Evaluation of glaucoma using the PhNR based on electrophysiological techniques.

• Project/Area Number: 20K18385
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 56060:Ophthalmology-related
• Research Institution: University of Miyazaki
• Principal Investigator: Hidaka Takako 宮崎大学, 医学部, 助教 (00751140)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Project Status: Completed (Fiscal Year 2022)
• Budget Amount: ¥3,510,000 (Direct Cost: ¥2,700,000、Indirect Cost: ¥810,000); Fiscal Year 2022: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000); Fiscal Year 2021: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000); Fiscal Year 2020: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000)
• Keywords: PhNR / レチバル / 網膜内層機能 / 緑内障 / 網膜電図 / 電気生理

Outline of Research at the Start

日本人の成人の失明原因第1位である緑内障の現在確実な治療法は眼圧下降であるが、 眼圧下降治療に抵抗する症例も多く今後さらなる原因の解明が必要と考えられる。
現在緑内障検査として網膜内層機能を評価する実用的な他覚的検査法は少ない。本研究では電気生理学的手法を用いた他覚的な網膜内層機能検査であるPhotopic negative response (PhNR)を、血流を含めた他検査との関係を解析検討することで新たな緑内障検査として確立されることが期待される。

Outline of Final Research Achievements

The PhNR was measured in 76 control eyes and 90 eyes with primary open-angle glaucoma (POAG) including normal tension glaucoma (30 eyes in the early stage and 60 eyes in the moderate to advanced stage) using a RETeval hand-held electroretinogram (ERG) measuring device (LKC Technologies) with a less invasive skin electrode. We used 5 PhNR parameters (base to trough (BT), peak to trough (PT), 72msPhNR, W-ratio, and P-ratio). We also examined the correlation between the PhNR and retinal nerve fiber layer thickness measured by optical coherence tomography and visual field test. The results showed that PhNR correlated significantly with visual field and retinal nerve fiber layer thickness. BT had the best diagnostic performance in both early and moderate to advanced stages. No significant correlation was found between blood flow and the PhNR in this study.

Academic Significance and Societal Importance of the Research Achievements

本研究では緑内障の有無を調べる判別一次関数をPhNRパラメーターの中で最も診断能力が高かったBTで以下のように定量的に求めることができた。BT: 判別式 = 0.505 x BT + 2.017; 正で疾患あり。正解率 = 80.7%。 PhNRの閾値を出した報告はわれわれが調べた限りいまだなく、より定量的に緑内障の有無を調べることが可能となった学術的意義があると考えている。またPhNRをレチバルを用い測定したことにより、小児や緑内障術後の患者に対し簡便に網膜内層機能評価を行う足がかりとなった。将来的に視野検査が困難な症例に対する緑内障の評価法として発展させる社会的意義も見いだせた。

Research Products

• [Presentation] Evaluation of inner retinal function at different stages of primary open angle glaucoma using the PhNR measured by RETeval electroretinography (2023)
  • Author(s): Takako Hidaka, MD, PhD, Hideki Chuman, MD, PhD, Yasuhiro Ikeda, MD, PhD
  • Organizer: The 60th ISCEV meeting in Kyoto
  • Int'l Joint Research
• [Presentation] The usefulness of the PhNR using the RETeval device for evaluation of inner retinal function (2023)
  • Author(s): Takako Hidaka, MD, PhD, Hideki Chuman, MD, PhD, Yasuhiro Ikeda, MD, PhD
  • Organizer: Fujiretina 2023
  • Int'l Joint Research
• [Presentation] Evaluation of inner retinal function of glaucoma in different stage using photopic negative response measured by RETeval portable electroretinogram. (2022)
  • Author(s): Takako Hidaka, MD, PhD, Hideki Chuman, MD, PhD, Yasuhiro Ikeda, MD, PhD
  • Organizer: the 15th Joint Meeting of Chinese- Japanese- Korean Ophthalmologists
  • Int'l Joint Research
• [Presentation] RETevalを用いたPhNRによる開放隅角緑内障の病期別視機能評価の有用性の検討 (2021)
  • Author(s): 日髙 貴子
  • Organizer: 第75回日本臨床眼科学会
• [Presentation] Evaluation of the clinical utility of PhNR in different stages of glaucoma using RETeval. (2021)
  • Author(s): Takako Hidaka
  • Organizer: the 14th Joint Meeting of Japan-China-Korea Ophthalmologists.
  • Int'l Joint Research