An observational study in Myopia, High-Grade and Myopia; Refractive Error, sponsored by Zhongshan Ophthalmic Center, Sun Yat-sen University. Not yet recruiting. Open to participants aged 18 Years to 30 Years. Per ClinicalTrials.gov, last updated 2025-07-04.
Sponsored by Zhongshan Ophthalmic Center, Sun Yat-sen University · Observational
Changes in retinal hemodynamics play a key role in the development of various eye diseases. Currently, mainstream hemodynamic evaluation techniques have low resolution and poor measurement accuracy, limiting their widespread application. Adaptive optical laser scanning ophthalmoscopy (AO-SLO) can capture retinal vascular images at the cellular level, offering the potential for high-precision retinal hemodynamic evaluation. This project will: ① innovate the AO-SLO blood flow imaging scanning module and acquisition mode, develop algorithms for extracting spatiotemporal signal features from blood flow images, and achieve quantitative analysis of retinal hemodynamics based on AO-SLO; ② construct an in vitro retinal hemodynamic measurement simulation eye, conduct multidimensional AO-SLO hemodynamic measurements, and establish an intelligent model for precise calibration of retinal hemodynamic parameters; ③ conduct AO-SLO-based retinal hemodynamic studies in high myopia, integrating multi-modal ophthalmic imaging to investigate the patterns of changes in retinal vascular structure and blood flow function in high myopia. Ultimately, a new precision measurement imaging technology platform for retinal hemodynamics will be established.
The retina is the initial site where the eye receives external light and forms vision, and it is also the site where various blinding eye diseases occur. Retinal diseases such as diabetic retinopathy (DR), high myopia-related retinal disease, and age-related macular degeneration (AMD) impose a significant visual burden worldwide. The retinal vascular system is involved in the nutrient supply and waste transport of retinal cells, and the integrity of its structure and function is the foundation for maintaining retinal function. Therefore, assessing changes in retinal blood flow can help understand the mechanisms underlying disease progression, thereby promoting early diagnosis and precise treatment of retinal diseases.
Retinal vessels are the only circulatory system in the human body that can be directly observed, allowing for direct visualization and assessment of changes in hemodynamic characteristics such as retinal vascular blood flow velocity. Traditional fluorescein fundus angiography (FFA) involves intravenous injection of fluorescein to indirectly assess retinal perfusion velocity by observing the distribution of fluorescein in the retinal vascular system over time. However, FFA is an invasive procedure and is not suitable for evaluating early hemodynamic changes.
With the development of ophthalmic imaging technology, new fundus imaging techniques can provide more objective, convenient, and non-invasive tools for measuring blood flow velocity. Currently, mainstream hemodynamic evaluation devices, such as laser Doppler, retinal function imaging (RFI), and laser speckle technology, can quantify parameters such as blood flow velocity, blood flow volume, and vascular resistance by extracting spatiotemporal imaging signals of red blood cell movement or analyzing the optical effects caused by movement. However, these devices are limited in clinical application due to issues such as low resolution, low measurement accuracy, and poor reproducibility.
Adaptive optics (AO) is a technology that corrects aberrations and improves the imaging resolution of optical systems. By combining high-definition fundus scanning with a scanning laser ophthalmoscope (SLO), it is possible to achieve cellular-level resolution imaging and quantitative analysis of retinal vascular structures. By using AO-SLO to collect high spatio-temporal resolution image sequences of retinal vessels, it is possible to establish a novel method for evaluating retinal hemodynamics, enabling precise and stable measurements of blood flow velocity and blood flow volume.
Myopia is a highly prevalent eye disease worldwide, with an estimated prevalence exceeding 50% by 2050. Compared to moderate and low myopia, high myopia significantly increases the incidence of macular degeneration and glaucoma. The exact mechanisms underlying the pathological changes in high myopia remain controversial, but increasing evidence suggests that blood flow alterations may be a key pathological mechanism in high myopia-related retinal diseases. Due to the lack of objective evaluation methods, the patterns of hemodynamic changes in high myopia remain unclear. In summary, there is currently a lack of objective, precise hemodynamic quantification assessment tools in ophthalmic clinical practice. Developing a novel retinal hemodynamic imaging assessment model based on AO-SLO, establishing precise hemodynamic measurement methods, and achieving real-time, non-invasive, high-resolution imaging and quantitative analysis of retinal blood flow in living human eyes will provide important imaging evidence for the early diagnosis of retinal diseases such as high myopia-related retinal lesions.
This project will Innovate the AO-SLO blood flow imaging scanning module and acquisition mode, develop algorithms for extracting spatio-temporal signal features from blood flow images, and achieve quantitative analysis of retinal hemodynamics based on AO-SLO; construct an in vitro retinal hemodynamic measurement simulation eye, conduct multi-dimensional AO-SLO hemodynamic measurements, and establish an intelligent model for precise calibration of retinal hemodynamic parameters; conduct AO-SLO-based retinal hemodynamic studies in high myopia, integrating multi-modal ophthalmic imaging to investigate the patterns of changes in retinal vascular structure and blood flow function in high myopia. Ultimately, a new precision measurement imaging technology platform for retinal hemodynamics will be established.
This study will analyze the following indicators: retinal blood flow velocity, flow velocity standard deviation, flow rate, vessel diameter, lumen diameter, wall thickness, wall-to-lumen ratio, vascular density, diameter, and tortuosity measurements in participants with high myopia and non-high myopia one week after enrollment. Quantitative data will be described using mean ± standard deviation (M±SD), and differences between the two groups will be analyzed, along with correlation analysis.
1,159 studies on the registry are indexed under Myopia; 225 are open to participants now.
This study's planned enrollment of 120 is below the median of 150 across 204 observational studies indexed under Myopia.
Browse Myopia studies →Zhongshan Ophthalmic Center, Sun Yat-sen University is the lead sponsor of 164 studies on the registry; 80 are open to participants now.
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The people From Guangzhou, Guangdong Province, China
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Blood flow velocity in the central arteries and veins of the retina
Measure the blood flow velocity and flow velocity standard deviation of the central arteries and veins of the retina of the subject using an adaptive optical laser scanning ophthalmoscope.
Time frame: 7 days after the enrollment
The structure of central retinal arteries and veins
Measure the diameter of the central arteries and veins of the retina, the thickness of the vessel walls, and the wall-to-lumen ratio of the subjects using an adaptive optics laser scanning ophthalmoscope.
Time frame: 7 days after the enrollment
Retinal and choroidal capillary morphological parameters
Use OCTA to obtain images of superficial and deep capillaries and choroidal capillaries within a 3×3 mm area of the posterior pole of the retina, and use a proprietary algorithm to extract morphological parameters.
Time frame: 7 days after the enrollment
The examination for anterior segment of eyes
Use a slit lamp microscope to examine the cornea, conjunctiva, anterior chamber, lens, and other anterior structures of the anterior segment of the eye
Time frame: Baseline
Axis of the eye
Measure the axial length of the subject's eye using the IOL-Master 500
Time frame: Baseline
Best corrected vision cutiy
Assess the best corrected vision by subjective refraction
Time frame: Baseline
Intraocular pressure
Measure intraocular pressure in both eyes using a non-contact tonometer.
Time frame: Baseline
Fundus color photography
Using non-mydriatic fundus photography to obtain images of the posterior pole of the retina
Time frame: Baseline
No study locations are listed for this record.
Plan to share: Yes
Supporting information: Study protocol, Informed consent form, Clinical study report
No publications or documents are linked to this record.
Start is estimated for Jun 2025; primary completion for Jul 2025, 1 month later.
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This study is not yet recruiting, as verified in Feb 2025. You cannot join it, but the record below documents what was studied.
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