Power-controlled temperature guided retinal laser therapy.

Laser photocoagulation has been a treatment method for retinal diseases for decades. Recently, studies have demonstrated therapeutic benefits for subvisible effects. A treatment mode based on an automatic feedback algorithm to reliably generate subvisible and visible irradiations within a constant irradiation time is introduced.

Lesion strength control by automatic temperature guided retinal photocoagulation.

Laser photocoagulation is an established treatment for a variety of retinal diseases. However, when using the same irradiation parameter, the size and strength of the lesions are unpredictable due to unknown inter- and intraindividual optical properties of the fundus layers. The aim of this work is to investigate a feedback system to generate desired lesions of preselectable strengths by automatically controlling the irradiation time.

Temperature-Controlled Retinal Photocoagulation Reliably Generates Uniform Subvisible, Mild, or Moderate Lesions.

Purpose: Conventional retinal photocoagulation produces irregular lesions and does not allow reliable control of ophthalmoscopically invisible lesions. We applied automatically controlled retinal photocoagulation, which allows to apply uniform lesions without titration, and aimed at five different predictable lesion intensities in a study on rabbit eyes.

Methods: A conventional 532-nm photocoagulation laser was used in combination with a pulsed probe laser.

Photocoagulation in rabbits: optical coherence tomographic lesion classification, wound healing reaction, and retinal temperatures.

Background And Objective: The rabbit is the most common animal model to study retinal photocoagulation lesions. We present a classification of retinal lesions from rabbits, that is based on optical coherence tomographic (OCT) findings, temperature data, and OCT-follow-up data over 3 months.

Materials And Methods: Four hundred eighty-six photocoagulation lesions (modified Zeiss Visulas® 532 nm CW laser, lesion diameter 133 µm, exposure duration 200  milliseconds or variable, power variable) were analyzed from six eyes of three chinchilla gray rabbits.

Correlation of temperature rise and optical coherence tomography characteristics in patient retinal photocoagulation.

We conducted a study to correlate the retinal temperature rise during photocoagulation to the afterward detected tissue effect in optical coherence tomography (OCT). 504 photocoagulation lesions were examined in 20 patients. The retinal temperature increase was determined in real-time during treatment based on thermoelastic tissue expansion which was probed by repetitively applied ns laser pulses.

Real-time temperature determination during retinal photocoagulation on patients.

The induced thermal damage in retinal photocoagulation depends on the temperature increase and the time of irradiation. The temperature rise is unknown due to intraocular variations in light transmission, scattering and grade of absorption in the retinal pigment epithelium (RPE) and the choroid. Thus, in clinical practice, often stronger and deeper coagulations are applied than therapeutically needed, which can lead to extended neuroretinal damage and strong pain perception.

Temperature-controlled retinal photocoagulation--a step toward automated laser treatment.

Purpose: Retinal laser photocoagulation carries the risk of overtreatment due to effect variation of identically applied lesions. The degree of coagulation depends on the induced temperature increase and on exposure time. We introduce temperature controlled photocoagulation (TCP), which uses optoacoustics to determine individually exposure times necessary to create reproducible lesions.