BACKGROUND: To explore the safety of Neodymium:Yttrium-aluminum-garnet (Nd:YAG) laser vitreolysis based on the histological examination of the retina and the alteration of vitreous cytokines in the rabbits.
METHODS: Nine male New Zealand rabbits underwent Nd:YAG laser vitreolysis of 10 mJ x 500 pulses in the left eyes, while the right eyes were used as controls. Intraocular pressure, color fundus photography, and ultrasound B scan were measured before, as well as 1 day, 4 weeks, and 12 weeks after Nd:YAG laser vitreolysis. Three rabbits were euthanized 1 day, 4 weeks, and 12 weeks after treatment, respectively. Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining and hematoxylin-eosin (H&E) staining were used to look for pathological changes in the retina. An enzyme-linked immunosorbent assay (ELISA) was utilized to detect the expression of vascular endothelial growth factor (VEGF) and some inflammatory cytokines, including interferon inducible protein 10 (IP-10), monocyte chemoattractant protein 1 (MCP-1) and interlenkin 6 (IL-6) in the vitreous humor. The ascorbic acid (AsA) and total reactive antioxidant potential (TRAP) in the vitreous humor were also measured.
RESULTS: Following Nd:YAG laser vitreolysis, the levels of VEGF, IP-10, MCP-1, IL6, AsA, and TRAP in the vitreous humor did not change substantially (P > 0.05). There were no detectable pathological changes in the retinal tissues, and no apoptotic signal was found.
CONCLUSIONS: Rabbits tolerate Nd:YAG laser vitreolysis without observable impact on retinal tissue or the microenvironment of the vitreous.

Traumatic brain injuries (TBIs) are a large societal and individual burden. In the first year of life, the vast majority of these injuries are the result of inflicted abusive events by a trusted caregiver. Abusive head trauma (AHT) in infants, formerly known as shaken baby syndrome, is the leading cause of inflicted mortality and morbidity in this population. In this review we address clinical diagnosis, symptoms, prognosis, and neuropathology of AHT, emphasizing the burden of repetitive AHT. Next, we consider existing animal models of AHT, and we evaluate key features of an ideal model, highlighting important developmental milestones in children most vulnerable to AHT. We draw on insights from other injury models, such as repetitive, mild TBIs (RmTBIs), post-traumatic epilepsy (PTE), hypoxic-ischemic injuries, and maternal neglect, to speculate on key knowledge gaps and underline important new opportunities in pre-clinical AHT research. Finally, potential treatment options to facilitate healthy development in children following an AHT are considered. Together, this review aims to drive the field toward optimized, well-characterized animal models of AHT, which will allow for greater insight into the underlying neuropathological and neurobehavioral consequences of AHT.

We investigated the association between retinal microvascular changes and hearing loss based on the hypothesis that both may result from shared microvascular pathology. Data from 536 older adults from the National Health and Nutritional Examination Survey 2005 to 2006 including sociodemographic and health characteristics, pure-tone hearing thresholds, and retinal pathologies were collected and analyzed. Associations between retinal and hearing pathologies were modeled with multivariable-adjusted linear regressions. 75% of participants had hearing loss and 15% of participants had retinopathy. The association between retinopathy, microaneurysms, and blot hemorrhages with better speech-frequency pure tone average was -2.81 (95% confidence interval [CI]: -5.72 to 0.10), -4.75 (95% CI: -8.73 to -0.78), and -5.34 (95% CI: -8.68 to -2.00), respectively. The presence of retinopathy, microaneurysms, and blot hemorrhages was inversely associated with hearing loss. Further studies are needed to better understand the potential relationship between microvascular pathologies of the eye and ear.

OBJECTIVE: To further enhance understanding of the expanded clinical spectrum of unilateral retinal pigment epithelium dysgenesis (URPED) via numerous imaging modalities including novel markers of highly detailed indocyanine green angiography (ICGA) features.
METHODS: Retrospective, observational, case report.
RESULTS: URPED in this patient is expressed as a solitary, flat and pigmented lesion in the posterior pole with RPE hyperplasia and atrophic changes. An epiretinal membrane (ERM) causing fine, tortuous retinal vessels and retinal folds was observed. Green and blue excitation light fundus autofluorescence showed a biphasic appearance with hypoautofluorescent rounded lesions and a reticular configuration of normal RPE. Fundus fluorescein angiography revealed diffuse hypofluorescence and hyperfluorescent wisps of leakage in late-phases. Early-phase of ICGA evidenced diffuse hypocianescence and a delineated hypercianescent scalloped margin appeared in the late-phase, together with focal hypocianescent spots. SD-OCT demonstrated irregularity of the RPE with fibrosis and hyperplastic changes combined with atrophic areas. Flat RPE detachments intermingled with healthy-appearing RPE were also observed together with thinning of the outer retina. ERM with thickening and disorganization involving the whole retina was present. Optical coherence tomography angiography (14 × 14 mm) revealed an oval shape foveal avascular zone and vascular anomalies such as tortuosity and looping.
CONCLUSIONS: URPED is an extremely rare clinical entity with only a few cases reported. In this case the almost pathognomonic differential features of URPED were best appreciated with ICGA imaging. To our knowledge, this is the first reported case of URPED with these abnormal findings on ICGA meaning it could be part of the spectrum of the disease.

The retinal pathology of genetically confirmed neuronal intranuclear inclusion disease (NIID) is yet unknown. We report the ocular findings in four NIID patients with NOTCH2NLC GGC repeat expansion to investigate the pathology of retinopathy. All four NIID patients were diagnosed by skin biopsy and NOTCH2NLC GGC repeat analysis. Ocular findings in patients with NIID were studied using fundus photographs, optical coherence tomographic images (OCT), and full-field electroretinograms (ERGs). The histopathology of the retina was studied on autopsy samples from two cases with immunohistochemistry. All patients had an expansion of the GGC repeat (87-134 repeats) in the NOTCH2NLC. Two patients were legally blind and had been diagnosed with retinitis pigmentosa prior to the diagnosis of NIID and assessed with whole exome sequencing to rule out comorbidity with other retinal diseases. Fundus photographs around the posterior pole showed chorioretinal atrophy in the peripapillary regions. OCT showed thinning of the retina. ERGs showed various abnormalities in cases. The histopathology of autopsy samples showed diffusely scattered intranuclear inclusions throughout the retina from the retinal pigment epithelium to the ganglion cell layer, and optic nerve glial cells. And severe gliosis was observed in retina and optic nerve. The NOTCH2NLC GGC repeat expansion causes numerous intranuclear inclusions in the retina and optic nerve cells and gliosis. Visual dysfunction could be the first sign of NIID. We should consider NIID as one of the causes of retinal dystrophy and investigate the GGC repeat expansion in NOTCH2NLC.

Glaucoma has engulfed a huge population of the world into its claws of blindness as it remains asymptomatic until nearly 40% of the neurons are lost and the only option left is for patients to be subjected to symptomatic treatments or surgical methods, neither of which is completely effective in curing the disease as they do not restore the physiological dimensions at the neuronal level. Among the several factors that drive the pathophysiology of glaucoma, one is the involvement of fibrogenic factors, such as transforming growth factor β (TGFβ) which remodels the extracellular matrix (ECM) and, thus, the deposition of fibrotic material in the retina, resulting in the progression of primary open-angle glaucoma (POAG). The primary objectives of this study were to evaluate the protective effects of oxymatrine (OMT) in the steroid-induced glaucoma model in experimental rats and to determine the role of transforming growth factor β1 (TGFβ1) in the pathogenesis of glaucoma and its consequent inhibition due to the antioxidant and the antiinflammatory, and also the TGFβ1 antagonistic, behavior of OMT. To that end, we experimentally elucidated the role of OMT, a TGFβ1 antagonist, that is known to play antiinflammatory and antioxidant roles in the steroid-induced glaucoma model in experimental rats, and using the enzyme-linked immunosorbent assay (ELISA), we observed a direct inhibitory effect of OMT on the pathogenesis of glaucoma. The antioxidant and the antiinflammatory potentials of OMT were determined using several biochemical methods to determine the major antioxidants in the retinal layers, such as superoxide dismutase (SOD), glutathione peroxidase (GPX), catalase (CAT), and glutathione (GSH), along with the nitrite and the malondialdehyde (MDA) concentration levels. As a result, OMT was found to reduce the total protein content in the retinal layers, a correlation that has not been previously reported. Moreover, the impacts of OMT on the major governing ATPases, namely Na+/K+ ATPase and Ca2+ATPase, along with its impacts on the intracellular ionic concentrations of Na+, K+, and Ca2+, were determined and were found to point toward OMT, restoring homeostasis in glaucomatous animals. A clearer picture of the changes during the treatment was obtained using retinal images of the live animals and of the lenticular changes in the sacrificed animal; these images provided data on the pathological pathways leading to glaucoma inception and its consequent inhibition by OMT. The data reported in this study clearly indicate that OMT has a possible role in inhibiting the pathogenesis of glaucoma, and the data also permit the quantification of several biochemical parameters of concern.

BACKGROUND: Administration of retinal gene and stem cell therapy in patients with retinal degenerative diseases is in many cases dependent on a subretinal approach. It has been indicated that manual subretinal injection is associated with outer retinal damage, which may be explained by a high flow rate in the injection cannula. In the present porcine study, we evaluated flow-related retinal damage after controlled subretinal injection at different flow rates.
METHODS: The flow rate through a 41G cannula was estimated at different injection pressures (6-48 pounds per square inch [PSI]) in an in vitro setup. A linear correlation between the flow rate and injection pressure was found from 6 to 32 PSI. In full anesthesia, 12 pigs were vitrectomized and received a controlled subretinal injection of 300 μL balanced saline solution at injection pressures of 14, 24, and 32 PSI (four in each group). Prior to surgery and 2 and 4 weeks after surgery, the eyes were examined by multifocal electroretinogram (mfERG) and fundus photographs. At the end of follow-up, the eyes were enucleated for histology.
RESULTS: The in vitro flow study determined that the flow in a 41G cannula shifts from laminar to turbulent at 32 PSI and that the manual injection flow is turbulent. In the porcine study, we showed a significant difference in retinal pigment epithelium (RPE) damage between the three pressure groups (p = 0.0096). There was no significant difference in damage to the outer retina (p = 0.1526), but the high-pressure group (32 PSI) had the most outer retinal damage. The middle-pressure group (24 PSI) showed minimum retinal damage. There was no significant change in the mfERG ratios during follow-up.
CONCLUSIONS: This study indicates that an injection pressure at approximately 24 PSI might be safe for subretinal delivery. Retinal damage at low injection pressures may be explained by mechanical damage to the RPE due to prolonged needle time in the subretinal space, while retinal damage at high pressures can be related to high flow in the injection cannula. Controlled subretinal injection pressure of 24 PSI showed minimum mechanical- and flow-related damage to the porcine retina.

Visual impairments, notably loss of contrast sensitivity and color vision, were documented in Alzheimer\'s disease (AD) patients yet are critically understudied. This protocol describes a novel visual-stimuli four-arm maze (ViS4M; also called visual x-maze), which is a versatile x-shaped maze equipped with spectrum- and intensity-controlled light-emitting diode (LED) sources and dynamic grayscale objects. The ViS4M is designed to allow the assessment of color and contrast vision along with locomotor and cognitive functions in mice. In the color testing mode, the spectral distributions of the LED lights create four homogenous spaces that differ in chromaticity and luminance, corresponding to the mouse visual system. In the contrast sensitivity test, the four grayscale objects are placed in the middle of each arm, contrasting against the black walls and the white floors of the maze. Upon entering the maze, healthy wild-type (WT) mice tend to spontaneously alternate between arms, even under equiluminant conditions of illumination, suggesting that cognitively and visually intact mice use both color and brightness as cues to navigate the maze. Evaluation of the double-transgenic APPSWE/PS1ΔE9 mouse model of AD (AD+ mice) reveals substantial deficits to alternate in both color and contrast modes at an early age, when hippocampal-based memory and learning is still intact. Profiling of timespan, entries, and transition patterns between the different arms uncovers variable aging and AD-associated impairments in color discrimination and contrast sensitivity. The analysis of arm sequences of alternation reveals different pathways of exploration in young WT, old WT, and AD+ mice, which can be used as color and contrast imprints of functionally intact versus impaired mice. Overall, we describe the utility of a novel visual x-maze test to identify behavioral changes in mice related to cognition, as well as color and contrast vision, with high precision and reproducibility. Graphic abstract: Exploratory behavior of AD+ mice versus age- and sex-matched WT mice is tracked (top left: trajectory from a 5-min video file) in a novel visual-stimuli four-arm maze (ViS4M; also named visual x-maze) equipped with spectrum- and intensity-controlled LED sources or grayscale objects. Consecutive arm entries reveal that APPSWE/PS1ΔE9 (AD+) mice alternate less between arms, as opposed to WT mice. Sequence analysis, according to the three alternation pathways (depicted by white, yellow, and brown arrows) under different conditions of illumination, uncovers specific deficits linked to color vision in AD+ mice, evidenced by a color imprint chart.

UNASSIGNED: The purpose of this study is to report our experience with a case of punctate inner choroidopathy (PIC) reactivation following COVID-19.
UNASSIGNED: A 29-year-old caucasian woman with past ophthalmological history of bilateral PIC reported sudden visual acuity decrease in her right eye (RE) 3 weeks after SARS-CoV-2 infection. Her best-corrected visual acuity (BCVA) was 20/32 in RE; fundus examination and multimodal imaging (including indocyanine-green angiography, fundus autofluorescence, and optical coherence tomography) was consistent with unilateral PIC reactivation. The active choroidal lesions responded to high-dose corticosteroids, with functional improvement.
UNASSIGNED: Sars-CoV-2 infection could induce autoimmune and autoinflammatory dysregulation in genetically predisposed subjects. We report a case of PIC reactivation following COVID-19.

Aim To evaluate the possibility of retinal haemorrhages or any other retinal pathology caused by febrile seizures alone in children aged between 2 months and 15 years. Methods Children aged between 2 months and 15 years admitted to the hospital following seizures were examined within 48 hours of admission. The seizures were classified by a paediatric neurologist and a detailed ocular examination, including indirect ophthalmoscopy, was performed by an ophthalmologist. Results In the period between May 2019 and May 2020 a total number of 106 children were examined. There were 66 (62.3%) male and 40 (37.7%) female children. The youngest patient was 2 months old and the oldest patient was 15 years old. None of the children was found to have retinal haemorrhages or any other retinal pathology. Conclusion Retinal haemorrhages or any other acute retinal findings in children with febrile seizures are very rare, but we cannot rule out its occurrence. The finding of retinal haemorrhages in a child admitted with a history of seizure should trigger a detailed search for other causes of those haemorrhages, especially shaken baby syndrome. Due to the lack of any manifestations on the retina after febrile seizure, maybe it is time that the current protocol and guidelines, considering obligatory fundus examination, should be re-examined.