Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Randomized Controlled Trial
. 2020 Sep;34(9):1592-1599.
doi: 10.1038/s41433-019-0692-8. Epub 2019 Nov 29.

Efficacy and safety of subthreshold micropulse laser compared with threshold conventional laser in central serous chorioretinopathy

Zuhua Sun  1 , Ying Huang  1 , Chaochao Nie  1 , Zhijie Wang  1 , Junqing Pei  1 , Bing Lin  1 , Rong Zhou  1 , Junyan Zhang  2 , Victor Chong  3   4 , Xiaoling Liu  5
Affiliations
Randomized Controlled Trial

Efficacy and safety of subthreshold micropulse laser compared with threshold conventional laser in central serous chorioretinopathy

Zuhua Sun et al. Eye (Lond). 2020 Sep.

Abstract

Purpose: To compare the efficacy and safety of subthreshold micropulse laser (SML) with threshold conventional laser (TCL) in central serous chorioretinopathy (CSC).

Methods: Prospective, randomized, double-masked, non-inferiority, 12-week clinical trial. Patients were randomly assigned 1:1 to SML group or TCL group. Patients in the SML group were treated with 577 nm micropulse laser. The spot size was 160 µm, the duty cycle was 5% and exposure time was 0.2 s. The power was 50% threshold tested. Patients in the TCL group were treated with 577 nm continuous laser. The power was 100% threshold tested. The primary outcome was the mean change in best-corrected visual acuity (BCVA) at week 12, with a non-inferiority limit of five letters on the Early Treatment Diabetic Retinopathy Study (ETDRS) visual acuity charts.

Results: Eighty-eight patients were enroled. Seventy-seven patients were male. Forty-four patients were in SML group and 44 in TCL group. At week 12, SML was equivalent to TCL with a gain of 6.23 ± 8.59 and 6.61 ± 6.35 letters, respectively, (SML-TCL difference: -0.38 letters; 95% confidence interval (CI):-3.58-2.81; Pnon-inferiority = 0.0026). There was no statistically significant difference between the two groups (t = 0.240, P = 0.811). At week 12, the proportion of patients whose SRF had been totally absorbed was 63.63 and 81.82% respectively for SML and TCL groups. There was no statistically significant difference between the two groups (χ2 = 3.67, P = 0.056).

Conclusions: Both SML and TCL can improve visual acuity in CSC. SML was non-inferior to TCL in the improvement of BCVA.

PubMed Disclaimer

Conflict of interest statement

Victor Chong is a consultant for Quantel Medical. The other authors declare that they have no conflict of interest.

Figures

Fig. 1
Fig. 1
a FFA of mid-phase showed the leakage located at the ring 2. b Stimulated image of the subthreshold micropulse laser mode. The white square frames represented the treatment area. The red dots represented the laser points. c Stimulated image of the threshold conventional laser mode.
Fig. 2
Fig. 2
Study follow-up flow chart. SML Subthreshold micropulse laser, TCL threshold conventional laser.
Fig. 3
Fig. 3
a Mean change in BCVA. b Differences in BCVA change from baseline to week 12 between the two groups. The red vertical lines indicated the mean difference between the two groups, and the grey bar was the 95.0% CI. CI within −5 and +5 letters (dashed vertical lines) indicated that the two groups were equivalent. A lower limit of the 95.0% CI with a value above −5 showed that SML was non-inferior compared with TCL. c Proportions of patients with BCVA change from baseline to week 12. BCVA best-corrected visual acuity, CI confidence interval, SML subthreshold micropulse laser, TCL threshold conventional laser.
Fig. 4
Fig. 4
a Waterfall plots of BCVA changes from baseline to week 12 for individual patients. These plots showed that all the BCVA scores improved except six patients in SML group and seven patients in TCL group. b Waterfall plots of CRT changes from baseline to week 12 for individual patients. These plots showed that all the CRT thicknesses decreased from baseline except three patients in the SML group, but none in TCL group. BCVA best-corrected visual acuity, CRT central retinal thickness, SML subthreshold micropulse laser, TCL threshold conventional laser.
See this image and copyright information in PMC

Comment in

References

    1. Liew G, Quin G, Gillies M, Fraser-Bell S. Central serous chorioretinopathy: a review of epidemiology and pathophysiology. Clin Exp Ophthalmol. 2013;41:201–14. doi: 10.1111/j.1442-9071.2012.02848.x. - DOI - PubMed
    1. Gemenetzi M, De Salvo G, Lotery AJ. Central serous chorioretinopathy: an update on pathogenesis and treatment. Eye. 2010;24:1743–−56. doi: 10.1038/eye.2010.130. - DOI - PubMed
    1. Yannuzzi LA, Slakter JS, Gross NE, Spaide RF, Costa D, Huang SJ, et al. Indocyanine green angiography-guided photodynamic therapy for treatment of chronic central serous chorioretinopathy: a pilot study. Retina. 2003;23:288–98. doi: 10.1097/00006982-200306000-00002. - DOI - PubMed
    1. Lim JI, Glassman AR, Aiello LP, Chakravarthy U, Flaxel CJ, Spaide RF, et al. Collaborative retrospective macula society study of photodynamic therapy for chronic central serous chorioretinopathy. Ophthalmology. 2014;121:1073–8. doi: 10.1016/j.ophtha.2013.11.040. - DOI - PubMed
    1. Palanker D, Blumenkranz MS. Retinal laser therapy: biophysical basisand applications. In: Ryan S, Wilkinson H, Sadda W, editors. Ch. 39. RETINA. 5th ed. Vol. 1. Elsevier Inc; 2013, p. 752–5.

Publication types