Development and Resolution of Subfoveal Lucency and Hyperreflective Deposits Following Silicone Oil Insertion and Removal.

Silicone oil (SO) is commonly used as a retinal tamponade during pars plana vitrectomy for complicated retinal detachments. Although fairly inert, complications such as cataract formation, intraocular pressure elevation, corneal changes, inner retinal thinning, and optic neuropathy have been noted. We report two cases of postoperative subfoveal outer retinal lucency and hyperreflective deposits following SO insertion and resolution following removal. [Ophthalmic Surg Lasers Imaging Retina 2024;55:XX-XX.].

A rigorous and versatile statistical test for correlations between stationary time series.

In disciplines from biology to climate science, a routine task is to compute a correlation between a pair of time series and determine whether the correlation is statistically significant (i.e., unlikely under the null hypothesis that the time series are independent). This problem is challenging because time series typically exhibit autocorrelation and thus cannot be properly analyzed with the standard iid-oriented statistical tests. Although there are well-known parametric tests for time series, these are designed for linear correlation statistics and thus not suitable for the increasingly popular nonlinear correlation statistics. There are also nonparametric tests that can be used with any correlation statistic, but for these, the conditions that guarantee correct false positive rates are either restrictive or unclear. Here, we describe the truncated time-shift (TTS) test, a nonparametric procedure to test for dependence between 2 time series. We prove that this test correctly controls the false positive rate as long as one of the time series is stationary, a minimally restrictive requirement among current tests. The TTS test is versatile because it can be used with any correlation statistic. Using synthetic data, we demonstrate that this test performs correctly even while other tests suffer high false positive rates. In simulation examples, simple guidelines for parameter choices allow high statistical power to be achieved with sufficient data. We apply the test to datasets from climatology, animal behavior, and microbiome science, verifying previously discovered dependence relationships and detecting additional relationships.

Demographics, Presenting Features, and Outcomes of Adult Patients with Ocular Trauma.

Introduction: Ocular trauma is a common cause of permanent vision loss in adults. The combination of an accurate clinical examination and imaging offers the best prognostic indicators for patients and helps to navigate treatment modalities. This is a retrospective chart review of examination and imaging findings for ocular trauma and how they correlate with treatment course and visual acuity (VA) outcomes. Methods: Adult patients with ocular trauma presenting to a single institution between January 2013 and December 2020 were evaluated. Initial examination and imaging findings were compared for associations with each other and with VA outcomes. Results: 136 ocular traumas on 134 patients were included. The median presenting logMAR VA was 2.7 (interquartile range (IQR) 1.2-3.7) with 62% open globe injuries. The most commonly reported finding on initial CT scan was globe deformity (30%), on B-scan was choroidal detachment (20%), and on ultrasound biomicroscopy was intraocular foreign body, ciliochoroidal effusions, or angle recession (21% each). Worse vision was observed for patients positive for retinal detachment on initial B-scan compared to those negative for this finding at 6-month (median logMAR 2.7 vs. 0.5; P < 0.0001) and at final post-injury evaluation (median logMAR 3.7 vs. 0.4; P < 0.0001). Similarly, worse VA was observed for patients with choroidal detachment on initial B-scan compared to those without this finding at 6-month (median logMAR 1.4 vs. 0.5; P = 0.002) and at final post-injury evaluation (median logMAR 2.0 vs. 0.4; P < 0.0001). If positive conjunctiva/sclera examination findings were identified, 66% had positive findings on B-scan, whereas if the conjunctiva/sclera examination findings were absent, 41% had positive findings on B-scan (P = 0.005). If anterior chamber (AC) examination findings were positive, 59% had positive findings on B-scan, whereas if the AC examination findings were absent, 37% had positive findings on B-scan (P = 0.03). Discussion. The predictive value of examination findings in this study may offer insight as to long-term visual prognosis. Positive B-scan or CT findings should increase suspicion for open globe injuries.

Comparing Three-Dimensional Digitally Enabled Intraoperative OCT With Conventional Microscope-Integrated OCT in Vitreoretinal Surgery: A Post Hoc Analysis of the DISCOVER Study.

BACKGROUND AND OBJECTIVE: This study compared the surgeon experience between conventional microscope-integrated intraoperative optical coherence tomography (iOCT) and digitally enabled microscope-integrated iOCT in vitreoretinal surgery. PATIENTS AND METHODS: This is a post hoc case-control analysis of the DISCOVER study. Conventional microscope-integrated iOCT (Rescan 700, Zeiss) was compared with digitally enabled iOCT (Artevo 800, Zeiss). Compared variables included surgical field-based visualization (ie, ocular heads-up display in the conventional group; three-dimensional screen-based visualization in the digital iOCT group) and non-surgical field-based visualization (ie, review on the external two-dimensional monitor). RESULTS: A total of 200 patients were included. Surgical field-based visualization of iOCT was significantly higher in the digitally enabled group (P < 0.0001). Required endoillumination level was significantly lower in the digital iOCT group (P < 0.0001). Surgeons reported "significant" back discomfort and headache more frequently when using conventional iOCT (P = 0.003 and P = 0.001, respectively). CONCLUSIONS: Digitally enabled iOCT resulted in greater surgical visualization efficiency, appeared to require a lower illumination level, and may provide advantages for ergonomic-related discomfort. [Ophthalmic Surg Lasers Imaging Retina 2024;55:270-277.].

Extracellular vesicle biomarkers in ocular fluids associated with ophthalmic diseases.

Extracellular vesicles (EVs) are released as highly stable lipid bilayer particles carrying proteins, lipids, glycans and miRNAs. The contents of EVs vary based on the cellular origin, biogenesis route and the functional state of the cell suggesting certain diseased conditions. A growing body of evidence show that EVs carry important molecules implicated in the development and progression of ophthalmic diseases. EVs associated with ophthalmic diseases are mainly carried by one of the three ocular biofluids which include tears, aqueous humor and vitreous humor. This review summarizes the list of EV derived biomarkers identified thus far in ocular fluids for ophthalmic disease diagnosis. Further, the methods used for sample collection, sample volume and the sample numbers used in these studies have been highlighted. Emphasis has been given to describe the EV isolation and the characterization methods used, EV size profiled and the EV concentrations analyzed by these studies, thus providing a roadmap for future EV biomarker studies in ocular fluids.

Short-Term Outcomes of Faricimab in Patients with Neovascular Age-Related Macular Degeneration on Prior Anti-VEGF Therapy.

PURPOSE: A subset of patients with neovascular age-related macular degeneration (nAMD) experience treatment burden and suboptimal response with anti-VEGF therapy. The aim of this study was to investigate the effect of switching to a novel, bispecific agent, faricimab, in patients with nAMD currently treated with anti-VEGF. DESIGN: Retrospective, noncomparative cohort study. SUBJECTS: Patients with nAMD previously treated with anti-VEGF and switched to intravitreal faricimab injection (IFI) at the Cleveland Clinic's Cole Eye Institute. METHODS: Switching and administration schedule of IFI was at the discretion of the clinician. Visual acuity (VA) and macular OCT parameters, including central subfield thickness (CST), maximum pigment epithelial detachment (PED) height, and presence of subretinal (SRF) or intraretinal fluid (IRF), were assessed at baseline (day of first IFI) and after each IFI. MAIN OUTCOME MEASURES: Central subfield thickness and presence of IRF or SRF after ≥ 3 IFIs. RESULTS: One hundred twenty-six eyes of 106 patients were included in the analysis with a mean follow-up time of 24.3 ± 5.2 weeks. Before switching to IFI, patients received a mean of either aflibercept (20.0 ± 8.4, mean ± standard deviation), bevacizumab (7 ± 8.9), ranibizumab (1.9 ± 8.5), or brolucizumab (0.3 ± 1.6) injections. The most common agent used before switching to IFI was aflibercept (n = 110, 87%), and the mean treatment interval with any anti-VEGF was 5.6 ± 1.6 weeks before switching. Central subfield thickness was reduced from baseline after the first IFI (266.8 ± 64.7 vs. 249.8 ± 58.6 µm, P = 0.02) and persisted over the 3 IFIs (P = 0.01). Pigment epithelial detachment height was reduced after the third IFI (249.6 ± 179.0 vs. 206.9 ± 130.0 µm, P = 0.01). The mean VA (62.9 vs. 62.7 approximate ETDRS letters, P = 0.42) and interval between injections (6.3 vs. 5.7 weeks, P = 0.16) was similar after the third IFI compared with baseline. Eleven (8.7%) eyes were switched back to their previous anti-VEGF, including 2 (1.6%) eyes from 1 patient with intraocular inflammation requiring cessation of IFI. There were no other adverse events from switching. CONCLUSIONS: Switching to faricimab resulted in a reduction in mean CST (-11.6 µm, P = 0.01) and PED height (-44.2 µm, P = 0.01) after 3 injections, with stable VA and at a similar treatment interval to prior anti-VEGF therapy. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Collective production of hydrogen sulfide gas enables budding yeast lacking MET17 to overcome their metabolic defect.

Assimilation of sulfur is vital to all organisms. In S. cerevisiae, inorganic sulfate is first reduced to sulfide, which is then affixed to an organic carbon backbone by the Met17 enzyme. The resulting homocysteine can then be converted to all other essential organosulfurs such as methionine, cysteine, and glutathione. This pathway has been known for nearly half a century, and met17 mutants have long been classified as organosulfur auxotrophs, which are unable to grow on sulfate as their sole sulfur source. Surprisingly, we found that met17Δ could grow on sulfate, albeit only at sufficiently high cell densities. We show that the accumulation of hydrogen sulfide gas underpins this density-dependent growth of met17Δ on sulfate and that the locus YLL058W (HSU1) enables met17Δ cells to assimilate hydrogen sulfide. Hsu1 protein is induced during sulfur starvation and under exposure to high sulfide concentrations in wild-type cells, and the gene has a pleiotropic role in sulfur assimilation. In a mathematical model, the low efficiency of sulfide assimilation in met17Δ can explain the observed density-dependent growth of met17Δ on sulfate. Thus, having uncovered and explained the paradoxical growth of a commonly used "auxotroph," our findings may impact the design of future studies in yeast genetics, metabolism, and volatile-mediated microbial interactions.

BEST1 Variant Associated with an Atypical Macular and Peripheral Retinal Phenotype.

PURPOSE: Best vitelliform macular dystrophy (BVMD) is an inherited macular dystrophy associated with over 250 pathogenic variants of the Bestrophin-1 (BEST1) gene. While several of the types of lesions of BVMD are well-described, reports of phenotypic variations associated with rare genetic variants are limited. METHODS: Retrospective case-series performed in 2021 at a tertiary eye care center. PATIENTS: Three members of one family referred to a tertiary eye care clinic for evaluation of their autosomal dominant macular dystrophy. RESULTS: Study subjects presented with atypical findings of peripheral schisis-like lesions and atrophy with abnormal electroretinogram (ERG) in addition to typical macular lesions found in BVMD. Genetic analyses identified a heterozygous BEST1 c.227T>A, p.(Ile76Asn) pathogenic variant in all three subjects. CONCLUSIONS: This study represents the first report of the phenotype associated with the c.227T>A, p.(Ile76Asn) BEST1 variant, which - while mentioned twice in the literature - has not been previously described. The phenotype is unique, comprising features of typical BVMD with ERG and peripheral findings, suggestive of a panretinal dysfunction.

Patient-specific computational models of retinal prostheses.

Retinal prostheses stimulate inner retinal neurons to create visual perception for blind patients. Implanted arrays have many small electrodes. Not all electrodes induce perception at the same stimulus amplitude, requiring clinicians to manually establish a visual perception threshold for each one. Phosphenes created by single-electrode stimuli can also vary in shape, size, and brightness. Computational models provide a tool to predict inter-electrode variability and automate device programming. In this study, we created statistical and patient-specific field-cable models to investigate inter-electrode variability across seven epiretinal prosthesis users. Our statistical analysis revealed that retinal thickness beneath the electrode correlated with perceptual threshold, with a significant fixed effect across participants. Electrode-retina distance and electrode impedance also correlated with perceptual threshold for some participants, but these effects varied by individual. We developed a novel method to construct patient-specific field-cable models from optical coherence tomography images. Predictions with these models significantly correlated with perceptual threshold for 80% of participants. Additionally, we demonstrated that patient-specific field-cable models could predict retinal activity and phosphene size. These computational models could be beneficial for determining optimal stimulation settings in silico, circumventing the trial-and-error testing of a large parameter space in clinic.

Clinical Utility of Spectral-Domain Optical Coherence Tomography Marker Disorganization of Retinal Inner Layers in Diabetic Retinopathy.

BACKGROUND AND OBJECTIVE: Disorganization of retinal inner layers (DRIL) is a potential spectral-domain optical coherence tomography (SD-OCT) imaging biomarker with clinical utility in diabetic retinopathy (DR). PATIENTS AND METHODS: A cross-sectional study was conducted at a large academic center. The cohort was composed of 1,175 patients with type 2 diabetes with and without retinopathy on initial examination between September 2009 and January 2019 (n = 2,083 eyes). DR risk and progression factors were obtained from the medical record. Trained graders masked to patients' clinical histories evaluated SD-OCT scans for DRIL. RESULTS: Of 2,083 eyes, 28.1% (n = 585) demonstrated presence of DRIL with high interrater reliability (K = 0.88, 95% CI 0.86-0.90). DRIL was associated with worse visual acuity (VA) (P < 0.001) and DR severity (P < 0.0001). Insulin users had more severe DR (P < 0.0001). DR-related factors, race (Black, White) and sex (male) were significantly associated with DRIL (P < 0.05). CONCLUSIONS: DRIL was strongly associated with DR severity and worse VA, supporting its utility as an unfavorable prognostic indicator. [Ophthalmic Surg Lasers Imaging Retina 2023;54:692-700.].

Outcomes of a Multicenter 10-Year Review of Postinjection Endophthalmitis and Associated Systemic Medical Comorbidities.

Purpose: To investigate whether any systemic medical conditions may be associated with a higher risk for developing postinjection endophthalmitis. Methods: This case-control study is a retrospective review within the Emory Eye Center from 2009 to 2019 and The Cleveland Clinic Foundation from 2012 to 2019. Each case was matched in a 1:4 case-to-control ratio. The associations between medical comorbidities and endophthalmitis were explored using multivariable logistic regression models on the combined sample. Results: Sixty-six individuals were diagnosed with injection-associated endophthalmitis. Systemic immunocompromised status was found to be a risk factor associated with developing endophthalmitis with an adjusted odds ratio (aOR) of 3.17 (P = .009). Other conditions with increased risk approaching statistical significance included a history of pulmonary disease (aOR, 1.74; P = .08) and a history of smoking (aOR, 1.72; P = .06). Conclusions: This is the first report to our knowledge demonstrating that immunocompromised status is associated with an increased risk for developing postinjection endophthalmitis. While this study may be limited due to its retrospective nature, the result may nevertheless serve as a guidance for risk counseling. Future analysis using a large-scale database will be needed.

Patient-specific computational models of retinal prostheses.

Retinal prostheses stimulate inner retinal neurons to create visual perception for blind patients. Implanted arrays have many small electrodes, which act as pixels. Not all electrodes induce perception at the same stimulus amplitude, requiring clinicians to manually establish a visual perception threshold for each one. Phosphenes created by single-electrode stimuli can also vary in shape, size, and brightness. Computational models provide a tool to predict inter-electrode variability and automate device programming. In this study, we created statistical and patient-specific field-cable models to investigate inter-electrode variability across seven epiretinal prosthesis users. Our statistical analysis revealed that retinal thickness beneath the electrode correlated with perceptual threshold, with a significant fixed effect across participants. Electrode-retina distance and electrode impedance also correlated with perceptual threshold for some participants, but these effects varied by individual. We developed a novel method to construct patient-specific field-cable models from optical coherence tomography images. Predictions with these models significantly correlated with perceptual threshold for 80% of participants. Additionally, we demonstrated that patient-specific field-cable models could predict retinal activity and phosphene size. These computational models could be beneficial for determining optimal stimulation settings in silico, circumventing the trial-and-error testing of a large parameter space in clinic.

Deep Learning Algorithm Detects Presence of Disorganization of Retinal Inner Layers (DRIL)-An Early Imaging Biomarker in Diabetic Retinopathy.

Purpose: To develop and train a deep learning-based algorithm for detecting disorganization of retinal inner layers (DRIL) on optical coherence tomography (OCT) to screen a cohort of patients with diabetic retinopathy (DR). Methods: In this cross-sectional study, subjects over age 18, with ICD-9/10 diagnoses of type 2 diabetes with and without retinopathy and Cirrus HD-OCT imaging performed between January 2009 to September 2019 were included in this study. After inclusion and exclusion criteria were applied, a final total of 664 patients (5992 B-scans from 1201 eyes) were included for analysis. Five-line horizontal raster scans from Cirrus HD-OCT were obtained from the shared electronic health record. Two trained graders evaluated scans for presence of DRIL. A third physician grader arbitrated any disagreements. Of 5992 B-scans analyzed, 1397 scans (∼30%) demonstrated presence of DRIL. Graded scans were used to label training data for the convolution neural network (CNN) development and training. Results: On a single CPU system, the best performing CNN training took ∼35 mins. Labeled data were divided 90:10 for internal training/validation and external testing purpose. With this training, our deep learning network was able to predict the presence of DRIL in new OCT scans with a high accuracy of 88.3%, specificity of 90.0%, sensitivity of 82.9%, and Matthews correlation coefficient of 0.7. Conclusions: The present study demonstrates that a deep learning-based OCT classification algorithm can be used for rapid automated identification of DRIL. This developed tool can assist in screening for DRIL in both research and clinical decision-making settings. Translational Relevance: A deep learning algorithm can detect disorganization of retinal inner layers in OCT scans.

A novel ocular phenotype associated with pathogenic variants in MFSD8 leading to macular dystrophy.

BACKGROUND: The major facilitator superfamily domain-containing protein 8 (MFSD8) pathogenic variants are classically associated with autosomal recessive neuronal ceroid lipofuscinosis-7. Case reports have recently demonstrated an association of MFSD8 variants causing autosomal recessive macular dystrophy with central cone involvement without neurologic sequelae. We report a patient with a novel ocular phenotype associated with MFSD8 pathogenic variants causing macular dystrophy without systemic findings. CASE PRESENTATION: A 37-year-old female presented with a 20-year history of progressive bilateral vision loss. Fundus examination was notable for a slight pigmentary ring around the fovea in both eyes. Optical coherence tomography (OCT) of the macula showed bilateral subfoveal ellipsoid zone loss without outer retinal changes. Fundus autofluorescence (FAF) demonstrated foveal hypo-autofluorescence (AF) in both eyes as well as hyper-AF nasally to the optic nerve in the perifoveal area. Full-field and multifocal electroretinography demonstrated cone dysfunction with diffuse macular changes in both eyes. Subsequent genetic testing identified two pathogenic MFSD8 variants. The patient had no neurologic symptoms consistent with variant-late infantile neuronal ceroid lipofuscinosis. CONCLUSION: MFSD8 pathogenic variants are known to cause macular dystrophies. We report a novel MFSD8-associated macular dystrophy phenotype demonstrating foveal-limited disease with cavitary changes on OCT without inner retinal atrophy and foveal-specific changes on FAF. A threshold model can explain how a hypomorphic missense variant heterozygous with a loss-of-function nonsense variant can lead to a predominantly ocular phenotype with preserved neurologic function. We recommend careful monitoring of these patients for future signs of both retinal and systemic disease progression.

Vitreoretinal lymphoma with central nervous system involvement in a patient with sarcoidosis: a case report.

PURPOSE: To describe a case of primary vitreoretinal lymphoma with central nervous system involvement in a patient with sarcoidosis. METHODS: Single, retrospective chart review. PATIENT: A 59-year-old male with sarcoidosis. RESULTS: The patient presented with a 3-year history of bilateral panuveitis thought secondary to his sarcoidosis diagnosed 11 years prior. Shortly before presentation, the patient demonstrated recurrent uveitis with a lack of response to aggressive immunosuppression therapy. At presentation, ocular exam showed significant anterior and posterior inflammation. Fluorescein angiography demonstrated hyperfluorescence of the optic nerve with late and small vessel leakage in the right eye. The patient also described a two-month history of memory and word-finding deficits. An inflammatory and infectious disease work-up was unremarkable. A brain MRI showed multiple enhancing periventricular lesions with vasogenic edema, while a lumbar puncture was negative for malignant cells. A diagnostic pars plana vitrectomy confirmed a diagnosis of large B-cell lymphoma. CONCLUSION: Sarcoidosis and vitreoretinal lymphoma are known masqueraders. Recurrent inflammation typical of sarcoid uveitis may mask a more sinister diagnosis such as vitreoretinal lymphoma. Furthermore, sarcoid uveitis treatment with corticosteroids may transiently improve symptoms but further delay a timely diagnosis of primary vitreoretinal lymphoma.

Data-driven causal analysis of observational biological time series.

Complex systems are challenging to understand, especially when they defy manipulative experiments for practical or ethical reasons. Several fields have developed parallel approaches to infer causal relations from observational time series. Yet, these methods are easy to misunderstand and often controversial. Here, we provide an accessible and critical review of three statistical causal discovery approaches (pairwise correlation, Granger causality, and state space reconstruction), using examples inspired by ecological processes. For each approach, we ask what it tests for, what causal statement it might imply, and when it could lead us astray. We devise new ways of visualizing key concepts, describe some novel pathologies of existing methods, and point out how so-called 'model-free' causality tests are not assumption-free. We hope that our synthesis will facilitate thoughtful application of methods, promote communication across different fields, and encourage explicit statements of assumptions. A video walkthrough is available (Video 1 or https://youtu.be/AIV0ttQrjK8).

Rapid symptomatic and structural improvement of a retinal astrocytic hamartoma in response to anti-VEGF therapy: A case report.

Purpose: To describe a patient with bilateral peripapillary astrocytic hamartomas with exudation of subretinal fluid into the macula and loss of vision without evidence of choroidal neovascularization. The patient rapidly responded to intravitreal bevacizumab injections resulting in reduced subretinal fluid and clinical improvement. Observation: A 70-year-old female presented with worsening vision in her left eye due to subretinal fluid exudation from a peripapillary astrocytic hamartoma. The patient was treated with two doses of bevacizumab with rapid improvement in vision and resolution of subretinal fluid. Genetic testing was negative for common pathogenic variants for tuberous sclerosis and neurofibromatosis, which are highly associated with bilateral optic nerve and retinal astrocytic hamartomas. Conclusion: Astrocytic hamartomas with exudation may be responsive to bevacizumab suggesting a dependence of these lesions on vascular endothelial growth factor (VEGF) independent of secondary choroidal neovascularization. Furthermore, this case describes a patient with bilateral astrocytic hamartomas without genetic or clinical confirmation of associated phakomatoses, such as tuberous sclerosis and neurofibromatosis.

RaacFold: a webserver for 3D visualization and analysis of protein structure by using reduced amino acid alphabets.

Protein structure exhibits greater complexity and diversity than DNA structure, and usually affects the interpretation of the function, interactions and biological annotations. Reduced amino acid alphabets (Raaa) exhibit a powerful ability to decrease protein complexity and identify functional conserved regions, which motivated us to create RaacFold. The RaacFold provides 687 reduced amino acid clusters (Raac) based on 58 reduction methods and offers three analysis tools: Protein Analysis, Align Analysis, and Multi Analysis. The Protein Analysis and Align Analysis provide reduced representations of sequence-structure according to physicochemical similarities and computational biology strategies. With the simplified representations, the protein structure can be viewed more concise and clearer to capture biological insight than the unreduced structure. Thus, the design of artificial protein will be more convenient, and redundant interference is avoided. In addition, Multi Analysis allows users to explore biophysical variation and conservation in the evolution of protein structure and function. This supplies important information for the identification and exploration of the nonhomologous functions of paralogs. Simultaneously, RaacFold provides powerful 2D and 3D rendering performance with advanced parameters for sequences, structures, and related annotations. RaacFold is freely available at http://bioinfor.imu.edu.cn/raacfold.

Severe retinal complications in Knobloch Syndrome - Three siblings without clinically apparent occipital defects and a review of the literature.

BACKGROUND: Knobloch syndrome results from recessive mutations in COL18A1 and is characterized by retinopathy and occipital scalp, brain and skull defects. METHODS AND MATERIALS: We report three siblings, born to consanguineous parents, two of whom with genetically confirmed Knobloch syndrome due to a homozygous pathogenic variant c.4054_4055del; p.Leu1352Valfs*72 in COL18A1. RESULTS: With the lack of classic occipital findings, an initial diagnosis of familial exudative vitreoretinopathy was entertained in these siblings because of the history of retinal detachments, retinal pigmentary changes and abnormal vitreous. The diagnosis of Knobloch syndrome was eventually made through molecular genetic testing using an extensive panel. In one patient presenting with acute retinal detachment and posteriorly dislocated intraocular lens implant, reattachment surgery was successful in stabilizing vision. CONCLUSION: The clinical diagnosis of Knobloch syndrome can be difficult to reach in the absence of the typical occipital scalp defects. A careful medical history, detailed clinical examination and molecular genetic testing will reveal the correct diagnosis of Knobloch syndrome in atypical cases.

Suppression of electromagnetic interference in electroretinography from a patient with an implanted left ventricular assist device (LVAD).

PURPOSE: A left ventricular assist device (LVAD) is an implantable cardiac pump that uses a magnetically-levitating rotor to pump blood into circulation for patients with congestive heart failure. The continuous high-frequency motion of the pump can cause significant interference in electroretinography (ERG) recordings. We evaluate filtering methods to improve ERG quality in the presence of LVAD interference. METHODS: A patient with an implanted LVAD was referred to our clinic for ERG testing on suspicion of a retinal dystrophy. Full-field ERG (ffERG) and pattern ERG (pERG) were performed according to ISCEV standards. Recordings were acquired once in full-bandwidth mode and again in low-bandwidth mode. Digital low-pass and band-stop filtering were performed to mitigate ERG interference. Post-processing was also evaluated in a control subject with no implanted device. RESULTS: High-frequency interference was present in all ERG recordings and corresponded to the speed settings of the pump. When applied in post-processing, both low-pass and band-stop filters suppressed the interference and presented readable ERGs without affecting peak times or amplitudes. By contrast, when recording in low-bandwidth mode, the filter drop-off was not steep enough to completely remove the interference and peak delays were introduced that could not be readily corrected. CONCLUSIONS: LVAD interference in ERG waveforms can be successfully removed using simple digital filters. If post hoc data processing capabilities are unavailable, a large amount of interference can be removed by narrowing the acquisition bandwidth and averaging additional repeats of each stimulus response.