Dose-Related Structural Effects of Photodynamic Therapy on Rabbit Choroidal Structure

Safety and Efficacy of Half-dose and Half-fluence Photodynamic Therapy in Chronic Central Serous Chorioretinopathy: A Systematic Review and Meta-analysis

PURPOSE

To investigate the comparative efficacy and safety of half-dose photodynamic therapy (PDT) and half-fluence PDT in the management of chronic central serous chorioretinopathy.

DESIGN

Systematic review and meta-analysis.

METHODS

A comprehensive literature search was conducted on Ovid MEDLINE, Embase, and the Cochrane Library, covering publications from January 2000 to March 2024. The review focused on studies reporting the efficacy and safety of half-dose PDT compared to half-fluence PDT in treating chronic central serous chorioretinopathy. The primary outcome was the best-corrected visual acuity (BCVA) at the last study observation. Secondary outcomes included retinal thickness (RT), the presence of subretinal fluid (SRF), and SRF recurrence across follow-up visits. Random effects meta-analysis was performed using RevMan 5.4.

RESULTS

A total of 10 studies (eight observational and two randomized controlled trials) were included in the analysis. The results indicated that half-dose PDT and half-fluence PDT achieved similar BCVA at 1 month (P = .24), 3 months (P = .40), and 6 months (P = .16). Similarly, there were no significant differences in RT at 1 month (P = .23), 3 months (P = .99), and at 6 months (P = .54) between the two treatment protocols. Both treatment protocols were associated with minor complications, indicating similar safety profiles in patients with CSCR.

CONCLUSIONS

The findings suggest that both half-dose and half-fluence PDT are effective and safe for treating CSCR, with no significant differences in BCVA, RT, or SRF resolution between the two modalities. These results support flexibility in selecting treatment based on individual patient needs. Further research with larger sample sizes and longer follow-up is required to optimize these protocols and confirm these results.

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.

Anatomical and functional impact of verteporfin shortage in patients with chronic central serous chorioretinopathy

BACKGROUND

To describe the functional and anatomical impact that the worldwide shortage of verteporfin has had on patients diagnosed with chronic central serous chorioretinopathy (cCSCR) whose treatment with photodynamic therapy (PDT) had to be delayed.

METHODS

Prospective observational study. Patients were divided into two groups based on the time interval since PDT had been indicated: groups 1 and 2, with waiting times of less and more than 9 months respectively. Best corrected visual acuity (BCVA), the maximum height of the subretinal fluid (MSRF) and subfoveal choroidal thickness (SFCT) at the baseline visit and the last visit were compared.

RESULTS

49 eyes of 48 patients with cCSCR were included. The mean waiting time for PDT was 9.0 ±3.8 months. The mean BCVA was 69.0 ±17.1 letters and 68.9 ±16.4 letters for the baseline and last visit respectively, showing no difference (p= 0.958). Although there was no difference in the mean global BCVA, 15 eyes (30.5%) showed a deterioration of ≥5 letters, including 7 eyes (14%) with a decrease of ≥10 letters. Mean MSRF height was 151.4 ±97.2 μm and 98.2 ±83.1 μm for the baseline and last visit respectively (p= 0.005), persisting in 74.5% of the eyes.

CONCLUSION

No significant impact was observed in the BCVA in cCSCR due to the shortage of verteporfin. However, one-third of patients had BCVA loss. There was a significant spontaneous decrease in MSRF, but it persisted in the majority of the patients, still susceptible to PDT.

Choroidal hemodynamics in central serous chorioretinopathy after half-dose photodynamic therapy and the effects of smoking

This retrospective study aimed to evaluate choroidal hemodynamics after half-dose photodynamic therapy (PDT) for central serous chorioretinopathy (CSC) and the effects of smoking using laser speckle flowgraphy. This study included 29 eyes of 29 patients treated with half-dose PDT for CSC, who were followed-up for at least 6 months. The mean blur rate (MBR) in the PDT irradiation area (whole area), the pachyvessel (PV) area, non-PV (NPV) area, and filling delay (FD) area were assessed at baseline and 1, 3, and 6 months post-PDT, respectively. The MBR was also assessed by smoking status. The MBR significantly decreased from baseline in the whole, PV, NPV, and FD areas at all time points (P < 0.001). Of the 29 patients, 6 were never smokers, 13 were past smokers, and 10 were current smokers. At baseline, no significant difference was found in the MBR in the whole, PV, NPV, and FD areas among never, past, and current smokers. The MBR changes showed a significantly smaller decrease in current smokers than in never smokers in the whole (P = 0.021), PV (P = 0.009), and NPV (P = 0.034) areas, but not in the FD area (P = 0.172). Half-dose PDT for CSC reduced choroidal blood flow in the PDT-irradiated area, which was blunted by current smoking status.