Development Of A Near-infrared Light Therapy Instrument For Central Serous Chorioretinopath

OBJECTIVE:First,to observe the protective effect of low-energy near-infrared LED light on H₂O₂ oxidative damage model of human retinal pigment epithelial cells（RPE cells）,and to explore the effects of different irradiation time,irradiation power and optical power on RPE cells.Secondly,to design a portable low-energy near-infrared light therapeutic instrument for clinical use,and verify its safety for structure of rabbit eye retina.Finally,to evaluate the safety and clinical efficacy of low-energy near-infrared laser in the treatment of central serous chorioretinopathy（CSC）in the macular area.Methods:（1）treating RPE cells with H₂O₂ to establish an oxidative damage model.The experimental grouping was designed.The single variables of each group were:irradiation time:0 min,5 min,10 min,20 min,30 min.Irradiation frequency（light interval within 24h after treatment with H₂O₂）:12h,8h,and light power:0mW/cm²,10mW/cm²,20mW/cm²,30mW/cm²,40mW/cm²,50mW/cm²,60mW/cm²,70mW/cm²,80mW/cm²,90mW/cm²,100mW/cm².Cell viability and damage rate of each group were determined by CCK-8 and LDH respectively.（2）Preliminary design of each module of portable low-energy near-infrared light therapeutic instrument,measuring its optical power,optical density distribution,spectral distribution of LED light source and attenuation in rabbit eye under different current and voltage.Then set the optical power to 0mW/cm²,10mW/cm²,30mW/cm²,50mW/cm²,70mW/cm²,100mW/cm² and irradiate the rabbit eye under the anesthesia of dilated sputum.After one week of continuous irradiation,the eyeball is taken for pathological sectioning.Observe and compare the physiological morphology of the layers of the retina.（3）38 cases of 38eyes were diagnosed in the ophthalmology department of our hospital and the leakage point was located in the macular area.According to the willingness,they were divided into groups A and B.Group A was the drug treatment group,taking Yunnan Baiyao and vitamin tablets;Group B was the laser treatment group,using drug and laser combination therapy,the laser wavelength was 810nm,the spot diameter was 3mm,the power was 50mW,the treatment time was 10min,twice a week.Visual acuity,visual field,OCT and fundus angiography results were collected before and after treatment.Results:（1）Low-energy near-infrared LED light has protective effect on oxidatively damaged RPE cells,and the effect increases with the increase of irradiation time and optical power,but the excessive irradiation time and excessive optical power are both the inhibition was exhibited,but the increase in the irradiation frequency did not show an enhancement effect.（2）The center wavelength of the LED light source was810 nm,and no damage to the retinal structure of the rabbit eye was observed when the optical power was less than 70 mW/cm².（3）Low-energy 810nm laser（λ=810nm,L=3mm,P=50mW,t=10min）is safe to irradiate the macular area of the retina and is an effective method for the treatment of medium pulp.Conclusion:Low-energy near-infrared LED light has protective effect on RPE cells,and it does not cause damage to rabbit retina structure under reasonable and effective parameters.Low energy 810nm laser（λ=810nm,L=3mm,P=50mW,t=10min）is a safe and effective method for the treatment of medium pulp.