Functional and anatomical results of subthreshold micropulse laser as rescue treatment for central serous chorioretinopathy after verteporfin shortage.

Background: To evaluate the anatomical and functional outcomes of high-density subthreshold micropulse laser (HSML) treatment in a cohort of patients diagnosed with chronic central serous chorioretinopathy (CSCR) whose treatment with photodynamic therapy (PDT) was delayed due to the worldwide shortage of verteporfin.

Methods: Prospective interventional study which included 42 eyes of 40 patients diagnosed with chronic CSCR and on the waiting list for PDT who received rescue therapy with HSML using the Navilas® System device (OD-OS GmBH, Teltwo, Germany). Best corrected visual acuity (BCVA), subretinal fluid (SRF), and subfoveal choroidal thickness (SFCT) were measured at inclusion and during the follow-up visits at 2, 4, and 6 months.

Results: The mean waiting time from the indication of PDT until treatment with HSML was 14.6 ± 9.7 months (range 5-21). There were no differences in the pre-treatment BCVA compared with the 6-month follow-up visit (67 ± 16.7 letters and 67.5 ± 8.2 letters respectively, p = 0.136). However, there was a significant decrease in the mean SFCT of -39.6 ± 37.1 μm (p = 0.030). Additionally, there was a decrease in SRF height between the pre-treatment measure (123.0 ± 49.8 μm) and the 2, 4, and 6-month follow-up visits after HSML of -58.5 ± 68.2 μm, -53.2 ± 76.3 μm, and -65.4 ± 53.6 μm respectively (p < 0.001). A complete resolution of the SRF was observed in 16/42 eyes (38.1 %) and a reduction of the SRF height in 85.7 % of the overall cohort was observed after HSML treatment.

Conclusion: A significant anatomical improvement in SRF and a decrease in SFCT were observed in patients with CSCR who were previously waiting for PDT and were rescued by HSML. However, the rate of complete SRF resolution was low.