Ran Du

Dr. Ran Du

Tokyo Medical and Dental University, Tokyo, Japan
orcid

Research Focus & Metrics

Academic Career Length

9Years (2018-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 July 2019 in Ophthalmology
Verified
Journal Article
Closed access
YFYuxin Fang
Yuxin Fang
RDRan Du
Ran Du
NNNatsuko Nagaoka
Natsuko Nagaoka
TYTae Yokoi
Tae Yokoi
KSKosei Shinohara
Kosei Shinohara
KOKyoko Ohno-Matsui
Kyoko Ohno-Matsui

1 May 2020 in Retina
Verified
Journal Article
Closed access
RDRan Du
Ran Du
YFYuxin Fang
Yuxin Fang
JJJost B. Jonas
Jost B. Jonas
TYTae Yokoi
Tae Yokoi
HTHiroyuki Takahashi
Hiroyuki Takahashi
KOKyoko Ohno-Matsui
Kyoko Ohno-Matsui
Purpose: To reveal clinical features of patchy atrophy in pathologic myopia and investigate the status of the Bruch membrane and retinal pigment epithelium by swept-source optical coherence tomography. Methods: This study reviewed highly myopic patients who visited the high myopia clinic between January 2015 and February 2018. Wide-field photographs and wide-field fundus autofluorescence fundus images were used as the primary method for identifying PAs, and swept-source optical coherence tomography images were used for investigating the retinochoroid status of PAs. Results: Four hundred fifty-six PAs were detected in 137 eyes (118 patients). Patchy atrophys were located most often in the macular area (28.3%), followed by the inferior (25.9%), temporal (18.9%), nasal (14.5%), and superior (12.5%) region. All 210, PAs which had been fully or partially scanned by swept-source optical coherence tomography, showed a retinal pigment epithelium defect, and 174 (82.9%) PAs showed a Bruch membrane defect on the available scans. In 101 (82.8%) of 122 PAs with clearly detectable borders of the retinal pigment epithelium and Bruch membrane defect, the Bruch membrane defects were smaller than the retinal pigment epithelium defects. A dome-shape inward bulging of the sclera was observed in 10 PAs. Conclusion: These morphological findings may provide a basis for exploring the biomechanical etiology of the PAs as part of the development of pathologic myopia.

10 December 2019 in Retina
Verified
Journal Article
Closed access
YFYuxin Fang
Yuxin Fang
TYTae Yokoi
Tae Yokoi
NSNoriaki Shimada
Noriaki Shimada
RDRan Du
Ran Du
KSKosei Shinohara
Kosei Shinohara
KOKyoko Ohno-Matsui
Kyoko Ohno-Matsui
Purpose: To determine the incidence and long-term outcome of macular atrophy (MA) after pars plana vitrectomy (PPV) in pathologic myopia. Methods: Highly myopic patients who underwent PPV for myopic traction maculopathy and macular hole retinal detachment at Tokyo Medical and Dental University between 2012 and 2016 were studied. Fundus photographs and/or optical coherence tomography were examined before and after PPV at every visit. Results: A total of 133 eyes were followed for 39 months with the mean age of 62.8 years and the mean axial length of 30.0 mm. Postoperatively, 14 eyes (10.5%) developed fovea-centered MA, observed initially as a small, isolated, whitish lesion at the center of fovea at 3.5 months after PPV. The appearance of the MA was distinctly different from the choroidal neovascularization–related MA or patchy atrophy–related MA. With time, the lesions enlarged circumferentially. In these 14 eyes, the final best-corrected visual acuity was worse than the baseline, although the difference was not significant. The occurrence of MA was significantly associated with the preoperative foveal status. Conclusion: The development of MA can occur in 11% of highly myopic eyes after PPV for myopic traction maculopathy and macular hole retinal detachment. This postoperative MA might be a new complication of pathologic myopia.

12 May 2022 in Diagnostics
Verified
Journal Article
Open access
PDF file
RDRan Du
Ran Du
KOKyoko Ohno-Matsui
Kyoko Ohno-Matsui
Myopia is a global health issue, and the prevalence of high myopia has increased significantly in the past five to six decades. The high incidence of myopia and its vision-threatening course emphasize the need for automated methods to screen for high myopia and its serious form, named pathologic myopia (PM). Artificial intelligence (AI)-based applications have been extensively applied in medicine, and these applications have focused on analyzing ophthalmic images to diagnose the disease and to determine prognosis from these images. However, unlike diseases that mainly show pathologic changes in the fundus, high myopia and PM generate even more data because both the ophthalmic information and morphological changes in the retina and choroid need to be analyzed. In this review, we present how AI techniques have been used to diagnose and manage high myopia, PM, and other ocular diseases and discuss the current capacity of AI in assisting in preventing high myopia.

1 July 2020 in Retina
Verified
Journal Article
Closed access
SXShiqi Xie
Shiqi Xie
YFYuxin Fang
Yuxin Fang
RDRan Du
Ran Du
TYTae Yokoi
Tae Yokoi
HTHiroyuki Takahashi
Hiroyuki Takahashi
KOKyoko Ohno-Matsui
Kyoko Ohno-Matsui
Purpose: To determine the prevalence and characteristics of abruptly emerging vessels (AEVs) within patchy atrophy (PA) in myopic eyes. Methods: We studied 160 highly myopic eyes of 144 patients between March and November in 2016. Fundus photographs and swept-source optical coherence tomography images were analyzed. Results: Patient mean age was 67.1 ± 10.5 years. Mean axial length was 30.9 ± 2.0 mm. The mean size of the 264 PAs was 5.6 ± 8.3 mm2. Abruptly emerging vessels were detected in 69 (43.1%) eyes and were located within or near PA edge in fundus photographs. Swept-source optical coherence tomography showed that the AEVs were continuous with perforating scleral vessels and were observed on the inner surface of the sclera at the site where they appeared in fundus photographs. A slight bowing of sclera around the AEVs was observed in 41 (59%) eyes. Patchy atrophy with AEVs was significantly larger (10.7 ± 11.3 mm2) than PA without AEVs (3.4 ± 5.1 mm2). Conclusion: Abruptly emerging vessels are commonly found in eyes with myopic PA. The sclera surrounding the AEVs is slightly bowed. Further studies are needed to determine whether the penetrating site of AEVs is structurally more fragile and leads to Bruch membrane defects or AEVs are secondarily involved during PA progression.

11 March 2018 in Journal of Ophthalmology
Verified
Journal Article
Open access
PDF file
RDRan Du
Ran Du
ZMZhao-Yang Meng
Zhao-Yang Meng
JWJia-lin Wang
Jia-lin Wang
YWYanling Wang
Yanling Wang
Purpose. To determine the effect of osthole on the retina in a chronic cerebral hypoperfusion (CCH) rat model and to investigate its therapeutic activity. Methods. Seventy-two rats were randomly allocated into 6 groups. CCH was induced by permanent bilateral common carotid artery occlusion (BCCAO) in five groups. Sham surgery was performed without occlusion of the artery in the sixth group (control group). Animals were administered with saline (model group), osthole (osthole-IG group), aspirin (aspirin group), or ginaton (ginaton group); the osthole-PI group was performed with peribulbar injection of osthole. Four rats in each group were sacrificed every 5 days after drug administration, and histopathology along with morphology of retina were observed. Fundus fluorescein angiography was performed before the animals were sacrificed at day 15. Retinal Akt, NF-κB, Bax, and Bcl-2 levels were assessed using immunohistochemistry, immunofluorescence, and reverse-transcription PCR; retinal injury was assessed using TUNEL in situ; retinal levels of superoxide dismutase (SOD) and malondialdehyde (MDA) were measured. Results. Fundus fluorescein angiography revealed the retinal vascular diameter in the osthole-IG group rats to be wider than that in the model, osthole-PI, aspirin, or ginaton group rats. Histological analysis of retinal tissue revealed an increase in retinal thickness in all treatment groups, and significant improvement was noticed in the osthole-IG group. TUNEL staining revealed fewer apoptotic cells in the osthole-IG and osthole-PI groups than in the other groups. For immunohistochemistry results, in the osthole-IG group, levels of NF-κB and Akt were lower than those in the other treated groups, while levels of the ratio Bcl-2/Bax were higher. Levels of MDA were lower and levels of SOD were higher in the osthole-IG group than in the other groups. Conclusions. Osthole protects the retina from ischemia injury secondary to CCH induced by BCCAO, mainly through anti-inflammatory, antioxidant, and antiapoptotic effects.