Telementoring versus face-to-face mentoring in the training of scleral fixation surgery of intraocular lenses.

PURPOSE: To assess telementoring as a complementary tool for surgical training of a scleral fixation technique. DESIGN: Randomized, controlled, two-arm, blinded clinical trial. METHODS: Using a 3D visualization system, 132 participants were randomized in order of enrollment into traditional face-to-face mentoring (n = 66) and telementoring (n = 66). A single surgeon mentored all participants in the 2 groups. The procedure was performed in a model suitable for training in intraocular lens fixation SimulEYE® (INSEYET, WESTLAKE VILLAGE, CA, USA). In the telementoring group, the images captured on a local computer were sent to a second computer located in another room through a teleconferencing platform in real-time. Nine steps of the recorded procedure were evaluated and scored by two masked independent surgeons experienced in the technique. MAIN OUTCOMES MEASURES: The primary outcomes evaluated were the global score (the sum of each score on the rubric), surgical failure, and surgical time (in seconds). RESULTS: Surgical success was achieved in 98.5% in the face-to-face group and in 95.5% in the telementoring group (p-value = 0.619). Minimal technical problems were reported in 8 procedures in the telementoring group (12%), without interfering with the surgical result, and completion of the procedure. CONCLUSIONS: Telementoring is an encouraging educational tool that can overcome geographical barriers to ease the transfer of abilities and knowledge. We lack evidence in terms of group differences for superiority comparing face-to-face and telementoring, in addition to presenting comparable results regarding surgical success and failure. More studies are needed to explore the impact of telementoring in other ophthalmological surgeries. TRIAL REGISTRATION: The Federal University of São Paulo institution's Research Ethics Committee reviewed and approved this study protocol (approval number, 5.383.484).

Noninvasive Blue-Light Channel Imaging of Retinal Nonperfusion in Vein Occlusion.

This case report discusses the use of blue-light channel imaging as an alternative to fluorescein angiography to evaluate the extent of retinal nonperfusion due to vein occlusion.

Preliminary study of rabbits as an animal model of mammalian eye transplantation and literature review / Estudo preliminar de coelhos como modelo animal para transplante de olho em mamíferos e revisão da literatura

ABSTRACT Purpose: To describe an innovative animal model of eye transplantation used in rabbits. Methods: six Dutch-belted male rabbits were submitted to lateral orbitotomy in the right eye, wide retrobulbar anatomy exposure, dissection of the structures, identification and distal section of the optic nerve followed by anastomosis either by vicryl (group 1) or fibrin glue (group 2). Electroretinography recording was performed before the section of the optic nerve and every 30 seconds after, to monitor the function of retina. Left eye was used as control group. Results: After optic nerve resection and anastomosis, stable ERG amplitude of the right eye was lost after 302 seconds in group 1 and after 296 seconds on group 2. Left eye kept longer stable ERG amplitude curves. Conclusions: The animal model of whole eye transplantation was effective in describing a novel technique to be used in rabbits, with success of the anatomic procedure. Further studies will clarify the best anastomosis methods and maintenance of function of the receptor organ. Translational relevance: this animal model of whole eye transplantation provides a novel perspective for blind patients and the research models, since we describe a novel mammal animal model. This model can be used as basis of a human model of whole eye transplantation in future studies.

RESUMO Objetivo: Descrever uma técnica cirúrgica inovadora para transplante de olho em um modelo animal em coelhos. Métodos: Seis coelhos machos com Dutch Belted foram submetidos à orbitotomia lateral do olho direito, com ampla exposição da anatomia retrobulbar, dissecção do cone muscular, exposição e secção distal do nervo óptico seguida de anastomose por vicryl (Grupo 1) ou cola de fibrina (Grupo 2). O registro da eletrorretinografia foi realizado antes da secção do nervo óptico e a cada 30 segundos após, para monitorar a função da retina. O olho esquerdo foi usado como grupo controle. Resultados: Após a ressecção do nervo óptico, a estabilidade da amplitude da eletrorretinografia foi perdida no olho direito após 302 segundos no Grupo 1 e após 296 segundos no Grupo 2. O olho esquerdo manteve eletrorretinografia estável por períodos mais longos. Conclusão: O modelo animal de transplante total de olho foi eficaz em descrever uma nova técnica cirúrgica para ser utilizada em laboratório com coelhos, com sucesso do procedimento anatômico. Novos estudos esclarecerão os melhores métodos de anastomose e manutenção da função do órgão receptor.

New findings useful for clinical practice using swept-source optical coherence tomography angiography in the follow-up of active ocular toxoplasmosis.

BACKGROUND: Ocular toxoplasmosis is one of the most common causes of intraocular inflammation and posterior uveitis in immunocompetent patients. This paper aims to investigate swept-source optical coherence tomography angiography (SS-OCTA) findings in eyes with active toxoplasmic retinochoroiditis. METHODS: This case series was conducted from November 2017 through October 2019 in two Brazilian centers. 15 eyes of 15 patients with active toxoplasmic retinochoroiditis were included, and were imaged at baseline and after at least 4 weeks of follow-up. All patients underwent ophthalmic examinations and multimodal imaging including SS-OCT and SS-OCTA before and after treatment of ocular toxoplasmosis. The differential diagnoses included toxoplasmosis, syphilis, and human immunodeficiency virus, which were eliminated through serologic and clinical evaluations. RESULTS: All 15 patients presented with positive anti-Toxoplasma gondii immunoglobulin G titers and three also presented with positive anti-T. gondii immunoglobulin M titers. The mean age at examination was 32.4 years ± 12.7 years (range 15-59 years). Sixty percent of the patients were female. In all eyes, the inner retinal layers were abnormally hyperreflective with full-thickness disorganization of the retinal reflective layers at the site of the active toxoplasmic retinochoroiditis. At baseline, 80% of eyes had focal choroidal thickening beneath the retinitis area, and all eyes had a choroidal hyporeflective signal. Before treatment, SS-OCTA showed no OCTA decorrelation signal next to the lesion site in all eyes, and flow signal improvement was noticed after treatment. Three eyes presented with intraretinal vascular abnormalities during follow-up. SS-OCTA showed retinal neovascularization in one patient and a presumed subclinical choroidal neovascular membrane in another patient. CONCLUSIONS: SS-OCT and SS-OCTA are useful for assessing unexpected structural and vascular retinal and choroidal changes in active and post-treatment toxoplasmic retinochoroiditis and these findings are useful for clinical practice.

Comparison of anterior segment optical coherence tomography angiography and fluorescein angiography for iris vasculature analysis.

PURPOSE: The aim of this study is to perform imaging of irises of different colors using spectral domain anterior segment optical coherence tomography angiography (AS-OCTA) and iris fluorescein angiography (IFA) and compare their effectiveness in examining iris vasculature. METHODS: This is a cross-sectional observational clinical study. Patients with no vascular iris alterations and different pigmentation levels were recruited. Participants were imaged using OCTA adapted with an anterior segment lens and IFA with a confocal scanning laser ophthalmoscope (cSLO) adapted with an anterior segment lens. AS-OCTA and IFA images were then compared. Two blinded readers classified iris pigmentation and compared the percentage of visible vessels between OCTA and IFA images. RESULTS: Twenty eyes of 10 patients with different degrees of iris pigmentation were imaged using AS-OCTA and IFA. Significantly more visible iris vessels were observed using OCTA than using FA (W = 5.22; p < 0.001). Iris pigmentation was negatively correlated to the percentage of visible vessels in both imaging methods (OCTA, rho = - 0.73, p < 0.001; IFA, rho = - 0.77, p < 0.001). Unlike FA, AS-OCTA could not detect leakage of dye, delay, or impregnation. Nystagmus and inadequate fixation along with motion artifacts resulted in lower quality images in AS-OCTA than in IFA. CONCLUSIONS: AS-OCTA is a new imaging modality which allows analysis of iris vasculature. In both AS-OCTA and IFA, iris pigmentation caused vasculature imaging blockage, but AS-OCTA provided more detailed iris vasculature images than IFA. Additional studies including different iris pathologies are needed to determine the most optimal scanning parameters in OCTA of the anterior segment.

Large colloid drusen analyzed with structural en face optical coherence tomography.

Drusen are extracellular deposits between the basal lamina of the retinal pigment epithelium (RPE) and the inner collagenous layer of Bruch's membrane. Large colloid drusen (LCD) are located below the RPE and are characterized by multiple, large, dome-shaped RPE detachments, with marked attenuation of the ellipsoid zone overlaying the drusen. This report presents the structural en face optical coherence tomography (OCT) findings of LCD and relates them to findings from fluorescein and indocyanine green angiography. We describe the case of a 55-year-old woman who presented with the chief complaint of a 5-year history of progressively worsening vision. Her best-corrected visual acuities were 20/40 and 20/400 in the right eye and the left eye, respectively. Fundus examination showed large bilateral, symmetrical, sub-retinal, yellowish lesions compatible with LCD. We describe the structural en face OCT characteristics and angiographic findings from this patient.

Large colloid drusen analyzed with structural en face optical coherence tomography / Análise de drusas grandes coloidais através de OCT en face estrutural

ABSTRACT Drusen are extracellular deposits between the basal lamina of the retinal pigment epithelium (RPE) and the inner collagenous layer of Bruch's membrane. Large colloid drusen (LCD) are located below the RPE and are characterized by multiple, large, dome-shaped RPE detachments, with marked attenuation of the ellipsoid zone overlaying the drusen. This report presents the structural en face optical coherence tomography (OCT) findings of LCD and relates them to findings from fluorescein and indocyanine green angiography. We describe the case of a 55-year-old woman who presented with the chief complaint of a 5-year history of progressively worsening vision. Her best-corrected visual acuities were 20/40 and 20/400 in the right eye and the left eye, respectively. Fundus examination showed large bilateral, symmetrical, sub-retinal, yellowish lesions compatible with LCD. We describe the structural en face OCT characteristics and angiographic findings from this patient.

RESUMO Drusas são depósitos extracelulares localizados entre a lâmina basal do epitélio pig mentado da retina (RPE) e a camada colágena interna da membrana de Bruch. Drusas grandes coloidais (LCD) estão localizadas abaixo do EPR, e são caracterizadas por múltiplos descolamentos cupuliformes do EPR com atenuação da zona elipsoide sobrejacente às drusas. O objetivo deste relato é apresentar os achados de tomografia de coerência óptica (OCT en face estrutural em uma paciente com LCD, bem como correlacioná-los com angiografia fluoresceínica e angiografia com indocianina verde. Descrevemos o caso de uma paciente do sexo feminino, 55 anos, que referiu baixa acuidade visual em ambos os olhos há 5 anos. Sua acuidade visual corrigida era de 20/40 no olho direito e 20/400 no olho esquerdo. Ao exame fundoscópico a paciente apresentava lesões compatíveis com drusas grandes coloidais. As características tomográficas e angiográficas também são descritas neste relato de caso.

CLINICAL AND ELECTROPHYSIOLOGICAL EVALUATION AFTER INTRAVITREAL ZIV-AFLIBERCEPT FOR EXUDATIVE AGE-RELATED MACULAR DEGENERATION.

PURPOSE: To evaluate the 6-month safety and efficacy of ziv-aflibercept intravitreal injections for treating exudative age-related macular degeneration. METHODS: Fifteen patients with unilateral exudative age-related macular degeneration were enrolled. The best-corrected visual acuity was measured and spectral domain optical coherence tomography was performed at baseline and monthly. Full-field electroretinography and multifocal electroretinography were obtained at baseline and 4, 13, and 26 weeks after the first injection. All patients received three monthly intravitreal injections of ziv-aflibercept (1.25 mg) followed by as-needed treatment. RESULTS: Between baseline and 26 weeks, the mean logMAR best-corrected visual acuity improved (P = 0.00408) from 0.93 ± 0.4 (20/200) to 0.82 ± 0.5 (20/160) logarithm of the minimum angle of resolution, respectively; the central retinal thickness decreased significantly (P = 0.0007) from 490.3 ± 155.1 microns to 327.9 ± 101.5 microns; the mean total macular volume decreased significantly (P < 0.0001) from 9.51 ± 1.36 mm to 8.08 ± 1.34 mm, and the a-wave implicit time increased, with no differences in the other full-field electroretinography parameters. The average multifocal electroretinography macular responses within the first central 15° showed significantly (P < 0.05) increased P1 amplitudes at 26 weeks. No systemic or ocular complications developed. CONCLUSION: Intravitreal ziv-aflibercept significantly improved the best-corrected visual acuity, multifocal electroretinography amplitudes, central retinal thickness, and total macular volume from baseline to 26 weeks. No retinal toxicity on full-field electroretinography or adverse events occurred during the follow-up period.

Fusion proteins for treatment of retinal diseases: aflibercept, ziv-aflibercept, and conbercept.

In the last few years, monoclonal antibodies have revolutionized the treatment of retinal neovascular diseases. More recently, a different class of drugs, fusion proteins, has provided an alternative treatment strategy with pharmacological differences. In addition to commercially available aflibercept, two other drugs, ziv-aflibercept and conbercept, have been studied in antiangiogenic treatment of ocular diseases. In this scenario, a critical review of the currently available data regarding fusion proteins in ophthalmic diseases may be a timely and important contribution. Aflibercept, previously known as VEGF Trap Eye, is a fusion protein of VEGF receptors 1 and 2 and a treatment for several retinal diseases related to angiogenesis. It has firmly joined ranibizumab and bevacizumab as an important therapeutic option in the management of neovascular AMD-, DME- and RVO-associated macular edema. Ziv-aflibercept, a systemic chemotherapeutic agent approved for the treatment of metastatic colorectal cancer, has recently drawn attention because of its potential for intravitreal administration, since it was not associated with ERG-related signs of toxicity in an experimental study and in human case reports. Conbercept is a soluble receptor decoy that blocks all isoforms of VEGF-A, VEGF-B, VEGF-C, and PlGF, which has a high binding affinity for VEGF and a long half-life in vitreous. It has been studied in a phase three clinical trial and has shown efficacy and safety. This review discusses three fusion proteins that have been studied in ophthalmology, aflibercept, ziv-aflibercept and conbercept, with emphasis on their clinical application for the treatment of retinal diseases.

Analysis of Scleral Feeder Vessel in Myopic Choroidal Neovascularization Using Optical Coherence Tomography Angiography.

To describe the appearance of a scleral-derived feeder vessel in a highly myopic eye with secondary choroidal neovascularization (CNV) as visualized on both en face high-speed swept-source (SS) optical coherence tomography angiography (OCTA) prototype, and a commercially available spectral-domain (SD) OCTA, with the corresponding en face and cross-sectional structural OCT images. In this case report, a 60-year-old white male presented with high myopia and secondary CNV in the right eye, previously treated with anti-vascular endothelial growth factor, and was imaged on both SD-OCT and SS-OCT. The neovascular complex could be visualized on both devices. Structural en face SS-OCT images demonstrated a large choroidal-scleral feeder vessel that was not visualized with SD-OCT. The authors concluded that structural en face SS-OCT better visualizes scleral feeder vessel compared to SD-OCT due to the longer wavelength (∼1,050 nm) with increased choroidal penetration and decreased sensitivity roll-off in the SS-OCT system. [Ophthalmic Surg Lasers Imaging Retina. 2016;47:960-964.].

Contemporary retinal imaging techniques in diabetic retinopathy: a review.

Over the last decade, there has been an expansion of imaging modalities available to clinicians to diagnose and monitor the treatment and progression of diabetic retinopathy. Recently, advances in image technologies related to OCT and OCT angiography have enabled improved visualization and understanding of this disease. In this review, we will describe the use of imaging techniques such as colour fundus photography, fundus autofluorescence, fluorescein angiography, infrared reflectance imaging, OCT, OCT-Angiography and techniques in adaptive optics and hyperspectral imaging in the diagnosis and management of diabetic retinopathy.

Correlation Between Choroidal Thickness and Ciliary Artery Blood Flow Velocity in Normal Subjects.

BACKGROUND AND OBJECTIVE: To study the correlation between the choroidal thickness (CT) measured by spectral-domain optical coherence tomography (SD-OCT) and retrobulbar blood flow measured by color Doppler flowmetry (CD) in normal subjects. PATIENTS AND METHODS: Healthy subjects underwent enhanced-depth imaging SD-OCT and CD using a linear 6 MHz to 18 MHz transducer. The maximal peak systolic velocity and resistance index (RI) were obtained for the ophthalmic artery (OA), short posterior ciliary artery (SPCA), and central retinal artery (CRA) and correlated with the subfoveal CT measured by SD-OCT. RESULTS: Twenty-seven eyes of 27 healthy patients were enrolled (mean age: 40.6 ± 12.4 years; range: 27-68 years). An inverse proportional relationship (P = .0496) was identified between the RI of the SPCA (mean, 0.6117 ± 0.07911) and the subfoveal CT (319.9 µm ± 83.79 µm) but not between the RI and the OA (mean: 0.7019 µm ± 0.07317 µm) or the CRA (mean: 0.68843 µm ± 0.08994 µm). CONCLUSION: The results of this study suggested there is an inverse proportional relationship between the RI of the SPCA and the subfoveal CT. The data also suggested a correlation between a decrease in the CT and increased RI in the retrobulbar arteries. Therefore, lower choroidal blood flow may explain the thinner CT in normal subjects.

Regression of drusen after combined treatment using photodynamic therapy with verteporfin and ranibizumab.

Drusen are the clinical hallmark of age-related macular degeneration. The regression of these deposits in patients treated with argon, krypton, or diode laser photocoagulation has been reported previously. However, previous protocols with conventional laser for drusen may result in retinal pigment epithelium (RPE) damage and unwanted scotomas. The authors report a case of complete regression of soft drusen in a 65-year-old man with central visual loss and metamorphopsia due to a drusenoid RPE detachment and soft drusen who underwent reduced-fluence photodynamic therapy (PDT) and three monthly intravitreal injections of ranibizumab. Reduced-fluence PDT combined with anti-VEGF therapy may reduce drusen without inducing RPE cell damage.

Preclinical investigations of intravitreal ziv-aflibercept.

BACKGROUND AND OBJECTIVE: To investigate the retinal safety of intravitreal (IVT) ziv-aflibercept in rabbits. MATERIALS AND METHODS: Eighteen rabbits were given an IVT injection of ziv-aflibercept (25 mg/mL) or aflibercept (40 mg/mL) and examined by funduscopy, electroretinography (ERG), optical coherence tomography (OCT), light microscopy, and transmission electron microscopy (TEM). Serum, aqueous, and vitreous were obtained afterward for osmolarity analysis. The effect of ziv-aflibercept on human retinal cultured cells (ARPE-19) was assessed by the MTT cell viability assay. RESULTS: All eyes showed normal funduscopy, OCT, and ERG findings at baseline and 24 hours or 7 days after the procedure. Median baseline serum, vitreous, and aqueous osmolarity remained unchanged. Histology and TEM showed no major anatomic signs of toxicity. No cytotoxic effect was observed in ARPE-19 cells exposed to ziv-aflibercept. CONCLUSION: IVT injection ziv-aflibercept at a concentration of 25 mg/mL proved to be safe for the rabbit retina.

Retinal biocompatibility of brilliant blue g with deuterated water for chromovitrectomy.

PURPOSE: To investigate the retinal biocompatibility of Brilliant Blue G with deuterated water (BBG-D2O) as a vital dye for chromovitrectomy. METHODS: In this animal study, 0.05 mL of 0.25 g/L Brilliant Blue G (BBG) associated with 0.13 mL/mL of deuterium oxide (D2O) was injected intravitreally in the right eye and the same amount of balanced salt solution (BSS) was injected similarly in the left eye of rabbits. Clinical examination and histology with light microscopy were performed after seven days. Retinal cell layers were evaluated for morphologic alterations. Electroretinographic (ERG) changes were also assessed at baseline and 7 days after the injections. RESULTS: A total of 6 rabbits were included in the study. The gross histopathologic appearance of the retina, choroid, sclera and optic nerve was within normal limits without any sign of severe retinal necrosis or cystic degeneration. Light microscopy showed that BBG-D2O caused no substantial alterations in retinal layers as compared to control eyes. The injection of BBG-D2O did not induce considerable functional ERG alterations. CONCLUSION: Intravitreal injection of BBG-D2O 0.25 g/L seems to induce no retinal toxicity as documented by lack of functional and histological changes.

Development of an experimental model of proliferative retinopathy by intravitreal injection of VEGF165.

PURPOSE: To develop an experimental model of proliferative retinopathy by intravitreal injection of vascular endothelial growth factor 165 (VEGF165) in pigmented rabbits. METHODS: A prospective, controlled, comparative intervention study. Six pigmented rabbits (Chinchilla breed) were subjected to intravitreal injection of VEGF165 in their right eye. The left eye was used as control and received an injection of balanced salt solution. In group 1, 3 rabbits received a 10-µg injection, and in group 2, 3 rabbits received a 20-µg injection. At baseline, all subjects were analyzed by anterior biomicroscopy, retinography, fluorescein angiography, and optical coherence tomography (OCT) fundus images. Biomicroscopy and all ancillary examinations were repeated at weeks 1, 2, and 5. In the fifth week after the injection, the rabbits were euthanized and the eyes were enucleated and subjected to histological evaluation. RESULTS: Seven days after the intravitreal VEGF165 injection, all rabbits developed intense neovascularization of the retina and anterior segment. Neovascularization of the posterior pole was similar in both groups, and the anterior segment was more florid in group 2. At weeks 1 and 2, neovascularization persisted with a minor decrease in conjunctival hyperemia in both groups. At week 5, there was a partial regression of neovascularization of the posterior pole, which was more prominent in group 1 than group 2, with persistent anterior neovascularization in both groups. OCT showed a statistically significant increase in retinal thickness, hyaloid detachment, and tractional retinal detachment. After the 5-week period, ocular histopathological evaluation showed an increase in retinal thickness, hyaloid detachment, and intense neovascularization in both groups, especially group 2. CONCLUSION: This pilot study of a neovascularization model using intravitreal injection of VEGF165 in pigmented rabbits showed that both doses of 10 and 20 µg were successful and effective in inducing vascular growth in the retina and anterior segment and can therefore be used for evaluating drug efficacy in future studies.

Vital dyes in ophthalmology: a chemical perspective.

Vital dyes have advanced diagnosis and surgical technique in various specialties, including oncology, gastroenterology and ophthalmology. Intra-operative and diagnostic dyes are finding uses in all areas of ophthalmology, including cornea, cataract, retina, glaucoma, orbit and conjunctiva. We provide a summary of current knowledge of the chemical concepts of vital dyes in ophthalmology. We review the properties of dyes, techniques of application, indications and complications in ocular surgery. Vital dyes represent an expanding area of research, and novel dyes deserve further investigation.

Investigation of the retinal biocompatibility of acid violet for chromovitrectomy.

PURPOSE: The primary objective was to investigate the retinal biocompatibility of acid violet (AV) as a vital dye for chromovitrectomy. The secondary objective was to evaluate the capacity of AV to stain the anterior capsule of the lens. METHODS: An amount of 0.05 ml of 0.25 g/l and 0.5 g/l AV was injected intravitreally in the OD, while balanced salt solution (BSS) was applied in the OS for control. Clinical examination and histology with light microscopy (LM) were performed after 7 days. Retinal cell layers were evaluated for morphologic alterations and number of cells. The electroretinographic (ERG) changes were assessed at baseline and 7 days. In another part of the study, 0.1 ml of 0.25 g/l AV was injected into the anterior chamber of ex-vivo porcine eyes, and its capacity to stain the anterior capsule was determined. Cadaveric eyes were used to test the capacity of AV to stain the internal limitant membrane (ILM) during vitrectomy. RESULTS: The gross histopathologic appearance of the retina, choroids, sclera, and optic nerve was within normal limits, without any signs of severe retinal necrosis or cystic degeneration. AV caused no substantial retinal alterations in retinal layers by LM at either the lower or higher dose when compared with the control eye. The injection of AV did not induce considerable ERG alterations. The violet dye stained the anterior capsule after anterior chamber injection and the ILM, allowing a safer capsulorrhexis and vitrectomy. CONCLUSION: Acid violet may be safe for the retina at concentrations of 0.25 and 0.50 g/l after intravitreous injection, and may be used as a vital dye for staining the anterior capsule and the ILM.