Evaluation of Increase in Retinal Thickness as Diagnostic Marker in Central Artery Occlusion.

PURPOSE: To evaluate the increase in retinal thickness as a marker in predicting the onset of central retinal artery occlusions. METHODS: Retrospective clinical study conducted at one Swiss hospital. Electronic records were filtered for patients with artery occlusions. Optical coherence tomography data, including time between the imaging and ischemic event, were reviewed. Increase in relative retinal thickness was measured, defined as an increase in retinal thickness compared to the unaffected partner eye. This was correlated with the time from symptom onset. A cutoff value of relative increase of < 24.5% was applied, as suggested in previous studies. The results were compared to the time gathered from the electronic records, and sensitivity, specificity, positive predictive value as well as negative predictive value were calculated for predicting an ischemia time of < 4.5 h. RESULTS: Forty-two eyes from 41 patients with central artery occlusions were identified. Fourteen were female. Mean age was 66.4 ± 15.8 years. Initial corrected visual acuity was 2.41 ± 0.68 logMAR, and 2.13 ± 0.87 logMAR at the last follow-up (p > 0.05). Of eyes with a visual acuity of counting fingers (n = 38) or worse, 89.5% showed no improvement during follow-up, while eyes with logMAR 1 or better (n = 4) improved. Thirteen eyes (13 patients) presented within 4.5 h of the ischemic event. Four patients received i. v. thrombolysis, with visual recovery in one. In 12 eyes with an ischemia time of < 4.5 h, relative increase was below 24.5%. In the remaining 29 eyes with > 4.5 h, relative increase was below 24.5% in 4 eyes and above 24.5% in 25 eyes. This yielded a sensitivity of 92.3%, a specificity of 86.2%, with a positive predictive value of 75.0% and a negative predictive value of 96.2%. CONCLUSION: Central retinal artery occlusion is associated with severe vision loss. There is no current established therapy. Parameters that objectify the presence of a therapeutic window for thrombolysis are gaining in importance as patient history is often imprecise. Relative retinal thickness increase proved a noninvasive imaging parameter demonstrating adequate performance in detecting patients within the therapeutic window of thrombolysis. Further investigation of this parameter in central retinal occlusion is warranted.

Ophthalmological Outcomes in Patients with Susac Syndrome.

BACKGROUND: To report ophthalmological outcomes and treatment regimen in patients with Susac syndrome. METHODS: This is a retrospective analysis of patients with Susac syndrome treated between November 2015 and March 2023. Multimodal imaging findings, ophthalmic examination data, information on neurological and sensorineural involvement, and therapeutic regimen were reviewed. Visual acuity was recorded as the logarithm of the minimum angle of resolution (logMAR). Ophthalmological manifestations and disease severity were assessed using the previously described clinical activity score (CAS). RESULTS: Ten patients with Susac syndrome m : f = 5 : 5 were identified. The mean follow-up time was 31.2 ± 23.3 months (range 1 to 78 months). The mean age was 41.4 ± 13.8 years (range 21 to 59 years). At baseline, corrected distance visual acuity (CDVA) was 0.03 ± 0.08 logMAR. At the last follow-up, CDVA improved to 0.00 ± 0.03 logMAR (p = 0.029). Three of 20 eyes showed an improvement of 5 letters, while no loss of visual acuity was recorded during the follow-up time. Baseline CAS was 10.65 ± 12.69, and CAS at the last follow-up was 5.15 ± 5.49 (p = 0.068). Except for one patient, all were initially treated with intravenous (i. v.) steroids and subsequent oral tapering. Depending on the treatment response, cyclophosphamide (n = 4), i. v. immunoglobulins (IVIGs) (n = 4), anti-CD20 antibodies (n = 3), or plasmapheresis (n = 1) were applied. All patients under treatment for more than 1 month (n = 9) showed improvement in CAS and CDVA. CONCLUSION: Susac syndrome is a rare autoimmune vascular endotheliopathy. Treatment of Susac syndrome appears to result in improving CAS and CDVA. The majority of patients, in addition to the systemic steroids, required systemic immunosuppressive agents. Interdisciplinary communication is crucial to reduce the time to diagnosis and initiation of therapy in patients with Susac syndrome.

Imaging Assessment of Peripapillary Vessel Diameters in Postmortem Eyes.

PURPOSE: Proof of concept of ex vivo retinal vessel diameter measurements in human postmortem eyes. METHODS: En face near-infrared (IR) images and optical coherence tomography (OCT) of the optic nerve head (ONH) were captured ex vivo with a Heidelberg Engineering Spectralis (Spectralis, version 7.0.4, Image Capture Module, version 1.2.4, Heidelberg Heidelberg, Germany) device, using a custom-made eye chamber holding and positioning the eyes during the image process. Thirty-two formaldehyde-fixated eyes of 16 patients were imaged. In the IR images, two independent graders measured retinal vessel diameters at the intersection of a drawn circle centered on the ONH with diameters of 2.0 mm and 3.4 mm, respectively. The anatomically corresponding measurements between both graders were statistically analyzed using a Wilcoxon signed-rank test. RESULTS: A total of 246 matched measurements of both graders were analyzed across all 32 imaged eyes. Statistically significant differences between the graders were found for arterioles at 2 mm from the ONH. The other measurements did not show statistically significant intergrader differences. The mean values for arteriole diameters were 72.2 µm at 2.0 mm and 61.5 µm at 3.4 mm for grader 1, and 66.4 µm at 2.0 mm and 63.2 µm at 3.4 mm for grader 2. The mean diameter for venules were 75.5 µm at 2.0 mm and 79.3 µm at 3.4 mm for grader 1, and 67.4 µm at 2 mm and 79.1 µm at 3.4 mm for grader 2. CONCLUSION: To the best of our knowledge, this is the first study to present IR image-based retinal vessel diameters in ex vivo postmortem eyes. Retinal IR/OCT imaging is possible, and measurements are reproducible in formaldehyde-fixated human eyes. Fixation artefacts result in lower image quality, and this can impose challenges in correctly detecting, classifying, and measuring retinal vessels.

Severe Complications after Corneal Collagen Cross-Linking (CXL).

PURPOSE: To present a case series of rare and severe complications after corneal collagen cross-linking (CXL) of keratoconus patients. METHODS: Single-center descriptive case series covering the period of 2012 to 2022 at the Department of Ophthalmology at the University Hospital, Zurich, Switzerland. RESULTS: We present four eyes of four patients that showed severe unusual complications within the first month after CXL. Three patients had been treated with the classical epithelium-off "Dresden" protocol. One patient had been treated with the accelerated epithelium-off protocol. One patient presented with extensive corneal edema due to rubbing the eye after treatment. Two patients showed a bacterial infectious keratitis: one due to Streptococcus pneumoniae and the other due to Staphylococcus hominis, Micrococcus luteus, and Streptococcus epidermidis. The latter of the two patients exhibited extensive infectious crystalline keratopathy. The fourth patient showed a severe ulcerative lesion where no infectious cause could be found. Therefore, an autoimmune keratolytic process had to be suspected. Apart from the corneal edema, which resolved ad integrum, the other complications resulted in permanent corneal scarring and thinning. One patient needed an emergency amniotic transplant. CONCLUSION: Severe complications after CXL remain rare. Most common causes are complications that are not directly associated with the treatment as such. Those indirect complications occur after the treatment during the healing course of the epithelium. Associations with bandage contact lenses, topical steroids, atopic disease, and inappropriate patient behavior are often suspected. Correctly performed corneal scrapings with repeated microbiological analysis and a detailed patient history are essential for establishing the correct diagnosis, especially in complicated cases that do not respond to a standard therapeutic regimen. This case series supports the efforts that are currently taken to improve the CXL technique in a way that postoperative complications are further reduced. A more efficient epithelium-on technique might be a step in that direction.

Feasibility and Clinical Utility of Wide-Field Optical Coherence Tomography Angiography Compared to Ultrawide-Field Fluorescein Angiography in Patients with Diabetic Retinopathy.

PURPOSE: To test the diagnostic performance of a novel wide-field swept-source optical coherence tomography angiography (WF-OCTA) device in detecting retinal non-perfusion (NP) and neovascularization (NV) in eyes with diabetic retinopathy (DR) and to compare this with the standard-of-care imaging method, ultrawide-field fluorescein angiography (UWFFA). METHODS: Prospective, observational, cross-sectional single-center study evaluating patients with DR imaged with WF-OCTA (Xephilio OCT-S1; Canon Inc., Tokyo, Japan) and UWFFA (Optos California; Optos plc, Dunfermline, United Kingdom). WF-OCTA images of the superficial capillary plexus (SCP) consisted of single capture 23 × 20 mm scans centered on the fovea. In UWFFA and WF-OCTA, qualitative and quantitative measurements were assessed to analyze retinal NP and NV. Vessel density (VD) in WF-OCTA and ischemic index (ISI) in UWFFA were calculated. Qualitatively, the presence of NV and NP was assessed in both WF-OCTA (posterior pole/midperipheral retina) and UWFFA (posterior pole/midperipheral retina/far peripheral retina). RESULTS: Ten consecutive patients with variable DR severity stages (17 eyes) were evaluated. Two eyes had to be excluded due to low quality of the WF-OCTA images. Therefore, 15 eyes were included for final analysis. Mean age was 57 years (± SD: 15.2) and the male : female ratio was 4 : 6. UWFFA identified retinal NP in 11 eyes (73%). Posterior pole NP was present in eight eyes, midperiphery NP was present in eight eyes, and far periphery NP was present in seven eyes. Retinal NV was detected in four eyes using UWFFA (two eyes with only midperiphery NV). WF-OCTA detected retinal NP in 11 eyes (9 cases with both posterior pole and midperiphery NP). NV was detected in three eyes (two with posterior pole and midperipheral NV, four with only midperipheral NV). Mean VD evaluated using WF-OCTA of the SCP was 0.40 (± SD: 0.1), and mean ISI in UWFFA was 0.09 (± SD: 1.3). Spearman's test did not show a significant correlation between the ISI in UWFFA and VD in WF-OCTA (p = 0.803). CONCLUSIONS: Noninvasive WF-OCTA has great potential for the management of patients with DR. This new imaging modality might be useful in daily clinical routine in order to lower the number of invasive examinations. However, in a small percentage of patients, OCTA images cannot be reliably graded for the presence of NP and NV. In these cases, conventional FA needs to be performed.

Natural Course of Solar and Laser-Associated Retinal and Macular Injuries at a Primary Care Hospital in Switzerland.

BACKGROUND: Solar and laser-associated retinopathies are rare occurrences. The two retinopathies are both photo-induced but differ in the involved intensity and duration of exposure. The purpose of this study was to evaluate the clinical features and natural course of these two entities, with a focus on the changes in the outer retina over time. PATIENTS AND METHODS: This retrospective analysis assessed patients with solar or laser maculopathy seen at the Department of Ophthalmology of the University Hospital Zurich in Switzerland over the last 10 years. Visual acuity (VA; Snellen) and optical coherence tomography (OCT) findings were reviewed and analyzed at baseline and last follow-up visit. Areas of damaged outer retina, identified on en face OCT images as hyporeflective areas, were tagged and compared between visits. Descriptive analysis was performed by calculating mean values ± standard deviation (SD). Statistical evaluation was done using the Wilcoxon signed rank test. A p value < 0.05 was considered statistically significant. RESULTS: Five patients with solar retinopathy and six patients with laser-associated retinopathy were identified. In the solar retinopathy group, mean VA at baseline was 0.80 (SD ± 0.37) and improved to 0.90 (SD ± 0.36). This was not statistically significant (p = 0.066). In the laser-associated retinopathy group, mean VA at baseline was 0.89 (SD ± 0.18) and improved to 1.03 (SD ± 0.09), which was not statistically significant either (p = 0.063). At baseline, in OCT cross-sections, initial changes were observed in the interdigitation, myoid, and ellipsoid zone, as well as the outer nuclear layer and the Henle fiber layer. At follow-up, most cases presented an alteration in the residual ellipsoid zone, with the degree of the aforementioned alterations depending on the size of the initial defect. A decrease of the hyporeflective alterations measured in en face OCT scans was observed in both groups but was only statistically significant in the laser-associated retinopathy group (p = 0.018 versus p = 0.172). CONCLUSIONS: OCT can help to detect and monitor solar and laser-associated retinal injuries. Most injuries are minor, with good functional restitution. Minor changes in the ellipsoid zone often persist, even in cases with full visual recovery.

Analysis of Blood Flow in the Macula and Optic Nerve Head in Healthy Young Volunteers Using Laser Speckle Flowgraphy.

PURPOSE: To assess optic nerve head (ONH) and macular blood flow in young healthy volunteers using laser speckle flowgraphy (LSFG). METHODS: This is a prospective single-center study conducted at the Department of Ophthalmology, University Hospital Zurich from May to November 2021. Young, healthy men aged ≥ 18 years without ocular or systemic diseases were included. A corrected visual acuity (VA) of 0.0 logMAR or better in both eyes and an intraocular pressure (IOP) of 21 mmHg or lower were required for inclusion. Subjects exceeding a spherical equivalent (SE) of ± 6 diopters (dpt) were excluded. Blood flow in the macula and the ONH was recorded using the Nidek LSFG RetFlow device (Nidek Company, Ltd., Hirioshi-cho, Japan). Laser power was set to 0.5 Millivolts (mV). Mean blur rate (MBR) was recorded as a parameter for blood flow. MBR is a calculated parameter that represents relative blood flow velocity correlated with the real anatomical blood flow rate. Colored heat maps of the recorded retinal area were generated automatically by the RetFlow device. RESULTS: Final analyses included 83 eyes of 43 male volunteers. Mean age was 21.9 years (SD ± 1.5, range: 20 to 29). Mean corrected VA was - 0.1 logMAR (SD ± 0.05, range: - 0.2 to 0.0), mean IOP was 15.4 mmHg (SD ± 2.5, range: 8.5 to 18.5), and mean SE was - 0.3 dpt (SD ± 1.2, range: - 5.0 to 1.2). Mean ONH MBR was 37.44 (SD ± 7.9, range: 22.5 to 53.5) and mean macular MBR was 27.8 (SD ± 9.7, range: 6.4 to 57.7). Pearson's Test showed a strong correlation between macular and papillary blood flow (p < 0.05, coefficient: 0.647). CONCLUSION: This study provides both ONH and macular blood flow data in a healthy young male population, showing a strong correlation between ONH and macular blood flow in the examined eyes. Further investigations are required to assess the validity of MBR as a parameter for the combined evaluation of retinal blood flow at the macula and ONH in healthy volunteers and patients with various diseases.

Relationship of Vessel Density to Vessel Length Density in Patients with Treated Fabry Disease.

BACKGROUND: Fabry disease (FD) is a potentially lethal lysosomal disorder with systemic vascular changes. Previous studies demonstrated retinal vascular involvement using optical coherence tomography angiography (OCTA) in affected patients; Aim: To analyze and quantify the retinal vasculature measuring vessel density (VD), vessel length density (VLD), and the ratio of VD to VLD (VD/VLD) in superficial capillary plexuses (SCP) and deep capillary plexuses (DCP) using OCTA in patients with FD and to show whether they differ from healthy controls (HC); Patients and methods: Single-center, retrospective, consecutive cohort study of patients with genetically proven FD. Patients underwent an ophthalmological examination including OCTA. VD, VLD, foveal avascular zone (FAZ), and the VD/VLD were compared to an HC group using a linear mixed model; Results: A statistically significant difference in the VLD and VD/VLD of DCP was observed between the two groups (p < 0.001). Using ROC curves with AUC and Youden's Index, a cut-off value for differentiating both groups using VD/VLD in DCP FD with high specificity and high sensitivity was established; Conclusions: FD and HC groups seem to be separable using the VD/VLD ratio in DCP. This new biomarker might differentiate changes in the retinal microvasculature that are not detectable by VD or VLD alone.

Analysis of Optical Coherence Tomography (OCT) and Optical Coherence Tomography Angiography (OCTA) Parameters in Young Adults after SARS-CoV-2 Infection (COVID-19) Compared with Healthy Young Controls.

PURPOSE: To compare retinal changes in young adults with previous SARS-CoV-2 infection with healthy young controls using optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA). METHODS: This prospective single-center study was conducted at the University Hospital of Zurich, Zurich, Switzerland. Participants were imaged from May to November 2021 using the SOLIX device (Visionix International SAS, Pont-de-l'Arche, France). We performed 12 mm × 12 mm, 6.4 mm × 6.4 mm, 6 mm × 6 mm and 3 mm × 3 mm OCT and OCTA scans, as well as fundus photography of each participant's eyes. RESULTS: In total, 466 participants were imaged. Of these, 233 were healthy controls with negative RT-PCR tests for SARS-CoV-2, 168 were young adults who had a SARS-CoV-2 infection at least 180 days previously, 19 were participants who had a SARS-CoV-2 infection < 180 days previously, and 46 were participants with asymptomatic SARS-CoV-2 infection (i.e., serologically positive but with no symptoms). Compared with healthy controls, statistically significant differences were found for OCTA recordings of the optic disc for the whole image (WI) and WI capillary vessel density, with both being higher in the SARS-CoV-2 group. CONCLUSION: Statistically significant results were only observed for selected variables, and in parts, only unilaterally, with relatively large p values (p = 0.02-0.03). Thus, we did not interpret these as clinically significant, leading to the conclusion that young and otherwise healthy individuals (mainly men) seem to recover from mild COVID-19 infections with no ophthalmological residues.

Differences in Mean Values and Variance in Quantitative Analyses of Foveal OCTA Imaging.

PURPOSE: Multiple approaches for quantifying parameters such as vessel density (VD) and vessel length density (VLD) in optical coherence tomography angiography (OCTA) en-face segmentations are currently available. While it is common knowledge that data gathered from different methods should not be directly compared to each other, a comparison of the different methods can help to further the understanding of differences between different methods of measurement. Here we compare a common method of semiautomatically quantifying VD and VLD with an automated method supplied by the manufacturer of an OCTA device and report on differences in performance in order to probe for and highlight differences in values gathered by both methods. METHODS: OCTA was performed using the swept source PLEX Elite 9000 device, software version 2.0.1.47652 (Carl Zeiss Meditec Inc., Dublin, CA, USA). Scans of 3 mm × 3 mm from healthy volunteers centred on the fovea were acquired by a well-trained certified ophthalmologist. Scans with a signal strength of 8 out of 10 or higher were included. Quantitative parameters of the 3 mm × 3 mm cube scans were automatically generated and segmented into superficial capillary plexus (SCP) and deep capillary plexus (DCP) layers using layer segmentation produced by the instrument software and prototype analysis VD quantification software (Macular Density v.0.7.1, ARI Network Hub, Carl Zeiss Meditec Inc., Dublin, CA, USA) supplied by the manufacturer. An alternative approach of quantitative analysis of VD and VLD was performed manually with ImageJ (National Institutes of Health, Bethesda, Maryland, USA), as previously reported. VD was assessed as the ratio of the retinal area occupied by vessels. VDL was measured as the total length of the skeletonised vessels using 1-pixel centre line extraction of the blood vessels. RESULTS: We report differences in standard deviation (SD) in OCTA parameters obtained using different methods. The standard deviation of VD and VLD measurements was statistically significantly different in VD of 3 mm × 3 mm DCP (p = 0.009), VLD of 3 mm × 3 mm SCP (p = 0.000), and VLD of 3 mm × 3 mm DCP (p = 0.021). No statistically significant differences were found in VD of 3 mm × 3 mm SCP (p = 0.128) or VLD of 3 mm × 3 mm SCP (p = 0.107). CONCLUSIONS: As expected, we were able to demonstrate significant differences in quantitative OCTA parameters gathered from the same images using different methods of quantification. Values gathered using different methods are not interchangeable. In scientific studies and in situations where long-term follow-up is necessary, the same device and the same method of quantification should be used to maintain retrospective comparability of measurements.

Effect of Valsalva Maneuver on Choriocapillary Retinal Microvasculature.

PURPOSE: We aimed to identify and evaluate possible quantitative changes in retinal and choriocapillary blood flow utilizing optical coherence tomography angiography (OCTA) imaging in healthy study subjects during the Valsalva maneuver (VM). METHODS: OCTA imaging with a ZEISS PlexElite 9000 on one eye was performed. OCTA images were acquired before VM and 5 seconds after. Images were segmented and underwent projection removal using algorithms supplied by the manufacturer. Analysis of vessel density (VD) and vessel length density (VLD) were performed on superficial (SCP) and deep capillary plexus (DCP) layer slabs using ImageJ. ImageJ was also utilized for analyzing flow voids (FVs) in the choriocapillary slabs. RESULTS: Ten (8 right, 2 left) eyes of 10 (5 male, 5 female) healthy study subjects were included. Pre-VM, -VD, and -VLD were 0.428 (± 0.291) and 17.871 mm-1 (± 2.22 mm-1) in the SCP and 0.423 (± 0.0213) and 23.850 mm-1 (± 1.023 mm-1) in the DCP. Pre-VM and -FV were measured at 19.686 (± 1.959). During VM, VD, and VLD in the SCP were 0.417 (± 0.024) and 17.376 mm-1 (± 2.007 mm-1), and in the DCP, 0.426 (± 0.221) and 23.944 mm-1 (± 1.021 mm-1), respectively. FV post-VM was 20.440 (± 2.062). A paired samples t-test test revealed no significant changes in any of the observed parameters. CONCLUSION: We did not observe any significant changes in the VD, VLD, or FV. This might be due to autoregulatory processes in the ocular vasculature. Due to the small sample size, confidence intervals are comparatively large. Further study with more probands might yield different results.

Assessing Choroidal Nevi, Melanomas and Indeterminate Melanocytic Lesions Using Multimodal Imaging-A Retrospective Chart Review.

Using multimodal imaging, the literature proposed the following risk factors for choroidal nevus growth into melanoma: increased tumor thickness, subretinal fluid, decreased visual acuity, presence of orange pigment, ultrasound acoustic hollowness, and increased tumor diameter. This study investigated the presence of the mentioned risk factors in choroidal nevi, choroidal melanomas, and indeterminate choroidal melanocytic lesions. This retrospective, single-center chart review assessed choroidal melanocytic tumors with multimodal imaging. We defined our primary outcome as the cumulative presence of mentioned risk factors. Further, we evaluated various optical coherence tomography (OCT), ultrasound, and autofluorescence findings. We analyzed 51 tumors from 49 patients during the period from April 2008 to June 2021. The median (IQR) age was 64.0 (56.0 to 70.5) years, with 23 of 49 (46.9%) patients being female. The follow-up time for all tumors was median (IQR) 25.0 (12.0 to 39.0) months. The choroidal nevi had a median (range) risk score of 0.0 (0.0 to 3.0), and the choroidal melanoma of 5.0 (3.0 to 6.0), with statistically significant different ratings (p < 0.001). Multimodal imaging creates a score that may help to distinguish choroidal nevi from choroidal melanomas objectively.

Total Neuro-retinal Tubulation (TNT), a novel imaging finding.

A peculiar tubular structure was found in the left eye (LE) of a 71-year-old patient with diabetic retinopathy, who already had undergone panretinal-photocoagulation, detected by spectral-domain optical coherence tomography (SD-OCT) as an incidental finding. The reason for consultation was vitreous hemorrhage of the fellow-eye. Fundoscopic examination of LE revealed three oval retinal holes separated by small bridges of retinal tissue, which corresponded to tubular structures visible in SD-OCT, surrounded by photocoagulation scars. Optical coherence tomography B-scans of these structures revealed a tubular arrangement of tissue, composed of solid parts and hyporeflective cystoid spaces. Intermittent choroidal hypertransmission was detected deep to the tubular structures indicating impaired or absent retinal pigment epithelium (RPE). OCT-Angiography was performed using the Zeiss Plex Elite 9000 swept source device (Zeiss Meditec, Dublin, California, USA). Within the tubular structures, no flow signal was detected. Segmentation at the level of the outer retina choriocapillaris (ORCC) indicated partially intact choriocapillaris in the areas of tubular structures and retinal holes. We hypothesize that the tubular structures mainly consist of neuro-retinal tissue and propose the term total neuro-retinal tubulation (TNT). We postulate that the edge curling effect that leads to the tubular arrangement relates to focal retinal tears caused by tractional forces acting on the retina in this case by scarring in response to laser photocoagulation. Since the retinal periphery is more prone to retinal tears, widefield OCT imaging modalities are likely to offer further insights into this newly described finding and shed greater light on the biomechanical properties of the retina. Histopathological investigation is required to make a valid statement about the histology of TNT.

Assessment of Retinal Capillary Dropout after Transcatheter Aortic Valve Implantation by Optical Coherence Tomography Angiography.

Transcatheter aortic valve implantation (TAVI) is an alternative to open heart surgery in the treatment of symptomatic aortic valve stenosis, which is often the treatment of choice in elderly and frail patients. It carries a risk of embolic complications in the whole cerebral vascular bed, which includes the retinal vasculature. The main objective was the evaluation of retinal emboli visible on optical coherence tomography angiography (OCTA) following TAVI. This is a prospective, single center, observational study enrolling consecutive patients over two years. Patients were assessed pre- and post-TAVI. Twenty-eight patients were included in the final analysis, 82.1% were male, median age was 79.5 (range 52-88), median BCVA was 82.5 letters (range 75-93). Eight patients (28.6%) presented new capillary dropout lesions in their post-TAVI OCTA scans. There was no statistically significant change in BCVA. Quantitative analysis of macular or peripapillary OCTA parameters did not show any statistically significant difference in pre- and post-intervention. In conclusion, capillary dropout lesions could frequently be found in patients after TAVI. Quantitative measurements of macular and peripapillary flow remained stable, possibly indicating effective ocular blood flow regulation within the range of left ventricular ejection fraction in our cohort.

Differences between Mycobacterium chimaera and tuberculosis Using Ocular Multimodal Imaging: A Systematic Review.

Due to their non-specific diagnostic patterns of ocular infection, differential diagnosis between Mycobacterium (M.) chimaera and tuberculosis can be challenging. In both disorders, ocular manifestation can be the first sign of a systemic infection, and a delayed diagnosis might reduce the response to treatment leading to negative outcomes. Thus, it becomes imperative to distinguish chorioretinal lesions associated with M. chimaera, from lesions due to M. tuberculosis and other infectious disorders. To date, multimodal non-invasive imaging modalities that include ultra-wide field fundus photography, fluorescein and indocyanine green angiography, optical coherence tomography and optical coherence tomography angiography, facilitate in vivo examination of retinal and choroidal tissues, enabling early diagnosis, monitoring treatment response, and relapse detection. This approach is crucial to differentiate between active and inactive ocular disease, and guides clinicians in their decisional-tree during the patients' follow-up. In this review, we summarized and compared the available literature on multimodal imaging data of M. chimaera infection and tuberculosis, emphasizing similarities and differences in imaging patterns between these two entities and highlighting the relevance of multimodal imaging in the management of the infections.

Long-Term Clinical and Multimodal Imaging Findings in Patients with Disseminated Mycobacterium Chimaera Infection.

BACKGROUND: To analyze long-term ophthalmic clinical and multimodal imaging findings of disseminated Mycobacterium (M.) chimaera infection after cardiothoracic surgery among the Swiss Cohort. METHODS: Systemic and multimodal ophthalmic imaging and clinical findings including rate of recurrence were reviewed and correlated to a previously proposed classification system of choroidal lesions and classification of ocular disease. MAIN OUTCOMES MEASURES: long-term clinical and multimodal ocular imaging findings of M. chimaera. RESULTS: Twelve patients suffering from systemic infection from M. chimaera were included. Mean age at the first ophthalmic examination was 59 years (range from 48 to 66 years). Mean duration of the follow-up was 22.63 ± 17.8 months. All patients presented with bilateral chorioretinal lesions at baseline; 5 patients had additional signs, including optic disc swelling (2), choroidal neovascularization (1), retinal neovascularization (1) and cilioretinal vascular occlusion (1). Four recurrence events after discontinuation or adjustment of the antibiotic treatment were observed. Progressive choroiditis was seen in 5 patients under treatment, 4 of them deceased. CONCLUSIONS: Expertise from ophthalmologists is not only relevant but also critical for the assessment of the adverse drug effect of antimycobacterial treatment along with monitoring therapeutic response and identifying recurrences.

Acute and subacute macular and peripapillary angiographic changes in choroidal and retinal blood flow post-intravitreal injections.

Whether post injectional acute intraocular pressure (IOP) increase is associated with decreased peripapillary and macular perfusion is still under debate. Here, we investigated early changes in the choroidal and retinal blood flow using OCTA imaging in a cohort of patients undergoing anti-VEGF intravitreal injections (IVI) for macular edema following retinal vein occlusion and diabetic retinopathy. In this prospective single-center, observational study, the pre- and post-IVI changes in retinal perfusion were examined via assessment of vessel length density (VLD) and vessel density (VD) in deep and superficial capillary segmentations (DCP and SCP), foveal avascular zone (FAZ) in SCP, as well as flow signal deficits in the choriocapillaris segmentation. Mean IOP significantly changed over the study course (p = 0.000; ANOVA). Measurements at 5 min post-IVI (33.48 ± 10.84 mmHg) differed significantly from baseline (17.26 ± 2.41 mmHg, p = 0.000), while measurements from one day, one week, and one-month post-IVI did not (p = 0.907, p = 1.000 and p = 1.000 respectively). In comparison to baseline, no changes in OCTA parameters, including FAZ, VD, VLD, and FV, were detected 5 min post-IVI. No significant alterations in OCTA parameters were observed during study course. Increased IOP spikes were detected post-IVI; however, no potential permanent ischemic retinal damage was suspected.