Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Masafumi Ota is active.

Publication


Featured researches published by Masafumi Ota.


British Journal of Ophthalmology | 2007

Association between integrity of foveal photoreceptor layer and visual acuity in branch retinal vein occlusion

Masafumi Ota; Akitaka Tsujikawa; Tomoaki Murakami; Mihori Kita; Kazuaki Miyamoto; Atsushi Sakamoto; Noritatsu Yamaike; Nagahisa Yoshimura

Aim: To study the correlation between integrity of the photoreceptor layer after resolution of macular oedema (MO) associated with branch retinal vein occlusion (BRVO) and final visual acuity (VA), and to determine prognostic factors for visual outcome. Methods: We retrospectively studied 46 eyes from 46 patients with resolved MO secondary to BRVO, the foveal thickness of which was less than 250 µm at final observation. We assessed the status of the third high reflectance band (HRB) in the fovea using optical coherence tomography (OCT) at final observation, and studied OCT images taken at the initial visit in the hope of identifying a factor that would be prognostic of visual outcome. Results: No differences were found in initial VA or in foveal thickness between eyes with or without complete third HRB at final observation. However, final VA in eyes without a complete HRB was significantly poorer (p<0.002). Additionally, initial status of the third HRB in the parafoveal area of unaffected retina was associated with final VA; lack of visualisation of the third HRB at 500 µm (p = 0.0104) or 1000 µm (p = 0.0167) from the fovea on initial OCT images was associated with poor visual recovery after resolution of the MO. Conclusion: Integrity of the photoreceptor layer in the fovea is associated with VA in resolved MO, and status of the third HRB before treatment might be predictive of visual outcome.


American Journal of Ophthalmology | 2009

Association between Foveal Photoreceptor Integrity and Visual Outcome in Neovascular Age-related Macular Degeneration

Hisako Hayashi; Kenji Yamashiro; Akitaka Tsujikawa; Masafumi Ota; Atsushi Otani; Nagahisa Yoshimura

PURPOSE To evaluate the correlation between visual outcome and foveal photoreceptor integrity after successful treatment of eyes with neovascular age-related macular degeneration (AMD). DESIGN Retrospective chart review. METHODS We retrospectively studied the medical records of 51 eyes of 51 patients with neovascular AMD who were treated successfully with photodynamic therapy (PDT). All eyes were followed-up for more than 24 months after the initial treatment. Using spectral-domain optical coherence tomography, the status of the inner segment and outer segment (IS/OS) photoreceptor junction was assessed as a hallmark of the integrity of the foveal photoreceptor layer. RESULTS At the final visit, no eyes showed an exudative change. A complete or discontinuous IS/OS line was detected beneath the fovea in 8 (15.7%) and 25 (29.4%) eyes, respectively, whereas 28 (54.9%) had no IS/OS line. Eyes with a continuous or discontinuous IS/OS line beneath the fovea had better final visual acuity (VA) than did eyes without an IS/OS line (P < .001, respectively). Of the 51 eyes, 36 showed polypoidal choroidal vasculopathy (PCV), whereas 15 were diagnosed as having typical AMD without PCV. Visual outcome was significantly better in eyes with PCV (P = .026). Most eyes (13/15; 86.7%) with typical AMD had no IS/OS line at the final visit, whereas only 13 (36.1%) of the 36 eyes with PCV had no IS/OS line beneath the fovea. CONCLUSIONS Integrity of the photoreceptor layer beneath the fovea is associated with the final VA in neovascular AMD after successful PDT.


Retina-the Journal of Retinal and Vitreous Diseases | 2008

Integrity of foveal photoreceptor layer in central retinal vein occlusion.

Masafumi Ota; Akitaka Tsujikawa; Mihori Kita; Kazuaki Miyamoto; Atsushi Sakamoto; Noritatsu Yamaike; Yuriko Kotera; Nagahisa Yoshimura

Purpose: To study the correlation between final visual acuity and integrity of the foveal photoreceptor layer after resolution of macular edema (ME) associated with central retinal vein occlusion (CRVO). Methods: We studied retrospectively 27 eyes of 27 patients with resolved ME associated with central retinal vein occlusion. On optical coherence tomography, integrity of the foveal photoreceptor layer was studied using the junctions between inner and outer segments of the photoreceptor (IS/OS) line as a hallmark. Results: At the final visit, foveal thickness was decreased to a physiologic level in all eyes. On optical coherence tomography, 14 eyes showed the IS/OS line in the fovea, whereas 13 eyes showed no IS/OS line. In concordance with resolution of the ME, visual acuity had improved significantly by the final visit. However, final visual acuity in eyes without an IS/OS line was significantly poorer than that in eyes with an IS/OS line (P < 0.0001). In addition, integrity of the foveal photoreceptor layer after resolution of the ME had a significant correlation with the initial retinal perfusion status (P = 0.0156) and with initial visual acuity (P = 0.0050). Conclusions: After resolution of the ME associated with central retinal vein occlusion, visual acuity is closely associated with integrity of the foveal photoreceptor layer.


American Journal of Ophthalmology | 2010

Serous Retinal Detachment Associated With Retinal Vein Occlusion

Akitaka Tsujikawa; Atsushi Sakamoto; Masafumi Ota; Yuriko Kotera; Hideyasu Oh; Kazuaki Miyamoto; Mihori Kita; Nagahisa Yoshimura

PURPOSE To study the pathomorphology of serous retinal detachment (RD) associated with retinal vein occlusion by optical coherence tomography (OCT). DESIGN Retrospective chart review. METHODS Ninety-one eyes of 91 patients with macular edema associated with retinal vein occlusion had undergone a comprehensive ophthalmologic examination, including measurement by spectral-domain OCT. RESULTS Eyes with macular edema associated with retinal vein occlusion typically showed foveal cystoid spaces and marked retinal swelling, especially in the outer retina. In addition, 76 eyes (83.5%) showed serous RD involving the fovea, which ranged in thickness from 64 microm to 871 microm (219.2 +/- 161.6 microm). Fifty-two eyes showed a small pointed RD, with a small base. The point of the RD was always located beneath the fovea, where the outer surface of the swollen neurosensory retina seemed to be contracted inward, resulting in development of the pointed RD. Two eyes with no RD at the initial visit developed such a pointed RD during follow-up. In contrast, 24 eyes showed a more dome-shaped RD, with a large base, and in 18 eyes, a pointed RD seen at the initial visit changed into a dome-shaped RD during follow-up. In some cases, small outer retinal discontinuity was seen on the external surface of the swollen neurosensory retina. CONCLUSIONS In eyes with retinal vein occlusion, a small pointed RD initially developed just beneath the fovea, but subsequently changed into a dome-shaped RD. Based on the findings by OCT, we hypothesize that the foveal architecture, especially that of the Müller cell cone, is involved in the formation of serous RD.


Ophthalmology | 2010

Optical Coherence Tomographic Evaluation of Foveal Hard Exudates in Patients with Diabetic Maculopathy Accompanying Macular Detachment

Masafumi Ota; Kazuaki Nishijima; Atsushi Sakamoto; Tomoaki Murakami; Kohei Takayama; Takahiro Horii; Nagahisa Yoshimura

OBJECTIVE To study morphologic changes of serous retinal detachment (SRD) and hyperreflective dots, which have been reported to be precursors of hard exudates, detectable in SRD using optical coherence tomography (OCT) to assess whether or not the OCT findings are correlated with the subfoveal deposition of hard exudates in patients with diabetic macular edema (DME) accompanied by SRD. DESIGN Retrospective chart review. PARTICIPANTS Twenty-eight eyes of 19 patients with DME accompanied by SRD. METHODS We imaged SRD and the hyperreflective dots in SRD using spectral domain OCT (SD-OCT). The number and distribution of the hyperreflective dots in SRD were evaluated before the initial treatment at our hospital for DME accompanied by SRD. Based on a difference in the SD-OCT findings, the study eyes were divided into 2 groups: eyes with a few dots and those with many dots. We studied the clinical course of these 2 groups to assess whether or not the findings of SRD and hyperreflective dots on the SD-OCT images were correlated with deposition of hard exudates in the subfoveal space during follow-up. MAIN OUTCOME MEASURES Correlation of the SD-OCT findings of SRD and hyperreflective dots with deposition of hard exudates in the subfovea of patients with DME accompanied by SRD. RESULTS Subfoveal deposition of hard exudates was seen in 11 of the 28 eyes at the final examination. Before initial treatment at our hospital, 14 eyes had a few hyperreflective dots SRD and 14 eyes had many hyperreflective dots. Whereas no deposition of hard exudates in the subfoveal space was seen in the former eyes, it was seen in 11 of the latter 14 eyes (P < 0.0001). In addition, using SD-OCT, we found discontinuity of the outer border of detached neurosensory retina in 9 of the 28 eyes. Of these 9 eyes, 1 was in the group with few hyperreflective dots and eight were in the group with many hyperreflective dots (P = .0046). CONCLUSIONS In patients with DME accompanied by SRD, SD-OCT revealed that hyperreflective dots may be associated with the subfoveal deposition of hard exudates during follow-up.


Ophthalmology | 2011

Foveal cystoid spaces are associated with enlarged foveal avascular zone and microaneurysms in diabetic macular edema.

Tomoaki Murakami; Kazuaki Nishijima; Atsushi Sakamoto; Masafumi Ota; Takahiro Horii; Nagahisa Yoshimura

OBJECTIVE To study the association between pathomorphology at the foveal center delineated by spectral domain optical coherence tomography (SD-OCT) and vascular changes around the fovea in fluorescein angiography (FA) in patients with diabetic macular edema (DME). DESIGN Retrospective, observational, cross-sectional study. PARTICIPANTS Consecutive series of 86 eyes from 72 patients with clinically significant macular edema (CSME) on which SD-OCT and FA were performed on the same day. METHODS Fluorescein angiography using HRA2 (Heidelberg Engineering, Heidelberg, Germany) and SD-OCT images using Spectralis OCT (Heidelberg Engineering) were obtained for all patients. Microaneurysms (MAs) in the perifoveal capillary network (PCN) and foveal avascular zone (FAZ) in the FA images were quantified. The pathomorphology at the foveal center was evaluated in OCT images. We then investigated the association between pathologic perifoveal capillaries in FA and the neuroglial morphology in OCT. MAIN OUTCOME MEASURES The relationship between pathologic changes in perifoveal capillaries in FA and foveal pathomorphology in OCT. RESULTS According to the foveal morphology in OCT images, 44 eyes presented foveal cystoid spaces (cystoid macular edema [CME]), 25 eyes had serous retinal detachment (SRD) at the foveal center, and 17 eyes had foveal thickening without cystoid spaces or retinal detachment (retinal swelling). After 3 eyes with ischemic maculopathy were excluded, the relationship was evaluated. The number of MAs in the PCN was significantly greater in eyes with CME (3.20 ± 1.76) than in eyes with SRD (0.40 ± 1.04; P < 0.01) or retinal swelling (0.47 ± 0.72; P < 0.01). In addition, the FAZ in the eyes with CME (0.553 ± 0.323 mm(2)) was significantly larger than that of the eyes with SRD (0.302 ± 0.245 mm(2); P < 0.01) or retinal swelling (0.268 ± 0.142 mm(2); P < 0.01). These associations were found in eyes with thickened posterior hyaloid membranes. CONCLUSIONS The eyes with cystoid spaces at the foveal center delineated by OCT had more MAs in the PCN and larger FAZ in FA images.


American Journal of Ophthalmology | 2010

Optical Coherence Tomographic Characteristics of Microaneurysms in Diabetic Retinopathy

Takahiro Horii; Tomoaki Murakami; Kazuaki Nishijima; Atsushi Sakamoto; Masafumi Ota; Nagahisa Yoshimura

PURPOSE To characterize microaneurysms in diabetic retinopathy (DR) depicted by spectral-domain optical coherence tomography (SD-OCT). DESIGN Retrospective, observational case series. METHODS We surveyed a consecutive series of 76 eyes from 60 patients with DR (22 mild nonproliferative diabetic retinopathy [NPDR]; 43 moderate NPDR; 9 severe NPDR; 2 proliferative diabetic retinopathy [PDR]) who underwent Spectralis OCT, fluorescein angiography (FA), and color fundus photography on the same day. The microaneurysms on OCT were oval and well demarcated at the points where those on color fundus photographs and FA were delineated. The characteristics of microaneurysms were evaluated. RESULTS Based on the status of the capsular structure shown in the sectional images of OCT (called ring sign), we classified 147 microaneurysms depicted by all of SD-OCT, FA, and color fundus photographs in 76 eyes: 28 with complete ring sign, 54 with incomplete one, and 65 with no structure. Microaneurysms with no ring sign had hyperreflective spots in the lumen and were accompanied by nearby cystoid spaces more frequently than other types (P = .033 and P = .007). Thirteen of 75 microaneurysms with nearby cystoid spaces protruded into the cystoid spaces, and 11 of those 13 microaneurysms presented with no ring sign. Microaneurysms resided mainly in the inner nuclear layer (INL) (80.3%), and 65 of such microaneurysms (55.1%) were accompanied by nearby cystoid spaces. CONCLUSIONS SD-OCT delineated the capsular structure, hyperreflective spots, and location of microaneurysms, and microaneurysms with the ring sign were positively correlated with nearby cystoid spaces and protrusion into the cystoid spaces.


Retina-the Journal of Retinal and Vitreous Diseases | 2012

Characteristics of optical coherence tomographic hyperreflective foci in retinal vein occlusion.

Ken Ogino; Tomoaki Murakami; Akitaka Tsujikawa; Kazuaki Miyamoto; Atsushi Sakamoto; Masafumi Ota; Nagahisa Yoshimura

Purpose: To evaluate the hyperreflective foci in branch retinal vein occlusion and central retinal vein occlusion depicted by spectral-domain optical coherence tomography (OCT). Methods: Consecutive series of 73 eyes of 73 patients with retinal vein occlusion (58 branch retinal vein occlusion and 15 central retinal vein occlusion) who had Spectralis OCT images obtained were retrospectively reviewed, comparing color fundus photographs and fluorescein angiography. Results: Hyperreflective foci were detected in 54 eyes (74.0%) by spectral-domain OCT, and hard exudates were detected in 17 eyes (23.3%) by color fundus photography. Hard exudates on the color photographs corresponded to the confluence of hyperreflective foci mainly around the outer plexiform layer in the unaffected areas on the spectral-domain OCT images, whereas fine hyperreflective foci were scattered in all retinal layers of the affected areas (P < 0.001). Most eyes with hyperreflective foci attached to the inner side of the external limiting membrane also had serous retinal detachment (P < 0.001). Compared with diabetic macular edema, we did not find subfoveal hard exudates in retinal vein occlusion. Conclusion: Hyperreflective foci delineated on spectral-domain OCT suggest the pathogenesis regarding the flow of extravasated blood constituents in retinal vein occlusion.


Retina-the Journal of Retinal and Vitreous Diseases | 2009

Retinal structural changes associated with retinal arterial macroaneurysm examined with optical coherence tomography.

Akitaka Tsujikawa; Atsushi Sakamoto; Masafumi Ota; Hideyasu Oh; Kazuaki Miyamoto; Mihori Kita; Nagahisa Yoshimura

Purpose: To study the retinal structural changes associated with a retinal arterial macroaneurysm and their association with visual prognosis. Methods: We studied retrospectively the medical records of 44 eyes of 44 patients with a retinal arterial macroaneurysm; all eyes showed hemorrhagic and/or exudative changes of the fovea with a visual disturbance. The retinal structural changes were examined by optical coherence tomography (OCT). Results: At the initial visit, 30 eyes (68%) showed severe hemorrhagic complications. In eyes with subretinal hemorrhage beneath the fovea, retinal structure was relatively preserved at the initial visit. At the final visit, however, foveal structure was often degenerated, especially in its outer aspect, with limited visual recovery. The 14 eyes (32%) with minimal hemorrhagic complications showed an extensive exudative change caused by the aneurysm. In 13 of these eyes, OCT examination revealed extensive retinal edema, predominantly in the outer retina. Retinal edema beneath the fovea caused a focal serous retinal detachment in 12 eyes. Eight eyes with extensive exudative change showed an accumulation of hard exudates in the macular area, and visual recovery of these eyes was often limited. Conclusion: Subretinal hemorrhage or extensive exudative change from a retinal arterial macroaneurysm can cause destruction of the foveal outer photoreceptor layer, resulting in a poor visual outcome.


Retina-the Journal of Retinal and Vitreous Diseases | 2009

Retinal sensitivity after intravitreal injection of bevacizumab for the treatment of macular edema secondary to retinal vein occlusion.

Noritatsu Yamaike; Akitaka Tsujikawa; Atsushi Sakamoto; Masafumi Ota; Yuriko Kotera; Kazuaki Miyamoto; Mihori Kita; Nagahisa Yoshimura

Purpose: To evaluate the change in macular function after intravitreal injection of bevacizumab for the treatment of macular edema associated with retinal vein occlusion. Methods: For this interventional case series, 20 eyes of 20 patients with macular edema associated with retinal vein occlusion were treated with an intravitreal injection of bevacizumab. Microperimetry in the macular area was performed with a Micro Perimeter 1 before and at 1, 3, and 6 months after treatment. Results: Improvement in macular function was detected immediately after treatment and lasted for at least 6 months. As measured by the Micro Perimeter 1, mean retinal sensitivities within the central 10° field (4.9 ± 2.7 dB at baseline) improved to 7.2 ± 3.1 dB at 1 month, to 7.6 ± 3.4 dB at 3 months, and to 7.7 ± 3.9 dB at 6 months (P < 0.001). Of the 20 eyes, a recurrence of macular edema was observed in 14 (70%), but with the use of optical coherence tomography, integrity of the outer aspect of the foveal photoreceptors was detected at 3 months to 6 months in 15 (75%) eyes. Conclusion: In eyes with macular edema associated with retinal vein occlusion, improvement in macular function was detected immediately after intravitreal injection of bevacizumab and lasted for at least 6 months.

Collaboration


Dive into the Masafumi Ota's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge