To evaluate the reproducibility of parafoveal microvascular anatomy of 7 different optical coherence tomography angiography (OCT-A) devices by comparing vessel density (VD), fractal dimension (FD), ...and foveal avascular zone (FAZ) of superficial and deep capillary plexus in healthy volunteers.
Reliability analysis.
Consecutive healthy volunteers presenting at the Eye Clinic, Department of Biomedical and Clinical Sciences, Luigi Sacco Hospital, University of Milan in the same clinic visit were imaged by 7 different OCT-A devices: Optovue RTVue XR Avanti (Optovue, Inc, Fremont, California, USA), prototype Spectralis OCT-A (Spectralis; Heidelberg Engineering, Heidelberg, Germany), AngioPlex (Cirrus 5000 HD-OCT; Carl Zeiss Meditec, Inc, Dublin, California, USA), prototype PlexElite (Carl Zeiss Meditec), RS-3000 Advance (Nidek, Gamagori, Japan), OCT-HS100 (Canon, Tokyo, Japan), and Revo NX (Optopol Technology SA, Zawiercie, Poland). OCT-A examinations were performed using a 3 × 3 mm volume scan pattern centered on the fovea. Mean VD, FD, and FAZ values between the instruments were compared.
The 7 different devices presented measurements with different mean values, with only a limited number of comparisons not significantly different between the instruments. Moreover, Bland-Altman analysis revealed that the limits of agreement for all the comparisons were not acceptable. Regression analysis was used in the development of tables to compare various devices, despite which large standard errors were found for both intercepts and slope conversion values.
Our results suggest that the comparison between instruments is nearly impossible and the set of measurements from the various instruments are not interchangeable regarding VD, FD, and FAZ for both the superficial and deep capillary plexus.
Age-related macular degeneration (AMD) constitutes a prevalent, chronic, and progressive retinal degenerative disease of the macula that affects elderly people and cause central vision impairment. ...Despite therapeutic advances in the management of neovascular AMD, none of the currently used treatments cures the disease or reverses its course. Medical treatment of neovascular AMD experienced a significant advance due to the introduction of vascular endothelial growth factor inhibitors (anti-VEGF), which dramatically changed the prognosis of the disease. However, although anti-VEGF therapy has become the standard treatment for neovascular AMD, many patients do not respond adequately to this therapy or experience a slow loss of efficacy of anti-VEGF agents after repeated administration. Additionally, current treatment with intravitreal anti-VEGF agents is associated with a significant treatment burden for patients, caregivers, and physicians. New approaches have been proposed for treating neovascular AMD. Among them, designed ankyrin repeat proteins (DARPins) seem to be as effective as monthly ranibizumab, but with greater durability, which may enhance patient compliance with needed injections.
To evaluate the occurrence of retinal microvasculopathy in patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and who developed coronavirus disease (COVID-19).
...Systematic review and meta-analysis.
The Pubmed and Embase databases were comprehensively searched to identify studies that reported retina vascular changes in eyes with COVID-19. Two independent reviewers selected papers and extracted data for analysis. Data of interest were extracted and analyzed in RevMan Web versions 3.3. Quality of evidence was assessed using the National Institute of Health quality assessment tool for a case-control study.
Thirty-one studies reporting on 1373 subjects (972 COVID-19 and 401 controls) were included. Only case-control studies were included in the pooled analysis. There was a significantly higher likelihood of retinal microvasculopathy in subjects with COVID-19 compared to controls (odds ratio 95% confidence interval, 8.86 2.54-27.53, P < .01). Optical coherence tomography angiography (OCTA) revealed reduced vessel density and enlarged foveal avascular zone in subjects with COVID-19 compared to controls.
The results suggested that COVID-19-related retinal microvasculopathy is a significant ocular manifestation of COVID-19 and may herald future retinal complications. These microvascular impairments might have occurred antecedent to clinically visible changes and could be detected earlier by OCTA. These findings are significant, due to the large numbers with COVID-19, and need to be recognized by ophthalmologists as a potential long-term sequalae of the disease.
To compare swept source OCTA device, with and without the extended field imaging (EFI) technique, to standard fluorescein angiography (FA) in the clinical practice.
Consecutive patients with vascular ...disorder patients underwent FA with 55-degree lens (Spectralis Heidelberg Engineering, Heidelberg, Germany) and OCTA with the prototype PlexElite (Carl Zeiss Meditec, Dublin, CA) using a 12 mm x 12 mm volume scan pattern centered on the fovea and a prototype of + 20.00-diopter designed specifically by Zeiss. The imaging methods were compared for visible field of view, extension of non-perfused areas, presence and number of neovessels, vessel density (VD) and fractal dimension (FD).
Forty-three eyes of 27 patients were included. The mean extension ratio of EFI SS-OCTA compared to SS-OCTA without EFI and FA were 1.97 ± 0.02 and 0.85 ± 0.01. The mean extension of non-perfused areas with EFI SS-OCTA (34.22 ± 33.4 mm2) was significantly higher than SS-OCTA without EFI (20.46 ± 18.70 mm2), and with FA (27.55 ± 4.4 mm2). The mean VD and FD of EFI SS-OCTA were significantly different compared to SS-OCT without EFI.
EFI SS-OCTA captured larger areas than SS-OCTA without EFI and FA. OCTA in a single shot is able to obtain more information of the retina without the use of montage techniques. Despite the determination of retinal ischemia seems to be easier and more accurate using EFI SS-OCTA, FA offers more details of the perfusion status of the retina.
Optical coherence tomography (OCT) has dramatically changed the understanding and management of uveitis and other ocular conditions. Currently, OCT angiography (OCTA) combines structural information ...with the visualization of blood flow within the imaged area. The aim of this review is to present the basic principles of OCT and OCTA interpretation and to investigate the role of these imaging techniques in the diagnosis and management of uveitis. Common complications of intraocular inflammation such as macular oedema and inflammatory choroidal neovascularization are often diagnosed and followed with OCT/OCTA scans. However, uveitis specialists can obtain much more information from tomographic scans. This review provides a comprehensive description of typical OCT/OCTA findings characterizing different ocular structures in uveitis, proceeding from the cornea to the choroid. A careful interpretation of OCT/OCTA images can help in the differential diagnosis, the prediction of clinical outcomes, and the follow‐up of patients with uveitis.
The advent of optical coherence tomography (OCT) revolutionized both clinical assessment and research of vitreoretinal conditions. Since then, extraordinary advances have been made in this imaging ...technology, including the relatively recent development of swept-source OCT (SS-OCT). SS-OCT enables a fast scan rate and utilizes a tunable swept laser, thus enabling the incorporation of longer wavelengths than conventional spectral-domain devices. These features enable imaging of larger areas with reduced motion artifact, and a better visualization of the choroidal vasculature, respectively. Building on the principles of OCT, swept-source OCT has also been applied to OCT angiography (SS-OCTA), thus enabling a non-invasive in depth-resolved imaging of the retinal and choroidal microvasculature. Despite their advantages, the widespread use of SS-OCT and SS-OCTA remains relatively limited.
In this review, we summarize the technical details, advantages and limitations of SS-OCT and SS-OCTA, with a particular emphasis on their relevance for the study of retinal conditions. Additionally, we comprehensively review relevant studies performed to date to the study of retinal health and disease, and highlight current gaps in knowledge and opportunities to take advantage of swept source technology to improve our current understanding of many medical and surgical chorioretinal conditions. We anticipate that SS-OCT and SS-OCTA will continue to evolve rapidly, contributing to a paradigm shift to more widespread adoption of new imaging technology to clinical practice.
•Swept source (SS) OCT/OCTA provide high speed and deep resolution.•These features allow simultaneous imaging of the vitreous, retina and choroid.•We critically reviewed SS-OCT/SS-OCTA applications to studying vitreoretinal conditions.•Wider use of SS-OCT/OCTA can increase the current understanding of retinal diseases.
To compare the efficacy of intravitreal aflibercept and ranibizumab on the exudative activity of neovascular age-related macular degeneration (nAMD) using optical coherence tomography (OCT) and to ...correlate morphologic findings with visual acuity (VA) outcomes.
Post hoc analysis of the prospective VIEW trials.
Data of 1815 patients randomized to 0.5 mg ranibizumab every 4 weeks (Q4wks), 2 mg aflibercept Q4wks, or 2 mg aflibercept every 8 weeks (Q8wks).
Standardized OCT evaluation was performed by masked reading centers for the presence of intraretinal cystoid fluid (IRC), subretinal fluid (SRF), and pigment epithelial detachment (PED). Rates of feature resolution were compared between drugs and regimen. Associations between morphologic features and VA were analyzed using multivariate modeling.
Resolution rates of IRC, SRF, and PED, and associations between morphology and VA.
At baseline, the proportions of eyes with IRC, SRF, and PED were balanced between the aflibercept and ranibizumab groups. At week 12, IRC resolved in 50% of eyes with both agents. Subretinal fluid resolved in 70% of pooled aflibercept-treated eyes and in 59% of ranibizumab-treated eyes, and PED resolved in 29% and 24% of pooled aflibercept-treated eyes and ranibizumab-treated eyes, respectively. At week 52, IRC resolved in 57% (aflibercept Q4wks), 50% (aflibercept Q8wks), and 52% (ranibizumab) of patients; SRF resolved in 75% (both aflibercept Q4wks/Q8wks) and 66% (ranibizumab) of patients; and PED resolved in 40% (aflibercept Q4wks), 34% (aflibercept Q8wks), and 28% (ranibizumab) of patients. During fixed dosing (weeks 12-52) all exudative features showed synchronized fluctuations after treatment-free visits in the Q8wks aflibercept regimen. During pro re nata dosing (weeks 52-96), greater proportions of patients showed recurrent fluid in all treatment arms. Presence of IRC was generally associated with lower VA at baseline, which translated into poorer final VA outcomes.
Fluid resolution in all compartments was consistently greater for aflibercept Q4wks than for aflibercept Q8wks and ranibizumab. At week 52, Q8wks aflibercept-treated eyes were, on average, as dry as or drier than with ranibizumab despite the extended treatment interval. Independent of agent or regimen, preexisting morphologic features of the retina at baseline markedly influenced VA outcomes.
To evaluate differences between the retinal nerve fiber layer (RNFL) thickness and RNFL + ganglion cell layer (GCL) thickness in patients affected by Alzheimer's disease (AD) and healthy patients ...using spectral-domain optical coherence tomography (SD-OCT).
This was a case-control prospective study. Twenty-one AD patients and 21 healthy subjects underwent neurological examination, clock-drawing test (CDT), Mini Mental State Examination (MMSE), and comprehensive ophthalmic evaluation with visual acuity. SD-OCT examination was performed using Spectralis and RTVue-100. An RNFL thickness map was obtained using the Spectralis volume protocol with 19 lines on the 30° field centered on the macula. On each B-scan, the outer RNFL limit was manually set. Statistical analysis was performed to assess interoperator RNFL evaluation thickness. An RNFL+GCL thickness map was obtained using the RTVue-100 MM6 protocol. Maps were divided into the nine ETDRS subfields and each map value in every area was evaluated. A single eye from each patient was randomly chosen to perform the analysis. Differences between AD and healthy subjects were assessed.
The two study groups were age and sex matched. MMSE results were 19.9 ± 3.1 and 27.9 ± 1.3, respectively (P < 0.001). There was good agreement in the manual delimitation of the RNFL layer. There was a significant difference in the thickness of both the RNFL and the RNFL+GCL in all examined fields. For example, in the inferior internal subfield, the RNFL thickness was 28.1 ± 3.1 μm for AD patients and 32.6 ± 3.8 μm for healthy subjects (P < 0.001).
These results indicate that RNFL and RNFL+GCL thickness measurements are reduced in AD patients compared with healthy subjects. This finding may represent a useful element for the diagnosis and follow-up of this pathology.
To evaluate the safety and efficacy of individualized ranibizumab treatment in patients with neovascular age-related macular degeneration.
Twelve-month, phase III, multicenter, open-label, single-arm ...study.
A total of 513 ranibizumab-naïve SUSTAIN patients.
Three initial monthly injections of ranibizumab (0.3 mg) and thereafter pro re nata (PRN) retreatment for 9 months based on prespecified retreatment criteria. Patients switched to 0.5 mg ranibizumab after approval in Europe.
Frequency of adverse events (AEs), monthly change of best-corrected visual acuity (BCVA) and central retinal thickness (CRT) from baseline, the time to first re-treatment, and the number of treatments were assessed.
A total of 249 patients (48.5%) reported ocular AEs, and 8 (1.5%) deaths, 5 (1.2%) patients with ocular serious AEs of the study eye (retinal hemorrhage, cataract, retinal pigment epithelial tear, reduced visual acuity VA, vitreous hemorrhage), and 19 (3.7%) patients with arteriothromboembolic events were observed. Most frequent AEs in the study eye were reduced VA (18.5%), retinal hemorrhage (7.2%), increased intraocular pressure (7.0%), and conjunctival hemorrhage (5.5%). The average number of re-treatments from months 3 to 11 was 2.7. Mean best-corrected visual acuity increased steadily from baseline to month 3 to reach +5.8 letters, decreased slightly from month 3 to 6, and remained stable from month 6 to 12, reaching +3.6 at month 12. Mean change in CRT was -101.1 μm from baseline to month 3 and -91.5 μm from baseline to month 12.
The safety results are comparable to the favorable tolerability profile of ranibizumab observed in previous pivotal clinical studies; individualized treatment with less than monthly re-treatments shows a similar safety profile as observed in previous randomized clinical trials with monthly ranibizumab treatment. Efficacy outcomes were achieved with a low average number of re-treatments. Visual acuity in SUSTAIN patients with individualized re-treatment based on VA/optical coherence tomography assessment reached on average a maximum after the first 3 monthly injections, decreased slightly under PRN during the next 2 to 3 months, and was then sustained throughout the treatment period.
Abstract
Coronavirus disease 2019 (COVID-19) is an infectious disease caused by SARS-CoV-2 primarily affecting the respiratory system which can damage vessels walls virtually in any body district. ...Changes affecting retinal vessels are a good marker for systemic vascular alterations. This study investigated retinal vessels during the acute phase of COVID-19 and after patients recovery. Fifty-nine eyes from 32 COVID-19 patients and 80 eyes from 53 unexposed subjects were included. Mean arteries diameter (MAD) and mean veins diameter (MVD) were assessed through semi-automatic analysis on fundus color photos at baseline and 6 months later in patients and subjects unexposed to the virus. At baseline MAD and MVD were significantly higher in COVID-19 patients compared to unexposed subjects (p < 0.0001). Both MAD and MVD significantly decreased in COVID-19 patients at follow-up (from 97.5 ± 10.9 to 92.2 ± 11.4 µm, p < 0.0001 and from 133.1 ± 19.3 to 124.6 ± 16.1 µm, p < 0.0001, respectively). Despite this reduction vessels diameter remained significantly higher in severe COVID-19 patients compared to unexposed subjects. Transient retinal vessels dilation could serve a biomarker for systemic inflammation while long-lasting alterations seen in severe COVID-19 likely reflect irreversible structural damage to the vessels walls and should be further investigated for their possible effects on tissues perfusion and function.
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