Central Serous Chorioretinopathy: Morphological and Functional Outcome after Subthreshold Thermal Laser Coagulation...

Central serous chorioretinopathy (CSCR) presents itself as a serous detachment of the central neurosensory retina (NR), which may be accompanied by focal detachment of the retinal pigment epithelium (RPE) and changes in the RPE itself. It is often self-limiting; however, if the macular region is affected, visual impairment can be serious. If spontaneous remission does not occur, data on the effectiveness of further treatment options are sparse. We therefore decided to examine the effectiveness of subthreshold laser photocoagulation (ST-LP) on best-corrected visual acuity (BCVA) and subretinal fluid (SRF) resorption. We conducted a retrospective analysis of all patients who underwent ST-LP based on the diagnosis of CSCR in a German university eye hospital from 2009 to 2014.

The diagnosis of CSCR was based on the following criteria: detachment of the NR and possibly the RPE visible on ophthalmoscopy, evidence of SRF on optical coherence tomography (OCT), visualization of one or more source points typical for CSCR in fluorescein angiography, and exclusion of differential diagnoses. The time between the anamnestic onset of symptomatic complaints and ST-LP was determined as well as BCVA and OCT before ST-LP. ST-LP was performed as a subthreshold thermal laser coagulation with a frequency-doubled Nd:YAG continuous-wave laser. Follow-up examinations were scheduled at 4, 8, and 12 weeks after ST-LP.

Fifty-four eyes of 49 patients were included in the study. The median age of patients was 47 years. Eighty-nine percent of the included patients were male. Twenty percent of patients had a first manifestation of CSCR, 69% had a recurrence, and 11% had persistent SRF for >6 months. The median visual acuity rose from 0.30 at baseline (BL) to 0.10 at 4 weeks and 0.00 at 8 weeks, before dropping slightly to 0.05 at 12 weeks. Changes of visual acuity in comparison to BL were statistically significant (p < 0.05). The initial median retinal thickness of 397 μm at BL decreased to 264 μm at 4 weeks, to 236 μm at 8 weeks, and to 239 μm at 12 weeks (decreases to BL all statistically significant p < 0.05).

In our cohort, we were able to achieve substantial and significant clinical benefit through ST-LP measured by improvement in BCVA. Furthermore, we were also able to demonstrate measurable, significant morphological improvements as decreased retinal thickness and increased resorption of SRF as probable mechanisms explaining clinical improvement of CSCR with ST-LP. The advantage of ST-LP over other methods is the low risk of adverse events and its high availability. Controlled, randomized studies are necessary to confirm the data and demonstrate the effect over a longer period of time.