groups B and C (P < 0.05); it was significantly thinner in group B than in group C (P < 0.05). Inside disc capillary density and peripapillary capillary density were significantly lower (P < 0.05) and greater (P < 0.05), respectively, in groups A and B than in group C. CONCLUSIONS: Superficial plexus VD, FAZ area, capillary density, and inner retinal thickness changed significantly in hypertensive patients without hypertensive retinopathy. However, only RNFL thickness was significantly thinner in patients who had >10 years of hypertension, compared to patients who had 5-10 years of hypertension. In addition, OCTA provided a method to prospectively assess changes in retinal microvasculature and thickness, thereby avoiding further long-term retinal damage in hypertensive patients.

Effect of Photodynamic Therapy on Optical Coherence Tomography Angiography in Eyes with Chronic Central Serous Chorioretinopathy.

PURPOSE: To analyze the use of optical coherence tomography angiography (OCTA) in order to observe the changes in chronic central serous chorioretinopathy (CCSC) after half-dose photodynamic therapy (PDT). METHODS: This is a retrospective study evaluating an imaging technique in a cohort of patients. Fundus photography, fluorescein angiography (FA), indocyanine green angiography (ICGA) (Heidelberg Spectralis, Heidelberg, Germany), OCT, and OCTA with the split-spectrum amplitude-decorrelation angiography algorithm (XR Optovue, Fremont, CA, USA) were performed prior to half-dose PDT. OCT and OCTA were conducted at week 1, month 1, month 2, and month 3 after half-dose PDT. RESULTS: A total of 33 eyes of 28 patients were enrolled in the study. At the baseline assessment, the patient pool had a mean best-correct visual acuity of logMAR 0.29 ± 0.34 and the mean choroidal thickness was 407.45 ± 77.98 µm. At month 3 after PDT, the patient pool had a mean best-correct visual acuity of logMAR 0.1 ± 0.17 and the mean choroidal thickness was 355.48 ± 67.90 µm. Abnormal flow in the choriocapillary, which corresponded to the initial examinations using OCTA, was observed in all 33 eyes (100%). The images show an irregular high pixel values interval from low pixel values. At week 1 after half-dose PDT, 25 eyes (75.8%) resembled the baseline images of the choriocapillary layer of OCTA. Areas of nonperfusion in the choriocapillary were observed in 5 eyes (15.2%), and vessel-like material in the choriocapillary was observed in 3 eyes (9.0%). At month 3 after PDT, the choriocapillary layer of OCTA was shown to return to normal in 32 eyes (97%). CONCLUSIONS: We have detected choriocapillary changes in patients diagnosed with CCSC following half-dose PDT by using noninvasive OCTA. These findings provide new evidence in support of the previously proposed hypothesis on the effect of PDT and suggest that OCTA may become a useful tool in the follow-up of CCSC.