Issei Nishiyama

Dr. Issei Nishiyama

orcid

Research Focus & Metrics

Academic Career Length

8Years (2019-Present)

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

Representative Publications

View All Publications
7 December 2023 in American Journal of Ophthalmology Case Reports
Verified
Journal Article
Open access
MSMiki Sawa
Miki Sawa
NNNorihiko Nakagawa
Norihiko Nakagawa
TSTakuya Shunto
Takuya Shunto
INIssei Nishiyama
Issei Nishiyama
To report two cases of diabetic macular edema (DME) treated with intravitreal faricimab injections (IVFs), including the assessment of retinal microaneurysms and extent of retinal capillary non-perfusion using fluorescein angiography (FA) and indocyanine green angiography (IA). Case 1: A 72-year-old man presented with aflibercept-resistant DME in the left eye, with a best-corrected visual acuity (BCVA) of 20/16. FA showed areas of retinal capillary non-perfusion and focal leakage in the macular area of the left eye. IA revealed numerous microaneurysms in the temporal region of the macula. Four consecutive monthly IVFs were administered to the left eye, and DME eventually diminished. After the loading phase, the BCVA was maintained at 20/16 with reduced visual distortion. FA showed improvement of macular leakage and stable retinal capillary non-perfusion areas, and the foveal avascular zone was clearly observed. The disappearance of numerous microaneurysms was confirmed on IA images. Case 2: An 80-year-old woman developed DME with macular vein occlusion in the left eye after panretinal laser photocoagulation for proliferative diabetic retinopathy. The patient's BCVA was 20/32. DME was resistant to subtenon triamcinolone injections. FA revealed focal areas of retinal capillary non-perfusion and persistent leakage in the macular area of the left eye. IA revealed scattered microaneurysms within the retinal arcade. Four consecutive monthly IVFs were administered to the left eye, and DME eventually diminished. After the loading phase, the BCVA was maintained at 20/32. FA showed improvement of macular leakage and stable retinal capillary non-perfusion areas. The reduction of microaneurysms was confirmed on IA images. These case reports highlight the potential of faricimab as an alternative anti-vascular endothelial growth factor drug for treatment-resistant DME, including reduction of retinal microaneurysms and stabilization of the areas of retinal capillary non-perfusion. However, continuation of a robust treatment regimen may be required to achieve these objectives.

1 September 2019 in American Journal of Ophthalmology Case Reports
Verified
Journal Article
Open access
INIssei Nishiyama
Issei Nishiyama
YOYoshinori Oie
Yoshinori Oie
KMKenji Matsushita
Kenji Matsushita
SKShizuka Koh
Shizuka Koh
AWAndrew Winegarner
Andrew Winegarner
KNKohji Nishida
Kohji Nishida
To report a case of Mycobacterium chelonae keratitis that resulted in a transient reduction of anterior chamber depth. A 46-year-old man with keratoconus and reduced visual acuity (20/286) in his left eye presented with ciliary injection 16 months after femtosecond laser-assisted penetrating keratoplasty (PK). A slit-lamp examination showed a corneal ulcer with infiltrates and edema in both the host and graft between the 3 o'clock and 6 o'clock positions. Microbiologic tests confirmed the presence of M. chelonae. Topical arbekacin and moxifloxacin, erythromycin/colistin ointment, and oral clarithromycin were prescribed. We monitored anterior chamber depth by anterior segment optical coherence tomography (AS-OCT) throughout the recovery period. The anterior chamber depth was normal before treatment, with an intraocular pressure (IOP) of 7 mmHg. Although ciliary injection and infiltrates were gradually resolved, slit-lamp examination and AS-OCT revealed an extreme reduction of anterior chamber depth without corneal perforation, 1 month after beginning treatment. The IOP was 5 mmHg, and ciliochoroidal detachment (CCD) was present. The anterior chamber increased with the resolution of CCD and keratitis. Although hypotony continued despite the resolution of CCD and keratitis, the IOP eventually recovered to ≥10 mmHg at 1 month after remission. Onset and resolution of transient reduction of anterior chamber depth presumably occurred by anterior rotation and recovery of the ciliary body, respectively. Subsequent PK triple surgery enabled visual recovery to 20/100. severe anterior segment inflammation due to infectious keratitis may cause CCD and subsequent reduction of anterior chamber depth due to anterior rotation. AS-OCT is a non-invasive and efficient tool for the evaluation of iridociliary structure and the anterior chamber in patients with infectious keratitis.

21 April 2025 in Vision
Verified
Journal Article
Open access
PDF file
NNNorihiko Nakagawa
Norihiko Nakagawa
TSTakuya Shunto
Takuya Shunto
INIssei Nishiyama
Issei Nishiyama
KMKohei Maruyama
Kohei Maruyama
MSMiki Sawa
Miki Sawa
Purpose: The purpose of this paper is to investigate the relationship between short-wavelength autofluorescence (SWAF) and infrared autofluorescence (IRAF) patterns in pachychoroid neovasculopathy (PNV) with serous retinal detachment (SRD). Methods: This study used an observational case series of 62 eyes of 58 consecutive patients diagnosed with symptomatic PNV from January 2019 and October 2021 at a single institution. SWAF and IRAF patterns were analyzed with disease chronicity, and autofluorescence changes in macular neovascularization (MNV) were assessed in two images. Results: SWAF patterns and the mean duration of symptoms were as follows: blocked (15 eyes, 24%), 1.0 months; mottled (8 eyes, 13%), 2.8 months; hyper (24 eyes, 39%), 5.0 months; hyper/hypo (10 eyes, 16%), 7.0 months; descending tract (5 eyes, 8%), 12.0 months (p < 0.01). IRAF patterns and the mean duration of symptoms were as follows: blocked (17 eyes, 27%), 1.0 months; hyper (22 eyes, 35%), 4.0 months; mixed/hyper dominant (9 eyes, 15%), 5.0 months; mixed/hypo dominant (9 eyes, 15%), 6.8 months; descending tract (5 eyes, 8%), 12.0 months (p < 0.01). Abnormal autofluorescence corresponding to MNV lesion was seen in 34 eyes (55%) with SWAF and 59 eyes (95%) with IRAF (p < 0.01). Conclusions: SWAF and IRAF show multiple patterns and are related to disease chronicity in symptomatic PNV. IRAF could be helpful in detecting the lesion of MNV.