Seika Den

Dr. Seika Den


Research Focus & Metrics

Academic Career Length

11Years (2016-Present)

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

Representative Publications

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Verified
Journal Article
Open access
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MSMegumi Shinzawa
Megumi Shinzawa
Murat DogruMurat Dogru
Murat Dogru
SDSeika Den
Seika Den
TITakehiro Ichijima
Takehiro Ichijima
KHKazunari Higa
Kazunari Higa
Jun ShimazakiJun Shimazaki
Jun Shimazaki
Purpose: Sjögren syndrome (SS) is a chronic inflammatory autoimmune disease of the lacrimal and salivary glands. This study compared the concentrations of epidermal fatty-acid binding protein (E-FABP) in the saliva, serum, and tears of SS patients with dry eye and dry mouth, with those of healthy adults to investigate the usefulness of E-FABP as a diagnostic marker for SS. Design: Prospective, observational case series. Participants: The subjects were 11 new patients with untreated Sjogren syndrome and 12 healthy control individuals. Methods: The diagnosis of SS was in accordance with the Ministry of Health, Labour and Welfare (Japan) Diagnostic Criteria (1999). Saliva, serum, and tear specimens were collected during internal medicine, dental, and ophthalmological examinations. The ophthalmological tests included the Dry Eye-related Quality of life Score (DEQS), tear break-up time (BUT), vital staining with fluorescein (FS) and lissamine green (LG), and the Schirmer test-1. The E-FABP concentration in the tears, saliva, and serum was measured by enzyme-linked immunosorbent assay (ELISA). Main outcome measure: The E-FABP concentrations were compared between patients and controls. Results: There were significant differences between the patient and healthy control groups in all ophthalmological test results. There were no significant differences between the groups in the E-FABP concentrations in the saliva (p = 0.1513) or the serum (p = 0.4799), but the E-FABP concentration in the tears significantly differed between groups. The E-FABP concentration in tears tended to be significantly lower in patients with SS (mean, 323.5 ± 325.6 pg/mL) than healthy control subjects (mean, 4076 pg/mL; p = 0.0136). The E-FABP concentration in tears significantly correlated with the results of dry eye parameters. Conclusion: The E-FABP concentration in tears appears to be related to ocular surface epithelial damage and tear stability and may be a promising novel biomarker in the diagnosis of SS.

1 April 2018 in Journal of Cataract & Refractive Surgery
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Journal Article
Closed access
SDSeika Den
Seika Den
SSShigeto Shimmura
Shigeto Shimmura
JSJun Shimazaki
Jun Shimazaki
To assess the efficacy and safety of cataract surgery after deep anterior lamellar keratoplasty (DALK) and penetrating keratoplasty (PKP). Tokyo Dental College Ichikawa General Hospital, Chiba, Japan. Retrospective case series. Age-matched and disease-matched eyes that had phacoemulsification and intraocular lens insertion after DALK or PKP were studied. Graft clarity was assessed at the final follow-up. The difference in the endothelial cell density (ECD), corrected distance visual acuity (CDVA), spherical equivalence, and refractive error between the expected values and values 1, 3, 6, and 12 months after cataract surgery were compared between the 2 groups. Indications for keratoplasty were corneal stromal scar (22 eyes), lattice dystrophy (2 eyes), keratoconus (2 eyes), and postherpetic keratitis (4 eyes). All 30 eyes in each group had successful cataract surgery after keratoplasty. Graft clarity rates were 90.0% and 80.0% in the DALK group and PKP group, respectively (P = .47). The decrease in ECD at 12 months was significantly greater in the PKP group than in the DALK group (8.7% [SD] ± 21.7% versus 26.3% ± 27.8%) (P = .043). The CDVA was significantly improved in both groups. At 1 month, the mean refractive error was -0.5 diopter (D) ± 2.4 (SD) in the DALK and -0.4 ± 1.9 D in the PKP groups and remained stable thereafter. Cataract surgery was successfully performed in eyes that had DALK or PKP, providing excellent visual and refractive outcomes. In cases of combined cataract and corneal pathology, and in the absence of endothelial involvement, DALK followed by cataract surgery might cause less endothelial damage.

6 October 2016 in BMC Ophthalmology
Verified
Journal Article
Open access
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Jun ShimazakiJun Shimazaki
Jun Shimazaki
CSChika Shigeyasu
Chika Shigeyasu
YSYumiko Saijo-Ban
Yumiko Saijo-Ban
Murat DogruMurat Dogru
Murat Dogru
SDSeika Den
Seika Den
To assess the efficacy of bandage contact lens (BCL) application to promote epithelialization and alleviate pain following corneal transplantation. Twenty-six consecutive patients who underwent corneal transplantation were randomly assigned to undergo BCL application (BCL group, n = 14) or no BCL application (control group, n = 12) at the end of the surgery. Corneal epithelialization was analyzed by photography using fluorescein staining, and ocular pain was measured using a visual analog scale. The mean size of the epithelial defect relative to the graft area in the BCL group was 21.80 ± 35.10 % at the end of surgery, 18.20 ± 31.10 % on postoperative day 1, and 5.45 ± 11.10 % on postoperative days 3 to 5. These values in the control group were 9.64 ± 17.60 % at the end of surgery, 11.50 ± 25.70 % on postoperative day 1, and 0.00 ± 0.00 % on postoperative days 3 to 5. There were no significant differences in the speed of epithelialization between the two groups. The mean preoperative pain score in the BCL group was slightly higher than that control (4.27 ± 1.96 vs. 2.41 ± 2.18, respectively; P = 0.039). The scores significantly increased on postoperative day 1 and promptly returned to preoperative levels by day 7 in both groups, and there were no significant differences between the groups. No significant benefits of BCL application at the time of corneal transplantation were observed in this study. The efficacy and safety of BCLs in eyes with compromised epithelialization require further study. UMIN 000019091 . Date of registration: 2015/09/22

5 October 2020 in Diagnostics
Verified
Journal Article
Open access
PDF file
Jun ShimazakiJun Shimazaki
Jun Shimazaki
MSMiki Sakata
Miki Sakata
SDSeika Den
Seika Den
MIMiki Iwasaki
Miki Iwasaki
ITIkuko Toda
Ikuko Toda
We studied the efficacy and safety of a handheld osmolarity measurement system (I-PEN) in Japanese patients with dry eye disease (DED) and non-DED subjects. In this prospective, multicenter study, tear osmolarity was examined using the I-PEN in a total of 122 eyes divided into DED (n = 71) and non-DED (n = 51) groups. Subjective symptoms were assessed using the Dry Eye-Related Quality-of-Life Score (DEQS) questionnaire. Ocular surface condition was evaluated in terms of fluorescein tear breakup time (FBUT) and tear breakup pattern (TBUP), and by fluorescein staining and Schirmer’s test. The I-PEN measurements were performed safely in the majority of cases. There was no statistically significant difference in mean tear film osmolarity between the DED and non-DED groups (294.76 ± 16.39 vs. 297.76 ± 16.72 mOsms/L, respectively, p = 0.32). No significant correlations were observed between osmolarity values and DEQS score, FBUT, or the Schirmer score. Osmolarity did not differ among TBUP subgroups. This prospective clinical study found no correlations between the tear film osmolarity values obtained with the I-PEN system and any subjective or objective parameters of DED. Further studies are required to determine the utility of the I-PEN system in other settings.

4 September 2026 in Journal of Clinical Medicine
Verified
Journal Article
Open access
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MKMutsumi Koyama
Mutsumi Koyama
SDSeika Den
Seika Den
ABAkinori Baba
Akinori Baba
HAHirokazu Ashida
Hirokazu Ashida
MKMASAO KOBAYASHI
MASAO KOBAYASHI
TNTadashi Nakano
Tadashi Nakano
Objectives: To characterize the frequency and temporal patterns of anterior segment findings after radiotherapy for sinonasal and nasopharyngeal cancer, with particular focus on anterior segment neovascularization and its association with superselective intra-arterial cisplatin infusion with concurrent radiotherapy (RADPLAT). Methods: We retrospectively reviewed 113 patients treated with intensity-modulated radiotherapy between 2019 and 2022. Anterior segment findings were evaluated using the whole cohort as the denominator and among patients referred for ocular symptoms. Cumulative incidence was estimated with death as a competing risk using the Aalen–Johansen estimator and compared using Gray’s test. Results: Median follow-up was 1666 days. Forty-seven patients (41.6%) were referred to ophthalmology. Anterior segment findings occurred in 16/60 patients (26.7%) with nasal cavity cancer and 13/31 (41.9%) with maxillary sinus cancer (p = 0.16); 5-year cumulative incidences were 27.7% and 46.1%, respectively (p = 0.018). Anterior segment neovascularization occurred in 7/113 patients (6.2%), including 6/21 (28.6%) treated with RADPLAT and 1/92 (1.1%) without RADPLAT (p < 0.001); 5-year cumulative incidences were 31.4% and 1.4%, respectively (p < 0.001). Among patients with maxillary sinus cancer, neovascularization occurred in 5/19 RADPLAT-treated patients and 0/12 non-RADPLAT patients (p = 0.13); however, median follow-up was substantially shorter in the non-RADPLAT group (385 vs. 1784 days). Neovascularization developed late (median, 975 days), and four affected patients had final best-corrected visual acuity below 0.05. Conclusions: Anterior segment findings showed distinct temporal patterns after radiotherapy. Late, vision-threatening neovascularization was strongly associated with RADPLAT, although causality cannot be established because treatment selection was confounded by tumor site, disease extent, orbital invasion, and radiotherapy characteristics. These findings identify anterior segment neovascularization as an important safety signal warranting prospective evaluation. Standardized baseline ophthalmological assessment, long-term surveillance, and patient-level ocular dosimetry are needed to clarify mechanisms and define appropriate follow-up strategies.

Verified
Journal Article
Open access
PDF file
SDSeika Den
Seika Den
YAYukako Abukawa
Yukako Abukawa
NKNanami Kishimoto
Nanami Kishimoto
RSRyuichi Shimada
Ryuichi Shimada
HYHigashi Yuka
Higashi Yuka
TNTadashi Nakano
Tadashi Nakano
Background: Recessive dystrophic epidermolysis bullosa (RDEB) is a rare inherited disorder characterized by extreme epithelial fragility and progressive cicatrization, frequently leading to severe ocular surface disease and early visual impairment. Surgical interventions such as ocular surface reconstruction (OSR) in childhood are often delayed because of anesthetic risks and concerns regarding recurrence. Consequently, the effectiveness of OSR, including amniotic membrane transplantation (AMT), and its impact on visual development remain poorly documented. Methods: We report a case series of two pediatric patients (three eyes) with genetically confirmed RDEB who underwent single-step OSR using AMT. Clinical outcomes, long-term visual acuity, perioperative management, and histopathological findings were evaluated. Results: Ocular manifestations included corneal epithelial damage, symblepharon, and pseudopterygium extending over the cornea. One patient underwent symblepharon lysis, superficial keratectomy, and AMT onto the bare sclera in the right eye at age 4 and in the left eye at age 8, both under intubated general anesthesia. The other patient underwent the same procedure in the right eye at age 6. Best spectacle-corrected visual acuity improved from ≤20/300 to 20/30 in all eyes, and pupillary zone clarity was maintained during the follow-up period (up to 6 years). Histopathology confirmed pseudopterygium with squamous metaplasia, goblet cell loss, and fibrovascular stroma. Safe general anesthesia was achieved through meticulous multidisciplinary perioperative planning involving anesthesiologists, dermatologists, and pediatricians. No systemic complications related to anesthesia or perioperative management were observed. Conclusions: Single-step OSR with on-lay AMT can restore and preserve visual function in pediatric RDEB. Early surgical intervention may prevent profound amblyopia and provide durable ocular surface stability. A multidisciplinary approach enables safe general anesthesia and perioperative management.