Longitudinal Changes of Macular Curvature in Patients with Retinitis Pigmentosa.

Purpose: To investigate the longitudinal changes of the macular curvature in eyes with retinitis pigmentosa (RP) and to determine the factors associated with the changes. Methods: We reviewed the medical charts of 107 RP patients, for whom the axial length of their right eyes ranged from 21.5 to 26.0 mm and who had had been followed by spectral-domain optical coherence tomography (OCT). The OCT images at the initial and the most recent examinations were compared. The mean curvature of Bruch's membrane within 6 mm of the central macula obtained from the OCT images was evaluated as the mean macular curvature index (MMCI). Changes in the MMCI and their relationships with other clinical factors, including the ellipsoid zone (EZ) width, were assessed. Results: The MMCI decreased significantly in the vertical OCT images, from -15.47 × 10-5 µm-1 to -16.36 × 10-5 µm-1 (P = 0.008) during the mean observation period of 3.4 ± 1.4 years (mean ± SD). This indicated that the macular shape became more concave. The change to a steeper shape was more prominent in eyes with less photoreceptor degeneration and for which the EZ width was preserved at >2000 µm. In three eyes, the MMCI increased markedly by >5 × 10-5 µm-1, and this was accompanied by absorption of the macular edema. Conclusions: The macular curvature in RP eyes becomes more concave in eyes with preserved EZ width. Translational Relevance: Longitudinal changes of the macular curvature in RP should be considered in future therapies, such as the implantation of the retinal prosthesis.

Steeper Macular Curvature in Eyes With Non-Highly Myopic Retinitis Pigmentosa.

Purpose: A posterior staphyloma has been reported to be present in some eyes with retinitis pigmentosa (RP), and the purpose of this study was to determine the macular curvature of non-highly myopic RP eyes. Methods: This was a retrospective, observational study. The medical charts of the right eyes of 143 patients with RP and 60 controls whose axial length ranged from 21.5 mm to 26.0 mm were reviewed. The mean curvature of Bruch's membrane within 6 mm of the central macula obtained from the horizontal optical coherence tomographic images were evaluated as the mean macular curvature index (MMCI). The relationships between the MMCI and other clinical factors were assessed. Results: The mean MMCI of RP patients (-13.73 ± 9.63 × 10-5 µm-1) was significantly lower than that of the controls (-6.63 ± 5.63 × 10-5 µm-1). This indicated a deeper concave shape of the macula in RP eyes (P < 0.001). The MMCI was significantly correlated with the age (r = 0.20; P = 0.016) and the axial length (r = -0.24; P = 0.004). Further analysis suggested a nonlinear effect of the ellipsoid zone width on the macular curvature in the RP eyes. Conclusions: There is a high incidence of steeper macular curvatures even in non-highly myopic RP eyes, and the steepness was also affected by the degree of photoreceptor degeneration.

Danon disease presenting with early onset of hypertrophic cardiomyopathy and peripheral pigmentary retinal dystrophy in a female with a de novo novel mosaic mutation in the LAMP2 gene.

Purpose: To describe the phenotype and genotype in a young woman with Danon disease. Methods: The patient underwent an ophthalmic examination including best corrected visual acuity (BCVA), fundus photography and fundus autofluorescence (FAF), full-field electroretinography (full-field ERG), multifocal ERG, optical coherence tomography (OCT) and SAP-Humphrey 30-2 at the ages of 20 and 25. Electrooculography, fluorescein angiography (FA), indocyanine angiography and OCT angiography were performed only once. Genetic testing using a Next-Generation Sequencing panel and immunohistochemical analysis of LAMP2 protein expression were performed in the patient's explanted heart, and the patient's cardiologic and ophthalmologic records were retrospectively reviewed. Results: A de novo, novel, mosaic mutation, c.135dupA; p.(Trp46Metfs*10) was identified in exon 2 of the LAMP2 gene. Immunohistochemical investigation of the myocardium in the explanted heart revealed pronounced deficiency of LAMP2 protein in cardiomyocytes. The color photographs, FAF images and FA revealed more extensive peripheral pigmentary retinal dystrophy (PPRD) at the 5-year follow-up examination. No changes were observed in BCVA, OCT, SAP-Humphrey 30-2 or multifocal ERG findings at follow-up. Full-field ERG showed an asymmetric interocular reduction in ERG response at follow-up: the b-wave amplitude of the rod response had decreased by 29% in the right eye, but by only 6 % in the left eye. The a-wave amplitude of single-flash response had decreased by 9 % in the left eye, while it had increased by 3% in the right eye. Conclusions: Although PPRD progressed slowly, it was an important clue in the diagnosis of the life-threatening condition of Danon disease.

Three cases of acute-onset bilateral photophobia.

PURPOSE: To report the findings in 3 cases of bilateral negative electroretinograms (ERGs) with acute onset of photophobia. STUDY DESIGN: Retrospective case series. METHODS: The medical charts of the 3 patients were reviewed. RESULTS: A 43-year-old woman, a 68-year-old woman, and a 41-year-old woman were referred to Nagoya University Hospital. Their main symptom was bilateral acute photophobia. None of the patients had any systemic diseases or specific medical history. The decimal best-corrected visual acuity (> 0.8) and Humphrey visual fields (mean deviation > -3 dB) were relatively well preserved in all 3 patients. The optical coherence tomography (OCT) and fundus autofluorescence findings were essentially normal. Fluorescein angiography showed mild leakage in 1 patient but no abnormality in the other 2 patients. However, the ERGs of the 3 patients had the features of abnormal ERGs found in patients with incomplete congenital stationary night blindness (CSNB). Exome analyses found no pathogenic variants related to known CSNB-related genes. The symptoms and ERGs of the 3 patients have not progressed or recovered after a relatively long follow-up period. CONCLUSION: The ERG characteristics of 3 patients with bilateral photophobia were similar to those of incomplete CSNB, suggesting post-phototransductional abnormalities. The symptoms and genetic analyses indicated the possibility of an acquired condition rather than a hereditary retinal disease.

PDK1 Determines Collagen-Dependent Platelet Ca2+ Signaling and Is Critical to Development of Ischemic Stroke In Vivo.

OBJECTIVE: Activation of platelets by subendothelial collagen results in an increase of cytosolic Ca(2+) concentration ([Ca(2+)]i) and is followed by platelet activation and thrombus formation that may lead to vascular occlusion. The present study determined the role of phosphoinositide-dependent protein kinase 1 (PDK1) in collagen-dependent platelet Ca(2+) signaling and ischemic stroke in vivo. APPROACH AND RESULTS: Platelet activation with collagen receptor glycoprotein VI agonists collagen-related peptide or convulxin resulted in a significant increase in PDK1 activity independent of second-wave signaling. PDK1 deficiency was associated with reduced platelet phospholipase Cγ2-dependent inositol-1,4,5-trisphosphate production and intracellular [Ca(2+)]i in response to stimulation with collagen-related peptide or convulxin. The defective increase of [Ca(2+)]i resulted in a substantial defect in activation-dependent platelet secretion and aggregation on collagen-related peptide stimulation. Furthermore, Rac1 activation and spreading, adhesion to collagen, and thrombus formation under high arterial shear rates were significantly diminished in PDK1-deficient platelets. Mice with PDK1-deficient platelets were protected against arterial thrombotic occlusion after FeCl3-induced mesenteric arterioles injury and ischemic stroke in vivo. These mice had significantly reduced brain infarct volumes, with a significantly increased survival of 7 days after transient middle cerebral artery occlusion without increase of intracerebral hemorrhage. Tail bleeding time was prolonged in pdk1(-/-) mice, reflecting an important role of PDK1 in primary hemostasis. CONCLUSIONS: PDK1 is required for Ca(2+)-dependent platelet activation on stimulation of collagen receptor glycoprotein VI, arterial thrombotic occlusion, and ischemic stroke in vivo.

Late stage infection in sleeping sickness.

At the turn of the 19(th) century, trypanosomes were identified as the causative agent of sleeping sickness and their presence within the cerebrospinal fluid of late stage sleeping sickness patients was described. However, no definitive proof of how the parasites reach the brain has been presented so far. Analyzing electron micrographs prepared from rodent brains more than 20 days after infection, we present here conclusive evidence that the parasites first enter the brain via the choroid plexus from where they penetrate the epithelial cell layer to reach the ventricular system. Adversely, no trypanosomes were observed within the parenchyma outside blood vessels. We also show that brain infection depends on the formation of long slender trypanosomes and that the cerebrospinal fluid as well as the stroma of the choroid plexus is a hostile environment for the survival of trypanosomes, which enter the pial space including the Virchow-Robin space via the subarachnoid space to escape degradation. Our data suggest that trypanosomes do not intend to colonize the brain but reside near or within the glia limitans, from where they can re-populate blood vessels and disrupt the sleep wake cycles.