Intravenous rituximab for the treatment of cancer-associated retinopathy

Clinical Outcomes of Therapeutic Interventions for Autoimmune Retinopathy: A Meta-analysis and Systematic Review

Topic

Autoimmune retinopathy (AIR) is a group of rare inflammatory diseases treated with immunosuppression; however, there is no treatment consensus. This meta-analysis and review aims to investigate treatment effectiveness in slowing AIR progression.

Clinical Relevance

Autoimmune retinopathy is a group of diseases characterized by progressive vision loss that is both difficult to diagnose and treat. While there is some consensus regarding diagnostic criteria, evidence-based treatment consensus remains poorly understood. Current first-line treatment is systemic steroids and conventional steroid-sparing agents. However, patients often experience treatment failure and systemic adverse effects with these medications. Understanding the effect of medications on slowing multiple visual outcomes in AIR can help to guide future treatment protocols.

Methods

PubMed, Cochrane Library, Embase, and ClinicalTrials.gov were systematically searched from inception to November 2023. Included studies treated patients with AIR with systemic, local, and biologic therapy and reported visual acuity (VA), visual field (VF), cystoid macular edema (CME), electroretinogram, central retinal thickness (CRT), and/or ellipsoid zone (EZ) loss. Risk of bias was assessed using the Critical Appraisal Skills Programme checklist. Data for meta-analysis were pooled using a random-effects model.

Results

Analysis of 40 case reports demonstrated that treatment type significantly affects the improvement of VA in patients with nonparaneoplastic retinopathy. Meta-analysis of 12 studies demonstrated that any treatment decreases the risk of progression of all 6 outcomes. Systemic therapy slows VA loss (risk ratio [RR] = 0.04, 95% confidence interval [0.00, 0.91], P = 0.04), VF loss (RR = 0.01, 95% confidence interval [0.00, 0.14], P = 0.0007), and CME (RR = 0.02, 95% confidence interval [0.00, 0.34], P = 0.007). Local therapy slows VA loss (RR = 0.02, 95% confidence interval [0.00, 0.12], P < 0.00001), CME (RR = 0.06, 95% confidence interval [0.01, 0.43], P = 0.005), CRT loss (RR = 0.02, 95% confidence interval [0.00, 0.36], P = 0.007), and EZ loss (RR = 0.31, 95% confidence interval [0.14, 0.70], P = 0.004). Biologics slow VA loss (RR = 0.28, 95% confidence interval [0.12, 0.65], P = 0.003), VF loss (RR = 0.25, 95% confidence interval [0.15, 0.42], P < 0.00001), and CRT loss (RR = 0.19, 95% confidence interval [0.04, 0.79], P = 0.02).

Conclusion

Systemic therapy significantly reduces the risk of progressive visual loss. Local therapy significantly decreases the risk of both progressive visual loss and retinal morphology loss, and therefore may offer precise targeting of the retina. Biologics significantly reduce both functional and morphological retinal changes. Immunosuppressive therapy may slow AIR progression; however, additional research is needed to assess long-term outcomes.

Financial Disclosures

The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Electrodiagnostic Biomarkers in Paraneoplastic Retinopathy

OBJECTIVE

Paraneoplastic retinopathy (PNR) is a rapid-onset photoreceptor and post-photoreceptor dysfunction triggered by a cross-reaction between antigens expressed by the underlying tumour and retinal proteins. The present study aims to determine the electrodiagnostic biomarkers that support the diagnosis of PNR and evaluate the effect of treatment.

METHODS

A retrospective observational case-controlled study including 25 patients with suspected PNR, of which 11 patients were diagnosed with PNR. The presence of PNR was confirmed based on clinical examination, supported by colour fundus photography, fundus autofluorescence imaging, optical coherence tomography, fluorescein angiography, retinal vessel oximetry, colour test, full-field electroretinogram (ffERG), on-/off ERG, S-cone ERG, and multifocal ERG (mfERG). The relationships between the clinical symptomatology and the effect of therapy were evaluated.

RESULTS

All PNR patients (Nr: 11) presented with subjective symptoms of newly reported central vision or visual field deterioration. Posterior segment findings showed a severe patchy-like retinal atrophy, attenuation of the retinal vessels, and a waxy optic disc. Optical coherence tomography revealed a discontinued ISe line, and multiple hyperreflective foci. Retinal vessel oxygen saturation was increased. Multifocal ERG revealed reduced central and paracentral responses and ffERG severely attenuated scotopic-, photopic-, on-/off- and S-cone responses. The colour vision test revealed a tritan-tetartan-weakness. Two of the PNR patients underwent rituximab therapy with no further progression and even recovery of electrodiagnostic responses.In 1 nPNR (non-paraneoplastic retinopathy) patient (total Nr: 14) pseudoxanthoma elasticum-related retinopathy was the reason for impaired vision. In 3 of 13 patients with bronchopulmonary cancer a MEK- and FGFR-inhibitor- drug toxicity was the reason for the visual deterioration.

CONCLUSION

Careful investigation for signs of central and/or peripheral visual field deterioration must be performed in the presence of history of a co-existing malignancy. The possibility of PNR should be taken into account. The electrodiagnostic biomarkers, suggested in this study, may help to promptly recognise PNR and also to evaluate the effect of implemented therapy.

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.

Rituximab for non-infectious Uveitis and Scleritis

Purpose

To provide a comprehensive review of rituximab use for the treatment of non-infectious uveitis and scleritis.

Methods

Review of literature through December 2020.

Results

Individual data was available for 229 patients with refractory non-infectious uveitis (n = 108) or scleritis (n = 121) who received treatment with rituximab (RTX). Rituximab was generally utilized as third-line or later treatment (uveitis: 67/90, 74.4%; scleritis: 90/96, 93.8%) at a mean of 33.5 months following the diagnosis of uveitis (range = 0 to 168.0 months; median = 24.0 months) and 39.4 months after diagnosis of scleritis (range = 1.0 to 168.0 months; median = 21.0 months). Patients with non-infectious uveitis and scleritis either received prior treatment with corticosteroids only (uveitis: 18/90, 20%; scleritis: 4/94, 4.3%), or with one (uveitis: 19/90, 21.1%; scleritis: 30/94, 31.9%), two (uveitis: 11/90, 12.2%; scleritis 27/94, 28.7%), or three or more (uveitis: 37/90, 41.1%; scleritis: 31/94, 33.0%) corticosteroid-sparing immunosuppressive agents with or without corticosteroids before initiation of RTX treatment. The rheumatologic protocol (two infusions of 1 gram of RTX separated by 14 days) was utilized most frequently (uveitis: 45/87, 51.7%; scleritis: 87/114, 76.3%), followed by the Foster protocol (eight weekly infusions of 375 mg/m² RTX; uveitis: 18/87, 20.7%; scleritis: 10/114, 8.8%), and the oncologic protocol (four weekly infusions of 375 mg/m² RTX; uveitis: 5/87, 5.7%; scleritis: 6/114, 5.3%). Various other off-label regimens were used infrequently (uveitis: 19/87, 21.8%; scleritis 11/114, 9.6%). Rituximab treatments resulted in a positive therapeutic response for the majority of patients with non-infectious uveitis (81/97, 83.5%). Commonly treated uveitic diagnoses included non-paraneoplastic autoimmune retinopathy (30/107, 28.0%), juvenile idiopathic arthritis (21/107, 19.6%), Vogt-Koyanagi-Harada disease (12/107, 11.2%), and Behçet disease (11/107, 10.3%). Cases of non-infectious scleritis were most commonly attributed to granulomatosis with polyangiitis (75/121, 62.0%) and rheumatoid arthritis (15/121, 12.4%), and showed an even greater rate of positive therapeutic response (112/120, 93.3%) following RTX treatment. No side effects were reported in 76.3% (74/97) of uveitis and 85.5% (71/83) scleritis cases. Of those cases associated with RTX-induced adverse events, the most common were infusion reactions of various severity (11/35, 31.4%).

Conclusions

Overall, RTX appeared to be both effective and well-tolerated as second or third-line therapy for patients with non-infectious uveitis and scleritis.

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.

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.

Rituximab for autoimmune retinopathy: Results of a Phase I/II clinical trial

PURPOSE:

This prospective study evaluates whether rituximab is a safe and potentially effective treatment for nonparaneoplastic autoimmune retinopathy (npAIR).

MATERIALS AND METHODS:

Five npAIR patients were enrolled in a Phase I/II, prospective, nonrandomized, open-label, single-center study. All patients received a cycle of 1000 mg intravenous rituximab at weeks 0 and 2, with a second cycle of rituximab 6 to 9 months later. Clinical evaluation was performed at baseline, 6 and 12 weeks after each rituximab cycle, and then every 3 months for a total duration of 18 months. The primary outcome for this study was treatment success based on visual field and full-field electroretinography at 6 months. The secondary outcomes included treatment success at months 12 and 18, drug-related adverse events, changes in visual symptoms, and changes in quality of life.

RESULTS:

Two patients met criteria for treatment success: one based solely on electroretinography and the other based solely on visual field area, but treatment success was not sustained. Clinical response over the course of the 18-month study showed disease stabilization in three patients and treatment failure in two patients. There were no severe drug-related adverse events.

CONCLUSION:

This is the first clinical trial prospectively evaluating the effect of rituximab in npAIR and, although rituximab was well tolerated, there was no clear-cut clinical improvement conferred by B cell depletion with rituximab.

Improvement of reduced electroretinographic responses in thymoma-associated retinopathy: a case report and literature review

PURPOSE

To report a patient with thymoma-associated retinopathy presenting as having a good visual prognosis.

METHODS

Case report and literature review.

CASE REPORT

A 42-year-old female patient was referred to our hospital for complaints of sudden visual-field defects bilaterally. Decimal corrected visual acuity (VA) was 1.5 and 1.2 in the right (RE) and left eyes (LE), respectively. Fundus autofluorescence revealed hyper-autofluorescence from the posterior pole to mid-peripheral retina in both eyes. Full-field electroretinography (ERG) amplitudes were reduced to 20-50% and 30-50% of our controls for the scotopic and photopic conditions, respectively. A systemic examination revealed the presence of thymoma, and the patient underwent thymectomy and immunosuppression therapies. Immunohistochemical analysis using the patient's serum showed immunolabeling on the photoreceptor inner segment and outer plexiform layer in the monkey retina. Two years later, VA remained at 1.5 and 1.2 in RE and LE. ERG amplitudes improved to 30-60% of the controls for the scotopic conditions. However, photopic ERG showed no remarkable change.

CONCLUSIONS

To our knowledge, improvement of reduced rod-mediated ERG responses has not been described in seven previously reported patients with thymoma-associated retinopathy. The good visual prognosis of our patient may be associated with well-timed intervention.

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.

Recovery of outer retinal laminations on optical coherence tomography after treatment of cancer associated retinopathy

Purpose

To report novel optical coherence tomography findings in a case of anti-α-enolase cancer associated retinopathy.

Observations

An elderly female presented with bilateral decreased vision and a recent diagnosis of ovarian carcinoma. Optical coherence tomography demonstrated bilateral loss of outer retinal structures and macular edema. Serum testing found antibodies against α-enolase and 82-84 kDa proteins. Outer retinal structures showed recovery, macular edema resolved and repeat anti-retinal antibody testing became negative following cancer therapy and topical difluprednate treatment.

Conclusions and importance

Cancer associated retinopathy is a paraneoplastic disease that results in damage to retinal structures through an autoimmune response. The damage is generally considered to be irreversible; however, in rare cases, such as observed here, retinal structures may demonstrate recovery after treatment.

Unilateral cancer-associated retinopathy: diagnosis, serology and treatment

PURPOSE

To report a case of unilateral cancer-associated retinopathy (CAR) with clinical, serological and electroretinogram (ERG) normalization after aggressive cancer treatment combined with steroids and rituximab.

METHODS

Work-up included extensive clinical and electrophysiological testing. Also, serological work-up for antiretinal antibodies and oncological screening was organized.

RESULTS

A 45-year-old female presented with progressive photopsias, photophobia and relative central scotoma in the right eye since 6 weeks prior. BCVA was 1.0 in both eyes. Biomicroscopy, IOP and fundus exam were unremarkable. Also, colour vision, autofluorescence imaging, OCT and EOG were normal. Visual fields showed decreased central sensitivity in the right eye. ERG showed a unilateral, electronegative combined and ON-bipolar response. A diagnosis of CAR was suspected. After a diagnosis of an adenocarcinoma of the right ovary, radical ovariectomy and hysterectomy were performed, followed by adjuvant chemotherapy. A whole-body PET scan revealed no metastasis. Treatment with rituximab monoclonal antibodies in combination with corticosteroids was initiated. The patient tested positive for serum autoantibodies against TRPM1, a transient receptor potential cation channel expressed in ON-bipolar cells. During treatment, there was progressive improvement in symptoms and the ERG normalized. Serology confirmed complete clearance of autoantibodies.

CONCLUSIONS

Although rare, unilateral CAR does occur and in cases with high clinical suspicion an oncological work-up is mandatory. Aggressive cancer treatment combined with steroids and rituximab can lead to normalization of the clinical and ERG phenotype, with clearing of antiretinal antibodies.

Outcomes in Autoimmune Retinopathy Patients Treated With Rituximab

PURPOSE

To evaluate clinical and ancillary testing, including adaptive optics, outcomes in autoimmune retinopathy (AIR) patients treated with rituximab.

DESIGN

Retrospective, interventional case series.

METHODS

patients: Sixteen AIR patients treated with rituximab.

OBSERVATION PROCEDURES

All patients were treated with a loading and maintenance dose schedule of intravenous rituximab. Visual acuity (VA), electroretinography (ERG), and spectral-domain optical coherence tomography (SDOCT) and visual field (VF) results were recorded. A subset of patients was also imaged using adaptive optics scanning laser ophthalmoscopy (AO-SLO).

MAIN OUTCOME MEASURES

Rates of VA change before vs after rituximab initiation were compared with mixed-model linear regression.

RESULTS

The rate of visual decline was significantly less after rituximab initiation compared with the rate of visual decline prior to rituximab initiation (P = .005). Seventy-seven percent of eyes had stable or improved VA 6 months after rituximab initiation. Amplitudes and implicit times on ERG, mean deviation on VF, central subfield mean thickness, and total macular volume did not decrease to a significant degree over the rituximab treatment period. Six eyes had serial AO-SLO imaging. Cone densities did not change significantly over the treatment period.

CONCLUSION

VA was stable or improved in a majority of AIR patients while they were being treated with rituximab. OCT and ERG parameters, as well as AO-SLO cone densities, were stable during treatment. Studies with additional patients and longer follow-up periods are needed to further explore the utility of rituximab in the management of AIR.

Efficacy of rituximab in non-paraneoplastic autoimmune retinopathy

Background

Autoimmune retinopathy (AIR) is a rare but potentially blinding condition that is often underdiagnosed. Common features in AIR presentation include rapidly progressive vision loss with abnormal electrophysiological responses of the retina associated with positive anti-retinal antibodies. AIR is also challenging to treat, and thus, the introduction of new potential therapeutic agents is welcomed. The goal of this communication is to assess the effects of rituximab infusions on electroretinogram (ERG) responses and visual function outcomes in patients with non-paraneoplastic autoimmune retinopathy (npAIR).

Results

Following infusion(s), three out of five patients showed no evidence of disease progression or improved, while two patients continued to progress on ERG. One patient demonstrated improvement in visual acuity (2 lines) in both eyes. ERG responses provided objective monitoring of patients’ visual function and response to immunosuppression over time.

Conclusions

These findings suggest that patients with npAIR unresponsive to other immunosuppression therapies may benefit from rituximab infusion, although stabilization rather than improvement was more frequently the outcome in our case series. Furthermore, regularly scheduled ERG follow-up examinations are recommended for monitoring patients’ progression during treatment.

Impact of Autoantibodies against Glycolytic Enzymes on Pathogenicity of Autoimmune Retinopathy and Other Autoimmune Disorders

Autoantibodies (AAbs) against glycolytic enzymes: aldolase, α-enolase, glyceraldehyde-3-phosphate dehydrogenase, and pyruvate kinase are prevalent in sera of patients with blinding retinal diseases, such as paraneoplastic [cancer-associated retinopathy (CAR)] and non-paraneoplastic autoimmune retinopathies, as well as in many other autoimmune diseases. CAR is a degenerative disease of the retina characterized by sudden vision loss in patients with cancer and serum anti-retinal AAbs. In this review, we discuss the widespread serum presence of anti-glycolytic enzyme AAbs and their significance in autoimmune diseases. There are multiple mechanisms responsible for antibody generation, including the innate anti-microbial response, anti-tumor response, or autoimmune response against released self-antigens from damaged, inflamed tissue. AAbs against enolase, GADPH, and aldolase exist in a single patient in elevated titers, suggesting their participation in pathogenicity. The lack of restriction of AAbs to one disease may be related to an increased expression of glycolytic enzymes in various metabolically active tissues that triggers an autoimmune response and generation of AAbs with the same specificity in several chronic and autoimmune conditions. In CAR, the importance of serum anti-glycolytic enzyme AAbs had been previously dismissed, but the retina may be without pathological consequence until a failure of the blood–retinal barrier function, which would then allow pathogenic AAbs access to their retinal targets, ultimately leading to damaging effects.

Rituximab as a monotherapy or in combination therapy for the treatment of non-paraneoplastic autoimmune retinopathy

PURPOSE

To examine the efficacy of rituximab as a monotherapy or in combination therapy for the treatment of patients with non-paraneoplastic autoimmune retinopathy.

METHODS

Twelve eyes of six patients with non-paraneoplastic autoimmune retinopathy who were treated with rituximab and had at least 6 months of follow-up were included. Demographic data, clinical data, visual field parameters, electroretinography parameters, and anti-retinal and anti-optic nerve autoantibody bands were collected from the Massachusetts Eye Research and Surgery Institution database between September 2010 and January 2015. Changes in visual acuity, visual field parameters, electroretinography parameters, and anti-retinal and anti-optic nerve autoantibody bands from the initial visit to the most recent visit were examined.

RESULTS

From the initial visit to the last visit, visual acuity was stable in eight (66.7%) eyes. Visual field was stable in six (50%) eyes and improved in two (16.7%) eyes. Electroretinography was stable or improved in eight (66.7%) eyes. The average number of anti-retinal and anti-optic nerve antibody bands was reduced.

CONCLUSION

Stabilization and/or improvement of visual acuity, visual field parameters, and electroretinography parameters were observed in a high number of patients (75%) on rituximab, as a monotherapy (one patient) or in combination therapy.

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.

Electroretinographic improvement after rituximab therapy in a patient with autoimmune retinopathy

Purpose

To describe the effect of rituximab on full-field electroretinography (ERG) in a patient with nonparaneoplastic autoimmune retinopathy (npAIR).

Observations

A 58-year-old male patient with visual complaints, positive anti-retinal antibodies and negative work-up for cancer was diagnosed with npAIR. Visual acuity and ancillary tests were normal except abnormal ERG in both eyes. The patient was given one course of rituximab 375 mg/m²/week for 4 weeks and cyclophosphamide 1 gr/m²/month for 6 months. A second course of rituximab was necessary as autoantibody titers showed no change and as new antibodies were noted after treatment with rituximab and cyclophosphamide. Electroretinography was repeated after the first course of rituximab, after cyclophosphamide, and the second course of rituximab therapy.

Conclusions and importance

Rituximab therapy led to marked improvement in full-field ERG readings and regression of symptoms was reported by the patient after rituximab infusions. The effect of rituximab in npAIR was objectively demonstrated with ERG.

Retinal imaging with en face and cross-sectional optical coherence tomography delineates outer retinal changes in cancer-associated retinopathy secondary to Merkel cell carcinoma

Background

The study aims to correlate Fourier-domain optical coherence tomography (FD-OCT) with Goldmann visual field (GVF) to show the photoreceptor (PR) structure and function relationship in the first described case of cancer-associated retinopathy (CAR) from Merkel cell carcinoma.

Findings

A case study of a patient with CAR who was imaged with serial GVF and FD-OCT over a 2-year period was carried out. En face images were created using a custom algorithm from the volumetric Fourier-domain OCT scans at the PR level. The areas of decreased PR reflectivity on the en face images were compared with GVF obtained at the same time point. Regions of reduced signal on en face scans corresponded with the position and shape of the GVF scotomas. Initially, the vision improved without PR changes. Cross-sectional OCTs showed early recovery of the outer nuclear layer and later improvement in the nerve fiber layer. Worsening vision corresponded with recurrence of the underlying cancer. Progressive global retinal atrophy was seen over time.

Conclusions

Merkle cell carcinoma can cause CAR. Retinal function recovered without structural PR recovery. Transient vision improvements in treated CAR patients may be due to layers other than the PRs, but eventual vision decline results from significant progressive retinal atrophy.

Autoimmune retinopathy

PURPOSE

To provide a detailed review of current clinical guidelines for the diagnosis, work-up and treatment of autoimmune retinopathy and to preview briefly possible future therapies.

DESIGN

Perspective based on literature review and clinical expertise.

METHODS

Interpretation of current literature, relying on the authors' clinical experience.

RESULTS

Autoimmune retinopathy is a rare immunologic disease characterized by the presence of circulating antiretinal antibodies along with electroretinographic and visual field abnormalities. An ophthalmic examination can be normal or show minimal findings. The diagnosis of autoimmune retinopathy is made difficult by diagnostic criteria that are both limited and nonstandardized. Currently, the diagnosis is made based on the demonstration of serum antiretinal antibodies and the presence of clinical manifestations (including abnormal electroretinographic findings). The mere presence of these antibodies is not diagnostic. Lack of an accepted gold standard for antiretinal antibodies detection and poor interlaboratory concordance make the diagnosis challenging. There are anecdotal reports of immunosuppressive therapy in autoimmune retinopathy; however, the response to treatment is variable, with more favorable results achieved in paraneoplastic retinopathy, particularly cancer-associated retinopathy, with a combination of chemotherapy and immunosuppression. Whether an earlier attempt to treat nonparaneoplastic autoimmune retinopathy would be more beneficial is unknown. Early treatment attempts are limited by lack of sensitive and specific assays and definitive clinical criteria.

CONCLUSIONS

Little is known about the clinical course, prognosis and treatment of autoimmune retinopathy. Additional studies should examine the specificity and pathogenicity of antiretinal antibodies and screen for biomarkers, and they should be conducted concurrently with studies seeking to identify appropriate treatment.

Autoimmune retinopathy

PURPOSE OF REVIEW

Autoimmune retinopathy (AIR) is an immune-mediated disorder characterized by progressive visual loss, abnormal electroretinographic and visual field findings in the presence of circulating anti-retinal antibodies. This review highlights advances made toward understanding the pathophysiology, clinical manifestations, and trends in the management of AIR.

RECENT FINDINGS

The pathophysiology of AIR is likely antibody-mediated. AIR serum autoantibodies are variable in their size and retinal tissue they target and can also be present in healthy controls and multiple autoimmune diseases. Rarely, AIR may be associated with dysregulated self-tolerance mechanisms in the thymus. Despite progress in research, our understanding of AIR remains incomplete. Lack of standardized methods for anti-retinal antibody testing continues to challenge the interpretation of seropositivity. Conventional immunosuppressives have been further studied, and promising immunomodulatory therapies, such as targeted B-cell therapy, have been introduced. Newer imaging modalities such as fundus autofluorescence and spectral domain optical coherence tomography may be helpful in diagnosis, monitoring progression of disease and response to treatment.

SUMMARY

AIR is a rare but vision-threatening disease whose pathogenesis is poorly defined. Lack of standardized clinical or laboratory criteria further complicates the diagnosis and management. Despite recent progress, further basic science research into the autoimmune process is needed. Prospective controlled clinical trials with immunomodulatory therapy can help define future treatment paradigms.