Retinal pigment epithelial responses based on the irradiation density of selective retina therapy.
Graefes Arch Clin Exp Ophthalmol
; 259(1): 101-111, 2021 Jan.
Article
in En
| MEDLINE
| ID: mdl-32794108
ABSTRACT
PURPOSE:
We evaluated the response of the retinal pigment epithelium (RPE) to high-density (HD) or low-density (LD)-selective retina therapy (SRT) with real-time feedback-controlled dosimetry (RFD) in rabbits.METHODS:
Sixteen eyes of 8 Chinchilla Bastard rabbits underwent SRT with RFD (527-nm wavelength, 1.7-µs pulse duration), using automatically titrated pulse energy, by using optoacoustic dosimetry or real-time reflectometry. Fifty-six 25-µJ SRT, including LD-SRT (1-spot or 2-spot-spacing) and HD-SRT (4-spot, 7-spot, or 9-spot-no-spacing), were applied per eye. Color fundus photography and fundus fluorescein angiography (FFA) were used to confirm SRT spots 1-h post-SRT. Light microscopy and scanning electron microscopy (SEM) were performed at 2-h, 3-day, 7-day, and 1-month post-treatment.RESULTS:
We tested 896 spots irradiated by SRT with RFD and confirmed that SRT lesions were adequate, based on invisibility on fundoscopy and visibility on FFA. On SEM, at 2-h post-SRT, flattened RPE cells were observed in the center of the SRT lesion. While normal RPE cells were clearly observed between LD-SRT lesions, healthy RPE cells were rare in HD-SRT lesions at 2-h post-treatment. At 7-day post-SRT, SEM revealed completely restored LD-SRT lesions with small or large RPE cells with microvilli, whereas HD-SRT lesions were covered with RPE cells without microvilli. At 1-month post-SRT, SEM revealed restored RPE cells with microvilli in HD-SRT lesions. On light microscopy, both HD- and LD-SRT lesions were completely restored with adjacent RPE cells and spared photoreceptors at 1-month post-treatment.CONCLUSIONS:
Although both HD- and LD-SRT lesions had recovered at 1-month post-SRT, LD-SRT lesions healed faster than HD-SRT lesions.Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Laser Coagulation
/
Lasers, Solid-State
Limits:
Animals
Language:
En
Journal:
Graefes Arch Clin Exp Ophthalmol
Year:
2021
Type:
Article