Morphological and functional outcome after subthreshold laser coagulation with a frequency-doubled Nd:YAG laser
Reviewed by Sofia Rokerya

This retrospective study examines the effectiveness of subthreshold laser photocoagulation (ST-LP) on best-corrected visual acuity (BCVA) and subretinal fluid (SRF) resorption. Fifty-four eyes of 49 patients were included in the study. The median age of patients was 47 years (range 31-70 years). Eighty-nine percent of the included patients were male and 11% were female. Central serous chorioretinopathy (CSCR) affected only the right eye in 15%, only the left eye in 28%, and both eyes in 57%. Of the eyes treated, 46% were the right eye, and 54% the left eye. Twenty percent of patients had a first manifestation of CSCR, 69% had a recurrence and 11% had persistent SRF for >6 months. Arterial hypertension was present in 35%, hyperlipoproteinemia in 38%, and systemic steroid use in 6% of patients. Fifteen percent of patients had one previous laser treatment and 2% had two previous treatments. One patient (2%) had received prior photodynamic therapy (PDT). The median duration to ST-LP was nine weeks since the symptom onset, ranging from a minimum of one week to a maximum of 261 weeks. The median duration between onset and time of ST-LP was 31.5 days (minimum three, maximum 423 days). A median of nine, a minimum of two, and a maximum of 60 laser foci were applied. The median visual acuity rose from 0.30 logMAR at baseline (BL) to 0.10 at four weeks and 0.00 at eight 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 four weeks, to 236 μm at eight weeks, and to 239 μm at 12 weeks (decreases from BL all statistically significant p < 0.05). The authors recommend that the subthreshold laser treatment using frequency-doubled Nd:YAG laser with a wavelength of 532 nm, is safe and readily available due to its broad spectrum of applications. After subthreshold laser treatment, there is a rapid, pronounced decrease of SRF and a corresponding marked increase in BCVA. Follow-up examinations do not show any morphologically visible structural damage to the retina or scarring. Limitations of this study: Retrospective nature. Due to lack of a control group, it cannot be excluded that the improvement of visual acuity could have been due to the natural course of the disease. Lacks long-term follow-up.

Central serous chorioretinopathy: morphological and functional outcome after subthreshold laser coagulation with a frequency-doubled Nd:YAG laser.
Enders C, Lang GE, Mayer B, Werner JU.
OPHTHALMOLOGICA
2022;245:59-68.