---
title: "OCTA quantifies choroidal and retinal thinning and blood flow loss in lens-induced myopia rats"
id: "plos-one-17-quantitative-analysis-of-choroidal-and-retinal-thickness-and-blood-flow-in-a"
canonical_url: "https://medichelpline.com/clinical-feed/plos-one-17-quantitative-analysis-of-choroidal-and-retinal-thickness-and-blood-flow-in-a"
content_type: "clinical_feed_article"
specialty: "Radiology"
source_name: "PLOS ONE (Medicine)"
source_url: "https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0357037"
published_at: "2026-08-27T14:00:00.000Z"
evidence_level: "Journal Feed"
license: "CC-BY-NC-4.0 / Informational Use"
---
# OCTA quantifies choroidal and retinal thinning and blood flow loss in lens-induced myopia rats
## Provenance & Clinical Metadata
- **Canonical URL:** https://medichelpline.com/clinical-feed/plos-one-17-quantitative-analysis-of-choroidal-and-retinal-thickness-and-blood-flow-in-a
- **Specialty:** [Radiology](https://medichelpline.com/clinical-feed/radiology.md)
- **Primary Source:** PLOS ONE (Medicine)
- **Source URL:** [Original Journal Publication](https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0357037)
- **Published At:** 2026-08-27T14:00:00.000Z
- **Evidence Rating:** Journal Feed
## Executive GIST (TL;DR)
- This study used **OCTA** (Intalight Saiwei Ruyi Panoramic Eye OCT) to quantify axial length, choroidal thickness, retinal layer thicknesses, and inner retinal blood flow in a rat lens-induced myopia (LIM) model versus normal controls (NC). - Twenty SPF Sprague–Dawley rats (21 days old; equal male/female) were randomized to LIM or NC groups; the LIM model applied a -5D defocus lens over the right eye for 8 weeks. - Axial length (AL) was measured from anterior corneal surface to the RPE using AS Cube 16 mm × 16 mm; each measurement was averaged from three repeats by the same operator. - Choroidal thickness (CT) and retinal thickness (inner, outer, whole) were measured on horizontal cross-sections through the optic disc using a 33 Line R16 scan and concentric rings (2, 4, 6 mm); CT was measured at nasal and temporal points at 1000, 2000, 3000 μm from the optic disc. - Inner retinal blood flow density was quantified with OCTA segmentation focused on the inner retinal layer (ILM to OPL). - Compared with NC, LIM eyes showed **axial elongation**, reduced choroidal thickness, thinning of inner, outer and total retina, and decreased inner retinal blood flow density; most differences were statistically significant by t-test. - The authors conclude OCTA noninvasively detected three myopia hallmarks—axial elongation, **choroidal/retinal thinning**, and **retinal hypoperfusion**—and propose OCTA as a tool for longitudinal monitoring and translational imaging biomarkers for early myopia-related retinal lesion screening. - Animal care details: 7-day acclimation, standard housing (22 ± 1°C, 55 ± 5% humidity, 12 h light/dark), daily health checks; ethics approval and animal license numbers were reported. - Specific quantitative values for thicknesses, blood flow densities, and p values were not reproduced in the provided source excerpt; detailed numerical results are reported in the manuscript figures and tables referenced but not transcribed here.
## Clinical Analysis & Structured Key Points
Quantitative analysis of choroidal and retinal thickness and blood flow in a rat model of lens-induced myopia using OCTA | PLOS One Browse Subject Areas ? Click through the PLOS taxonomy to find articles in your field. For more information about PLOS Subject Areas, click here . Article Authors Metrics Comments Media Coverage Reader Comments Figures Figures Abstract Purpose The aim of this study was to use optical coherence tomography angiography (OCTA) to quantitatively analyze the changes in the thickness of the choroidal and retinal layers as well as the alterations in intraretinal blood flow in lens-induced myopia (LIM) rats, and to provide a basis for mechanistic studies of myopia models from the perspective of the choroid and the retina. Methods We conducted LIM modeling in rats and set up a normal control (NC). After 8 weeks of modeling, use a high-resolution anterior and posterior segment biometric OCTA to measure the axial length, choroidal thickness, and the thickness of the inner, outer, and entire retinal layers in two groups of rats, and quantify changes in blood flow in the inner layer of the retina. The results were analyzed using t-test. Results Compared with NC, LIM rats had longer axis, thinner choroid thickness, thinner inner, outer and whole retinal thickness, and lower blood flow density in inner retina. The differences were statistically significant at most measurement points. Conclusions OCTA revealed three myopia hallmarks: axial elongation, choroidal/retinal thinning, and retinal hypoperfusion. These findings enhance clinical understanding of myopic morphological changes and provide mechanistic insights into choroidal-retinal contributions. OCTA’s noninvasive high-resolution enables longitudinal monitoring of ocular structural/vascular changes, offering a basis for diagnosing and preventing high-myopia retinopathy. Translational relevance This study used OCTA to non-invasively quantify retinal and choroidal structure and blood flow abnormalities in a myopia animal model, providing translatable imaging biomarkers for the early clinical screening of retinal lesions associated with high myopia. Citation: Zhang Q, Wu Z, Zhang J, Zhang H, Yuan J, Zuo T, et al. (2026) Quantitative analysis of choroidal and retinal thickness and blood flow in a rat model of lens-induced myopia using OCTA. PLoS One 21(8): e0357037. https://doi.org/10.1371/journal.pone.0357037 Editor: Yalong Dang, Sanmenxia Central Hospital, Henan University of Science and Technilogy, CHINA Received: March 3, 2026; Accepted: August 11, 2026; Published: August 27, 2026 Copyright: © 2026 Zhang et al. This is an open access article distributed under the terms of the Creative Commons Attribution License , which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Data Availability: All relevant data are within the manuscript and its Supporting Information files. Funding: The author(s) received no specific funding for this work. Competing interests: The authors have declared that no competing interests exist. Abbreviations: AL, axial length; ACS, anterior corneal surface; CT, choroidal thickness; ILM, inner limiting membrane; IRL, inner retinal layer; LIM, lens-induced myopia; NC, normal control; OCTA, optical coherence tomography angiography; ORL, outer retinal layer; RPE, retinal pigment epithelium; RT, retinal thickness Introduction In recent years, the prevalence of myopia has risen sharply worldwide and has reached epidemic proportions. It is predicted that by 2050, half of the global population will suffer from myopia [ 1 ].Myopia, particularly high myopia, may lead to macular degeneration, choroidal neovascularization, retinal detachment, and various other conditions that are significant contributors of visual impairment and blindness [ 2 ]. Since the pathogenesis of myopia has not been fully clarified and our comprehension of myopia-related fundus lesions is incomplete, there are currently no effective treatments for myopia. Therefore, investigating the mechanisms associated with the initiation and development of myopia remains a a focal point of research [ 3 ]. Research has found that the characteristic manifestations of myopia are an elongation of axial length (AL) and the mechanical stretching and thinning of the retina and choroid [ 4 , 5 ]. Furthermore, numerous research reports indicate that retinal perfusion also decreases in highly myopic eyes [ 2 ]. As a result, researchers have focused on the axial length, the choroid, and the retina of myopic eyes, and they hope to obtain data on the thickness of the retina and choroid, as well as blood flow of the retina in myopic animal models to simulate the results in humans, in order to further in-depth basic experimental research. Optical Coherence Tomography Angiography (OCTA) uses near-infrared light to provide high-resolution cross-sectional images of ocular tissues that allow analysis of the spatial relationships between layers in the posterior segment of the eye. It is a noninvasive, reproducible, noncontact, noninvasive ophthalmic imaging technique, and in contrast to OCT, OCTA allows for high-resolution imaging of the vascular network, which is of high practical value.Therefore, researchers often utilize OCTA to distinguish and evaluate the blood flow and structures of the choroid and retina layers for more profound studies on myopic eye structures [ 6 ]. This study employed the OCTA for Anterior and Posterior Segment Biometries (Intalight Saiwei Ruyi Panoramic Eye OCT) to quantitatively analyze the axial length, choroidal and retinal thickness, and alterations in inner retinal blood flow in a myopic rat model with lens-induced myopia, using rats as a model. This study aims to provide a basis and foundation for exploring the relationship between myopia and changes in the retina and choroid, and for future experiments in humans. Materials and methods Experimental animals and grouping Twenty SPF-grade healthy SD rats without eye diseases, aged 21 days, weighing between 65g and 75g, consisting of an equal number of males and females, were purchased from Liaoning Changsheng Bio-technology Co.,with an experimental animal license (SCXK (Liaoning) 2023---0004). The experimental animals were raised in the Animal Experiment Center of the Second Affiliated Hospital of Liaoning University of Traditional Chinese Medicine.Prior to the commencement of the study, approval was granted by the Animal Ethics Committee of the Second Affiliated Hospital of Liaoning University of Traditional Chinese Medicine (No. LZYY240403). All animals were housed under normal barrier laboratory conditions, with free access to food and water, at a room temperature of 22 ± 1°and a humidity of (55 ± 5)%. The light or dark cycle was set to alternate every 12 hours. Animal health and behavior were observed daily. Following a 7-day acclimation period with feeding, animals were examined and any with eye abnormalities were excluded. The rats were then randomly divided into two groups: normal control (NC) and lens-induced myopia (LIM). In the normal control group, the right eye was designated as the experimental eye, while the left eye served as the within-animal control, with neither eye receiving any treatment, and both were kept under conventional housing conditions for 8 weeks. In the lens-induced myopia group, the right eye was the experimental eye, where a model of lens-induced myopia was established, and the left eye served as the within-animal control without any treatment, and both were also housed for 8 weeks. Establishment of a lens-induced myopic model After anesthetizing the myopic lens-induced group rats by intraperitoneal injection of sodium pentobarbital (20 g/L, 0.2 mL/100 g), a -5D myopic defocus lens with a diameter of approximately 1.7 cm was sutured around the skin tissue of the right eye using 5−0 polyester braided thread, completely covering the right eye without pressing on the eyeball, not affecting normal blinking, and leaving the left eye naturally exposed. The periocular skin was disinfected with iodine before the operation, and after the operation, tobramycin dexamethasone eye drops were administered to the suture site between the lens and eyelid skin to prevent infection. The eyes of the rats were observed daily, and if the lens was found to be loose or dirty, it was reinforced and cleaned in a timely manner to ensure that the optical defocus state remained unchanged. If myopic refractive media opacity was observed during the experiment, the rat would be excluded. After continuous covering of the right eye of the rats for 8 weeks, subsequent measurements were taken. Axial length measurement After 8 weeks of modeling, rats were anesthetized with an intraperitoneal injection of sodium pentobarbital (20 g/L, 0.2 mL/100 g), and their pupils were dilated employing compound tropicamide eye drops (drug specification: 1 ml∶5 mg). Utilizing the Intalight Saiwei Ruyi Panoramic Eye OCT, the AL was measured with the instrument’s built-in scanning mode AS Cube 16 mm × 16 mm. AL represents the distance from the high reflective signal of the anterior corneal surface (ACS) to the high reflective signal of the retinal pigment epithelium (RPE) layer. Each rat was measured three times by the same experimenter, with the results being averaged. The method for Axial Length Measurement is shown in Fig 1 . Download: PNG larger image TIFF original image Fig 1. Legend for axial length measurement. https://doi.org/10.1371/journal.pone.0357037.g001 The thickness of choroidal and retinal Utilize the 33 Line R16 scan pattern to capture choroidal images, obtaining horizontal cross-sectional images through the optic disc. Divide into three concentric circles with diameters of 2 mm, 4 mm, and 6 mm, placing them at the center of the optic disc, add navigation lines, and measure the choroidal thickness (CT) at six points on the nasal and temporal sides at 1000, 2000, and 3000μm, which is the distance from the RPE to the inner edge of the sclera. Capture retinal images using the 33 Line R16 scan pattern, obtaining horizontal cross-sectional images through the optic disc. Divide into three concentric circles with diameters of 2 mm, 4 mm, and 6 mm, placing them at the center of the optic disc, add navigation lines, and measure the thickness of the inner, outer, and entire layers of the rat retina at six points on the nasal and temporal sides at 1000, 2000, and 3000μm. The inner retinal layer (IRL) is from the inner limiting membrane (ILM) to the outer plexiform layer (OPL), the outer retinal layer (ORL) is from the inner edge of the OPL to the RPE, and the entire retinal thickness (RT) refers to the distance from the ILM to the inner edge of the RPE. The method for retinal layer segmentation and thickness measurement is shown in Fig 2 . Download: PNG larger image TIFF original image Fig 2. Localization of layers in the choroid and retina. https://doi.org/10.1371/journal.pone.0357037.g002 Retinal blood flow density measurement Capture retinal blood flow density images using the Angio 6 × 6 512 × 512 R4 scan mode, and divide them into three concentric circles with diameters of 1 mm, 3 mm, and 5 mm, corresponding to the central, inner ring, and outer ring areas, respectively. Next, use four radial lines to divide the inner and outer ring areas into temporal, superior, nasal, and inferior regions, resulting in a total of nine segments, as shown in Fig 3 . Retinal blood flow density is calculated as the ratio of the projected area of blood vessels to the projected area of the specified region on the retinal plane, expressed as a percentage. All measurements were performed by one researcher between 14:00 and 16:00 to minimize differences to mitigate changes in biological rhythms. Download: PNG larger image TIFF original image Fig 3. Schematic of the 9 regions of the optic disc (right eye) and Schematic diagram of retinal inner layer blood flow partitioning. https://doi.org/10.1371/journal.pone.0357037.g003 (Central area: diameter of 1 mm; T3, S3, N3, I3 are the inner ring areas of the optic disc with a diameter of 3 mm, located on the temporal, superior, nasal, and inferior sides respectively; T5, S5, N5, I5 are the outer ring areas of the optic disc with a diameter of 5 mm, located on the temporal, superior, nasal, and inferior sides respectively.) Euthanasia method The rats were fasted for at least 12 hours prior to euthanasia. After all tests are completed, animals were deeply anesthetized via an intraperitoneal injection of sodium pentobarbital at a dose of 0.2g per 100g body weight. Anesthetic depth was assessed by the absence of pedal and palpebral reflexes. Once a surgical plane of anesthesia was confirmed, animals were euthanized by cervical dislocation performed by trained personnel. Death was confirmed by cessation of respiration and lack of reflex responses. All efforts were made to minimize animal suffering and to use the minimum number of animals necessary to achieve the scientific objectives of the study. Statistical analysis Data was statistically analyzed using SPSS 25.0 software, with all data presented as mean ± standard deviation ( ). Independent samples t-test was used for comparison between two groups, with a P 0.05). https://doi.org/10.1371/journal.pone.0357037.g008 Download: PNG larger image TIFF original image Fig 9. Comparison of IRL thickness in
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