Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2021 Jun 1;41(6):1302-1308.
doi: 10.1097/IAE.0000000000003032.

THE LOSS OF INFRARED LIGHT SENSITIVITY OF PHOTORECEPTOR CELLS MEASURED WITH TWO-PHOTON EXCITATION AS AN INDICATOR OF DIABETIC RETINOPATHY: A Pilot Study

Grzegorz Łabuz  1 , Asu Rayamajhi  1 , Ramin Khoramnia  1 , Grażyna Palczewska  2   3 , Krzysztof Palczewski  2   3 , Andreas Holschbach  4 , Gerd U Auffarth  1
Affiliations

THE LOSS OF INFRARED LIGHT SENSITIVITY OF PHOTORECEPTOR CELLS MEASURED WITH TWO-PHOTON EXCITATION AS AN INDICATOR OF DIABETIC RETINOPATHY: A Pilot Study

Grzegorz Łabuz et al. Retina. .

Abstract

Purpose: Human photoreceptors are sensitive to infrared light (IR). This sensitivity can be used as a novel indicator of retinal function. Diabetic retinopathy patients were assessed using in vivo two-photon excitation and compared their scotopic IR threshold with that of healthy patients.

Methods: Sixty-two participants, 28 healthy and 34 with diabetic retinopathy, underwent a comprehensive eye examination, where visual acuity and contrast sensitivity were assessed. Infrared thresholds were measured in the fovea and parafovea following 30-minute dark adaptation. A two-photon excitation device was used with integrated pulsed laser light (1,045 nm) for sensitivity testing and scanning laser ophthalmoscopy for fundus imaging.

Results: The mean Snellen visual acuity of diabetic patients (6/7.7) was worse than that of the healthy patients (6/5.5), which was significantly different (P < 0.001). Disease patients had decreased contrast sensitivity, especially at 6 and 18 cycles/degree. The mean retinal sensitivity to IR light in eyes with diabetic retinopathy (11.6 ± 2.0 dB) was significantly (P < 0.001) lower than that in normal eyes (15.5 ± 1.3 dB).

Conclusion: Compared with healthy control subjects, the IR light sensitivity of diabetic patients was significantly impaired. Two-photon measurements can be used in the assessment of retinal disease, but further studies are needed to validate IR light stimulation in various stages of diabetic retinopathy.

PubMed Disclaimer

Conflict of interest statement

K. Palczewski is a Chief Scientific Officer and receives consulting fees from Polgenix, Inc. G. Palczewska owns a patent on systems and methods of infrared psychophysical measurement. G.U. Auffarth and R. Khoramnia report grants, lecture fees, and nonfinancial support from Alcon, grants, lecture fees, and nonfinancial support from Oculentis, grants from Carl Zeiss Meditec, grants, lecture fees, and nonfinancial support from Hoya, grants and nonfinancial support from Kowa, grants and nonfinancial support from Ophtec, grants from Physiol, grants from Powervision, grants, lecture fees, and nonfinancial support from Rayner, grants, lecture fees, and nonfinancial support from SIFI, grants, lecture fees, and nonfinancial support from Johnson&Johnson, grants from Acufocus, and lecture fees, and nonfinancial support from Polytech. The remaining authors have no financial/conflicting interests to disclose.

Figures

Fig. 1.
Fig. 1.
Log contrast sensitivity of healthy and diabetic retinopathy patients measured at four spatial frequencies. *Statistically significant differences (t-test; P < 0.05); error bars = standard deviation.
Fig. 2.
Fig. 2.
Infrared light sensitivity maps of healthy (upper panels) and diabetic retinopathy (lower panels) overlaid on exemplary fundus images with respective OCT scans.
Fig. 3.
Fig. 3.
Infrared light sensitivity as a function of age. The comparison between healthy (black circles) and diabetic retinopathy (red crosses) patients. The solid lines refer to a linear regression model.
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. Griffin DR, Hubbard R, Wald G. The sensitivity of the human eye to infra-red radiation. J Opt Soc Am 1947;37:546–554. - PubMed
    1. Palczewska G, Vinberg F, Stremplewski P, et al. . Human infrared vision is triggered by two-photon chromophore isomerization. Proc Natl Acad Sci U S A 2014;111:E5445–E5454. - PMC - PubMed
    1. Ruminski D, Palczewska G, Nowakowski M, et al. . Two-photon microperimetry: sensitivity of human photoreceptors to infrared light. Biomed Opt Express 2019;10:4551–4567. - PMC - PubMed
    1. Ding J, Wong TY. Current epidemiology of diabetic retinopathy and diabetic macular edema. Curr Diab Rep 2012;12:346–354. - PubMed
    1. Saeedi P, Petersohn I, Salpea P, et al. . Global and regional diabetes prevalence estimates for 2019 and projections for 2030 and 2045: results from the international diabetes federation diabetes atlas. Diabetes Res Clin Pract 2019;157:107843. - PubMed