Unilateral manifestation of autoimmune retinopathy

Acute unilateral inner retinal dysfunction with photophobia: importance of electrodiagnosis

PURPOSE

To establish with negative electroretinogram (ERG) the clinical entity of eight patients with unilateral severe photophobia, essentially normal fundus, good visual acuity, and severe cone and rod dysfunction.

STUDY DESIGN

Multicenter retrospective observation case series.

METHODS

Comprehensive ophthalmologic examinations were performed, including best-corrected visual acuity (BCVA), full-field ERGs and multifocal ERGs (mfERGs), fundus photographs, and OCT. Systemic and genetic examinations were performed.

RESULTS

The mean (± SD) age at the onset was 60.0 ± 8.4 years, and the six patients noticed severe photophobia in the affected eye in spite of almost normal fundus appearance and good BCVA. The dark-adapted bright flash ERGs in the affected eye had relatively well-preserved a-waves and depressed b-waves, i.e., a negative ERG. Cone ERGs and both b- and d-waves of the photopic long-duration ERGs were almost undetectable. Rod ERGs were severely reduced; however, only two patients complained of night blindness. In five patients, the mfERGs were extinguished in the periphery but preserved in the central retina, resulting in good BCVA. Electrophysiological findings indicated a severe diffuse dysfunction of the inner retina affecting bipolar cells of both ON- and OFF-pathways, and in five patients there was a reduction in the thickness of the inner nuclear layer. In seven patients the retinal arteries were attenuated. Anti-retinal antibodies were detected in the serum of two patients. No genetic causes were found.

CONCLUSIONS

The common features in the eight patients with unilateral negative ERGs suggest a new disease entity of unilateral acute inner retinal layer dysfunction. In most patients, the only subjective complain was photophobia.

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.