Epithelial phenotype restoring drugs suppress macular degeneration phenotypes in an iPSC model

Age-related Macular Degeneration (AMD), a blinding eye disease, is characterized by pathological protein- and lipid-rich drusen deposits underneath the retinal pigment epithelium (RPE) and atrophy of the RPE monolayer in advanced disease stages - leading to photoreceptor cell death and vision loss. Currently, there are no drugs that stop drusen formation or RPE atrophy in AMD. Here we provide an iPSC-RPE AMD model that recapitulates drusen and RPE atrophy. Drusen deposition is dependent on AMD-risk-allele CFH(H/H) and anaphylatoxin triggered alternate complement signaling via the activation of NF-κB and downregulation of autophagy pathways. Through high-throughput screening we identify two drugs, L-745,870, a dopamine receptor antagonist, and aminocaproic acid, a protease inhibitor that reduce drusen deposits and restore RPE epithelial phenotype in anaphylatoxin challenged iPSC-RPE with or without the CFH(H/H) genotype. This comprehensive iPSC-RPE model replicates key AMD phenotypes, provides molecular insight into the role of CFH(H/H) risk-allele in AMD, and discovers two candidate drugs to treat AMD.

EXAMINING LOCALLY EXPRESSED mRNA OF INFLAMMATORY MEDIATOR GENES IN A MODEL OF RETINAL PIGMENT EPITHELIUM ATROPHY AND RETINAL DEGENERATION INDUCED BY SUBRETINAL SALINE INJECTION IN RABBITS

Degenerative-dystrophic retinal diseases, particularly age-related macular degeneration (AMD), are now considered to be the lead cause of blindness and low vision in developed countries, with a steadily increasing trend. Recent publications provide evidence for the involvement of inflammatory mechanisms in TMD development and progression unveiled due to advances in innate and adaptive immunity research. However, the immunopathogenesis of atrophic AMD form, “geographic atrophy” (GA) remains largely unstudied. Objective: to investigate local mRNA expression of inflammatory cytokines IL-1β, IL-18, CCL2/MCP-1 in a model of RPE atrophy induced after subretinal injection of 0.9% sodium chloride solution in experimental rabbits. The investigation was carried out in tissue complex retina-RPE-choroid (TC) samples isolated from eyes of 23 albino New Zealand rabbits after modeling RPE atrophy by subretinal injection of 0.9% sodium chloride solution and 5 healthy rabbits lacking eye lesions. Animals in the experimental group (one week before surgical intervention, in the early period, and in the period of sustained RPE atrophy formation) and controls were subjected to optical coherence tomography (OCT) and ocular fundus autofluorescence (FAF). Evaluation of proinflammatory cytokine gene expression levels in TC was performed by RT-PCR. Results. Subretinal injection of 0.01 ml of 0.9% sodium chloride solution induced experimental RPE atrophy development in rabbits vs. control that was associated with multidirectional changes of IL-1β, IL-18, MCP-1/CCL2 gene mRNA expression. Three types of response in the TC, formed during development of atrophic changes and determined by the value of local cytokine gene expression were characterized: 1) hypo/ no response – decreased/no expression; 2) normal response – moderate increase; 3) hyper response – overexpression. 69.6% of animals with persistent atrophy had a moderate to hypertrophic increase in locally expressed mRNA MCP-1/CCL2, whereas 30% cases had significantly increased IL-1β mRNA expression – factors damaging the blood-retinal barrier and contributing to posterior segment immune privilege. It should be taken into account while developing new strategies for treatment of ophthalmic pathology, in particular the currently actively studied and tested options for RPE stem cell transplantation into subretinal space. The data obtained may be useful to investigate various types of RPE atrophy and develop new strategies of ophthalmopathology treatment in preclinical studies.

Chronic choriocapillaris ischemia in dilated vortex vein region in pachychoroid neovasculopathy

We evaluated choroidal congestion using multimodal imaging in pachychoroid neovasculopathy (PNV). In a retrospective case series of 100 eyes of 99 treatment-naïve PNV patients, their clinical records were reviewed and the corresponding multimodal imaging studies were analyzed. We assessed areas of choriocapillaris filling delay which overlapped with dilated outer choroidal vessels, choroidal neovascularization (CNV), and retinal pigment epithelium (RPE) atrophy. The study subjects were 78 men (78.8%) and 21 women (21.2%). The mean patient age was 67.5 ± 10.5 years. On indocyanine green angiography, all eyes showed choriocapillaris filling delay in the early phase. Dilated outer choroidal vessels were demonstrated in all eyes by en face optical coherence tomography. The areas of choriocapillaris filling delay overlapped extensively with that of dilated outer choroidal vessels. All eyes showed CNV localized within the sites of choriocapillaris filling delay. RPE atrophy was noted in 71 eyes (71.0%), and 68 of these (95.8%) had RPE atrophy within the areas showing choriocapillaris filling delay. These findings indicate that chronic choriocapillaris ischemia secondary to vortex vein congestion may lead to CNV development as well as RPE atrophy in eyes with PNV.

Small Choroidal Melanoma: Correlation of Growth Rate with Pathology

<b><i>Purpose:</i></b> The aim of the study was to evaluate equivalence of growth rate and pathologic confirmation in small choroidal melanoma (SCM). <b><i>Design:</i></b> This study is a case series. <b><i>Subjects, Participants, and Controls:</i></b> A total of 61 patients with a choroidal melanocytic tumor of size 5.0–16.0 mm in the largest basal diameter and 1.0–2.5 mm in thickness were classified into the pathology-confirmed group (<i>n</i> = 19), growth-confirmed group (<i>n</i> = 30), and with combined observations (<i>n</i> = 12). <b><i>Methods:</i></b> Distribution of clinical variables (age, gender, laterality, tumor dimensions, tumor location, and presence of orange pigment, subretinal fluid, drusen, and retinal pigment epithelial [RPE] atrophy) between the groups was analyzed. Patient and disease characteristics were summarized as the median and interquartile range for continuous variables and the frequency and percentage for categorical variables. Comparisons were made using the Wilcoxon rank sum test for continuous variables and either Fisher’s exact test or the χ² test for categorical variables with a <i>p</i> value threshold of 0.05 for statistical significance. Growth rate (change in basal dimension/12 months) diagnostic of SCM was quantified. <b><i>Main Outcome Measures:</i></b> The primary aim of this study was to test the hypothesis that “growth” was diagnostic of SCM with the secondary aim of quantifying the malignant “growth rate” (growth rate of SCM). <b><i>Results:</i></b> The clinical characteristics among all 3 groups were similar except more patients with symptoms (68 vs. 20 vs. 42%, <i>p</i> = 0.004) and juxtapapillary location (<i>p</i> = 0.03) were in the pathology group than in the growth-confirmed group. Those in the combined and growth-confirmed groups had more patients with drusen (11 vs. 60 vs. 50%, <i>p</i> = 0.003) and RPE atrophy (11 vs. 23 vs. 67%, <i>p</i> = 0.003), respectively, than in the pathology group. The median time to detect growth was 9 months (range 3–26 months). The mean growth rate in basal dimension was 1.8 mm/12 months (range, 0.0–7.4 mm; [95% CI: 1.32–2.28]). <b><i>Conclusions and Relevance:</i></b> Choroidal melanocytic lesions exhibiting a defined growth rate can be clinically diagnosed as SCM without a need for biopsy.

Observation of the characteristics of the natural course of Bietti crystalline dystrophy by fundus fluorescein angiography

Background Bietti crystalline dystrophy (BCD) is an autosomal recessive genetic disorder that causes progressive vision loss. Here, 12 patients were followed up for 1–5 years with fundus fluorescein angiography (FFA) to observe BCD disease progression. Methods FFA images were collected for 12 patients with BCD who visited our clinic twice or more over a 5-year period. Peripheral venous blood was collected to identify the pathogenic gene related to the clinical phenotype. Results We observed two types in FFA images of patients with BCD. Type 1 showed retinal pigment epithelium (RPE) atrophy in the macular area, followed by choriocapillaris atrophy and the subsequent appearance of RPE atrophy appeared at the peripheral retina. Type 2 showed RPE atrophy at the posterior pole and peripheral retina, followed by choriocapillaris atrophy around the macula and along the superior and inferior vascular arcades and the nasal side of the optic disc. The posterior and peripheral lesions of both type 1 and type 2 BCD subsequently extended to the mid-periphery; finally, all the RPEs and choriocapillaris atrophied, exposing the choroid great vessels, but type 2 macular RPE atrophy could last longer. Conclusions The characterization of two different types of BCD development provides a better understanding of the phenotype and the progression of the disease for a precise prognosis and prediction of pathogenesis.

Chronic choriocapillaris ischemia secondary to choroidal congestion in pachychoroid neovasculopathy

We evaluated choroidal congestion using multimodal imaging in pachychoroid neovasculopathy (PNV). In a retrospective case series of 100 eyes of 99 treatment-naïve PNV patients, their clinical records were reviewed and the corresponding multimodal imaging studies were analyzed. We assessed areas of choriocapillaris filling delay which overlapped with dilated outer choroidal vessels, choroidal neovascularization (CNV), and retinal pigment epithelium (RPE) atrophy. The study subjects were 78 men (78.8%) and 21 women (21.2%). The mean patient age was 67.5 ± 10.5 years. On indocyanine green angiography, all eyes showed choriocapillaris filling delay in the early phase. Dilated outer choroidal vessels were demonstrated in all eyes by en face optical coherence tomography. The areas of choriocapillaris filling delay overlapped extensively with that of dilated outer choroidal vessels. All eyes showed CNV localized within the sites of choriocapillaris filling delay. RPE atrophy was noted in 71 eyes (71.0%), and 68 of these (95.8%) had RPE atrophy within the areas showing choriocapillaris filling delay. These findings indicate chronic choriocapillaris ischemia secondary to vortex vein congestion may lead to CNV development as well as RPE atrophy in eyes with PNV.

The Spectrum of Maculopathy in Mitochondrial DNA A3243G Mutation: A Case Series of Six Patients

Background The mitochondrial DNA (mtDNA) A3243G point mutation encompasses a heterogenous group of disorders including mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes (MELAS), maternally inherited diabetes and deafness (MIDD), and, rarely, chronic progressive external ophthalmoplegia (CPEO). Regardless of the clinical phenotype, a specific retinopathy has been associated with the presence of this mitochondrial DNA mutation. We present six female patients exhibiting retinopathy of the A3243G point mutation at various stages. History and Signs Six female patients (37 – 70 years old) with the A3243G point mutation (four MELAS, one MIDD, and one CPEO) exhibited a maculopathy. Visual acuity ranged from 1/60 to 10/10. Visual field abnormalities varied from minimal decreased sensitivity to absolute central scotomas. They all exhibited, at various degrees, a characteristic pattern of perimacular and peripapillary retinal pigment epithelium (RPE) alterations, with mottled dys-autofluorescence and RPE atrophy and deposits on OCT. Therapy and Outcome The level of visual impairment depended on the foveal involvement and the extension of RPE atrophy. The severity of the maculopathy was not related to age. In the only long-term follow-up (15 years), evolution was slowly progressive. Conclusions A single mtDNA point mutation at locus 3243 can result in a variety of clinical presentations (MELAS, MIDD, or CPEO). Ocular involvement may manifest as a perimacular/peripapillary RPE atrophy/deposit, which can variably impact central visual function (from asymptomatic to legal blindness). The discovery of such a maculopathy should prompt the ophthalmologist to complete the personal and family history, namely, asking for the presence of diabetes mellitus and/or deafness.

Observation of Natural Course Characteristics of Bietti Crystalline Dystrophy by Fundus Fluorescein Angiography

Background: Bietti crystalline dystrophy (BCD) is an autosomal recessive genetic disorder that causes progressive vision loss. Here, 12 patients were followed up for 1–5 years with fundus fluorescein angiography (FFA) to clarify BCD disease development and its classification. Methods: FFA images were collected for 12 patients with BCD who visited our clinic twice or more in 5 years. Peripheral venous blood was collected to identify a pathogenic gene related to the clinical phenotype.Results: FFA images identified two BCD types. Type 1 showed retinal pigment epithelium (RPE) atrophy at the macular area, followed by choriocapillaris atrophy, then RPE atrophy appeared at the peripheral retina. Type 2 showed RPE atrophy at the posterior pole and peripheral retina, followed by choriocapillaris atrophy around the macula and along the superior and inferior vascular arcades and optic disc nasal side. Then the posterior and peripheral lesions of type 1 and type 2 were extended to the mid-periphery; at last, all the RPE and choriocapillars atrophied, exposed choroid great vessels, but the macular RPE atrophy of type 2 can existed for a long time. Conclusions: The two different BCD development types provide a better understanding of the phenotype and the progression of the disease for a precise prognosis and prediction of pathogenesis.

Outer nuclear layer relevance in visual function correlated to quantitative enface OCT parameters in Stargardt disease

Purpose: To evaluate the correlation between Best Corrected Visual Acuity (BCVA) and the following parameters in Stargardt Disease (STGD): Central Retinal Thickness (CR-T), Central Outer Nuclear Layer Thickness (C-ONL-T), Areas of macular Photoreceptor loss (PHRa), and Retinal Pigment Epithelium (RPE) loss (RPEa). Methods: A total of 64 eyes of 32 STGD patients were included in the study. All patients received a comprehensive ophthalmological examination, color fundus photographs, fundus auto-fluorescence imaging, and Optical Coherence Tomography (OCT). The CR-T and C-ONL-T were evaluated from standard SD-OCT scans. The PHRa and RPEa were calculated from enface OCT scans (sub RPE slab and photoreceptor slab). The collected OCT parameters were evaluated for possible association with BCVA. Results: The mean macular PHRa and RPEa was 16.16 ± 13.36 and 12.05 ± 12.57 mm2 respectively. The mean CR-T measured 120.78 ± 41.49 μm while the mean C-ONL-T was assessed at 4.60 ± 13.73 μm. BCVA showed the highest correlation with the C-ONL-T ( r = −0.72; p < 0.001) while there was no correlation with the CR-T ( r = −0.17; p = 1.00). Conclusions: Enface OCT permits a rapid and precise quantitative evaluation of the macular PHR and RPE atrophy area in STGD. Nonetheless, the OCT parameter that showed the highest correlation with visual acuity in STGD was the ONL thickness.

Outcome of half-dose photodynamic therapy in chronic central serous chorioretinopathy with fovea-involving atrophy

Purpose To evaluate the clinical outcomes after half-dose photodynamic therapy (PDT) in chronic central serous chorioretinopathy (cCSC) patients with pre-existent fovea-involving atrophy. Methods In this retrospective study, cCSC patients who had a window defect of the retinal pigment epithelium (RPE) on fluorescein angiography (FA), compatible with RPE atrophy, prior to half-dose PDT were included. Results Thirty-four cCSC eyes with typical findings of cCSC on multimodal imaging, and fovea-involving RPE atrophy on FA, were included. At the first visit after PDT (at a median of 1.8 months after half-dose PDT), 20 eyes (59%) had a complete resolution of SRF (p < 0.001), while this was the case in 19 eyes (56%) at final visit (median of 11.3 months after half-dose PDT; p < 0.001). The mean BCVA in Early Treatment of Diabetic Retinopathy Study letters was 71. 2 ± 15.9 at last visit before PDT, which increased to 74.1 ± 14.1 at first visit after PDT (p = 0.093, compared with baseline), and changed to 73.0 ± 19.1 at final visit (p = 0.392, compared with baseline). Both at first visit after PDT and at final visit, a significant decrease in subfoveal choroidal thickness was observed (p = 0.032 and p = 0.004, respectively). Conclusions Half-dose PDT in cCSC patients with pre-existing fovea-involving atrophy may lead to anatomical changes, but not to functional improvements. Ideally, cCSC should be treated with half-dose PDT before the occurrence of such atrophy.