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Selective targeting of the retinal pigment epithelium in rabbit eyes with a scanning laser beam
- Source :
- Investigative ophthalmologyvisual science. 48(4)
- Publication Year :
- 2007
-
Abstract
- PURPOSE. Selective targeting of the retinal pigment epithelium (RPE) with repetitive laser pulses that minimize thermal damage to the adjacent photoreceptors is a promising new therapeutic modality for RPE-related retinal diseases. The selectivity of an alternative, more versatile scanning approach was examined in vivo by using a broad range of scanning parameters. METHODS. Acousto-optic deflectors repeatedly scanned the focus of a continuous wave (cw)-laser across the retina of Dutch belted rabbits, producing microsecond irradiation at each RPE cell. Two irradiation patterns forming separated lines (SEP) or interlaced lines (INT), different dwell times (2.5‐75 s), and repetition numbers (10 and 100 scans with 100-Hz repetition rate) were tested. Thresholds were evaluated by fundus imaging and angiography. Histology was performed for selected parameters. RESULTS. Selective RPE cell damage was obtained with moderate laser power. The angiographic threshold power decreased with pulse duration, number of exposures, and applying the INT pattern. Ophthalmoscopic thresholds, indicating onset of thermal coagulation, were higher than twice the angiographic threshold for most tested parameters. Histology confirmed selective RPE cell damage for SEP irradiation with 7.5 and 15 s; slower scan speeds or closed lines caused photoreceptor damage. CONCLUSIONS. A cw-laser scanner can be set up as a highly compact and versatile device. Selective RPE damage is feasible with dwell times up to 15 s. Greatest selectivity is achieved with short exposure times and separated scan lines. Interlaced lines and long exposure times facilitate heat conduction into photoreceptors. A scanner is an attractive alternative for pulsed selective targeting, because both selective targeting and thermal photocoagulation can be realized. (Invest Ophthalmol Vis Sci. 2007;48:1782‐1792) DOI:10.1167/iovs.06-0797
- Subjects :
- Materials science
Fundus (eye)
Retina
law.invention
Ophthalmoscopy
chemistry.chemical_compound
Eye Injuries
law
medicine
Animals
Fluorescein Angiography
Pigment Epithelium of Eye
Cell damage
Balayage
Retinal pigment epithelium
Laser Coagulation
medicine.diagnostic_test
Retinal
Anatomy
Laser
medicine.disease
medicine.anatomical_structure
chemistry
sense organs
Rabbits
Biomedical engineering
Photoreceptor Cells, Vertebrate
Subjects
Details
- ISSN :
- 01460404
- Volume :
- 48
- Issue :
- 4
- Database :
- OpenAIRE
- Journal :
- Investigative ophthalmologyvisual science
- Accession number :
- edsair.doi.dedup.....cc68b5514eab4486939418d0c205bc4d