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Indian Journal of Ophthalmology Jul 2024In the field of ophthalmology, slit-lamp gonioscopy has long been a cornerstone for examining anterior chamber angles and diagnosing conditions such as angle closure,...
In the field of ophthalmology, slit-lamp gonioscopy has long been a cornerstone for examining anterior chamber angles and diagnosing conditions such as angle closure, secondary causes of raised intraocular pressure, neovascularization of angle, angle recession, angle tumors, and foreign bodies. However, the conventional approach for goniophotography is a demanding procedure requiring juggling a gonioscopy lens in one hand and a smartphone in the other. Balancing a gonioscopy lens with one hand makes it difficult to adjust and focus the image in busy clinical settings. This article introduces a groundbreaking solution to this problem - a universal slit-lamp-mounted gonioscope ingeniously repurposed from discarded materials, that is, indirect goniophotography (IndiGo). This novel system simplifies the process of both gonioscopy and goniophotography, allowing ophthalmologists to easily assess anterior chamber angles and capture high-quality images. These images can be swiftly shared with glaucoma specialists worldwide for digital analysis. Not only does this approach enhance examination efficiency, but also it fosters sustainability in ophthalmic diagnostics.
Topics: Gonioscopy; Humans; Intraocular Pressure; Equipment Design; Glaucoma, Angle-Closure; Anterior Chamber; Slit Lamp; Slit Lamp Microscopy
PubMed: 38634755
DOI: 10.4103/IJO.IJO_3035_23 -
Scientific Reports Apr 2024Choroideremia (CHM) is an X-linked retinal degeneration leading to loss of the photoreceptors, retinal pigment epithelium (RPE), and choroid. Adaptive optics...
Choroideremia (CHM) is an X-linked retinal degeneration leading to loss of the photoreceptors, retinal pigment epithelium (RPE), and choroid. Adaptive optics optoretinography is an emerging technique for noninvasive, objective assessment of photoreceptor function. Here, we investigate parafoveal cone function in CHM using adaptive optics optoretinography and compare with cone structure and clinical assessments of vision. Parafoveal cone mosaics of 10 CHM and four normal-sighted participants were imaged with an adaptive optics scanning light ophthalmoscope. While acquiring video sequences, a 2 s 550Δ10 nm, 450 nW/deg stimulus was presented. Videos were registered and the intensity of each cone in each frame was extracted, normalized, standardized, and aggregated to generate the population optoretinogram (ORG) over time. A gamma-pdf was fit to the ORG and the peak was extracted as ORG amplitude. CHM ORG amplitudes were compared to normal and were correlated with bound cone density, ellipsoid zone to RPE/Bruch's membrane (EZ-to-RPE/BrM) distance, and foveal sensitivity using Pearson correlation analysis. ORG amplitude was significantly reduced in CHM compared to normal (0.22 ± 0.15 vs. 1.34 ± 0.31). In addition, CHM ORG amplitude was positively correlated with cone density, EZ-to-RPE/BrM distance, and foveal sensitivity. Our results demonstrate promise for using ORG as a biomarker of photoreceptor function.
Topics: Humans; Choroideremia; Ophthalmoscopy; Retinal Cone Photoreceptor Cells; Choroid; Retinal Pigment Epithelium; Tomography, Optical Coherence
PubMed: 38594294
DOI: 10.1038/s41598-024-58059-x -
Clinical Ophthalmology (Auckland, N.Z.) 2024Refractive error is a major cause of visual impairment in children and its early detection can prevent ocular morbidity such as amblyopia and strabismus. Brückner test...
PURPOSE
Refractive error is a major cause of visual impairment in children and its early detection can prevent ocular morbidity such as amblyopia and strabismus. Brückner test is a comprehensive test which can be easily administered in children using a direct ophthalmoscope. We aimed to determine refractive error in children by analysis of the red reflex using modified Brückner test.
PATIENTS AND METHODS
This prospective observational study was conducted on 683 undilated eyes of 683 children aged four to 10 years. They were evaluated with a direct ophthalmoscope from one meter in a dimly lit room. The characteristics of the red reflex and crescent obtained were compared with photoscreener refraction value and analyzed.
RESULTS
The presence of superior crescent was associated with hypermetropia (Chi square 37.11, p < 0.001, kappa = 0.15) and inferior crescent with myopia (Chi square 157.29, p < 0.001, kappa = 0.477). Superior crescent was 98.4% sensitive in detecting hypermetropia. Hypermetropia greater than +1.5D, was associated with larger superior crescent crossing horizontal midline of pupil (Chi square = 5.29, p = 0.021).
CONCLUSION
The modified Brückner test is useful in detection and quantification of refractive error in children. It is easy, simple, quick and can be employed in the community as a screening test to detect potentially amblyogenic refractive errors.
PubMed: 38584720
DOI: 10.2147/OPTH.S453207 -
Translational Vision Science &... Apr 2024To assess the agreement of retinoscope-based peripheral refraction techniques with the criterion standard open-field autorefractor.
PURPOSE
To assess the agreement of retinoscope-based peripheral refraction techniques with the criterion standard open-field autorefractor.
METHODS
Fifty young adults (mean age, 24 ± 3 years) participated in this study. Two masked, experienced senior examiners carried out central refraction and peripheral refraction at the temporal 22° (T22°) and nasal 22° (N22°) eccentricities. Peripheral refraction techniques were (a) peripheral refraction using ancillary retinoscope component (P-ARC), (b) retinoscopy with eye rotation, and (c) open-field autorefractor. Peripheral refraction with retinoscopy values was compared with an open-field autorefractor (Shinn Nippon NVision-K) to assess the agreement. All measurements were taken from the right eye under noncycloplegic conditions.
RESULTS
The mean difference ±95% limits of agreement of peripheral refraction values obtained using P-ARC from T22° (+0.11 diopters [D] ± 1.20 D; P = 0.20) or N22° (+0.13 D ± 1.16 D; P = 0.13) were comparable with open-field autorefractor. The eye rotation technique compared to autorefractor showed a significant difference for T22° (+0.30 D ± 1.26 D; P = 0.002); however, there was an agreement for N22° (+0.14 D ± 1.16 D; P = 0.10). With respect to the identification of peripheral refraction patterns, examiners were able to identify relative peripheral hyperopia in most of the participants (77%).
CONCLUSIONS
Peripheral refraction with P-ARC was comparable with open-field autorefractor at T22° and N22° eccentricities. Peripheral retinoscopy techniques can be another approache for estimating and identifying peripheral refraction and its patterns in a regular clinical setting.
TRANSLATIONAL RELEVANCE
Retinoscope with P-ARC has high potential to guide and enable eye care practitioners to perform peripheral refraction and identify peripheral refraction patterns for effective myopia management.
Topics: Young Adult; Humans; Adult; Retinoscopes; Refraction, Ocular; Vision Tests; Eye; Hyperopia
PubMed: 38568607
DOI: 10.1167/tvst.13.4.7 -
ABCA4 mediated traumatic proliferative vitreoretinopathy associated with PI3K/Akt signaling pathway.Heliyon Apr 2024Proliferative vitreoretinopathy (PVR) is the main cause of retinal detachment. However, the underlying mechanism of PVR is complex and has not yet been fully elucidated....
BACKGROUND
Proliferative vitreoretinopathy (PVR) is the main cause of retinal detachment. However, the underlying mechanism of PVR is complex and has not yet been fully elucidated. The PI3K/Akt/mTOR signaling pathway is involved in angiogenesis and plays an important role in cell proliferation and tumor formation. Therefore, our study was designed to investigate the potential biological mechanisms of alleviating ARPE-19 cell and traumatic PVR model involving PI3K/Akt signaling pathway by targeting ABCA4.
MATERIALS AND METHODS
ARPE-19 cell model was induced by ABCA4 overexpression vector and si-ABCA4, then the ABCA4 overexpression vector and si-ABCA4 were constructed, the plasmids were expanded for cell transfection and verification. In addition, OE-ABCA4, shRNA NC and si-ABCA4 were transfected into ARPE-19 cells. Cell viability was detected by CCK-8 assay, cell cycle was determined by flow cytometry. The expression level and location of ABCA4 were detected by immunofluorescence. Finally, rabbit traumatic PVR model was induced by surgery, the adenovirus was injected into the vitreous body respectively, and the fundus observation was performed by direct ophthalmoscope observation combined with fundus photography, and the retinal routine histopathology HE staining was performed. Analysis of P21, CDK4, Cyclin D1, BAX, BAD, and ABCA4 was used by quantitative RT-PCR and Western blot. Besides, the expression level of ABCA4, AKT, -AKT, PI3K, p-PI3K, P38, p-P38, JNK, -JNK, ERK, and -ERK was detected by Western blot.
RESULTS
All results indicated that the viability of cells with high expression of ABC4A increased, while the viability of cells with inhibition of ABC4A decreased, the number of cells with high ABC4A expression was significantly higher, and the migration level of cells was significantly reduced after ABC4A inhibition (P < 0.05). ABC4A could affect cell apoptosis by affecting G1/G2 phase. The cell proliferation level was significantly increased with high expression of ABC4A. High expression of ABC4A increased phosphorylation levels, including -AKT, -PIK3, and p-P38, while inhibition of ABC4A decreased the expression levels of these proteins (P < 0.05). Inhibition of ABC4A could significantly improve retinopathy, indicating that the proliferation ability of cells was restored after inhibition of ABC4A.
CONCLUSIONS
Our finding suggested that inhibition of ABC4A ameliorated the injury degree of traumatic PVR and performed the potential anti-PVR effect via inhibiting PI3K/Akt signaling pathway, while promoting cell proliferation in both rabbit and ARPE-19 cells PVR model. The study has a certain innovation by building a traumatic PVR model to explore whether the ABCA4 participates in the regulation of the PI3K/AKT signaling pathway and the pathological mechanism of PVR regulation. At the same time, ABCA4's participation in the regulation of PI3K/Akt signaling pathway can prevent and delay the occurrence and development of PVR, which has positive significance for improving the survival rate and quality of life of patients, and also provides an important basis for its therapeutic mechanism. Therefore, our study demonstrated a significant strategy for inhibiting traumatic PVR via targeting PI3K/Akt/ABCA4 pathway.
PubMed: 38560110
DOI: 10.1016/j.heliyon.2024.e27024 -
Biomedical Optics Express Mar 2024High-speed, phase contrast retinal and blood flow imaging using an adaptive optics partially confocal multi-line ophthalmosocope (AO-pcMLO) is described. It allows for...
High-speed, phase contrast retinal and blood flow imaging using an adaptive optics partially confocal multi-line ophthalmosocope (AO-pcMLO) is described. It allows for simultaneous confocal and phase contrast imaging with various directional multi-line illumination by using a single 2D camera and a digital micromirror device (DMD). Both vertical and horizontal line illumination directions were tested, for photoreceptor and vascular imaging. The phase contrast imaging provided improved visualization of retinal structures such as cone inner segments, vessel walls and red blood cells with images being acquired at frame rates up to 500 Hz. Blood flow velocities of small vessels (<40 m in diameter) were measured using kymographs for capillaries and cross-correlation between subsequent images for arterioles or venules. Cardiac-related pulsatile patterns were observed with normal resting heart-beat rate, and instantaneous blood flow velocities from 0.7 to 20 mm/s were measured.
PubMed: 38495707
DOI: 10.1364/BOE.507449 -
La Tunisie Medicale Jul 2023Pterygium surgery is a closed globe surface surgery. Although it is perfectly standard and followed by excellent results, it is not exempt from the general rule that...
INTRODUCTION
Pterygium surgery is a closed globe surface surgery. Although it is perfectly standard and followed by excellent results, it is not exempt from the general rule that there is no surgery without risk. It therefore seems important to integrate simulation as a pedagogical tool for training ophthalmology residents in pterygium surgery.
AIM
To evaluate the effectiveness of procedural simulation as a training tool for pterygium surgery.
RESULTS
During the study period, eight residents participated in the three workshops. The global assessment of residents' knowledge showed a mean score of 3/5 [1.5/5-4/5] and 4.1/5 [3.25/5-5/5] before and after the training respectively. There was a significant negative correlation between the initial score on the pre-test and the improvement of this score on the post-test, with an r'=-0.87 and a p=0.005. We noted a significant improvement in the global performance score (p<0.001) and even a significant improvement in the specific performance score (p=0.02) between the 3 workshops. The average training satisfaction score was 13.87/16 [10/16-16/16]. We noted a significant positive correlation with r=0.838 and p=0.009 between knowledge improvement and learner satisfaction.
CONCLUSION
The training of fundus examination using an ophthalmoscopic simulator can improve the skills and knowledge of ophthalmic learners. This type of training can be an innovative addition to traditional learning methods.
Topics: Humans; Pterygium; Fundus Oculi; Knowledge; Ophthalmology; Ophthalmoscopy
PubMed: 38445419
DOI: No ID Found -
Biomedical Optics Express Feb 2024Two major approaches for tracking cellular motion across a range of biological tissues are the manual labelling of cells, and automated analysis of spatiotemporal...
Two major approaches for tracking cellular motion across a range of biological tissues are the manual labelling of cells, and automated analysis of spatiotemporal information represented in a kymograph. Here we compare these two approaches for the measurement of retinal capillary flow, a particularly noisy application due to the low intrinsic contrast of single red blood cells (erythrocytes). Image data were obtained using a flood-illuminated adaptive optics ophthalmoscope at 750 nm, allowing the acquisition of flow information over several cardiac cycles which provided key information in evaluating tracking accuracy. Our results show that in addition to being much faster, the automated method is more accurate in the face of rapid flow and reduced image contrast. This study represents the first validation of commonly used kymograph approaches to capillary flow analysis.
PubMed: 38404315
DOI: 10.1364/BOE.504074