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

Burri, Christian; Salzmann, Simon Adrian; Amstutz, Mylène; Hoffmann, Leonie; Povazay, 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:	School of Engineering and Computer Science > Institute for Human Centered Engineering (HUCE) School of Engineering and Computer Science > Institute for Human Centered Engineering (HUCE) > HUCE / Laboratory for Optics School of Engineering and Computer Science
Name:	Burri, Christian0000-0003-2690-7527; Salzmann, Simon Adrian0000-0001-5453-8808; Amstutz, Mylène; Hoffmann, Leonie; Povazay, Boris0000-0001-5571-5116; Meier, Christoph and Frenz, Martin
Subjects:	R Medicine > R Medicine (General) R Medicine > RE Ophthalmology T Technology > T Technology (General)
ISSN:	2075-1729
Publisher:	MDPI
Language:	English
Submitter:	Christian Burri
Date Deposited:	07 Jul 2023 11:39
Last Modified:	09 Jul 2023 01:37
Publisher DOI:	10.3390/life13061314
ARBOR DOI:	10.24451/arbor.19561
URI:	https://arbor.bfh.ch/id/eprint/19561