- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Retinal Thickness Changes throughout the Natural History of Drusen in Age-related Macular Degeneration
摘要： SIGNIFICANCE: Drusen are associated with retinal thinning in age-related macular degeneration (AMD). These changes, however, have mostly been examined at single time points, ignoring the evolution of drusen from emergence to regression. Understanding the full breadth of retinal changes associated with drusen will improve understanding of disease pathogenesis. PURPOSE: The purpose of this study was to assess how the natural history of drusen affects retinal thickness, focusing on the photoreceptor and retinal pigment epithelium (RPE) layers. METHODS: Spectral domain optical coherence tomography of subjects with intermediate AMD (n = 50) who attended the Centre for Eye Health, Sydney, Australia, for two separate visits (476 ± 16 days between visits) was extracted. Scans were automatically segmented with manufacturer software then assessed for drusen that had emerged, grown, or regressed between visits. For each identified lesion, the thickness of each retinal layer at the drusen peak and at adjacent drusen-free areas (150 μm nasal and temporal to the druse) was compared between visits. RESULTS: Before drusen emergence, the RPE was significantly thicker at the drusen site (14.2 ± 2.6%) compared with neighboring drusen-free areas. There was a 71% sensitivity of RPE thickening predicting drusen emergence. Once drusen emerged, significant thinning of all outer retinal layers was observed, consistent with previous studies. Drusen growth was significantly correlated with thinning of the outer retina (r = ?0.38, P < .001). Drusen regression resulted in outer retinal layers returning to thicknesses not significantly different from baseline. CONCLUSIONS: The natural history of drusen is associated with RPE thickening before drusen emergence, thinning of the outer nuclear layer as well as photoreceptor and RPE layers proportional to drusen growth, and return to baseline thickness after drusen regression. These findings have useful clinical applications, providing a potential marker for predicting drusen emergence for AMD prognostic and intervention studies and highlighting that areas of normal retinal thickness in AMD may be former sites of regressed drusen.
关键词： spectral domain optical coherence tomography,drusen,age-related macular degeneration,retinal thickness
更新于2025-09-23 15:21:01
-
Femtosecond Laser Pulse Ablation of Sub-Cellular Drusen-Like Deposits
摘要： Age-related macular degeneration (AMD) is a condition affecting the retina and is the leading cause of vision loss. Dry AMD is caused by the accumulation of lipid deposits called drusen, which form under the retina. This work demonstrates, for the first time, the removal of drusen-like deposits underneath ARPE-19 cell layers using femtosecond laser pulses. A novel cell culture model was created in response to the limited access to primary cell lines and the absence of animal models that recapitulate all aspects of AMD. In the cell culture model, deposits were identified with fluorescent stains specific to known deposit constituents. Trains of sub-10 femtosecond laser pulses from a Ti:Sapphire laser were used to successfully ablate the deposits without causing damage to surrounding cells. this drusen removal method can be used as a potential treatment for dry-stage AMD.
关键词： drusen,ARPE-19,laser ablation,age-related macular degeneration,femtosecond laser
更新于2025-09-12 10:27:22
-
A DOUBLE-MASKED, RANDOMIZED, SHAM-CONTROLLED, SINGLE-CENTER STUDY WITH PHOTOBIOMODULATION FOR THE TREATMENT OF DRY AGE-RELATED MACULAR DEGENERATION
摘要： The LIGHTSITE I study investigated the efficacy and safety of photobiomodulation (PBM) treatment in subjects with dry age-related macular degeneration. Thirty subjects (46 eyes) were treated with the Valeda Light Delivery System, wherein subjects underwent two series of treatments (3· per week for 3–4 weeks) over 1 year. Outcome measures included best-corrected visual acuity, contrast sensitivity, microperimetry, central drusen volume and drusen thickness, and quality of life assessments. Photobiomodulation-treated subjects showed a best-corrected visual acuity mean letter score gain of 4 letters immediately after each treatment series at Month 1 (M1) and Month 7 (M7). Approximately 50% of PBM-treated subjects showed improvement of $5 letters versus 13.6% in sham-treated subjects at M1. High responding subjects ($5-letter improvement) in the PBM-treated group showed a gain of 8 letters after initial treatment (P , 0.01) and exhibited earlier stages of age-related macular degeneration disease. Statistically significant improvements in contrast sensitivity, central drusen volume, central drusen thickness, and quality of life were observed (P , 0.05). No device-related adverse events were reported. Photobiomodulation treatment statistically improved clinical and anatomical outcomes with more robust benefits observed in subjects with earlier stages of dry age-related macular degeneration. Repeated PBM treatments are necessary to maintain benefits. These pilot findings support previous reports and suggest the utility of PBM as a safe and effective therapy in subjects with dry age-related macular degeneration.
关键词： contrast sensitivity,best-corrected visual acuity,light-emitting diode,vision loss,low-level light therapy,mitochondria,photobiomodulation,dry age-related macular degeneration,drusen
更新于2025-09-12 10:27:22
-
In Vivo Quantification of Retinal Changes Associated With Drusen in Age-Related Macular Degeneration
摘要： PURPOSE. Drusen alters retinal architecture in early age-related macular degeneration (AMD). However, abnormalities also may exist in drusen-free areas of the AMD retina. This study examines retinal thickness above drusen relative to drusen-free areas in the same patient and a normal population. METHODS. Patients with early to intermediate AMD (n ? 122) or no disease (n ? 30) were examined at the Center for Eye Health. Spectral domain optical coherence tomography (SD-OCT) scans through single, isolated druse (n ? 125) or con?uent drusen (n ? 54) were obtained. The thickness of individual retinal layers was measured above the druse and in a drusen-free area, 150 lm from the drusen edge. RESULTS. Intraeye comparisons found total retinal thickness above drusen was 16 6 0.6% less than drusen-free areas. Thinning was mostly in the retinal pigment epithelium/photoreceptor layer (32 6 1% reduction) and the outer nuclear layer (22 6 1% reduction). Con?uent drusen showed similar thinning of the outer retina as well as inner retina loss (5%). Thinning was strongly correlated with drusen height, but only modestly correlated with drusen width. When compared to the normal population, retinal thickness above drusen and drusen-free areas were signi?cantly reduced. CONCLUSIONS. We con?rm outer retina thinning above drusen in early/intermediate AMD compared to drusen-free areas in the same retina or a normal population. Interestingly, drusen-free areas in AMD patients were not the same as control patients suggesting ‘‘normal’’ areas of the AMD retina are abnormal. The strong correlation between retinal thinning and drusen height, rather than width, suggests current grading systems for AMD may need re?nement.
关键词： drusen,age-related macular degeneration,optical coherence tomography,retinal thickness
更新于2025-09-09 09:28:46
-
Analysis of gabor filter based features with PCA and GA for the detection of drusen in fundus images
摘要： Human eye can be affected by different types of diseases. Age-Related Macular Degeneration (AMD) is one of the such diseases, and it mainly occurs after 50 years of age. This disease is characterized by the occurrence of yellow spots called as Drusen. In this work, an automated method for the detection of drusen in Fundus image has been developed, and it has been tested on 70 images consisting of 30 normal images and 40 images with drusen. Performance of the Support Vector Machine (SVM) and K Nearest Neighbor (KNN) classifier has been evaluated using Data's reduction using Principle Component Analysis (PCA) and Data's selection using Genetic Algorithm (GA).Performance evaluation has been done in terms of accuracy, sensitivity, specificity, misclassification rate, positive predictive rate, negative predictive rate and Youden’s Index. The proposed method has achieved highest accuracy of 98.7% when data selection using Genetic Algorithm has been applied.
关键词： Genetic Algorithm,Principal Component Analysis,Support Vector Machine,Drusen,Gabor Filters
更新于2025-09-04 15:30:14
-
Drusenoid retinal pigment epithelium detachments
摘要： The authors make a review of drusenoid retinal pigment epithelium detachments(DPDs), a form of retinal pigment epithelium detachment(PED) that evolves from confluent and large soft drusen.Drusenoidretinal pigment epithelial detachments are a recognized element of the “dry” AMD. Until now, no treatment is indicated in drusenoid PEDs. The authors describe the clinical characteristics of drusenoid retinal pigment epithelium detachments (DPEDs) and make a review of the DPEDs related in the international literature. We related in this revision paper the multimodal advanced image exams in two cases of dusenoid retinal pigment epithelium detachments (DPEDs) and the general characteristics of thisfinding associated with Dry Macular degeneration.Upon examination of the ocular fundusDPEDs emerge as well-circumscribed yellow or yellow–white elevations of the RPE that are usually found within the macula.They may show scalloped borders and a slightly irregular surface. When visualized using fluorescein angiography (FA),DPEDs are typically described as faint hyper-fluorescent in the early phase followed by a slow increase in fluorescence throughout the transit stage of the study without late leakage. With optical coherence tomography (OCT), drusenoid PEDs usually show a smooth contour of the detached hyperreflective RPE band that may have an undulating appearance.Drusenoid PEDs encompass far above the ground possibility type of “dry” AMD that develops in relationship with large confluent soft drusen.At this point no treatment is utilized in drusenoid retinal pigment epithelium detachment(DPEDs).
关键词： Macular degeneration,Aged,Fluorescein angiography,Age factors,fundus oculi,Retinal detachment,Retinal drusen
更新于2025-09-04 15:30:14