Validation of a method for measuring the retinal thickness with Shack–Hartmann aberrometry in an artificial eye

Objective: A retinal vein occlusion (RVO) is a relatively common retinal vascular disorder especially in the elder-ly. Many experiments have been performed on patients with a RVO but performing any type of experiments and especially longitudinal experiments on humans is difficult if not impossible on ethical grounds. Therefore, we have created a retinal vein occlusion (RVO) model by laser irradiation of cynomolgus monkeysafter an intravenous injection of rose bengal. Weevaluated the pathological changes of the retina, and the effects of ranibizumab, an anti-vascular endothelial growth factor (VEGF) antibody, on the characteristics of the RVO. Methods: The integrity of the vascular system was evaluated by fluorescein angiography (FA), and the retinal thickness and volume were determined by optical coherence tomography (OCT). The cytokines and growth factors in the aqueous humor were identified by multiplex profiling. Results: Our results showed that ranibizumab decreased the degree of vascular leakage and retinal edema at 1-3 days (acute phase) and 3-7 days (subacute phase), and suppressed foveal thinning at 28-42 days (chronic phase) after the laser irradia-tion. Ranibizumab also decreased the area of the foveal avascular zone, and the area was negatively and significantly corre-lated with the thickness of the ganglion cell layer (GCL) complex. Furthermore, ranibizumab reduced the increased expres-sion of VEGF in the aqueous humour, but did not affect the expressions of interleukin-6 (IL-6), monocyte chemotactic pro-tein-1 (MCP-1), angiopoietin-1 (ANG-1), or angiopoietin-2 (ANG-2).Thesefindings suggest that ranibizumab attenuates the retinal edema and subsequent retinal atrophy in partby neutralizing VEGF. However, other cytokines and growth factors were also affected by the ranibizumab which suggests that not only VEGF but also other unidentified agents might play a role in the pathogenesis of the RVO. Conclusion: We have created a non-human primate RVO model, which resembles the clinical RVO pathology. In this model, an injection of ranibizumab leads to a reduction in the vascular leakage and the retinal thickness and volume by blockingthe expression of VEGF. Our model might be useful for investigating the pathological mechanisms of RVOs and explore new therapeutic agents for RVO.

Download Full-text

Study on the Changes of Macular Retinal Thickness in Myopia

Proceedings of 2018 Chinese Intelligent Systems Conference - Lecture Notes in Electrical Engineering ◽

10.1007/978-981-13-2288-4_82 ◽

2018 ◽

pp. 881-888

Author(s):

Hejun Tong ◽

Dongmei Fu

Keyword(s):

Retinal Thickness ◽

Macular Retinal Thickness

Download Full-text

Retinal Optical Coherence Tomography Metrics Are Unchanged in Verubecestat Alzheimer’s Disease Clinical Trial but Correlate with Baseline Regional Brain Atrophy

Journal of Alzheimer s Disease ◽

10.3233/jad-200735 ◽

2021 ◽

Vol 79 (1) ◽

pp. 275-287

Author(s):

Robert C. Sergott ◽

Annaswamy Raji ◽

James Kost ◽

Cyrille Sur ◽

Saheeda Jackson ◽

...

Keyword(s):

Clinical Trial ◽

Optical Coherence Tomography ◽

Nerve Fiber ◽

Retinal Nerve Fiber Layer ◽

Brain Atrophy ◽

Retinal Thickness ◽

Optical Coherence ◽

Fiber Layer ◽

Nerve Fiber Layer ◽

Retinal Nerve Fiber

Background: We performed exploratory analyses of retinal thickness data from a clinical trial of the AβPP cleaving enzyme (BACE) inhibitor verubecestat in patients with Alzheimer’s disease (AD). Objective: To evaluate: 1) possible retinal thickness changes following BACE inhibition; and 2) possible association between retinal thickness and brain atrophy. Methods: Retinal thickness was measured using spectral-domain optical coherence tomography in a 78-week randomized placebo-controlled trial of verubecestat in 1,785 patients with mild-to-moderate AD. Changes from baseline in retinal pigment epithelium, macular grid retinal nerve fiber layer, central subfield retinal thickness, and macular grid volume were evaluated for verubecestat versus placebo. Correlation analyses were performed to investigate the potential association between macular grid retinal nerve fiber layer and central subfield retinal thickness with brain volumetric magnetic resonance imaging (vMRI) data at baseline, as well as correlations for changes from baseline at Week 78 in patients receiving placebo. Results: Verubecestat did not significantly alter retinal thickness during the trial compared with placebo. At baseline, mean macular grid retinal nerve fiber layer and central subfield retinal thickness were weakly but significantly correlated (Pearson’s r values≤0.23, p-values < 0.01) with vMRI of several brain regions including whole brain, hippocampus, and thalamus. At Week 78, correlations between retinal thickness and brain vMRI changes from baseline in the placebo group were small and mostly not statistically significant. Conclusion: BACE inhibition by verubecestat was not associated with adverse effects on retinal thickness in patients with mild-to-moderate AD. Correlations between retinal thickness and brain volume were observed at baseline. Trial registration: Clinicaltrials.gov NCT01739348 (registered December 3, 2012; https://clinicaltrials.gov/ct2/show/NCT01739348).

Download Full-text

Association between retinal thickness variation and visual acuity change in neovascular age‐related macular degeneration

Clinical and Experimental Ophthalmology ◽

10.1111/ceo.13927 ◽

2021 ◽

Author(s):

Kai Xiong Cheong ◽

Alvin Wei Jun Teo ◽

Chui Ming Gemmy Cheung ◽

Issac Horng Khit Too ◽

Usha Chakravarthy ◽

...

Keyword(s):

Visual Acuity ◽

Macular Degeneration ◽

Retinal Thickness ◽

Age Related Macular Degeneration ◽

Thickness Variation ◽

Age Related

Download Full-text

Quantitative Color Fundus Autofluorescence in Patients with Diabetes Mellitus

Journal of Clinical Medicine ◽

10.3390/jcm10010048 ◽

2020 ◽

Vol 10 (1) ◽

pp. 48

Author(s):

Stela Vujosevic ◽

Caterina Toma ◽

Paolo Nucci ◽

Marco Brambilla ◽

Stefano De Cillà

Keyword(s):

Diabetes Mellitus ◽

Retinal Thickness ◽

Fundus Autofluorescence ◽

Retinal Disease ◽

Metabolic Evaluation ◽

Glycation End Products ◽

Custom Software ◽

Patients With Diabetes ◽

Immunohistochemical Studies ◽

Present Pilot Study

A new short wavelength confocal blue-light 450 nm-fundus autofluorescence (color-FAF) allows for visualization of minor fluorophores (e.g., advanced glycation end products, AGEs), besides lipofuscin. The aim of the present pilot study was to quantitatively evaluate color-FAF in patients with diabetes mellitus (DM) and to correlate these data with different stages of retinal disease severity. Optical coherence tomography and color-FAF images of 193 patients/eyes and 18 controls were analyzed using a custom software for quantification of the long (red) and short (green) wavelength components of the emission spectrum (REFC/GEFC). Measurements were performed in nine quadrants of the 6-mm ETDRS macular grid. Foveal GEFC and REFC intensities were higher in patients with DM compared to controls (p = 0.015 and p = 0.006 respectively) and in eyes with center involving diabetic macular edema (DME) compared to eyes without DME (p < 0.001). A positive correlation was found between GEFC and REFC intensities and central retinal thickness, r = 0.37 (p < 0.001) and r = 0.42 (p < 0.001), respectively. No differences were found in color-FAF among different DR severity groups. Quantitative color-FAF could become helpful for the metabolic evaluation of retina in patients with DM and in DME; however, further histologic and immunohistochemical studies on distribution of different retinal fluorophores in DM are needed to better understand its role.

Download Full-text

Relationship between retinal sensitivities and optical coherence tomographic findings in eyes with myopic chorioretinal atrophy

European Journal of Ophthalmology ◽

10.1177/11206721211008038 ◽

2021 ◽

pp. 112067212110080

Author(s):

Masato Kakisu ◽

Takayuki Baba ◽

Takehito Iwase ◽

Hirotaka Yokouchi ◽

Shuichi Yamamoto

Keyword(s):

Axial Length ◽

Medical Records ◽

Choroidal Thickness ◽

Retinal Thickness ◽

Spectral Domain ◽

Retinal Sensitivity ◽

Optical Coherence ◽

Ellipsoid Zone ◽

Chorioretinal Atrophy

Purpose: To determine whether there is a significant correlation between the retinal sensitivity and the integrity of the ellipsoid zone (EZ) of the photoreceptors in eyes with myopic chorioretinal atrophy (CRA). We also determined the significance of the correlation between the retinal sensitivity and the retinal and choroidal thicknesses. Methods: The medical records of 10 eyes of six subjects with myopic CRA were reviewed. The integrity of the EZ was determined in the spectral-domain optical coherence tomographic (OCT) images at 37 points of six scans corresponding to the locations where the retinal sensitivities were measured by MP-3 microperimetry. The mesopic retinal sensitivities were determined within the central 16°. The significance of the correlations between the integrity of the EZ and the mesopic retinal sensitivities was determined. The relationships between the retinal and choroidal thickness and the retinal sensitivity were also determined. Results: The average age of the patients was 70.0 ± 6.7 years, and the average axial length of the eye was 29.2 mm. The mesopic sensitivities at the points where the EZ was present were significantly higher than those where the EZ was absent ( p < 0.01). The mesopic sensitivity was significantly correlated with the retinal thickness ( p < 0.01, r = 0.30) and the choroidal thickness ( p < 0.01, r = 0.23). Conclusions: The significant correlation between the mesopic retinal sensitivity and the integrity of the EZ indicates that the mesopic sensitivities can be used to assess the integrity of the photoreceptors in eyes with myopic CRA.

Download Full-text

Exacerbation of AMD Phenotype in Lasered CNV Murine Model by Dysbiotic Oral Pathogens

Antioxidants ◽

10.3390/antiox10020309 ◽

2021 ◽

Vol 10 (2) ◽

pp. 309

Author(s):

Pachiappan Arjunan ◽

Radhika Swaminathan ◽

Jessie Yuan ◽

Mohamed Elashiry ◽

Amany Tawfik ◽

...

Keyword(s):

Murine Model ◽

Retinal Thickness ◽

Age Related Macular Degeneration ◽

Periodontal Pathogen ◽

Fundus Photography ◽

Mouse Retina ◽

Rrna Gene ◽

Age Related ◽

Periodontal Infection

Emerging evidence underscores an association between age-related macular degeneration (AMD) and periodontal disease (PD), yet the biological basis of this linkage and the specific role of oral dysbiosis caused by PD in AMD pathophysiology remains unclear. Furthermore, a simple reproducible model that emulates characteristics of both AMD and PD has been lacking. Hence, we established a novel AMD+PD murine model to decipher the potential role of oral infection (ligature-enhanced) with the keystone periodontal pathogen Porphyromonas gingivalis, in the progression of neovasculogenesis in a laser-induced choroidal-neovascularization (Li-CNV) mouse retina. By a combination of fundus photography, optical coherence tomography, and fluorescein angiography, we documented inflammatory drusen-like lesions, reduced retinal thickness, and increased vascular leakage in AMD+PD mice retinae. H&E further confirmed a significant reduction of retinal thickness and subretinal drusen-like deposits. Immunofluorescence microscopy revealed significant induction of choroidal/retinal vasculogenesis in AMD+PD mice. qPCR identified increased expression of oxidative-stress, angiogenesis, pro-inflammatory mediators, whereas antioxidants and anti-inflammatory genes in AMD+PD mice retinae were notably decreased. Through qPCR, we detected Pg and its fimbrial 16s-RrNA gene expression in the AMD+PD mice retinae. To sum-up, this is the first in vivo study signifying a role of periodontal infection in augmentation of AMD phenotype, with the aid of a pioneering AMD+PD murine model established in our laboratory.

Download Full-text

Morphological Changes in Lamellar Macular Holes According to SD-OCT Examination over a Long Observation Period

Diagnostics ◽

10.3390/diagnostics11071145 ◽

2021 ◽

Vol 11 (7) ◽

pp. 1145

Author(s):

Magdalena Kal ◽

Izabela Chojnowska-Ćwiąkała ◽

Mateusz Winiarczyk ◽

Monika Jasielska ◽

Jerzy Mackiewicz

Keyword(s):

Retinal Thickness ◽

Morphological Changes ◽

Outer Diameter ◽

Corrected Visual Acuity ◽

Macular Holes ◽

Kolmogorov Smirnov ◽

Inner Diameter ◽

Observation Period ◽

Sd Oct

Background: The aim of this study was to evaluate the quantitative morphological changes in lamellar macular holes (LMHs) based on SD-OCT examinations and to assess the correlations among minimal retinal thickness (MRT), reading vision (RV), and best corrected visual acuity (BCVA) over a 36-month follow-up period. Methods: A group of 40 patients (44 eyes) with LMH was evaluated, with an average age of 69.87 (SD = 10.14). The quantitative parameters monitored in the follow-up period (at 0, 3, 6, 12, 18, 24, 30, and 36 months) were tested for normality of distribution by Shapiro–Wilk and Kolmogorov–Smirnov tests. Results: The RV and BCVA values were stable, and no significant changes were found at any of the check-ups during the 36-month follow-up period (BCVA p = 0.435 and RV p = 0.0999). The analysis of individual quantitative LMH parameters during the 36-month follow-up period did not demonstrate statistically significant differences: MRT (p = 0.461), Max RT temporal (p = 0.051), Max RT nasal (p = 0.364), inner diameter (ID) (p = 0.089), and outer diameter (OD) (p = 0.985). Conclusions: The observations at 0, 6, 12, 18, 24, 30, and 36 months revealed moderate and significant correlations between RV and MRT. No significant correlation between BCVA and MRT was observed.

Download Full-text