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Optimization of Parameters for Quantitative Analysis of <sup>123</sup> I-ioflupane SPECT Images for Monitoring of Progression of Parkinson's Disease
摘要： Objectives: Quantitative assessment of dopamine transporter (DAT) imaging can aid in diagnosing Parkinson’s disease (PD) and assessing disease progression in the context of therapeutic trials. Previously, the software program SBRquant was applied to 123I-ioflupane SPECT images acquired on healthy controls and subjects with PD. Earlier work on optimization of the parameters for differentiating between controls and subjects with dopaminergic deficits is extended here for maximizing change measurements associated with disease progression on longitudinally acquired scans. Methods: Serial 123I-ioflupane SPECT imaging for 51 subjects with PD (conducted approximately 1 year apart) were downloaded from the Parkinson’s Progression Markers Initiative database. The software program SBRquant calculates the Striatal Binding Ratio (SBR) separately for the left and right caudate and putamen regions of interest (ROI). Parameters were varied to evaluate the number of summed transverse slices and the positioning of the striatal ROIs for determining signal to noise associated with their annual rate of change in SBR. The parameters yielding the largest change of the lowest putamen's SBR from scan 1 to scan 2 were determined. Results: For the change from scan 1 to scan 2 in the 51 subjects, the largest annual change was observed when the putamen ROI was placed 3 pixels away from the caudate and by summing 5 central striatal slices. This resulted in an 11.2 ± 4.3% annual decrease in the lowest putamen's SBR for the group. Conclusions: Quantitative assessment of DAT imaging for assessing progression of PD requires specific, optimal parameters different than those for diagnostic accuracy.
关键词： Parkinson's Disease,Dopamine Transporter Imaging,Disease Progression,Quantitative Analysis,123I-ioflupane SPECT
更新于2025-09-23 15:21:21
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Changes on Confocal Scanning Laser Ophthalmoscopy with the Heidelberg Retinal Tomography after a Cardiac Catheterism in a Patient with Progressive Glaucoma
摘要： Purpose: We present a case of a patient with progressive open angle glaucoma who presented changes suggestive of improvement in the Heidelberg retinal tomography 3 (HRT3) analysis after a cardiac catheterization. Observation: A 69-year-old woman presented with progressive open angle glaucoma despite maximum tolerable antiglaucomatous topical treatment. A filtering surgery (trabeculectomy) was performed and successfully achieved intraocular pressure (IOP) levels of 10 mm Hg on average. Despite this, changes were evidenced in the HRT3 protocols (trend analysis and topographic change analysis) suggesting marked progression. Brimonidine 0.2% twice a day was initiated, and a cardiovascular examination was requested. A cardiac catheterism was performed in the following weeks, and afterward, all structural parameters improved until the last control. Medication was not discontinued, and no signs of apparent progression on the HRT3 parameters have been evidenced up until the time of writing this case report. Conclusions and Importance: There was a marked improvement in the HRT3 parameters (trend and topographic change analysis), suggesting that the progression stopped after a cardiac catheterism in a patient with progressive glaucoma despite having the IOP controlled. To our knowledge, this is the first case of a patient with progressive glaucoma that was medically and surgically managed, and despite achieving low IOP levels, the progression detected by the HRT3 analysis could not be stopped until a cardiac catheterization was performed.
关键词： Blood flow,Open-angle glaucoma,Disease progression,Heidelberg retinal tomography 3,Imaging technique
更新于2025-09-12 10:27:22
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Relationship Between Presumptive Inner Nuclear Layer Thickness and Geographic Atrophy Progression in Age-Related Macular Degeneration
摘要： To analyze inner retinal changes in patients with geographic atrophy (GA) secondary to age-related macular degeneration and identify morphological cues for progression. A total of 100 eyes with GA were assessed in this longitudinal, observational case series. Patients with GA and absent confounding pathology were compared with age-matched controls. The retinal layers on spectral-domain optical coherence tomography, acquired in tracking mode, were segmented manually on central scans through the fixation point. Zones of GA were defined based on choroidal signal enhancement from retinal pigment epithelium loss. An area of unaffected temporal retina was used for comparison. Progression of GA was quantified with fundus autofluorescence. We analyzed 41 eyes of 41 patients (mean age 79.2 ± 6.7 years). In areas of GA, the layer representing the inner nuclear layer (INL) in healthy retina was increased in thickness. Thickness of this presumptive INL was inversely correlated with best-corrected visual acuity (r = ?0.48, P < 0.01). The presumptive INL thickness increase in atrophic areas was less marked in eyes with foveal sparing. Increased INL thickness in areas adjacent to GA was associated with a higher progression rate. Optical coherence tomography findings demonstrate that atrophy of the retinal pigment epithelium-photoreceptor complex in GA is associated with an increase of thickness of the presumptive INL, presumably caused by remodeling of the degenerating retina. Similar alterations in the retina adjacent to areas clinically affected by GA were associated with higher atrophy progression rates.
关键词： geographic atrophy,retinal segmentation,optical coherence tomography,autofluorescence,disease progression
更新于2025-09-10 09:29:36
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High Symmetry of Visual Acuity and Visual Fields in <i>RPGR</i> -Linked Retinitis Pigmentosa
摘要： PURPOSE. Mutations in retinitis pigmentosa GTPase regulator (RPGR) cause 70% to 90% of X-linked retinitis pigmentosa (XLRP3) cases, making this gene a high-yield target for gene therapy. This study analyzed the utility of relevant clinical biomarkers to assess symmetry and rate of progression in XLRP3. METHODS. A retrospective, cross-sectional analysis of 50 XLRP3 patients extracted clinical data including visual acuity (VA), visual fields (I4e and III4e targets), foveal thickness, and ERG data points alongside molecular genetic data. Symmetry was assessed by using linear regression analysis. Kaplan-Meier survival curves (KMCs) and generalized linear mixed model calculations were used to describe disease progression. RESULTS. Ninety-six percent of patients exhibited a rod–cone phenotype, and 4% a cone–rod phenotype. Open reading frame 15 (ORF15) was confirmed as a mutational hotspot within RPGR harboring 73% of exonic mutations. Significant variability, but no clear genotype–phenotype relationship, could be shown between mutations located in exons 1–14 versus ORF15. All biomarkers suggested a high degree of symmetry between eyes but demonstrated different estimates of disease progression. VA and foveal thickness, followed by perimetry III4e, were the most useful endpoints to evaluate progression. KMC estimates predicted a loss of 6/6 vision at a mean of 34 years (62.9; 95% confidence interval). CONCLUSIONS. XLRP3 affects retinal structure and function symmetrically, supporting the use of the fellow eye as an internal control in interventional trials. VA and kinetic visual fields (III4e) seem promising functional outcome measures to assess disease progression. KMC analysis predicted the most severe decline in vision between the third and fourth decade of life.
关键词： gene therapy,retinitis pigmentosa GTPase regulator (RPGR),retinitis pigmentosa,disease progression
更新于2025-09-09 09:28:46
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Progression of retinitis pigmentosa on multimodal imaging: the PREP‐1 study
摘要： Importance: It is important to establish reliable outcome measures to detect progression in retinitis pigmentosa (RP). Background: To evaluate progression of RP using multimodal imaging, including spectral-domain optical coherence tomography (SD-OCT), fundus autofluorescence (FAF) and microperimetry (MP). Design: Retrospective longitudinal study at a tertiary teaching hospital. Participants: 205 eyes of 106 patients with RP with 1-5 years of follow-up. Methods: Demographics and visual acuity (VA) were recorded, and each modality was graded at baseline and every annual follow-up. SD-OCT was graded for the width of ellipsoid zone (EZ), FAF was graded for the diameter and area of the hyperautofluorescent ring (if present), and MP was graded for mean, central and paracentral sensitivity. Spearman’s correlation was used to measure correlations at baseline. Mixed effects models were used to estimate the annual change of each parameter, adjusted for disease duration. Main outcome measures: Rate of progression. Results: The median VA at baseline was 75 letters and was positively correlated with mean and central sensitivity (r: 0.372 and 0.394; p=0.01 for both). All parameters (except paracentral sensitivity) were strongly correlated with each other (r: 0.673-0.991; p<0.001 for all). The annual rates of change for each parameter were as follows: VA, -2.3 letters (p<0.001); EZ, -151um (p<0.001); ring diameter, -132um (p<0.001); ring area, -0.4mm2 (p<0.001); mean sensitivity, -0.3 dB (p<0.001); central sensitivity, -0.7 dB (p<0.001); paracentral sensitivity, -0.4 dB (p<0.001). Conclusion and relevance: Structural and functional measures are well correlated in RP and can reliable measure disease progression within the course of a year.
关键词： Optical Coherence Tomography,Multimodal Imaging,Microperimetry,Fundus Autofluorescence,Disease Progression
更新于2025-09-04 15:30:14