Indocyanine green enhanced subthreshold diode-laser micropulse photocoagulation treatment of chronic central serous chorioretinopathy

Abstract

To assess the efficacy and safety of indocyanine green (ICG) dye-enhanced subthreshold diode-laser micropulse (SDM) photocoagulation in patients with chronic central serous chorioretinopathy (CCSC) with no spontaneous resolution 6 months after the onset of the disease. Interventional prospective non-comparative case series of seven patients presenting with CCSC with well-defined active leaking sites (ALS) suitable for laser treatment and with serous neuroepithelial detachment persisting for 6 or more months. SDM treatment was performed 15 minutes after the injection of 25 mg of ICG in 2 cc of 5% glucose solution. ALS were treated with a series of 50 500-ms exposures separated by 500-ms pauses. Each 500-ms exposure delivered a train of 250 micropulses at 10% duty cycle and 500 mW power. ICG angiographic images were taken after the treatment without new ICG injection, to check for the presence of laser-induced spots of background hypofluorescence at the treated leakage sites. Within 7-14 days after treatment, all the patients showed improved visual acuity and reduction of serous neuroepithelial detachment on OCT. No signs of laser lesions were visible at fundus examination and on fluorescein angiography. In a period ranging from 4 to 8 weeks, the neuroepithelial detachment was completely resolved in five patients and reduced in two patients. At the 12-month follow-up visits, no recurrence had occurred in the patients, with resolution of the serous neuro-epithelial detachment, and no worsening of the serous detachment or of VA was noted in the patients with incomplete recovery. These preliminary results suggest that ICG dye-enhanced SMD photocoagulation appears to be an effective treatment, and can represent a viable approach for the management of CSCC with persistent serous neuroepithelial detachment. Post-treatment ICG angiography, without new ICG dye injection, can be used to verify the placement of the SDM laser applications.