Bilateral uveitis and Usher syndrome: a case report

A Very Rare Association of Fuchs Heterochromic Uveitis and Ectropion Uvea in Usher Syndrome

Usher syndrome is a heterogeneous genetic disease that is the most common cause of hereditary blindness–deafness. This syndrome is the most prevalent syndrome associated with retinitis pigmentosa. A 25-year-old man referred to us with hearing loss and vision diminution since childhood which has gradually worsened. Visual acuity of both eyes was 20/100. Slit lamp examination of the left eye revealed endothelial stellate keratic precipitates, mild anterior chamber reaction, iris heterochromia, ectropion of uvea, and mild posterior subcapsular cataract. There were also no crypts and abnormal vessels in the left eye iris. His intraocular pressure was 14 mmHg in the right eye and 18 mmHg in the left one. Funduscopy demonstrated waxy pallor optic nerve, marked arterial narrowing, and retinal bone spicule pigment formation in both eyes. We report for the first time a very rare association between Usher syndrome, Fuchs heterochromic uveitis (FHU), and ectropion uvea. To our knowledge, no association has been reported between ectropion uvea, FHU, and Usher syndrome.

Depletion of Retinal Dopaminergic Activity in a Mouse Model of Rod Dysfunction Exacerbates Experimental Autoimmune Uveoretinitis: A Role for the Gateway Reflex

The gateway reflex is a mechanism by which neural inputs regulate chemokine expression at endothelial cell barriers, thereby establishing gateways for the invasion of autoreactive T cells into barrier-protected tissues. In this study, we hypothesized that rod photoreceptor dysfunction causes remodeling of retinal neural activity, which influences the blood–retinal barrier and the development of retinal inflammation. We evaluated this hypothesis using Gnat1^rd17 mice, a model of night blindness with late-onset rod-cone dystrophy, and experimental autoimmune uveoretinitis (EAU). Retinal remodeling and its effect on EAU development were investigated by transcriptome profiling, target identification, and functional validation. We showed that Gnat1^rd17 mice primarily underwent alterations in their retinal dopaminergic system, triggering the development of an exacerbated EAU, which was counteracted by dopamine replacement with L-DOPA administered either systemically or locally. Remarkably, dopamine acted on retinal endothelial cells to inhibit NF-κB and STAT3 activity and the expression of downstream target genes such as chemokines involved in T cell recruitment. These results suggest that rod-mediated dopamine release functions in a gateway reflex manner in the homeostatic control of immune cell entry into the retina, and the loss of retinal dopaminergic activity in conditions associated with rod dysfunction increases the susceptibility to autoimmune uveitis.

Retinal Dystrophies and the Road to Treatment: Clinical Requirements and Considerations

: Retinal dystrophies (RDs) comprise relatively rare but devastating causes of progressive vision loss. They represent a spectrum of diseases with marked genetic and clinical heterogeneity. Mutations in the same gene may lead to different diagnoses, for example, retinitis pigmentosa or cone dystrophy. Conversely, mutations in different genes may lead to the same phenotype. The age at symptom onset, and the rate and characteristics of peripheral and central vision decline, may vary widely per disease group and even within families. For most RD cases, no effective treatment is currently available. However, preclinical studies and phase I/II/III gene therapy trials are ongoing for several RD subtypes, and recently the first retinal gene therapy has been approved by the US Food and Drug Administration for RPE65-associated RDs: voretigene neparvovec-rzyl (Luxturna). With the rapid advances in gene therapy studies, insight into the phenotypic spectrum and long-term disease course is crucial information for several RD types. The vast clinical heterogeneity presents another important challenge in the evaluation of potential efficacy in future treatment trials, and in establishing treatment candidacy criteria. This perspective describes these challenges, providing detailed clinical descriptions of several forms of RD that are caused by genes of interest for ongoing and future gene or cell-based therapy trials. Several ongoing and future treatment options will be described.

Progression of retinal pigmentation mimicking unilateral retinitis pigmentosa after bilateral pars planitis: a case report

Background

To report our findings in a young patient with unilateral retinitis pigmentosa (RP)-like appearance who developed pigmentary changes in his left retina after an episode of bilateral pars planitis.

Case presentation

A 17-year-old man presented with 6 months of blurry vision in both eyes. He was diagnosed with bilateral pars planitis. Progressive, intraretinal bone crepuscule pigmentation developed in his left retina during the following three months. An electroretinogram showed subnormal response only in the left eye, suggesting the diagnosis of unilateral pseudoRP.

Conclusion

An inflammatory disease like pars planitis can accelerate the pigmentation of the retina and mimic a RP in young patients. Causes of pseudoRP may be considered, especially in those rare cases with unilateral affection.