Investigation of the Influence of Pulse Duration and Application Mode on Microsecond Laser Microsurgery of the Retinal Pigment Epithelium

Burri, Christian; Salzmann, Simon; Amstutz, Mylène; Hoffmann, Leonie; Považay, Boris; Meier, Christoph; Frenz, Martin (2023). Investigation of the Influence of Pulse Duration and Application Mode on Microsecond Laser Microsurgery of the Retinal Pigment Epithelium. Life, 13(6), p. 1314. MDPI 10.3390/life13061314

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Optical microsurgery confined to the retinal pigment epithelium (RPE) requires locally optimized laser parameters and reliable real-time feedback dosimetry (RFD) to prevent unwanted neuroretinal overexposure. This study aimed to compare pulses of different durations and application modes (single, ramp, burst). Moreover, optical coherence tomography (OCT)-based RFD was investigated in an ex vivo experiment, utilizing nine porcine eyes that were exposed to laser pulses of 8, 12, 16 and 20 µs duration (wavelength: 532 nm, exposure area: 90 × 90 µm2, radiant exposure: 247 to 1975 mJ/µm2). Simultaneously, time-resolved OCT M-scans were recorded (central wavelength: 870 nm, scan rate: 85 kHz) for RFD. Post irradiation, retinal changes were assessed with color fundus photography (CFP) and cross-sectional OCT B-scans. RPE cell damage was quantified via fluorescence-based cell viability assay and compared to the OCT dosimetry feedback. Our experiments indicate cumulative RPE damage for pulse bursts of 16 µs and 20 µs, whereas no cumulative effects were found for pulse durations of 8 µs and 12 µs applied in ramp mode. According to statistical analysis, OCT-RFD correctly detected RPE cell damage with 96% sensitivity and 97% specificity using pulses of 8 µs duration in ramp mode.

Item Type:

Journal Article (Original Article)

Division/Institute:

08 Faculty of Science > Institute of Applied Physics > Biomedical Photonics
08 Faculty of Science > Institute of Applied Physics

UniBE Contributor:

Burri, Christian, Frenz, Martin

Subjects:

500 Science > 570 Life sciences; biology
600 Technology > 610 Medicine & health
600 Technology > 620 Engineering
000 Computer science, knowledge & systems
500 Science > 530 Physics

ISSN:

2075-1729

Publisher:

MDPI

Language:

English

Submitter:

Simone Corry

Date Deposited:

06 Jun 2023 10:15

Last Modified:

11 Jun 2023 02:21

Publisher DOI:

10.3390/life13061314

BORIS DOI:

10.48350/183179

URI:

https://boris.unibe.ch/id/eprint/183179

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