Laser photocoagulation of a hypofluorescent perifoveal exudative vascular anomalous complex/capillary macroaneurysm.

PURPOSE: To report successful treatment of a hypofluorescent perifoveal exudative vascular anomalous complex (PEVAC)/capillary macroaneurysm. CASE DESCRIPTION: A 63 year old healthy gentleman had a perifoveal isolated aneurysmal lesion with white rim. Optical coherence tomography (OCT) showed cystoid macular edema (CME) with neurosensory detachment. The aneurysmal lesion was seen in the inner retina as a hyperreflective intraretinal structure with a heterogenous lumen suggestive of PEVAC/capillary macroaneurysm. OCT angiography showed a capillary loop and a slightly hyperreflective lesion at the tip of the loop in the superficial capillary plexus slab. Minimal reduction in edema was noted following one dose of intravitreal triamcinolone (2 mg). Fundus fluorescein angiography performed at 6 weeks demonstrated the capillary loop, but the aneurysmal lesion remained hypofluorescent with no definite leak in the late phase. Few perifoveal microaneurysms were seen in both the eyes. Six weeks later, focal laser photocoagulation of the aneurysmal lesion was performed, which resulted in complete resolution of macular edema at 1 month. There was no recurrence of macular edema till his recent follow up, which is 4 month post laser. DISCUSSION: PEVAC is typically described as unifocal lesion and is not associated with other retinal vascular abnormalities. But in this case, in addition to the lesion, perifoveal microaneurysms were seen in both the eyes. Despite the absence of leak on fundus fluorescein angiography, targeted focal laser photocoagulation resulted in complete resolution of macular edema at 1 month. CONCLUSION: Laser photocoagulation would be helpful even in hypofluorescent PEVAC/capillary macroaneurysms.

The Masquerading Retinopathy of Revesz Syndrome.

Revesz syndrome is a rare telomeropathy characterized by bone marrow failure and exudative retinopathy. We report the case of a 2-year-old male child, initially treated with bilateral laser photocoagulation for retinopathy of prematurity. He developed exudative changes in the right eye, presumed to be Coats disease. Later, the left eye developed a total vitreous hemorrhage. Proliferative retinopathy was noted intraoperatively. Systemic features of bone marrow failure, growth retardation, and nail pigmentation were present. Genetic testing confirmed the diagnosis of Revesz syndrome. We describe our approach to diagnosis and surgical management of the case. [Ophthalmic Surg Lasers Imaging Retina 2022;53(6): 346-348.].

Impact of systemic parameters before commencing anti-vascular endothelial growth factor therapy for diabetic macular edema - Pan-Indian survey of retina specialists.

PURPOSE: Intravitreal anti-vascular endothelial growth factor (VEGF) injection therapy has emerged as the mainstay of treatment in the management of diabetic macular edema (DME) today. Various systemic risk factors have to be considered before initiating anti-VEGF therapy. The aim of our study was to form a consensus on various systemic factors to consider before starting anti-VEGF therapy for DME. METHODS: A questionnaire was created and sent across to various retina specialists across India. A GoogleTM form with various questions pertaining to what systemic parameters would one consider before giving anti-VEGF therapy for DME was sent to each of them by email/WhatsAppTM/direct telephonic interview. RESULTS: Of the 650 retina specialists contacted, 322 responded to the questionnaire. There was no difference in responses between private and institutional practitioners. The majority would consider RBS (85%), HbA1c (61%), blood pressure (63%), and renal function (57%) as a routine before administering the anti-VEGF injection, while the majority would not consider hemoglobin (63%) or lipid profile (55%) of the patient as a routine practice prior to administering the injection. CONCLUSION: In our study, most VR specialists prefer to consider RBS, HbA1c, BP, and renal profile (creatinine) routinely prior to anti-VEGF injection. We suggest that it is important to consider blood pressure control, glycemic control, HbA1c, Hb, lipid profile, and renal profile (UACR, eGFR, and creatinine) prior to anti-VEGF therapy in all diabetic patients and to discuss the need for statins in patients with dyslipidemias with the physician.

A Delphi method based consensus statement for surgical management of proliferative diabetic retinopathy in India.

PURPOSE: To derive consensus statements for surgical management of proliferative diabetic retinopathy (PDR) for vitreoretinal (VR) surgeons. METHODS: Thirteen prolific VR surgeons representing all regions of India were invited to participate in a 42-point questionnaire based on the Delphi methodology describing various surgical scenarios commonly encountered in PDR. Consensus was derived using predefined robust analytics. Scenarios that returned a moderate consensus in round 1 were taken to round 2 as per the Delphi methodology. After considering all inputs, the final consensus criteria were developed. RESULTS: A strong consensus was derived about waiting for 4 weeks before considering vitrectomy. In treatment-naïve eyes with fresh vitreous hemorrhage (VH), the wait time was slightly shorter for extramacular tractional retinal detachment (2-4 weeks) and longer (4-6 weeks) for eyes treated previously with laser or anti-VEGF agents. The expert panel recommended using preoperative anti-VEGF only in eyes with large membranes requiring extensive dissection. For post vitrectomy VH, while a conservative approach was recommended for the first episode of VH, experts recommended immediate vitreous lavage for recurrent episodes of VH. In eyes with iris neovascularization, the panel recommended immediate anti-VEGF injection followed by early vitreous lavage in nonresponsive eyes. A strong consensus was derived for stopping antiplatelet agents before surgery, while there was only a moderate consensus for performing vitrectomy for recalcitrant macular edema unresponsive to anti-VEGF injections in the absence of traction. CONCLUSION: This study provides valuable consensus on managing the different scenarios encountered during surgical management of PDR and should help guide the VR surgeons in clinical decision-making.

Synthesis of porous 2D layered nickel oxide-reduced graphene oxide (NiO-rGO) hybrid composite for the efficient electrochemical detection of epinephrine in biological fluid.

In the present research work, 2D-Porous NiO decorated graphene nanocomposite was synthesized by hydrothermal method to monitored the concentration of epinephrine (EPI). The morphology (SEM and TEM) results confirmed 2D-Porous NiO nanoparticles firmly attached over graphene nanosheets. FTIR and XPS analysis confirmed the formation of nickel oxide formation and complete reduction of GO to rGO. The electrochemical activity of the proposed NiO-rGO/GCE modified electrode on epinephrine was analyzed by simple cyclic voltammetry technique. The proposed low cost NiO-rGO/GCE modified electrode showed excellent catalytic activity over GCE and rGO/GCE electrodes. Due to its high conductivity and charge transfer ability of the NiO-rGO/GCE modified electrode exhibited high sensitivity of EPI at optimized conditions. The anodic peak current of the EPI linearly increases with increasing the concertation of EPI. A wide linear range (50 µM-1000 µM) was achieved with high correlation coefficient (R2 = 0.9986) and the limit of detection (LOD) of NiO-rGO/GCE modified electrode was calculated to be 10 µM. NiO-rGO/GCE electrode showed good stability and repeatability towards the EPI oxidation. Mainly, the proposed NiO-rGO/GCE modified electrode showed good sensitivity of EPI in the human biological fluid with high recovery percentage. The low cost, NiO-rGO/GCE electrode could be the promising sensor electrode for the detection of Epinephrine in the real samples.

Broad bandwidth air-coupled micromachined ultrasonic transducers for gas sensing.

The present work aims to develop ultra-wide bandwidth air-coupled capacitive micromachined ultrasonic transducers (CMUTs) for binary gas mixture analysis. The detection principle is based on time-of-flight (ToF) measurements, in order to monitor gas ultrasound velocity variations. To perform such measurements, CMUTs were especially designed to work out of resonance mode, like a microphone. The chosen membrane size is 32 × 32 µm2 and gap height is 250 nm. The resonance frequency and collapse voltage were found at 8 MHz and 58 V respectively. As mentioned, the CMUTs were exploited in quasi-static operating mode, in a very low frequency band, from 1 MHz to 1.5 MHz frequencies. The transducer impulse response was characterised, and a -6 dB relative fractional frequency bandwidth (FBW) higher than 100% was measured, enabling to use CMUT for the targeted application. Additionally, a measuring cell has been designed to hold the fabricated CMUT emitter and receiver prototypes facing each other. The volume inside the cell was kept lower than 3 mL and the surface of emitter/receiver was 1.6 × 8 mm2. To validate the general principle of the proposed technique, two binary gas mixtures of CO2/N2 and H2/N2, with varying concentrations, have been tested. The results are very promising with a measured limit of detection (LOD) of 0.3% for CO2 in N2 and 0.15% for H2 in N2.

Influence of selenium precursors on the formation of iron selenide nanostructures (FeSe2): Efficient Electro-Fenton catalysts for detoxification of harmful organic dyestuffs.

In this investigation, a sequences of iron diselenide (FeSe2) nanomaterials as the competent and highly stable catalysts for the detoxification of aqueous organic dye pollutants such as Congo red (CR) and methylene blue (MB) through Electro-Fenton (EF) process using hydrogen peroxide as an initiator have been studied. The utilized selenium precursors include selenium metal, selenious acid (H2SeO3) and selenium dioxide (SeO2) which were employed for the synthesis of FeSe2 catalysts through a wet chemical strategy. It has been observed that based on the employed precursors, different morphologies ranges of the FeSe2 catalysts were obtained: microgranualr particles to nano-stick to nanoflakes. The crystalline nature and phase purity of the obtained FeSe2 catalysts were determined through XRD, Raman and HR-TEM analyses which confirmed their orthorhombic ferroselite structure. Among the prepared FeSe2 catalysts, FS-2 (using H2SeO3) displayed better porous properties as compared to other catalysts and achieved the highest surface area of 74.68 m2g-1. The narrow bandgap (0.88 eV) and fast conversion of Fe2+/Fe3+ cycle of FeSe2 led CR and MB degradation of 93.3% and 90.4%, respectively. The outcome of this study demonstrates improved catalytic properties of FeSe2 nanostructures for the efficient detoxification of hazardous and toxic effluents.

Vitrectomy as a treatment modality in vitreous seeding secondary to ciliary body melanocytoma.

Melanocytoma is a locally invasive intraocular tumor usually located in the optic nerve head, iris, ciliary body and choroid. Melanocytoma can undergo necrosis and lead to pigment dispersion. We report a case of melanocytoma of the ciliary body with vitreous seeds filling the vitreous cavity. A sub conjunctival pigmented lesion was seen due to extra scleral extension of the tumor. The diagnosis of melanocytoma was confirmed by biopsy of the sub conjunctival lesion. Pars plana vitrectomy was performed to clear the vitreous cavity with good visual recovery.

Optical coherence tomography angiography-based analysis of intrinsic vasculature in juxtapapillary melanoma after ruthenium-106 plaque brachytherapy.

In this case report, we demonstrate the use of optical coherence tomography angiography (OCTA) as a tool to evaluate intrinsic vasculature in a case of juxtapapillary melanoma which underwent ruthinium.106 plaque brachytherapy. In this case, OCTA could demonstrate a decrease in caliber and density of the intrinsic vasculature of the tumor post brachytherapy.

Thioredoxin-1 improves the immunometabolic phenotype of antitumor T cells.

Adoptive transfer of tumor epitope-reactive T cells has emerged as a promising strategy to control tumor growth. However, chronically-stimulated T cells expanded for adoptive cell transfer are susceptible to cell death in an oxidative tumor microenvironment. Because oxidation of cell-surface thiols also alters protein functionality, we hypothesized that increasing the levels of thioredoxin (Trx), an antioxidant molecule facilitating reduction of proteins through cysteine thiol-disulfide exchange, in T cells will promote their sustained antitumor function. Using pre-melanosome protein (Pmel)-Trx1 transgenic mouse-derived splenic T cells, flow cytometry, and gene expression analysis, we observed here that higher Trx expression inversely correlated with reactive oxygen species and susceptibility to T-cell receptor restimulation or oxidation-mediated cell death. These Trx1-overexpressing T cells exhibited a cluster of differentiation 62Lhi (CD62Lhi) central memory-like phenotype with reduced glucose uptake (2-NBDGlo) and decreased effector function (interferon γlo). Furthermore, culturing tumor-reactive T cells in the presence of recombinant Trx increased the dependence of T cells on mitochondrial metabolism and improved tumor control. We conclude that strategies for increasing the antioxidant capacity of antitumor T cells modulate their immunometabolic phenotype leading to improved immunotherapeutic control of established tumors.

Optical coherence tomography angiography in assessment of response to therapy in retinal capillary hemangioblastoma and diffuse choroidal hemangioma.

In this series, we discuss the role of optical coherence tomography angiography (OCTA) in assessing response to treatment in intraocular vascular tumors. This is a series of two cases: Multiple retinal capillary hemangioblastoma (RCH) treated with laser photocoagulation and diffuse choroidal hemangioma (DCH) with radiotherapy. In large RCH and DCH, optical coherence tomography (OCT) showed significant reduction of subretinal and intraretinal fluid. But post-treatment mean tumor vascular density (MTVD) was slightly reduced. In one small RCH, vascular loop was seen suggesting minimal residual disease. So, OCTA helps in identifying treatment inadequacy and understanding alternate mechanism involved in treatment response in vascular tumors.

Optical coherence tomography angiography of fleeting macroaneurysm in retinal racemose angioma.

We present a rare case of retinal racemose angioma complicated with fleeting macroaneurysm (MA). A 50-year-old female presented with diminution of vision in her right eye for 6 years. Fundus examination showed a racemose angioma with hemorrhagic MA temporal to the fovea in the right eye. On subsequent follow-ups, spontaneous thrombosis of MA was noted with the development of new MA inferior to the fovea, with intraretinal hemorrhage extending into the fovea. Focal laser to MA resulted in resolution of MA with improvement in vision. We report optical coherence tomography angiographic features of the fleeting MA in a case of racemose angioma.

Optical coherence tomography angiography features of choroidal hemangioma.

This is an observational case series of four cases of choroidal hemangioma. All cases underwent OCT angiography with swept source OCTA (Topcon DRI OCT Triton plus) 6 mm * 6 mm protocol. OCTA at the level of large choroidal vessels demonstrated peculiar vascular pattern in all four eyes. Patterns observed were bag of worms, spaghetti like and vessels with terminal bulbs. In eye with diffuse choroidal hemangioma comparison of choroidal vascular pattern with the contralateral eyes showed significant difference in the vascular architecture. OCTA is an excellent non invasive tool in assessing the choroidal vascular pattern in eyes with choroidal hemangioma.

Sutureless scleral buckle in the management of rhegmatogenous retinal detachment.

PURPOSE: To evaluate the anatomical and functional outcomes of sutureless scleral buckling for the repair of rhegmatogenous retinal detachment (RD). DESIGN: Retrospective interventional case series. MATERIALS AND METHODS: Retrospective analysis of 50 eyes of 49 patients with rhegmatogenous RD, who underwent sutureless scleral buckling from January 2009 to March 2013. RESULTS: Primary retinal re-attachment rate of 86% was achieved with single surgery, but final anatomical success was 94% with additional interventions in the form of intravitreal gas, buckle revision, and/or pars plana vitrectomy. Best corrected logarithm of minimum angle of resolution visual acuity improved from 1.44 ± 1.01 preoperatively to 0.50 ± 0.40 at a mean follow-up of 6.7 months.XS Conclusion: Sutureless scleral buckling achieves excellent anatomical and functional success in majority of the patients with rhegmatogenous RD.