Analysis of the Retinal and Choroidal Vasculature Using Ultrawidefield Fundus Imaging in Mild Cognitive Impairment and Normal Cognition.

Purpose: To utilize ultrawidefield (UWF) imaging to evaluate retinal and choroidal vasculature and structure in individuals with mild cognitive impairment (MCI) compared with that of controls with normal cognition. Design: Prospective cross sectional study. Participants: One hundred thirty-one eyes of 82 MCI patients and 230 eyes of 133 cognitively normal participants from the Eye Multimodal Imaging in Neurodegenerative Disease Study. Methods: A scanning laser ophthalmoscope (California, Optos Inc) was used to obtain UWF fundus color images. Images were analyzed with the Vasculature Assessment Platform for Images of the Retina UWF (VAMPIRE-UWF 2.0, Universities of Edinburgh and Dundee) software. Main outcome measures: Imaging parameters included vessel width gradient, vessel width intercept, large vessel choroidal vascular density, vessel tortuosity, and vessel fractal dimension. Results: Both retinal artery and vein width gradients were less negative in MCI patients compared with controls, demonstrating decreased rates of vessel thinning at the periphery (P < 0.001; P = 0.027). Retinal artery and vein width intercepts, a metric that extrapolates the width of the vessel at the center of the optic disc, were smaller in MCI patients compared with that of controls (P < 0.001; P = 0.017). The large vessel choroidal vascular density, which quantifies the vascular area versus the total choroidal area, was greater in MCI patients compared with controls (P = 0.025). Conclusions: When compared with controls with normal cognition, MCI patients had thinner retinal vasculature manifested in both the retinal arteries and the veins. In MCI, these thinner arteries and veins attenuated at a lower rate when traveling toward the periphery. MCI patients also had increased choroidal vascular density. Financial Disclosures: Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Modernizing the evaluation of infantile nystagmus: the role of handheld optical coherence tomography.

BACKGROUND: Infantile nystagmus syndrome can be associated with an afferent problem (anterior or posterior segment) or constitute an isolated idiopathic disorder. With a normal ophthalmic examination, current guidelines recommend electroretinography (ERG) rather than magnetic resonance (MRI) for preliminary workup. Given the limited use of optical coherence tomography (OCT) in preverbal children, the purpose of this study was to evaluate the role of handheld OCT (HH-OCT) in the initial diagnostic evaluation of infantile nystagmus. METHODS: In this cross-sectional case series, the medical records of all children with infantile nystagmus and HH-OCT imaging at the Duke Eye Center from August 2016 to July 2021 were retrospectively reviewed. Children with anterior segment disorders or obvious retina/optic nerve structural pathology, bilateral ophthalmoplegia, or Down syndrome were excluded. Two masked pediatric ophthalmologists graded HH-OCT images for optic nerve head and macular abnormalities. A neuro-ophthalmologist reviewed clinical findings of each patient's presenting visit and recommended appropriate testing (MRI vs ERG), initially without, and again with HH-OCT image review. RESULTS: A total of 39 cases were included, with mean presenting age of 1.3 years. Final diagnoses included retinal or foveal abnormalities (7), optic nerve pathology (13), idiopathic (10), or unknown (9). HH-OCT findings included optic nerve hypoplasia (1), optic nerve elevation (3), persistence of the inner layers at the fovea (9), thin ganglion cell layer (8), ellipsoid zone abnormality (3), and thin choroid (1). HH-OCT findings altered initial clinical-only management in 16 cases (41%), including avoiding MRI (5) and ERG (10) testing. CONCLUSIONS: Our results suggest that HH-OCT has the potential to augment and streamline the evaluation of infantile nystagmus.

Unilateral Glaucoma Without Facial Angioma in a Pediatric Patient: A Suspected Sturge-Weber Syndrome Variant.

The authors report a case of a 5-month-old full-term infant with chronic conjunctival redness and elevated intraocular pressure in the right eye. Magnetic resonance imaging ruled out leptomeningeal angiomatosis. Despite lacking a typical port-wine mark, the diagnosis of Sturge-Weber syndrome was established based on specific observations in the right eye that involved unilateral vascular glaucoma. These findings included Haab striae, a larger axial length measurement, an increased number of episcleral vessels with blood in Schlemm canal, and a thicker choroid in the macular region. This is the first reported pediatric case with these specific ocular manifestations in the absence of facial angioma, highlighting the need for awareness among clinicians to avoid misdiagnosis and facilitate proper management. [J Pediatr Ophthalmol Strabismus. 2024;61(3):e19-e22.].

Differences in Retinal and Choroidal Microvasculature and Structure in Dementia With Lewy Bodies Compared With Normal Cognition.

Purpose: To evaluate the retinal and choroidal microvasculature and structure in individuals with dementia with Lewy bodies (DLB) compared with controls with normal cognition using optical coherence tomography (OCT) and OCT angiography (OCTA). Methods: An institutional review board-approved cross-sectional comparison of patients with DLB and cognitively normal controls was performed. The Cirrus HD-OCT 5000 with AngioPlex (Carl Zeiss Meditec) was used to obtain OCT and OCTA images. Results: Thirty-four eyes of 18 patients with DLB and 85 eyes of 48 cognitively normal patients were analyzed. The average capillary perfusion density (CPD) was higher in the DLB group than in the control group (P = .005). The average capillary flux index (CFI) and ganglion cell inner-plexiform layer (GC-IPL) thickness were lower in the DLB group than in the control group (P = .016 and P = .040, respectively). Conclusions: Patients with DLB had an increased peripapillary CPD, decreased peripapillary CFI, and attenuated GC-IPL thickness compared with those with normal cognition.

Characterizing differences in retinal and choroidal microvasculature and structure in individuals with Huntington's Disease compared to healthy controls: A cross-sectional prospective study.

OBJECTIVE: To characterize retinal and choroidal microvascular and structural changes in patients who are gene positive for mutant huntingtin protein (mHtt) with symptoms of Huntington's Disease (HD). METHODS: This study is a cross-sectional comparison of patients who are gene positive for mHtt and exhibit symptoms of HD, either motor manifest or prodromal (HD group), and cognitively normal individuals without a family history of HD (control group). HD patients were diagnosed by Duke movement disorder neurologists based on the Unified Huntington's Disease Rating Scale (UHDRS). Fovea and optic nerve centered OCT and OCTA images were captured using Zeiss Cirrus HD-5000 with AngioPlex. Outcome metrics included central subfield thickness (CST), peripapillary retinal nerve fiber layer (pRNFL) thickness, ganglion cell-inner plexiform layer (GCIPL) thickness, and choroidal vascularity index (CVI) on OCT, and foveal avascular zone (FAZ) area, vessel density (VD), perfusion density (PD), capillary perfusion density (CPD), and capillary flux index (CFI) on OCTA. Generalized estimating equation (GEE) models were used to account for inter-eye correlation. RESULTS: Forty-four eyes of 23 patients in the HD group and 77 eyes of 39 patients in the control group were analyzed. Average GCIPL thickness and FAZ area were decreased in the HD group compared to controls (p = 0.001, p < 0.001). No other imaging metrics were significantly different between groups. CONCLUSIONS: Patients in the HD group had decreased GCIPL thickness and smaller FAZ area, highlighting the potential use of retinal biomarkers in detecting neurodegenerative changes in HD.

A 13-Year-Old Girl With Unilateral Visual Changes.

Neuroretinitis is a condition typically characterized by unilateral optic neuropathy and is most commonly a sequelae of cat scratch disease (CSD) due to infection with Bartonella henselae. Ophthalmologic examination will reveal a swollen optic nerve and may eventually reveal a canonical macular star; optical coherence tomography (OCT) will reveal flattening of the fovea, a thickened neurosensory retina, and subretinal fluid accumulation. Although CSD rarely presents with isolated neuorretinitis, it should be considered in patients presenting with unilateral visual changes. The differential diagnosis for neuroretinitis includes optic neuritis, inflammatory optic neuropathies (sarcoid, para-infectious, autoimmune), compressive, toxic, and more. We describe a pediatric patient presenting with visual changes that were initially concerning for optic neuritis and the diagnostic workup that ultimately led to a diagnosis of CSD neuroretinitis.

Creation of Non-Contact Device for Use in Metastatic Melanoma Margin Identification in ex vivo Mouse Brain.

Because contemporary intraoperative tumor detection modalities, such as intraoperative MRI, are not ubiquitously available and can disrupt surgical workflow, there is an imperative for an accessible diagnostic device that can meet the surgeon's needs in identifying tissue types. The objective of this paper is to determine the efficacy of a novel non-contact tumor detection device for metastatic melanoma boundary identification in a tissue-mimicking phantom, evaluate the identification of metastatic melanoma boundaries in ex vivo mouse brain tissue, and find the error associated with identifying this boundary. To validate the spatial and fluorescence resolution of the device, tissue-mimicking phantoms were created with modifiable optical properties. Phantom tissue provided ground truth measurements for fluorophore concentration differences with respect to spatial dimensions. Modeling metastatic disease, ex vivo melanoma brain metastases were evaluated to detect differences in fluorescence between healthy and neoplastic tissue. This analysis includes determining required-to-observe fluorescence differences in tissue. H&E staining confirmed tumor presence in mouse tissue samples. The device detected a difference in normalized average fluorescence intensity in all three phantoms. There were differences in fluorescence with the presence and absence of melanin. The estimated tumor boundary of all tissue phantoms was within 0.30 mm of the ground truth tumor boundary for all boundaries. Likewise, when applied to the melanoma-bearing brains from ex vivo mice, a difference in normalized fluorescence intensity was successfully detected. The potential prediction window for the tumor boundary location is less than 1.5 mm for all ex vivo mouse brain tumors boundaries. We present a non-contact, laser-induced fluorescence device that can identify tumor boundaries based on changes in laser-induced fluorescence emission intensity. The device can identify phantom ground truth tumor boundaries within 0.30 mm using instantaneous rate of change of normalized fluorescence emission intensity and can detect endogenous fluorescence differences in melanoma brain metastases in ex vivo mouse tissue.

Engineering Atrazine Loaded Poly (lactic- co-glycolic Acid) Nanoparticles to Ameliorate Environmental Challenges.

The use of herbicides plays a vital role in controlling weeds and conserving crops; however, its usage generates both environmental and economic problems. For example, herbicides pose a financial issue as farmers must apply large quantities to protect crops due to absorption rates of less than 0.1%. Therefore, there is a great need for the development of new methods to mitigate these issues. Here, we report for the first time the synthesis of poly(lactic- co-glycolic-acid) (PLGA) nanoherbicides loaded with atrazine as an active ingredient. We used potato plants as a biological model to assess the herbicidal activity of the engineered PLGA nanoherbicides. Our method produced nanoherbicides with an average size of 110 ± 10 nm prior to lyophilization. Fifty percent of the loaded atrazine in the PLGA matrix is released in 72 h. Furthermore, we performed Monte Carlo simulations to determine the chemical interaction among atrazine, PLGA, and the solvent system. One of the most significant outcomes of these simulations was to find the formation of a hydrogen bond of 1.9 Å between PLGA and atrazine, which makes this interaction very stable. Our in vitro findings showed that as atrazine concentration is increased in PLGA nanoparticles, potato plants undergo a significant decrease in stem length, root length, fresh weight, dry weight, and the number of leaves, with root length being the most affected. These experimental results suggest the herbicidal effectiveness of atrazine-loaded PLGA nanoherbicides in inhibiting the growth of the potato plant. Hence, we present the proof-of-concept for using PLGA nanoherbicides as an alternative method for inhibiting weed growth. Future studies will involve a deep understanding of the mechanism of plant-nanoherbicide interaction as well as the role of PLGA as a growth potentiator.