Micropulse 577nm Laser vs Traditional Laser Treatment in Central Serous Chorioretinopathy

A Prospective Non-inferiority Study of the Use of Micropulse 577nm Laser vs Traditional Laser Treatment in Central Serous Chorioretinopathy

The purpose of this study is to observe whether micropulse laser (MPL) is noninferiority to traditional laser therapy in central serous chorioretinopathy.

Central serous chorioretinopathy (CSC) is characterized by serous detachment of neurosensory retina which can cause lose in visual acuity. Some studies have shown that traditional laser treatment (TLT) is effective on CSC, although accompanied with side-effects, such as scar. Recent retrospective studies suggest micropulse laser (MPL) therapy may also be effective without obvious complications in this disease. But to date, there is no study on effectiveness of CSC between TLT and MPL. The study is the first prospective randomized controlled trial about 577nm micropulse laser versus traditional laser treatment in central serous chorioretinopathy. It is a noninferiority study. The investigators hypothesize that application of 577nm micropulse laser in patients with CSC will prompt resolution of CSC as measured by ocular coherence tomography and best corrected visual acuity.This will be a pilot study to establish sound methods and provide some insights to the safety and efficacy of CSC treatment. The primary outcome measures is the change of BCVA in 12 week.

Central Serous Choroidopathy, Micropulse Laser Treatment, Traditional laser Treatment, optical coherence tomography

577nm subthreshold micropulse laser(577-MPL) will be performed on the areas identified on hyperfluorescent "hot spots" on the mid-phase (3 minutes) fluorescein. Multiple laser spots will be applied, covering the leakage area. Retreatment will be given in 12 weeks If SRF is not completely absorbed and CRT>= 250um.

Traditional laser will be performed of the areas identified on hyperfluorescent "hot spots" on the mid-phase (3 minutes) fluorescein.Traditional laser spots will be applied, covering the leakage area. Retreatment will be given in 12 weeks If SRF is not completely absorbed and CRT>= 250um.

9 spots multispot micropulse mode(without spacing between the spots),160 um spot size, 0.2 second duration, 5% duty cycle(ON time 0.1ms + OFF time 1.9ms), and 250~400 milliWatts of power(50% threshold power),150~200 spots, the laser area is the corresponding leakage on mid-phase FA and around leakage.

contimuous wave,100um spot size, 0.05 seconds duration, 55~60 milliwatts of power, 18~27 spots,the laser area is the corresponding leakage on mid-phase FA.

Inclusion Criteria: Patients with CSC； age>=18 years old; Duration is less than 6 months； the presence of subretinal fluid(SRF) involving the macula and detected by use of optical coherence tomography (OCT), and CRT>=250um; active leakage located at ring 2 and ring 3 (ETDRS rings) on fluorescein angiography (FA). Exclusion Criteria: Patients with no case of CSC； Patients with other macular comorbidities including but not limited to diabetic retinopathy, macular degeneration； Patients with prior retinal treatment less than 3 months； Inability to obtain photographs or to perform FA

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