Frequency of anti-retinal antibodies in normal human serum

Electrodiagnostic Tests as Potential Efficacy Endpoints in Clinical Trials of Novel Pharmacological Therapies for Acquired Retinal Disorders

BACKGROUND

Electrodiagnostic tests (EDTs) provide non-invasive, objective, and measurable indications of retinal and visual pathway function. These hold the promise of evaluating drug efficacy and disease progression over shorter periods than traditional "end-stage" outcome measures (e.g., best-corrected visual acuity) in various ophthalmological pathologies. The International Society for Clinical Electrophysiology of Vision has defined rigorous standards for EDTs, intended to optimize diagnostic power, enabling meaningful inter-laboratory comparisons and facilitating application as outcome measures in increasing numbers of multicentre clinical trials.

SUMMARY

This review outlines the main EDTs, including full-field, pattern, and multifocal electroretinography; the electro-oculogram; and the cortical visual-evoked potential, and highlights the possible role for monitoring disease progression and assessing treatment safety and efficacy. The utility and potential of EDTs are highlighted in studies that have assessed function and tested or monitored treatment safety or efficacy for a range of acquired retinal and optic nerve disorders, including central retinal vein occlusion, diabetic retinopathy, glaucoma, age-related macular degeneration, posterior uveitis, and autoimmune-related retinopathies.

KEY MESSAGES

EDTs are fundamental to the diagnosis and phenotyping of many acquired retinal and visual pathway disorders. They also provide methods for the objective assessment of the efficacy and safety of potential novel treatments across short periods. Conventional psychophysical tests, such as visual acuity, are of limited value in localizing and characterizing dysfunction and are not always suitable for monitoring purposes. This review highlights where EDTs may address the need for better outcome measures to evaluate novel treatments within clinical trials, helping to select early treatment candidates and for the assessment of safety and efficacy.

Hematopoietic stem cell transplantation as rescue therapy for refractory autoimmune retinopathy: a case report

Autoimmune retinopathy (AIR) is a rare, potentially blinding retinal disease that remains a challenging condition to manage when resistant to conventional immune-modulatory approaches. We report clinical and electrophysiological improvement in a 49-year-old patient who underwent an autologous hematopoietic stem cell transplant (aHSCT) for thymoma-associated AIR after experiencing progressive disease despite receiving periocular and systemic steroids, mycophenolate mofetil, baricitinib, tacrolimus, bortezomib, rituximab, plasmapheresis, and intravenous immunoglobulin. The aHSCT had two stages: (i) peripheral blood stem cell harvest following mobilization with cyclophosphamide and granulocyte colony-stimulating factor, and (ii) conditioning regimen with plasmapheresis, rituximab, cyclophosphamide, and anti-thymocyte globulin high-dose therapy, followed by autologous hematopoietic cell infusion of 5.74 million cells. Symptoms of photopsia rapidly abated after undergoing aHSCT, and objective investigations of structure and function similarly demonstrated improvement. At 22 months' follow-up, she continued to demonstrate the durability of the clinical response. The present report suggests that in judiciously selected patients, HSCT may provide a rescue option for refractory AIR. Further cases are needed to confirm these results.

Vitreous Haemorrhage and Retinal Neovascularization Secondary to Peripheral Retinal Ischemia as the Presenting Sign of a Disseminated Melanoma

PURPOSE

We describe a case of vitreous haemorrhage and retinal neovascularization secondary to peripheral retinal ischemia associated with disseminated melanoma.

METHODS

A retrospective case report.

RESULTS

A 48-year-old man presented with vitreous haemorrhage in the right eye, peripheral retinal ischemia, and retinal neovascularization in both eyes. CT and MRI scans were suggestive of disseminated malignancy and an ultrasound-guided biopsy of the abdominal mass confirmed metastatic melanoma. Immune checkpoint inhibitor therapy with ipilimumab/nivolumab was initiated. Regarding his ocular status, the vitreous haemorrhage cleared spontaneously, visual acuity improved to 6/7.5 and the patient underwent bilateral peripheral scatter laser photocoagulation to stabilize the retinopathy. The patient passed away 1 year after the initial presentation.

CONCLUSION

 Our patient presented with melanoma and peripheral retinal ischaemia, leading to retinal neovascularization and vitreous haemorrhage. Therefore, melanoma should be considered as a differential diagnosis when investigating the aetiology of peripheral retinal ischaemia.

Retinal Sublayer Analysis in Autoimmune Retinopathy and Identification of New Optical Coherence Tomography Phenotypes

PURPOSE

Autoimmune retinopathy (AIR) is a poorly characterized disease with a wide phenotypic spectrum, complicating investigations of its underlying pathophysiology. We sought to analyze optical coherence tomography (OCT) retinal thickness changes in AIR patients.

METHODS

A retrospective chart review from 2007 to 2017 was performed evaluating AIR patients at a single academic, tertiary referral center. OCT retinal sublayer analysis was performed, and paradoxical thickening phenotypes were reviewed.

RESULTS

Twenty-nine AIR patients with positive anti-retinal antibodies and OCT imaging were identified. Overall, AIR patients had thinner retinal sublayers compared to controls; however, 12 patients (41.4%) had paradoxical thickening of the outer plexiform layer (OPL). This revealed two distinct OCT phenotypes. No association was found between retinal sublayer thickness and specific antiretinal antibodies.

CONCLUSIONS

While the pathogenicity of antiretinal antibodies remains unclear, the OCT phenotypes observed underscore the potential for identifying clues in the underlying disease processes and clinical diagnosis.

Comparison of Clinical and Immunological Features of Para- and Non-Paraneoplastic Autoimmune Retinopathy in Chinese - A Series of 48 Cases

PURPOSE

To characterize and compare clinical and immunological features of para(p)-autoimmune retinopathy (AIR) and non-para(np)-AIR and to assess the clinical significance of the presence of serum anti-retinal antibodies (ARAs).

METHODS

We retrospectively reviewed 48 Chinese patients with p-AIR or np-AIR who took comprehensive ophthalmic examinations and lab tests of the presence of serum ARAs.

RESULTS

p-AIR patients differed from np-AIR patients in terms of disease progression, ocular inflammation, findings of OCT, FFA, and presence of ARAs. No significant difference was found in the band number of serum ARAs between AIR patients and healthy controls. The prevalence of antibodies to recoverin and ɑ-enolase in the sera of p-AIR was significantly higher than that of the healthy individuals.

CONCLUSION

While having many similar clinical signs, patients with p-AIR or np-AIR nevertheless displayed unique characteristics. Detection of ARAs subtypes, rather than their quantity, may be helpful in evaluating the conditions in the verified instances.

Anti-retinal Antibodies in Sarcoidosis

PURPOSE

To measure, characterize, and evaluate the clinical significance of anti-retinal antibodies in patients with sarcoid uveitis.

SUBJECTS/METHODS

Prospective study of anti-retinal antibodies in 45 patients with biopsy-proven sarcoidosis (25 with and 20 without uveitis). Results were compared with patients with confirmed infectious uveitis (n = 40) and non-infectious uveitis (n = 40).

RESULTS

Among sarcoidosis patients, anti-retinal antibodies were positive in 23/25 patients with uveitis and in 15/20 without uveitis [P = ns]. The most common antigens recognized were carbonic anhydrase II (14/23) and α-enolase (6/23). Anti-carbonic anhydrase II autoantibodies were infrequently detected in sarcoidosis patients without uveitis (2 out 15, P < .001), in patients with infectious uveitis (1 out 18, P < .001), and in patients with non-infectious uveitis (8 out 37, P < .001).

CONCLUSIONS

Anti-retinal antibodies recognizing carbonic anhydrase II are common in sarcoid uveitis. Although not fully sensitive and specific, they might be a useful non-invasive diagnostic tool for the diagnosis of sarcoid uveitis.

Association of Circulating Antiretinal Antibodies With Clinical Outcomes in Retinitis Pigmentosa

Purpose

To determine if circulating antiretinal antibodies (ARAs) differ between patients affected by retinitis pigmentosa (RP) and control participants and to assess whether ARAs are associated with clinical outcomes in patients with RP.

Methods

Cross-sectional study involving a group of patients clinically diagnosed with RP and a control group of healthy participants. Serum autoantibodies against enolase, heat shock protein 70 (HSP70), and carbonic anhydrase II (CAII) were tested in all participants using Jess capillary Western blot. We compared ARA prevalence between the RP and control groups and investigated the association of serum ARA positivity with macular edema and vitreomacular disorders in patients affected by RP.

Results

Thirty-six patients affected by RP and a control group of 39 healthy individuals were included. Overall, at least one ARA positivity was detected in 89% and 80% of participants in the RP and control groups, respectively. We observed a similar prevalence of anti-CAII and anti-enolase ARA between patients and controls (P = 0.87 and P = 0.35, respectively). Sera from patients with RP tested positive for anti-HSP70 ARAs more frequently than those from controls (53% vs. 36%), albeit without reaching statistical significance (P = 0.29). Among the 72 eyes with RP, 25% presented with macular edema (most often bilateral) and 33% with epiretinal membrane and/or lamellar macular hole. None of the three ARAs was associated with an increased risk of any macular complications in eyes affected by RP (all P > 0.05).

Conclusions

The prevalence of circulating ARAs against enolase, HSP70, and CAII is similar between patients affected by RP and healthy individuals. Our results provide evidence against the association of ARAs with macular edema and vitreomacular interface disorders in RP.

Serum antiretinal antibodies and cytokine profiling in autoimmune retinopathy and their association with clinical outcomes

PURPOSE

Autoimmune retinopathy (AIR) is a group of autoimmune retinal diseases that can cause blindness. The purpose of this study is to investigate the profiles of serum antiretinal antibodies (ARAs) and cytokines and their association with disease diagnosis as well as clinical features in AIR.

METHODS

The patients with presumed para (p) and non-paraneoplastic (np) AIR diagnosis, the patients with retinitis pigmentosa and bilateral uveitis as disease controls, and healthy subjects were prospectively enrolled. Western blotting and Luminex multiple cytokine assay/enzyme linked immunosorbent assay were used to determine the presence of serum ARAs and the concentration of cytokines, respectively. Kruskal-Wallis or chi square test was applied to compare the profiles of ARA and cytokines among various groups. The multilevel mixed-effect regression was used to investigate the association of ARA or cytokines with clinical features.

RESULTS

No significant difference in the band number and subtypes of serum ARAs was found between AIR patients and their controls. AIR patients had higher concentration of serum IFN-ɤ, CXCL9, or CXCL10 than non-AIR controls. A positive correlation was found between increased number of ARAs and elevated TNF-α in np-AIR patients. Elevated pro-inflammatory cytokines or ARA subtypes (antibody against recoverin and α-enolase) were associated with worse retinal functions or anatomy, including visual acuity, visual field, ERG parameters, and central retinal thickness.

CONCLUSIONS

The data of our study demonstrate that detection of serum ARAs has limited value in the diagnosis of AIR. Th1-type cytokines/chemokines or specific ARA subtypes are associated with pathogenesis and disease severity of the AIR.

Plasma Antiretinal Autoantibody Profiling and Diagnostic Efficacy in Patients With Autoimmune Retinopathy

PURPOSE

To evaluate plasma antiretinal autoantibody (ARA) profiling and diagnostic efficacy for autoimmune retinopathy (AIR).

DESIGN

A multicenter, diagnostic evaluation study.

METHODS

Forty-nine patients with a clinical diagnosis of AIR, disease controls including 20 patients with retinitis pigmentosa (RP), and 30 normal controls were included. Plasma samples from patients were analyzed for the presence of 6 ARAs, including recoverin, α-enolase, carbonic anhydrase II, heat shock protein 60, aldolase C, and cone-rod homeobox/cone-rod retinal dystrophy 2 using western blotting.

RESULTS

Autoantibody detection rates against cone-rod homeobox/cone-rod retinal dystrophy 2, heat shock protein 60, and aldolase C in AIR were 67.3%, 40.8%, and 42.9%, respectively, which were higher than those in RP and normal controls (P < .001, P < .001, and P = .007, respectively), but recoverin, α-enolase, and carbonic anhydrase II were not different from other control groups (P = .117, P = .774, and P = .467, respectively). Among ARAs, antirecoverin antibody was the most specific, as it was found in 3 (6.1%) patients with AIR and none of the control groups. As the number of detected ARAs increased, the probability of AIR increased (odds ratio: 1.913; P < .001; 95% confidence interval: 1.456-2.785). The positive number of ARAs was significantly higher when photoreceptor disruption was observed on optical coherence tomography, or severe dysfunction was observed in electroretinography (P = .022 and P = .029, respectively).

CONCLUSIONS

The profiles of ARAs in the AIR group were different from those in the RP and normal controls. The higher number of positive ARAs suggests a higher possibility of AIR diagnosis. ARAs should be used as adjunct tools for the clinical diagnosis of AIR.

Seroreactivity against retinal proteins in a case of POC1B gene associated cone dystrophy with normal funduscopic appearance: a systematic approach to diagnosis

PURPOSE

To report a case of cone dystrophy, associated with autosomal recessive homozygote POC1B gene variant, mimicking autoimmune retinopathy.

CASE

A 45-year-old female presented with a complaint of decreased vision in both eyes. Her best corrected visual acuity was 20/32 in the right eye and 20/50 in the left eye. Anterior segment and dilated fundus examinations were unremarkable. Spectral domain optical coherence tomography showed a subfoveal blurred dome-shaped ellipsoid zone and an extinguished interdigitation zone affecting the entire macula. Full field electroretinography revealed reduced cone responses. The differential diagnosis included inflammatory chorioretinopathies, autoimmune retinopathies (paraneoplastic or nonparaneoplastic), and hereditary retinal dystrophies. No remarkable finding was observed on combined fluorescein and indocyanine green angiographies. Paraneoplastic autoimmune antibody panel revealed nothing; however, aldolase, enolase, pyruvate kinase M2, and glyceraldehyde-3-phosphate dehydrogenase antibodies were positive on autoimmune retinopathy panel. To exclude hereditary retinal dystrophies, whole-exome sequencing (WES) was applied. WES identified an autosomal recessive homozygote POC1B gene variant (c.680A>G, p.His227Arg). Cone dystrophy diagnosis was given.

CONCLUSION

Cone dystrophy associated with POC1B gene variant may present without visible fundus abnormalities. It should be kept in mind that retinal autoantibodies may be positive in such a hereditary dystrophy case due to long-term exposure of the immune system to self-antigens. Therefore, autoimmune retinopathy is a diagnosis of exclusion and should not be diagnosed until all other causes, including hereditary dystrophies, have been ruled out.

Antireconverin antibodies in ocular chronic graft versus host disease: A new cause of nonparaneoplasic autoimmune retinopathy

INTRODUCTION

A case of a 48-year-old male with a nonparaneoplasic autoinmune retinopathy (nPAIR) due to chronic graft versus host disease (GVHD) after an allogenic stem cell transplantation (ASCT) is described.

CASE REPORT

The patient developed a bilateral rapidly progressive loss of visual acuity with bilateral optic disc edema and bilateral cystoid macular edema (CME) in the funduscopy, a ring scotoma in the visual field (VF) and photoreceptors dysfunction in the electroretinogram (ERG) 210 days after the ASCT. After ruling out other causes, the suspicion of autoimmune retinopathy (AIR) led to the study of antirecoverin antibodies which resulted positive. The exclusion of neoplasia discarded diagnosis of paraneoplasic autoinmune retinopathy (PAIR) and the temporal relationship with BMT led to the diagnosis of nonparaneoplasic autoinmune retinopathy (nPAIR) due to chronic graft versus host disease (GVHD). Oral corticosteroids led to resolution of the CME.

CONCLUSIONS

Diagnosis of AIR requires a high index of suspicion based on the typical findings on visual field, optical coherence tomography (OCT) and ERG, which force requesting antirecoverin antibodies. However, diagnosis is often delayed because of the need to exclude other causes. Knowing typical symptoms and signs in for a quick action is important because an earlier diagnosis and treatment will improve visual prognosis since the loss of vision already established is irrecoverable. To our knowledge, this is the first reported case in the literature of nPAIR with CME and optic disc edema due to GVHS after ASCT.

Ocular Paraneoplastic Syndromes: A Critical Review of Diffuse Uveal Melanocytic Proliferation and Autoimmune Retinopathy

Background: Dozens of paraneoplastic syndromes affect the visual system ranging from conjunctival pemphigoid to encephalopathy of the occipital cortex. The most profiled ocular syndromes are bilateral diffuse uveal melanocytic proliferation (BDUMP) and the autoimmune retinopathies.Purpose: To review the critical features of these 2 entities then concentrate on advancements in treatment made within the last 10 years.Study Design: Literature review with structured data abstraction.Results: Major insights into pathogenesis have been wanting. Plasmapheresis appears to improve vision in a substantial proportion of patients with BDUMP. The number of clinical variables that influence visual outcome in paraneoplastic retinopathies combined with the variety of local and systemic treatment options makes interpretation of clinical effectiveness difficult.Conclusions: The rarity of these disorders makes randomized clinical trials unlikely. It may be time for a clinical professional organization to use a modified Delphi method to establish a consensus algorithm for the diagnosis and management of retinal paraneoplastic syndromes to augment clinical communications and clinical trials.

Hyaluronic acid hydrogels, as a biological macromolecule-based platform for stem cells delivery and their fate control: A review

Stem cell-based therapies offer numerous potentials to repair damaged or defective organs. The therapeutic outcomes of human studies, however, fall far short from what is expected. Enhancing stem cells local density and longevity would possibly maximize their healing potential. One promising strategy is to administer stem cells via injectable hydrogels. However, stem cells differentiation process is a delicate matter which is easily affected by various factors such as their interaction with their surrounding materials. Among various biomaterial options for hydrogels' production, hyaluronic acid (HA) has shown great promise. HA is a naturally occurring biological macromolecule, a polysaccharide of large molecular weight which is involved in cell proliferation, cell migration, angiogenesis, fetal development, and tissue function. In the current study we will discuss the applications, prospects, and challenges of HA-based hydrogels in stem cell delivery and fate control.

Negative electroretinograms: genetic and acquired causes, diagnostic approaches and physiological insights

The dark-adapted human electroretinogram (ERG) response to a standard bright flash includes a negative-going a-wave followed by a positive-going b-wave that crosses the baseline. An electronegative waveform (or negative ERG) results when the b-wave is selectively reduced such that the ERG fails to cross the baseline following the a-wave. In the context of a normally sized a-wave, it indicates a site of retinal dysfunction occurring after phototransduction (commonly at the photoreceptor to bipolar cell synapse). This is an important finding. In genetic disease, the pattern of ERG abnormality can point to variants in a small group of genes (frequently those associated with congenital stationary night blindness and X-linked retinoschisis, but negative ERGs can also be seen in other conditions including syndromic disease). In acquired disease, there are numerous causes, but specific features may point to melanoma-associated retinopathy (MAR). In some cases, the visual symptoms precede the diagnosis of the melanoma and so the ERG findings can initiate investigations facilitating early detection and treatment. Negative ERGs can occur in other paraneoplastic conditions, and in a range of other diseases. This review will outline the physiological basis for the negative ERG, report prevalences in the literature from different cohorts, discuss the range of causes, displaying examples of a number of ERG phenotypes, highlight features of a clinical approach to patients, and briefly discuss further insights relating to current flows shaping the a-wave trough and from single-cell transcriptome analysis.

Clinical Utility of Antiretinal Antibody Testing

Importance

The clinical utility of most antiretinal antibodies (retina antibodies) currently available for testing remains unclear and unproven. Despite this, the presence of retinal antibodies is included in current diagnostic autoimmune retinopathy criteria.

Objective

To evaluate the clinical significance of comprehensive retinal antibody evaluations currently offered in North America.

Design, Setting, and Participants

In this cross-sectional study, 14 patients without autoimmune retinopathy were recruited into the Mayo Clinic Neuroimmunology Biorepository for this study between January 1, 2019, and October 1, 2019. These serum samples without autoimmune retinopathy were sent in masked fashion to a Clinical Laboratory Improvement Amendments-certified laboratory. Using similar methods, the Mayo Clinic Neuroimmunology Research Laboratory independently assessed the same sample to ascertain reproducibility of the findings.

Main Outcomes and Measures

Results of the autoimmune retinopathy and cancer-associated retinopathy panels.

Results

Thirteen of 14 (93%; 95% CI, 66%-100%) serum samples tested positive for retinal antibodies, with a median of 5 retinal antibodies (range, 0-8) per patient at the Clinical Laboratory Improvement Amendments-certified laboratory, which provides a specificity of 7% (95% CI, 0%-34%). Confirmatory immunohistochemistry staining in human retina was present in 12 of 14 samples (86%). α-Enolase was found in 9 (64%). The only retinal antibody not present was recoverin. These nonspecific retinal antibody results were replicated at the Mayo Clinic Laboratory on Western blot using pig retina proteins as substrate.

Conclusions and Relevance

The presence of retinal antibodies in 93% of the patients without autoimmune retinopathy indicates a lack of specificity and that most detectable retinal antibodies have limited clinical relevance in the evaluation of patients for suspected autoimmune retinopathy. Current retinal antibody testing, other than recoverin, should be interpreted with caution, especially for cases of low clinical suspicion. The poor specificity is important to recognize to prevent the potentially unnecessary commencement of systemic immunosuppressants that may result in significant extraocular adverse effects. Identification of biomarkers that have a high predictive value for inflammatory or autoimmune retinal diseases is needed to move the field forward.

An update on autoimmune retinopathy

Autoimmune retinopathy (AIR) refers to a group of rare autoimmune retinal degenerative diseases presumably caused by cross-reactivity of serum autoantibodies against retinal antigens. The pathogenesis of AIR remains largely presumptive and there are a significant number of antiretinal antibodies that have been detected in association with AIR. The diagnosis of AIR is largely based on the demonstration of antiretinal antibodies in the serum along with suggestive clinical features and ancillary investigations. A high index of suspicion along with early diagnosis and treatment may play a critical role to lower the risk of irreversible immunological damage to the retinal cells in these patients. A multi-disciplinary approach for complete management and evaluation is helpful in such conditions. Various therapeutic options have been described for the treatment of AIR, though there is no consensus on standard treatment protocol.

Normalization of electroretinogram and symptom resolution of melanoma-associated retinopathy with negative autoantibodies after treatment with programmed death-1 (PD-1) inhibitors for metastatic melanoma

Melanoma-associated retinopathy (MAR) is a paraneoplastic syndrome that involves the production of autoantibodies which can cross-react with retinal epitopes leading to visual symptoms. Autoantibodies can target intracellular proteins, and only a few are directed against membrane proteins. This discrepancy in autoantibody-protein target can translate into different immune responses (T-cell mediated vs B-cell mediated). Historically, treatment of MAR has focused on surgical reduction or immunosuppressive medication, mainly glucocorticoids. However, tumor resection is not relevant in metastatic melanoma in which MAR is mostly encountered. Moreover, the use of glucocorticoids can reduce the efficacy of immunotherapy. We report the first case to our knowledge with subjective resolution of visual symptoms and objective evidence of normalization of electroretinogram of MAR with undetectable autoantibodies after administration of programmed death-1 (PD-1) inhibitor (pembrolizumab) without the use of surgical reduction or systemic immunosuppression. This case highlights the potential improvement and resolution of negative autoantibody MAR with the use of PD-1 inhibitors and emphasizes the importance of multidisciplinary approach and team discussion to avoid interventions that can decrease immunotherapy-mediated anti-tumor effect.

The role of optical coherence tomography in the diagnosis of afferent visual pathway problems: A neuroophthalmic perspective

Optical coherence tomography (OCT) is a noninvasive ocular imaging technique that has become a standard tool in neuroophthalmic practice. Specifically, OCT captures retinal manifestations of neuroaxonal injury caused by lesions along anterior and posterior regions of the afferent visual pathway, in patients presenting with vision loss. More recently, the advent of OCT angiography (OCTA) has enabled evaluation of the choroidal and retinal microvasculature, thus informing our understanding regarding vascular mechanisms associated with optic nerve and retinal injuries. Much of our longitudinal experience with OCT in the field of neuroophthalmology has been acquired from the study of optic neuritis (ON) caused by inflammatory disorders of the central nervous system (CNS). Over the past two decades, OCT has emerged as a surrogate endpoint for CNS neuroaxonal injury in multiple sclerosis (MS) research trials. On a more pragmatic level, OCT is used in the clinical arena to diagnose ON associated with: MS, neuromyelitis optica spectrum disorder (NMOSD), and myelin oligodendrocyte glycoprotein (MOG) antibody associated disease (MOGAD). Subsequent advancements in swept-source (SS) and enhanced depth imaging (EDI) have established OCT as the new "gold standard" in the diagnosis of optic disc drusen. Recent studies have highlighted pathognomonic OCT features that distinguish cases of true papilledema from pseudopapilledema, in patients presenting with undifferentiated optic disc elevation. Preoperative OCT measures of neuroaxonal integrity have shown prognostic value in predicting postoperative visual outcomes for patients with compressive anterior visual pathway lesions. Finally, OCT is indispensable in differentiating optic neuropathies from retinal diseases in patients with visual loss and a nondiagnostic fundus examination. An in-depth discussion regarding the technical aspects of OCT is beyond the scope of this chapter. Instead, we wish to highlight the value OCT brings to the diagnosis and management of common neuroophthalmic conditions, with emphasis on optic neuropathies and retinal disorders.

Anti-Retinal Antibodies in Vitamin A Deficiency

Vitamin A is an important component of the visual cycle, and its deficiency causes a retinal degeneration that may be reversed with retinol supplementation. Here, the authors present a patient with vitamin A deficiency and rod-mediated retinopathy who was found to have multiple anti-retinal antibodies that gradually dissipated after vitamin A supplementation. This interesting case suggests the possibility that the photoreceptor degeneration induced by vitamin A deficiency may lead to transient immune exposure to retinal antigens and development of anti-retinal antibodies. [Ophthalmic Surg Lasers Imaging Retina. 2020;51:723-726.].

Correlation of Immunological Markers with Disease and Clinical Outcome Measures in Patients with Autoimmune Retinopathy

Purpose

To determine if immunological markers (1) are significantly different between autoimmune retinopathy (AIR) patients and controls and (2) correlate with disease progression in AIR patients.

Methods

We enrolled patients with a possible AIR diagnosis, as well as control participants without eye disease, autoimmunity, or cancer. Immunological markers were tested in all participants. In addition, AIR patients had up to three blood draws for testing over their disease course. For AIR patients, clinical measures, including visual acuity (VA) and Goldmann visual field (GVF) area, were recorded at each draw. We used the Mann-Whitney U test to compare the immunological markers between AIR patients and controls. We used multilevel mixed-effect regression to investigate the correlation between markers and clinical parameters over time in AIR patients.

Results

Seventeen patients with AIR and 14 controls were included. AIR patients had a higher percent of monocytes (Z = 3.076, P = 0.002). An increase in immunoglobulin G against recoverin was correlated with a VA decrease (β = 0.0044, P < 0.0001). An increase in monocyte proportion was correlated with a decrease in GVF area (β = -7.27, P = 0.0021). Several markers of B-cell depletion were correlated with GVF improvement.

Conclusions

Monocytes may play a role in AIR pathophysiology and be a disease activity marker. B-cell depletion markers correlated with clinical parameter improvement, particularly GVF.

Translational Relevance

This work elucidates immunologic markers that may improve the accuracy of diagnosis and treatment of AIR.

Melanoma-associated retinopathy

Melanoma-associated retinopathy (MAR) is a rare paraneoplastic autoimmune manifestation of cutaneous malignant melanoma. Patients classically present with acute onset night blindness, positive visual phenomena and visual field defects, and typically have significantly reduced quality of life as a result. Early recognition of MAR is of prognostic significance as it can precede the diagnosis of primary or metastatic malignant melanoma, and early treatment can lower the risk of irreversible immunological damage to the retinal cells with improved visual outcomes. The focus of our review article is therefore to raise awareness of MAR and present the latest evidence relating to the investigation and management of this condition.

Detection of circulating anti-retinal antibodies in dogs with sudden acquired retinal degeneration syndrome using indirect immunofluorescence: A case-control study

Sudden acquired retinal degeneration syndrome (SARDS) in dogs is proposed to have an immune-mediated etiology. However, there is conflicting evidence regarding the presence of antiretinal antibodies, as assessed by western blotting, in the serum of SARDS patients. Because of the possibility that antibodies recognize only conformational epitopes, we hypothesized that a more sensitive method to investigate circulating retinal autoantibodies in SARDS is immunofluorescence. Sera from 14 dogs with early SARDS, and 14 age- and breed-matched healthy control dogs were screened for circulating antiretinal IgG, IgM, IgE and IgA using indirect immunofluorescence on lightly fixed frozen sections of normal canine retina. Controls without canine serum were also performed. A nuclear counterstain was used to identify cellular retinal layers. Images were obtained using a fluorescence microscope, and 2-3 separate masked observers graded retinal layers for fluorescence staining intensity using a 0-3 scale. Total circulating IgG and IgM was assessed by radial immunodiffusion. Statistical analysis was performed using 2-way ANOVA, paired 2-tailed student's t-test and correlation analysis. Intensity of IgG staining of photoreceptor outer segments was significantly higher using serum from dogs with SARDS compared with healthy controls in 2/3 observers (P < 0.05). Intensity of IgM staining throughout the retina was higher in SARDS dogs compared to matched healthy controls (P < 0.0001), although no specific retinal layer was statistically significant. There were no differences in staining intensity for IgE or IgA. Dogs with SARDS had a comparably lower circulating IgG and higher IgM than healthy controls (P = 0.01 and 0.001 respectively) and IgG and IgM were negatively correlated (r = -0.69, P = 0.007). Despite having decreased serum IgG compared with healthy controls, circulating IgG in dogs with SARDS binds photoreceptor outer segments to a greater extent. Dogs with SARDS have a relatively higher circulating IgM than matched healthy controls. The pathogenic nature of these antibodies is unknown.

Cancer-associated Retinopathy with Neuroendocrine Combined Large-cell Lung Carcinoma and Adenocarcinoma

We herein report the case of a 74-year-old woman with a lung tumor. She presented with complaints of blurred and rapid, progressively impaired vision. A visual field examination revealed bilateral concentric contraction of the visual field and a ring scotoma in the right eye. She was diagnosed with cancer-associated retinopathy (CAR) combined with large-cell neuroendocrine carcinoma (LCNEC) of the lung via a visual field examination and underwent thoracoscopic surgery. CAR has been mostly associated with small-cell lung cancer (SCLC). Combined LCNEC is relatively rare and accounts for 10.6% of all LCNECs. This is the first case report of CAR-combined LCNEC.

Paraneoplastic Syndromes in Neuro-ophthalmology

PURPOSE OF REVIEW

This article discusses the varied types of paraneoplastic syndromes that commonly have neuro-ophthalmologic manifestations. Diagnostic considerations and therapeutic options for individual diseases are also discussed.

RECENT FINDINGS

Paraneoplastic syndromes can affect the afferent and efferent visual systems. Paraneoplastic syndromes may result in reduced visual acuity from retinal degeneration, alterations in melanocyte proliferation and uveal thickening, or acquired nystagmus. Ocular motor abnormalities related to paraneoplastic syndromes may present with symptoms from opsoclonus or from neuromuscular junction disease. Diagnosis remains challenging, but serologic identification of some specific antibodies may be helpful or confirmatory. Treatment, in addition to directed therapies against the underlying cancer, often requires systemic corticosteroids, plasma exchange, or immunosuppression, but some specific syndromes improve with use of targeted pharmacologic therapy.

SUMMARY

Diagnosis and therapy of paraneoplastic syndromes presenting with neuro-ophthalmic symptoms remain a challenge, but strategies are evolving and new approaches are on the horizon.

Non-paraneoplastic related retinopathy: clinical challenges and review

Autoimmune retinopathy (AIR) is a rare inflammatory condition characterized by progressive visual loss, abnormalities in visual fields and electroretinographic exams, along with presence of circulating anti-retinal antibodies. There are two main forms of AIR: paraneoplastic AIR (pAIR) and presumed non-paraneoplastic AIR (npAIR). NpAIR is considered a diagnosis of exclusion, since it is typically made after other causes of retinopathy have been investigated and the absence of malignancy is confirmed. Work-up of a npAIR case is challenging since there are no standartizaded protocols for diagnosis and treatment. The treatment regimen may vary from case to case, and it can be best guided by a set of parameters including electrophysiological responses, visual outcomes, and presence of anti-retinal antibodies. The purpose of this review is to summarize the principal clinical features, investigation, and management of npAIR.

Predictive value of genetic testing for inherited retinal diseases in patients with suspected atypical autoimmune retinopathy

Purpose

The clinical features of autoimmune retinopathy (AIR) can resemble and be difficult to differentiate from inherited retinal degenerations (IRDs). Misdiagnosis of an IRD as AIR causes unnecessary treatment with immunosuppressive agents. The purpose of this study is to calculate the predictive value of genetic testing for IRDs in patients with suspected AIR and provide clinical examples where genetic testing has been useful.

Methods

We identified patients seen at MEEI between April 2013 and January 2017 for whom the differentiation of AIR vs. IRDs was difficult based on clinical assessment alone. All patients had some atypical features for AIR, but tested positive for anti-retinal antibodies. Within this group, we identified six patients who had genetic testing for IRDs with the Genetic Eye Disease panel for retinal genes (GEDi-R). We calculated the positive predictive value (PPV) and negative predictive value (NPV) of genetic testing in a population with approximately equal numbers of IRD and AIR patients.

Results

Six patients had clinical features that made distinguishing between IRDs and AIR on a clinical basis difficult and were sent for genetic testing: four women and two men with a mean age of 59.5 years. In two of these six patients, genetic diagnoses were made based upon the identification of known pathogenic variants in the common IRD genes USH2A and RHO. Two patients had variants of unknown significance within genes associated with IRDs, and the other two had no relevant genetic findings. Given the 60% sensitivity and 3% false positive rate for GEDi-R testing and assuming a 50% pre-test probability of having an IRD, the PPV for GEDi-R for detecting IRD is 95.2% and the NPV is 70.8%.

Conclusions and Importance

In patients for whom the differential diagnosis of AIR and IRDs is unclear based on clinical information, genetic testing can be a valuable tool when it identifies an IRD, sparing the patient unnecessary immunosuppressive treatment. However, the test has a low NPV so a negative genetic testing result does not confidently exclude IRD as the true diagnosis.

T Helper 1 Cellular Immunity Toward Recoverin Is Enhanced in Patients With Active Autoimmune Retinopathy

Autoimmune retinopathy (AIR) causes rapidly progressive vision loss that is treatable but often is confused with other forms of retinal degeneration including retinitis pigmentosa (RP). Measurement of anti-retinal antibodies (ARA) by Western blot is a commonly used laboratory assay that supports the diagnosis yet does not reflect current disease activity. To search for better diagnostic indicators, this study was designed to compare immune biomarkers and responses toward the retinal protein, recoverin, between newly diagnosed AIR patients, slow progressing RP patients and healthy controls. All individuals had measurable anti-recoverin IgG and IgM antibodies by ELISA regardless of disease status or Western blot results. Many AIR patients had elevated anti-recoverin IgG1 levels and a strong cellular response toward recoverin dominated by IFNγ. RP patients and controls responded to recoverin with a lower IFNγ response that was balanced by IL-10 production. Both AIR and RP patients displayed lower levels of total peripheral blood mononuclear cells that were due to reductions of CD4⁺ T_H cells. A comparison of messenger RNA (mRNA) for immune-related genes in whole blood of AIR patients versus RP patients or controls indicated lower expression of ATG5 and PTPN22 and higher expression of several genes involved in T_H cell signaling/transcription and adhesion. These data indicate that an immune response toward recoverin is normal in humans, but that in AIR patients the balance shifts dramatically toward higher IFNγ production and cellular activation.

Papilloedema and Autoimmune Retinopathy from Systemic Lupus Erythematosus

A 33-year-old female presented with bilateral papilloedema and constricted visual fields from autoimmune retinopathy. She then developed a painful peripheral neuropathy that led to further work-up and the diagnosis of systemic lupus erythematosus. Papilloedema and autoimmune retinopathy from systemic lupus erythematosus is a unique presentation.

Levels of Anti-Retinal Antibodies in Retinal Detachment and Proliferative Vitreoretinopathy

PURPOSE

The purpose of the study is to investigate the correlation between intraocular anti-retinal antibodies and clinical measurements in patients with rhegmatogenous retinal detachment (RRD) and proliferative vitreoretinopathy (PVR).

MATERIAL AND METHODS

Aqueous humor and vitreous samples were collected from patients with RRD, PVR, and from control subjects with macular hole. The levels of total protein (TP), IgG, and anti-retinal antibodies were determined with a bicinchoninic acid assay, enzyme-linked immunosorbent assay, and dot blot, respectively. Correlations between these measurements were assessed using Pearson's correlation test. Analysis of variance followed by a post-hoc test or the Student t-test was used to compare differences between groups.

RESULTS

The levels of anti-retinal antibodies and IgG were correlated with each other (P < 0.010). The IgG concentration was higher in patients with PVR than in controls in both the aqueous humor (P < 0.001) and the vitreous (P < 0.001), but not in patients with RRD. Conversely, TP levels and anti-retinal antibodies in both ocular fluids from RRD and PVR patients did not significantly differ from the controls. In a subgroup analysis, vitreal anti-retinal antibody levels were correlated with average macular thickness in the re-attached macula following surgery for macula-off RRD/PVR (P = 0.012). Furthermore, patients with post-operative cystoid macular edema had a higher level of vitreal anti-retinal antibodies than those without (P = 0.009).

CONCLUSIONS

Intravitreal anti-retinal antibodies were increased in the eyes with maculopathy after surgical intervention for RRD/PVR.

Antiretinal antibodies in central serous chorioretinopathy: prevalence and clinical implications

PURPOSE

To investigate the possible role of autoimmune reactions directed against retinal tissue in central serous chorioretinopathy (CSC), by analysing the presence of serum antiretinal antibodies (ARAs) and establishing their clinical relevance.

METHODS

Sixty-three patients with CSC were included, and clinical characteristics were collected. Serum samples of all patients with CSC, 101 uveitis patients and 60 healthy donors were analysed for the presence of ARAs by indirect immunofluorescence. Furthermore, all CSC serum samples were analysed on Western blot. Correlations between laboratory findings and clinical features of CSC were determined by logistic regression.

RESULTS

Antiretinal antibodies (ARAs) were present in 54% of the patients with CSC, in 46% of uveitis patients (p = 0.153) and in 17% of healthy controls (p < 0.001). The majority of ARAs in CSC were directed against photoreceptors (27%), which occurred significantly more often compared to uveitis patients (15%, p = 0.039) and to healthy controls (5%, p = 0.003). No associations between clinical CSC characteristics and the presence of ARAs were found.

CONCLUSION

Serum ARAs are present in more than half of the patients with CSC, and especially, ARAs directed against photoreceptors were detected more frequently compared to both healthy controls and uveitis patients. Further research is warranted to unravel the role of ARAs in the pathogenesis of CSC.

Elevated serum levels of IL-6 and CXCL9 in autoimmune retinopathy (AIR) patients

Autoimmune retinopathy (AIR) is a rare immune-mediated retinopathy associated with circulating antiretinal antibodies (ARAs). Other prominent features of AIR include visual field deficits and photoreceptor dysfunction in the setting of progressive unexplained vision loss. The role of inflammation is poorly understood in AIR. Since cytokines play a central role in the initiation and development of inflammation, we evaluated the presence of proinflammatory cytokines and chemokines in AIR patient sera. We demonstrate that IL-6 and CXCL9 are both elevated in AIR patient sera. Moreover, the presence and concentration of these 2 molecules appear to correlate with AIR patient disease severity. This cytokine profile, IL-6 and CXCL9, has been described to participate in a variety of autoimmune and inflammatory diseases. Our study provides support for an activated inflammatory process in AIR and identifies possible mechanisms that can drive autoimmunity in this disease.

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IL-6 and CXCL9 are both elevated in AIR patient sera.

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The presence and concentration of IL-6 and CXCL9 correlate with AIR patient disease severity.

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These cytokines may play a prominent role in the initiation and development of inflammation and autoimmunity.

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The data provides evidence for activated inflammatory processes in AIR.

B Cell Anomalies in Autoimmune Retinopathy (AIR)

Purpose

Autoimmune retinopathy (AIR) is a retinopathy associated with unexplained vision loss presumably linked to circulating antiretinal antibodies; currently, however, there are no standardized criteria regarding the diagnosis, treatment strategy, or pathogenesis of this disease. The importance of B-lymphocyte immunophenotyping in the classification of AIR is unknown.

Methods

We utilized 15-color multiparametric flow cytometry to identify aberrations in B cell subsets that may contribute to the pathophysiology of AIR. Luminex cytokine analysis was also performed on plasma samples from AIR patients.

Results

Significant differences in AIR patients compared to individuals with other inflammatory conditions or healthy donors were found in the B cell memory compartment, including an increase in naïve B cells and a decrease in switched and unswitched memory B cells, which correlated with alterations in immunoglobulin secretion.

Conclusions

These findings suggest that the maturation process of B cells may be impaired and that B cell immunophenotyping may help in understanding disease process in AIR.

Autoimmune retinopathy: A case report from India

A first case report of autoimmune retinopathy (AIR) from India. A middle-aged female patient presented with subacute loss of vision in both eyes. Clinical examination revealed a near normal fundus in both the eyes. A presumed diagnosis of nonparaneoplastic AIR was made based on clinical features and suggestive investigations. Early detection and management with steroids or immunosuppression may be beneficial to patients with AIR.

Autoimmune retinopathy associated with systemic lupus erythematosus: A diagnostic dilemma

Visual loss in systemic lupus erythematosus (SLE) due to autoimmune retinopathy (AIR) is rare and easily misdiagnosed as hydroxychloroquine retinopathy. We report the rare clinical presentation of severe visual loss in a patient with SLE due to nonparaneoplastic AIR as differentiated from hydroxychloroquine toxicity. A 70-year-old female diagnosed and treated for lupus for 17 years and had been taking hydroxychloroquine for 15 years. Over the past 2 years, she developed progressive peripheral visual loss oculus uterque which rapidly advanced in the latter 6 months. Hydroxychloroquine toxicity was initially suspected, but diagnostic testing revealed a retinal degeneration. Antiretinal autoantibody testing using Western blot analysis revealed autoantibodies against 44-kDa, 46-kDa (anti-enolase), and 68-kDa proteins. Visual acuity improved in the first 6 months of treatment with mycophenolate mofetil. Our case suggests that AIR should be considered in the differential diagnosis of rapid, severe visual loss in patients with hydroxychloroquine treatment.

Serum Autoantibody Profiling of Patients with Paraneoplastic and Non-Paraneoplastic Autoimmune Retinopathy

PURPOSE

Although multiple serum antiretinal autoantibodies (ARAs) have been reported in patients with paraneoplastic and non-paraneoplastic autoimmune retinopathy ((n)pAIR), not all retinal antigens involved in (n)pAIR are specified. This study aims to serologically identify patients with presumed (n)pAIR through determination of both known and unknown ARAs by autoantibody profiling.

METHODS

An antigen suspension bead array using 188 different antigens representing 97 ocular proteins was performed to detect ARAs in serum samples of patients with presumed (n)pAIR (n = 24), uveitis (n = 151) and cataract (n = 21). Logistic regressions were used to estimate the associations between ocular antigens and diagnosis. Validation of interphotoreceptor matrix proteoglycan 2 (IMPG2) and recoverin antigens was performed by immunohistochemistry and immunoblot, respectively.

RESULTS

Samples of patients with presumed (n)pAIR exhibited a broad spectrum of ARAs. We identified retinal antigens that have already been described previously (e.g. recoverin), but also identified novel ARA targets. Most ARAs were not specific for (n)pAIR since their presence was also observed in patients with cataract or uveitis. High titers of autoantibodies directed against photoreceptor-specific nuclear receptor and retinol-binding protein 3 were more common in patients with presumed (n)pAIR compared to uveitis (p = 0.015 and p = 0.018, respectively). The presence of all other ARAs did not significantly differ between groups. In patients with presumed (n)pAIR, anti-recoverin autoantibodies were the most prevalent ARAs. Validation of bead array results by immunohistochemistry (anti-IMPG2) and immunoblot (anti-recoverin) showed concordant results in (n)pAIR patients.

CONCLUSIONS

Patients with (n)pAIR are characterized by the presence of a broad spectrum of ARAs. The diagnosis of (n)pAIR cannot be based on the mere presence of serum ARAs, as these are also commonly present in uveitis as well as in age-related cataract patients.

Paraneoplastic Syndromes in Neuro-Ophthalmology

BACKGROUND

Paraneoplastic syndromes that affect the visual pathways and present with neuro-ophthalmologic signs or symptoms may involve the afferent or efferent systems. Afferent syndromes may involve the optic nerve or retina and, in some cases, these may be associated with systemic neurologic disease. Efferent symptoms typically affect eye movements and may involve the neuromuscular junction or involuntary eye movements.

EVIDENCE ACQUISITION

Literature review and personal clinical and research experience.

RESULTS

Diagnosis of paraneoplastic syndromes relies on clinical and laboratory evaluations. In the appropriate clinical setting, the presence of specific antibodies may help confirm the diagnosis.

CONCLUSIONS

In some cases, the visual pathway disturbance precedes a diagnosis of malignancy. Astute observation and selective evaluation and management are critical to establish the correct diagnosis and institute therapeutic approaches that can be sight or life saving.

Prevalence and clinical impact of antiretinal antibodies in uveitis

PURPOSE

To determine the prevalence of serum antiretinal antibodies (ARAs) among patients with uveitis and establish their clinical relevance.

METHODS

This prospective study assessed the presence of ARAs by indirect immunofluorescence (IIF) using primate retina in 126 patients with uveitis and 60 healthy controls. Clinical data of uveitis patients were collected from medical charts and included the classification of uveitis, cause of uveitis or its association with systemic disease, stage and activity of uveitis and specific retinal features. Correlations between the presence of specific ARAs and various clinical characteristics were analysed.

RESULTS

The presence of ARAs was observed in 49 of 104 (47%) of patients with uveitis and in 10 of 59 (17%) of healthy controls (p < 0.001). Staining of the nuclear layers or the photoreceptors were both more often observed in patients with uveitis compared to healthy controls (p = 0.002 and p = 0.018, respectively). No specific associations were found between the presence of serum ARAs and various clinical characteristics.

CONCLUSION

Serum ARAs were more frequent in patients with uveitis compared to healthy controls, but their clinical role remains elusive. The assessment of intraocular production of specific ARAs may provide further insight into the role of ocular autoantibodies in diverse uveitis entities.

Latest updates on antiretinal autoantibodies associated with vision loss and breast cancer

Cancer-associated retinopathy (CAR) is an uncommon paraneoplastic disorder of the retina that is frequently associated with breast cancer in pre- and postmenopausal women older than 50 years. In this review, we will give an update on the current knowledge regarding the association of antiretinal autoantibodies with the breast-CAR syndrome. Women with breast cancer and visual indications of CAR have a significantly increased incidence of autoantibodies (AAbs) against retinal proteins when compared to healthy women. The onset of visual loss in association with antiretinal AAbs peaks 2 to 3 years after the clinical diagnosis of breast cancer. Differences in severity of symptoms between women with or without antiretinal AAbs are evident, revealing more unfavorable presentation in seropositive women. The incidence of CAR in breast cancer is likely to rise as the survival time of patients with breast cancer increases; consequently, a prediction of breast-CAR based on autoimmunity to individual retinal antigens, or to panels of antigens (signatures), is clinically important.