Real-time OCT feedback-controlled RPE photodisruption in ex vivo porcine eyes using 8 microsecond laser pulses

Area of Science:

• Ophthalmology
• Biomedical Optics
• Laser Medicine

Background:

• Selective retinal pigment epithelium (RPE) photodisruption necessitates precise dosimetry to avoid overexposure.
• Real-time feedback dosimetry (RFD) is crucial for controlling laser-tissue interactions.

Purpose of the Study:

• To investigate optical coherence tomography (OCT) based RFD for selective RPE photodisruption.
• To evaluate the correlation between OCT-based RFD measurements and RPE cell viability.

Main Methods:

• Ex vivo porcine eyes were exposed to laser pulses (8 µs duration, 532 nm wavelength).
• Time-resolved OCT M-scans (870 nm central wavelength, 85 kHz scan rate) were used for RFD by analyzing fringe washouts.
• RPE lesion size was assessed and compared to an RPE cell viability assay.

Main Results:

• A moderate correlation was found between RPE lesion size and applied laser energy.
• The results indicate that RFD can adapt to variations in RPE pigmentation and ocular transmission.
• OCT-based RFD shows potential for real-time monitoring and control of RPE photodisruption.

Conclusions:

• OCT-based RFD is a promising method for real-time dosimetry in selective RPE photodisruption.
• The adaptive capability of RFD to individual ocular characteristics is supported by the findings.
• This technology could enhance the safety and efficacy of laser-based ophthalmic treatments.