Two novel CACNA1F gene mutations cause two different phenotypes: Aland Eye Disease and incomplete Congenital Stationary Night Blindness

Congenital Stationary Night Blindness type 2 (CSNB2) and Aland island Eye Disease (AIED) associated with CACNA1F mutation demonstrate a significant phenotype overlapping. We report two cases with different clinical presentation carrying two novel mutations in CACNA1F gene. Subjects underwent a complete neurophtahlmological examination associated with structural and electrofunctional insight. Next Generation Sequencing (NGS) analysis of 31 genes previously associated with retinal dystrophy (RD) was performed. Messenger RNAs derived from probands 'peripheral blood samples were analyzed by RT-PCR and cDNA sequencing. The neuro-ophthalmological examinations revealed different clinical, structural and morphological presentations, more severe in patient 1 compared with patient 2. Molecular analysis revealed, that both patients had the hemizygous form of two novel mutations in CACNA1F gene. Patient 1 presented a duplication (c.425dupC) in exon 4, resulting in shifting of the reading frame with the insertion of a premature Stop codon. In Patient 2 variant c.5156G > C localized in the donor's splicing site of exon 43 was identified. Complementary DNA sequencing demonstrated skipping of exon 43 with a deletion of 55 amino acids that causes a frame shift with insertion of a Stop codon. These findings suggest that the effect and the localization of the mutations in the CACNA1F gene can explain different clinical phenotypes. Clinical spectrum is more severe and resembles the AIED phenotype when the mutation affects the first part of the protein, while it is more similar to CSNB2 if the mutation is localized at the end of the protein. Genetic testing results to be an essential tool to provide more accurate diagnosis and prognosis in patients with inherited retinal degenerative disorders and could help, in the future, to develop more specific therapeutic strategies.

Risdiplam treatment has not led to retinal toxicity in patients with spinal muscular atrophy

OBJECTIVE

Evaluation of ophthalmologic safety with focus on retinal safety in patients with spinal muscular atrophy (SMA) treated with risdiplam (EVRYSDI®), a survival of motor neuron 2 splicing modifier associated with retinal toxicity in monkeys. Risdiplam was approved recently for the treatment of patients with SMA, aged ≥ 2 months in the United States, and is currently under Health Authority review in the EU.

METHODS

Subjects included patients with SMA aged 2 months-60 years enrolled in the FIREFISH, SUNFISH, and JEWELFISH clinical trials for risdiplam. Ophthalmologic assessments, including functional assessments (age-appropriate visual acuity and visual field) and imaging (spectral domain optical coherence tomography [SD-OCT], fundus photography, and fundus autofluorescence [FAF]), were conducted at baseline and every 2-6 months depending on study and assessment. SD-OCT, FAF, fundus photography, and threshold perimetry were evaluated by an independent, masked reading center. Adverse events (AEs) were reported throughout the study.

RESULTS

A total of 245 patients receiving risdiplam were assessed. Comprehensive, high-quality, ophthalmologic monitoring assessing retinal structure and visual function showed no retinal structural or functional changes. In the youngest patients, SD-OCT findings of normal retinal maturation were observed. AEs involving eye disorders were not suggestive of risdiplam-induced toxicity and resolved with ongoing treatment.

INTERPRETATION

Extensive ophthalmologic monitoring conducted in studies in patients with SMA confirmed that risdiplam does not induce ophthalmologic toxicity in pediatric or adult patients with SMA at the therapeutic dose. These results suggest that safety ophthalmologic monitoring is not needed in patients receiving risdiplam, as also reflected in the United States Prescribing Information for risdiplam.

Optical coherence tomography in adult adrenoleukodystrophy: a cross-sectional and longitudinal study

BACKGROUND

Adrenoleukodystrophy (ALD) encompasses different neurological phenotypes, ranging from the most severe cerebral forms (C-ALD) to the less severe adrenomyeloneuropathy (AMN). As visual system can be varyingly involved, we aimed at exploring whether optical coherence tomography (OCT) may detect retinal abnormalities and their longitudinal changes in adult ALD patients.

METHODS

In this cross-sectional and longitudinal study, we measured the thicknesses of peripapillary retinal nerve fiber layer (pRNFL), macular ganglion cell complex (mGCC), and segmented inner and outer macula at baseline and their changes over time in 11 symptomatic adult ALD males and 10 age- and sex-matched healthy controls. Statistical analyses were performed for the patients as complete group, and splitting them into two subgroups, one (C-ALD) with and the other (AMN) without cerebral parieto-occipital white matter (WM) lesions.

RESULTS

In the complete ALD group and in the C-ALD subgroup, the average pRNFL, mGCC, and inner macula were significantly thinner than in controls (p ≤ 0.01), whereas in the AMN subgroup, they were constantly, though non-significantly, thinner. Significant outer macula thinning was also observed (p < 0.01). In the complete ALD group, follow-up assessment (mean 26.8 months, range 8-48) showed mildly progressive thinning of inferior pRNFL, average mGCC, and inner macula.

CONCLUSIONS

In adult ALD patients, OCT can reveal retinal abnormalities which are prominent in the more compromised patients, namely those with parieto-occipital WM lesions. The inferior pRNFL, average mGCC and inner macula thicknesses might be sensitive-to-change OCT parameters, but their utility and consistency for short-term longitudinal studies deserve further investigations.

Optical Coherence Tomography (OCT) in Retinal Angiomatous Proliferation (RAP)

Purpose

To verify the utility of optical coherence tomography (OCT) for diagnosing retinal angiomatous proliferations (RAP) in patients with exudative age-related macular degeneration (AMD).

Methods

Multiple cross-sections were taken with OCT from 41 eyes of 39 consecutive patients with AMD and RAP. The presence and the location of the angiomatous complexes had already been documented by fluorescein angiography (FA) and high-speed confocal indocyanine green videoangiography (ICGA).

Results

RAP was detectable by OCT scans in all 41 eyes, appearing as a focal hyper-reflecting area in the neuroretinal layers; it was frequently located close to the inner surface of the retinal pigment epithelium (29 eyes [70.7%]). All eyes had either no or only a low-reflecting OCT signal surrounding the RAP, caused by serous intraretinal edema. Only 13 eyes (31.7%), however, had large serous retinal detachment (SRD). OCT detected pigment epithelium detachment in 31 eyes (75.6%), but none had underlying choroidal neovascularization.

Conclusions

OCT findings confirm the intraretinal localization of the RAP which are always associated with impressive exudative phenomena. OCT is therefore a useful diagnostic tool, adding information to FA and high-speed ICGA.

Multimodal imaging and diagnosis of myopic choroidal neovascularization in Caucasians

Purpose

To investigate myopic choroidal neovascularization (mCNV) by fluorescein angiography (FA), spectral-domain optical coherence tomography (SD-OCT), near-infrared (NIR) reflectance, and autofluorescence (AF).

Methods

This retrospective study included 65 eyes of 62 Caucasian patients with a mean age of 66.72 years (95% confidence interval [CI] 63–70 years) and a mean refraction of −9.72 diopters (95% CI −8.74 to −10.70 diopters).

Results

Most of the mCNV cases were foveal-juxtafoveal (60/65, 92.3%), with thickening of the corresponding retina (62/65, 95.3%) and leakage on FA (44/65, 67.6%). No retinal fluid was detectable in 32 (49.2%) eyes and there was no hemorrhage in 25 (38.4%) eyes. Papillary chorioretinal atrophy was evident in 58 (89.2%), a shadowing effect in 48 (73.8%), and an epiretinal membrane in 38 (58.4%) eyes. If an area of macular chorioretinal atrophy was present, mCNV frequently developed adjacent to it and was hyperfluorescent rather than with leakage (P⩽0.001). In eyes with edema or hemorrhage, hyper-reflective foci were more frequent (P⩽0.005). NIR and AF features were indeterminable in 19 (29.2%) and 27 (41.5%) eyes, respectively. The predominant feature was black or grayish on NIR (34/65, 52.3%) and patchy (hypo- and hyperfluorescence was observed) on AF (25/65, 38.4%). FA and SD-OCT correctly detected mCNV in 49 (75.3%) and 48 (73.8%) eyes, respectively, whereas NIR and AF exhibited limited diagnostic sensitivity. Doubtful diagnosis was associated with hyperfluorescent mCNV (P⩽0.001), absence of retinal fluid and epiretinal membrane (P⩽0.05), and presence of macular chorioretinal atrophy (P⩽0.01).

Conclusion

Tomographic, angiographic, AF, and NIR features of mCNV are described in this study. Combination of SD-OCT and FA is recommendable for diagnosis.

Palmitoylethanolamide treatment reduces retinal inflammation in streptozotocin-induced diabetic rats

Although the pathogenesis of diabetic retinopathy (DR) is still insufficiently understood, new evidences indicate 'retinal inflammation' as an important player in the pathogenesis of the complication. Accordingly, common sets of upregulated inflammatory cytokines are found in serum, vitreous and aqueous samples obtained from subjects with DR, and these cytokines can have multiple interactions to impact the pathogenesis of the disease. Thus, based on previously published data, we investigated the effects of Palmitoylethanolamide (PEA), an endogenous lipid amide that belongs to the N-acyl-ethanolamines family, on DR in streptozotocin (STZ)-induced diabetic rats. PEA (10mg/kg) was administered orally daily starting 3 days after the iv administration of STZ. The rats were killed 15 and 60day later and eyes were enucleated to evaluate, through immunohistochemical analysis, the key inflammatory events involved in the breakdown of blood retinal barrier (BRB). Immunohistochemical analysis confirmed the presence of VEGF, ICAM-1, nitrotyrosine (a marker of peroxynitrite), and tight junctions in the retina of STZ-treated rats. Of interest, the extent of injury was significantly reduced after treatment with PEA. Altogether, this study provides the first evidence that PEA attenuates the degree of inflammation while preserving the blood-retinal barrier in rats with experimental DR.

Effect of chromogranin A-derived vasostatin-1 on laser-induced choroidal neovascularization in the mouse

PURPOSE

To verify the effect of vasostatin-1 (VS-1), an anti-angiogenic fragment of chromogranin A, in the prevention of choroidal neovascularization (CNV) in an established mouse model of laser-induced ocular neovascularization.

METHODS

Bruch's membrane, the innermost layer of the choroid, was broken by laser photocoagulation in C57/Bl6 mice, to induce CNV. Mice were then treated daily for 14 days by intraperitoneal injection of VS-1 or vehicle (6 mice/group). CNV and vascular leakage were measured at three time-points (day 0, 7 and 14) in vivo by spectral domain optical coherence tomography (OCT) and fluorescein angiography (FA). Ex vivo analysis of CNV was also performed at day 14 by confocal microscopy analysis of dextran-perfused choroidal flat-mounts.

RESULTS

In vivo analyses showed that VS-1 significantly reduced CNV at day 14 (p = 0.03) and vascular leakage at day 7 (p = 0.01) and 14 (p = 0.04). Ex vivo confocal microscopy analysis of CNV performed on dextran-perfused choroidal flat-mounts at day 14 confirmed the protective activity of VS-1 (p = 0.01). A significant correlation between the results of in vivo and ex vivo analyses of CNV was also observed (p = 0.001, R(2) = 0.81).

CONCLUSION

The results indicate that VS-1 can prevent CNV and vascular leakage in a mouse model of ocular neovascularization, suggesting that this polypeptide might have therapeutic activity in human ocular diseases that are complicated by neovascularization or excessive vascular permeability.

A dynamic distention protocol for whole-organ bladder decellularization: histological and biomechanical characterization of the acellular matrix

A combined physical-chemical protocol for whole full-thickness bladder decellularization is proposed, based on organ cyclic distention through repeated infusion/withdrawal of the decellularization agents through the urethra. The dynamic decellularization was intended to enhance cell removal efficiency, facilitating the delivery of detergents within the inner layers of the tissue and the removal of cell debris. The use of mild chemical detergents (hypotonic solution and non-ionic detergent) was employed to limit adverse effects upon matrix 3D ultrastructure. Inspection of the presence of residual DNA and RNA was carried out on decellularized matrices to verify effective cell removal. Histological investigation was focused on assessing the retention of adequate structural and functional components that regulate the biomechanical behaviour of the acellular tissue. Biomechanical properties were evaluated through uniaxial tensile loading tests of tissue strips and through ex vivo filling cystometry to evaluate the whole-organ mechanical response to a physiological-like loading state. According to our results, a dynamic decellularization protocol of 17 h duration with a 5 ml/min detergent infusion flow rate revealed higher DNA removal efficiency than standard static decellularization, resulting in residual DNA content < 50 ng/mg dry tissue weight. Furthermore, the collagen network and elastic fibres distribution were preserved in the acellular ECM, which exhibited suitable biomechanical properties in the perspective of its future use as an implant for bladder augmentation.

Endothelial progenitor cells carrying monocyte markers are selectively abnormal in type 1 diabetic patients with early retinopathy

Endothelial progenitor cells (EPCs) enter the systemic circulation in response to cues related to vascular damage and need for neovascularization. Thus, EPCs could become readily accessible informers of vascular status and enable the survey of vascular pathologies during preclinical stages. To identify EPC changes with biomarker potential, we investigated whether discrete EPC abnormalities were associated with early nonproliferative diabetic retinopathy (NPDR). Two EPC subtypes with different functions have been characterized to date-one solely committed to the endothelial lineage and the other carrying both endothelial and monocytic markers. We found that only the latter, colony-forming units (CFU)-Hill cells, manifested abnormalities in type 1 diabetic patients with NPDR compared with control subjects. The abnormalities consisted in an increased number of colonies formed in vitro and downregulation of the molecules that facilitate homing at sites of vascular injury. The abnormalities were absent in type 1 diabetic patients free of retinopathy and other complications, despite long diabetes duration, but were detected in some of the patients without clinical retinopathy after short diabetes duration. CFU-Hill cells are potential informers of diabetic microangiopathy but may be preempted from carrying out reparative functions if the molecular abnormalities compromise interactions with the damaged vascular wall.

Steroids as part of combination treatment: the future for the management of macular edema?

Diabetic macular edema (DME), defined as a retinal thickening involving or approaching the center of the macula, plays a major role in vision loss related to diabetic retinopathy. This article presents an in-depth analysis of therapeutic perspectives on DME by means of an approach based on combination therapy with steroids. Corticosteroid drugs have been demonstrated to both inhibit the expression of vascular endothelial growth factor (VEGF) and the VEGF gene, and to have antiinflammatory properties. A treatment algorithm is provided regarding the management of DME. While grid laser photocoagulation remains the first-line therapy for focal vasogenic DME, diffuse DME can be effectively treated by means of intravitreal injections of corticosteroids. Recalcitrant DME can also be managed beneficially with intravitreal steroids. The management of DME is complex, and often multiple treatment approaches are needed. Each form of DME should be properly classified and specifically treated. The combination treatment has still an important role in the combined treatment options for DME.

The therapeutic potential of VEGF inhibition in diabetic microvascular complications

During the last few years, the incidence of microvascular complications in diabetes mellitus has rapidly increased as a consequence of both an increase in incidence of type 2 and type 1 diabetes mellitus. The pathogenesis of diabetic microvascular complications is still largely unknown. Among the many hypotheses, a dysfunction in angiogenesis has been suggested as a common origin for retinopathy, nephropathy, and neuropathy. Based on this hypothesis, inhibition of vascular endothelial growth factor (VEGF) has been tested as a potential therapeutic approach to prevent and cure diabetic microvascular complications. Several VEGF inhibitors are currently under evaluation or are approved for the treatment of wet age-related macular degeneration and macular edema. These include inhibitors of intracellular transcription of VEGF (e.g. bevasiranib), inhibitors of extracellular VEGF (e.g. pegaptanib), inhibitors of VEGF receptor expression (e.g. aflibercept [VEGF-TRAP]) and inhibitors of the intracellular signaling cascade activating VEGF (e.g. midostaurin). According to the existing evidence base, although inhibition of VEGF results in a better outcome in the case of diabetic retinopathy and also, despite some discrepant results, in the case of diabetic nephropathy, there is no final confirmation that VEGF inhibition is a valid approach for diabetic neuropathy. The latter complication actually, in line with other chronic neuropathies, seems to improve with stimulation of angiogenesis through increased expression of VEGF.

Optical coherence tomography (OCT) angiomatous prolifieration (RAP) in retinal

PURPOSE

To verify the utility of optical coherence tomography (OCT) for diagnosing retinal angiomatous proliferations (RAP) in patients with exudative age-related macular degeneration (AMD).

METHODS

Multiple cross-sections were taken with OCT from 41 eyes of 39 consecutive patients with AMD and RAP. The presence and the location of the angiomatous complexes had already been documented by fluorescein angiography (FA) and high-speed confocal indocyanine green videoangiography (ICGA).

RESULTS

RAP was detectable by OCT scans in all 41 eyes, appearing as a focal hyper-reflecting area in the neuroretinal layers; it was frequently located close to the inner surface of the retinal pigment epithelium (29 eyes [70. 7%]). All eyes had either no or only a low-reflecting OCTsignal surrounding the RAP, caused by serous intraretinal edema. Only 13 eyes (31.7%), however, had large serous retinal detachment (SRD). OCT detected pigment epithelium detachment in 31 eyes (75.6%), but none had underlying choroidal neovascularization.

CONCLUSIONS

OCT findings confirm the intraretinal localization of the RAP which are always associated with impressive exudative phenomena. OCT is therefore a useful diagnostic tool, adding information to FA and high-speed ICGA.

Optical coherence tomography findings in adult-onset foveomacular vitelliform dystrophy

PURPOSE

The purpose of this article is to analyze cross-sectional images of a subretinal macular lesion, using optical coherence tomography (OCT) in eyes with adult-onset foveomacular vitelliform dystrophy (AOFVD), to compare thickness of the neurosensory retina over the lesion with best-corrected visual acuity (BCVA) of each eye, and to compare OCT tomograms of AOFVD patients with OCT of Best disease.

DESIGN

Observational case series.

METHODS

This is a retrospective study which took place in a clinical practice. Forty-three patients (72 eyes) with AOFVD and 12 patients (24 eyes) with Best's disease were studied. The observation procedures used were biomicroscopic fundus examination, fluorescein angiography (FA), indocyanine green angiography (ICGA), and optical coherence tomography (OCT). The main outcome measures were a description of the typical picture of AOFVD in OCT tomograms, the relationship between the neurosensory retinal thickness over the lesion, the BCVA expressed in decimal terms, and a comparison with description of OCT in Best disease.

RESULTS

Of the 43 patients affected by AOFVD, 29 had bilateral macular lesions. Fluorescein angiography showed a central hypofluorescent spot surrounded by an irregular hyperfluorescent ring in 65 of the 72 eyes. Indocyanine green angiography demonstrated a central nonfluorescent spot and a hyperfluorescent area surrounding the central spot in 22 of 27 eyes examined. In all 72 eyes of 43 patients, OCT showed a well-defined central region of thickening in the reflective band representing the retinal pigment epithelium (RPE). The relationship between the thickness of neurosensory retina over the lesion and BCVA was significant (P =.001, r(2) = 0.61). Optical coherence tomography in all 24 eyes with Best disease showed a well-defined central serous retinal detachment.

CONCLUSION

In the 72 eyes with AOFVD, FA and ICGA presented different features. Instead, OCT tomograms showed a well-defined subretinal thickening of the RPE in all the eyes. The lack of difference in OCT patterns between cases with or without the hypofluorescent spot on angiography was useful for confirming the diagnosis of AOFVD. Moreover, a reduced visual acuity was evident in patients with a thinner neurosensory retinal layer over AOFVD lesion. Finally, OCT images were also useful for distinguishing AOFVD from Best disease.

Ultrasound biomicroscopy of residual vitreous base after vitreoretinal surgery

Residual vitreous base after vitreoretinal surgery was evaluated by ultrasound biomicroscopy (UBM). Twenty aphakic and pseudoaphakic patients (20 eyes) undergoing surgery for different vitreoretinal diseases were evaluated by high-frequency (50 MHz), high-resolution (50 microm) UBM, performed the day before surgery, weekly up to 1 month after surgery and then monthly. One week after surgery, the vitreous remnants were 'hardly visible' in 3 cases, 'visible' in 6 cases and 'highly visible' in 11. At the end of the follow-up (2.2 months), the 'hardly visible' cases increased to 6 and the 'visible' cases to 12, while the 'highly visible' cases decreased to 2. UBM demonstrated that vitreous base remnants were present in spite of accurate surgery; a spontaneous volume reduction of vitreous was observed during the follow-up.