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

Micropulse Laser versus Eplerenone for Chronic Central Serous Chorioretinopathy: A 12-Month Comparison

INTRODUCTION

To compare the long-term efficacy of navigated subthreshold micropulse laser (NSML) and continuous oral eplerenone (EPL) in chronic central serous chorioretinopathy (cCSC).

METHODS

This retrospective observational study included 44 eyes with cCSC (EPL: n = 26; NSML: n = 18). Best-corrected visual acuity (BCVA), central macular thickness (CMT), subretinal fluid (SRF) height, and subfoveal choroidal thickness (SFCT) were evaluated over 12 months.

RESULTS

Both groups showed significant improvements in BCVA and CMT (p < 0.05). Complete SRF resolution was achieved in both groups by 12 months, with NSML showing faster resolution (2.77 ± 1.43 vs. 6.34 ± 2.17 months, p < 0.001). The EPL group demonstrated significant SFCT reduction at 6 and 12 months (p = 0.001), while the NSML group showed no significant SFCT changes (p > 0.05).

CONCLUSIONS

Both NSML and EPL improved retinal morphology and visual function in patients with cCSC. NSML achieved faster SRF resolution, while EPL resulted in more significant choroidal thickness reduction. These findings suggest distinct mechanisms of action: NSML primarily affects the retinal pigment epithelium, while EPL modulates choroidal vasculature. Treatment choice may depend on individual patient characteristics and treatment goals.

Subthreshold Micropulse Laser Versus Oral Spironolactone in Chronic Central Serous Chorioretinopathy: A Quasi-Randomized Controlled Trial

Purpose

To compare the efficacy and safety of subthreshold micropulse laser (SML) and spironolactone therapy for treating chronic central serous chorioretinopathy (CSC).

Methods

This was a quasi-randomized controlled trial. Eligible patients were quasi-randomized at a 1:1 ratio to receive SML or oral spironolactone and were assessed at 3 months after treatment.

Results

A total of 84 patients (90 eyes) were randomly assigned to receive SML (n = 45) or spironolactone (n = 39) initially. At last follow-up, 59.5% of patients in the SML group had complete resolution of subretinal fluid (SRF) compared to 43.6% in spironolactone group (P = 0.362). The mean visual acuity did not significantly improve between the two groups (0.38 ± 0.44 vs. 0.43 ± 0.43 logMAR). The central retinal thickness was decreased from 335.06 ± 120.25 µm to 222.15 ± 94.90 µm in the SML group and from 308.02 ± 90.69 µm to 257.27 ± 102.28 µm in the spironolactone group. After treatment, subfoveal choroidal thickness, total choroidal area, and stromal and luminal choroidal area were significantly lower in the spironolactone group as compared to the SML group. During the entire visit, the recurrence rate of SRF was 9.1% in the SML group compared to 35.3% in the spironolactone group. Slight adverse events occurred more frequently in the spironolactone group (0% vs. 16%).

Conclusions

Both SML and oral spironolactone were effective and safe treatments to ameliorate retinal anatomical structures for chronic CSC. A lower recurrence rate and fewer adverse effects were observed in the SML group, and better choroidal structure recovery was seen in the spironolactone group.

Translational Relevance

The investigation of SML and oral spironolactone may inform evidence-based clinical decisions for chronic CSC patients.

Laser Treatment of Central Serous Chorioretinopathy - An Update

Laser treatment has been a mainstay for management of central serous chorioretinopathy for a few decades. Different types of lasers have been used and non-damaging retinal laser is the most recent option. The aim of this review is to provide an update on this form of treatment, based on the research published during last 5 years, in comparison with earlier studies published. A MEDLINE database search was performed with a combination of the following terms: central serous chorioretinopathy and laser photocoagulation or subthreshold laser or subthreshold micropulse laser or nanosecond laser or microsecond laser or end-point management or photodynamic therapy. Results were analyzed separately for each modality of laser treatment. Reports published in recent years confirm findings of previous research and do not distinguish treatments of this clinical entity. Among all analyzed laser options, photodynamic therapy provides the fastest and most prominent morphological improvements, including subretinal fluid resorption and reduction of choroidal thickness. This modality is also associated with fewer recurrences than with other treatments. Subthreshold micropulse laser allows the physician to maintain and, in selected cases, improve the patient's vision. Conventional photocoagulation is still effective, especially with the introduction of navigated laser systems. Despite the availability of variable laser treatment options, long-term functional improvements in chronic cases are minor for each modality. Long-lasting central serous chorioretinopathy cases with significantly altered retinal morphology do not usually present with functional improvement, despite satisfactory morphological outcomes. Early initiation of treatment has the potential to prevent visual loss and to improve the patient's quality of life.

Central serous chorioretinopathy: An evidence-based treatment guideline

Central serous chorioretinopathy (CSC) is a relatively common disease that causes vision loss due to macular subretinal fluid leakage and it is often associated with reduced vision-related quality of life. In CSC, the leakage of subretinal fluid through defects in the retinal pigment epithelial layer's outer blood-retina barrier appears to occur secondary to choroidal abnormalities and dysfunction. The treatment of CSC is currently the subject of controversy, although recent data obtained from several large randomized controlled trials provide a wealth of new information that can be used to establish a treatment algorithm. Here, we provide a comprehensive overview of our current understanding regarding the pathogenesis of CSC, current therapeutic strategies, and an evidence-based treatment guideline for CSC. In acute CSC, treatment can often be deferred for up to 3-4 months after diagnosis; however, early treatment with either half-dose or half-fluence photodynamic therapy (PDT) with the photosensitive dye verteporfin may be beneficial in selected cases. In chronic CSC, half-dose or half-fluence PDT, which targets the abnormal choroid, should be considered the preferred treatment. If PDT is unavailable, chronic CSC with focal, non-central leakage on angiography may be treated using conventional laser photocoagulation. CSC with concurrent macular neovascularization should be treated with half-dose/half-fluence PDT and/or intravitreal injections of an anti-vascular endothelial growth factor compound. Given the current shortage of verteporfin and the paucity of evidence supporting the efficacy of other treatment options, future studies-ideally, well-designed randomized controlled trials-are needed in order to evaluate new treatment options for CSC.

Subthreshold micropulse laser therapy for early postoperative macular thickening following surgical removal of epiretinal membrane

BACKGROUND

This study aimed to investigate the functional and anatomical outcomes of subthreshold micropulse laser (SMPL) therapy in eyes with early postoperative macular thickening after idiopathic epiretinal membrane (iERM) removal.

METHODS

This was a prospective and interventional study. Forty-eight eyes from 48 patients with macular edema at 1 month after iERM removal were randomly divided into two groups. Patients in the SMPL group (n = 24) received SMPL therapy while no special intervention was used for the observation group (n = 24). Baseline demographic data and clinical findings before and at 1 and 3 months after SMPL treatment or observation, including best-corrected visual acuity (BCVA) and the changes in central subfield thickness (CST) and average macular thickness (AMT), were analyzed.

RESULTS

An improvement in BCVA with a decrease in CST and AMT from baseline to the 3-month follow-ups were observed in both SMPL and observation groups. No significant difference in BCVA was observed between the SMPL group and observation group either in the 1-month (0.26 [0.15, 0.52] vs. 0.26 [0.15, 0.39], P = 0.852) or the 3-month (0.15 [0.10, 0.30] vs. 0.23 [0.15, 0.30], P = 0.329) follow-up. There was a greater reduction in CST in the SMPL group versus observation group between baseline and the 3-month follow-up (-77.8 ± 72.3 μm vs. -45.0 ± 46.9 μm, P = 0.049). The alteration in AMT did not differ between the two groups in either 1-month (-16.5 ± 20.1 μm vs. -19.7 ± 16.3 μm, P = 0.547) or 3-month (-36.9 ± 26.9 μm vs. -34.0 ± 20.1 μm, P = 0.678) follow-up.

CONCLUSIONS

SMPL therapy led to a significant decrease in CST at the 3-month follow-up while did not significantly improve the visual acuity in patients with postoperative macular thickening following iERM surgery.

TRIAL REGISTRATION

The study was registered on Aug 27, 2020 (Trial Registration Number: ChiCTR 2000037227).

Half-dose photodynamic therapy versus 577 nm subthreshold pulse laser therapy in treatment-naive patients with central serous chorioretinopathy

BACKGROUND

To compare real-life anatomical and functional outcomes of half-dose photodynamic therapy (HD-PDT) and 577 nm subthreshold pulse laser therapy (SPL) in treatment-naïve patients with central serous chorioretinopathy (CSC).

METHODS

We retrospectively reviewed consecutive treatment-naïve CSC patients with non-resolving subretinal fluid (SRF) for more than 2 months who received either HD-PDT or SPL treatment. One repetition of the same treatment was allowed in patients with persistent SRF after first treatment. Functional and anatomical outcomes were assessed after first treatment and at final visit.

RESULTS

We included 95 patients (HD-PDT group, n = 49; SPL group, n = 46). Complete resolution of SRF after a single treatment was observed in 42.9% of HD-PDT-treated patients (n = 21; median time to resolution 7.1 weeks) and in 41.3% of SPL-treated patients (n = 19; median time to resolution 7.0 weeks). In the HD-PDT-group, 44.9% of patients (n = 22) and in the SPL-group, 43.5% (n = 20) of patients, received a second treatment due to persistent SRF, while 12.2% (n = 6) and 15.2% (n = 7), respectively, opted against a second treatment despite persistent SRF. After the final treatment, complete SRF resolution was observed in 61.2% of all HD-PDT-treated patients (n = 30; median time to resolution 8.8 weeks) and 60.9% of all SPL-treated patients (n = 28; median time to resolution 13.7 weeks, p = 0.876). In the final visit, both groups showed significant improvement of BCVA in comparison to baseline (p < 0.001 for all). The change in BCVA from baseline to final visit was similar for the two groups (HD-PDT, median BCVA change 0.10 logMAR (IQR: 0.0-0.2); in SPL group, median BCVA change 0.10 logMAR (IQR: 0.0-0.2), P = 0.344). The CSC subclassification (simple versus complex) had no influence on the anatomical or functional outcome.

CONCLUSIONS

High-density 577 nm SPL resulted in as good anatomical and functional treatment as HD-PDT and may thus represent a treatment alternative to HD-PDT in CSC.

Comparing treatment outcomes in randomized controlled trials of central serous chorioretinopathy

PURPOSE

To perform a qualitative analysis of outcomes published from randomized controlled trials (RCTs) on central serous chorioretinopathy (CSCR) from 1979 to 2022.

DESIGN

Systematic review.

METHODS

All RCTs (including both therapeutic and non-therapeutic interventions) on CSCR available online till July 2022 were included after an electronic search in multiple databases such as PubMed, CENTRAL, MEDLINE, EMBASE, BIOSIS, Scopus, and Cochrane database. We analyzed and compared the inclusion criteria, imaging modalities, study endpoints, duration, and the results of the study.

RESULTS

The literature search yielded 498 potential publications. After excluding duplicate studies and studies that met clear exclusion criteria, 64 were screened for further evaluation, of which 7 were removed due to a lack of necessary inclusion criteria. A total of 57 eligible studies are described in this review.

CONCLUSION

This review provides a comparative overview of key outcomes reported between RCTs investigating CSCR. We describe the current landscape of treatment modalities for CSCR and note the discrepancies between results in these published studies. Challenges arise when attempting to compare similar study designs without comparable outcome measures (i.e., clinical vs. structural) which may limit the overall evidence presented. To mitigate this issue, we present the collected data from each study in tables detailing the measures that are and are not assessed in each publication.

Continuous Eplerenone Treatment in Chronic Central Serous Chorioretinopathy: Long-Term Results from a Pilot Study

Purpose

To assess the long-term morpho-functional retinal and choroidal changes in chronic central serous chorioretinopathy (cCSC) pachychoroid eyes in response to continuous oral eplerenone (EPL) treatment.

Methods

This pilot study was conducted on patients with unilateral exudative cCSC. We enrolled a total of 17 exudative cCSC and 17 non-exudative fellow eyes of 17 patients. Baseline best-corrected visual acuity (BCVA) and anatomical (structural optical coherence tomography [OCT] and OCT angiography) parameters in both eyes were collected at baseline. Follow-up data were collected at 6, 12, and 48 months after initiation of EPL treatment.

Results

(i) Exudative cCSC eyes: Compared with baseline (0.34±0.13 LogMAR), BCVA significantly improved at follow-up examinations (6 months: 0.28±0.13 LogMAR, p=0.039; 12 months: 0.22±0.11 LogMAR, p=0.025; 48 months: 0.21±0.08 LogMAR, p=0.028). Furthermore, there was a significant reduction from baseline in all structural OCT parameters (subretinal fluid and subfoveal choroidal thickness [SFCT]; p<0.05). (ii) Non-exudative fellow eyes: There was no significant change in BCVA. There was a significant reduction from baseline in SFCT and choriocapillaris flow deficit percentage (p<0.05).

Conclusion

In this pilot study, continuous oral EPL therapy in cCSC pachychoroid eyes resulted in long-term morpho-functional improvement. The beneficial effect of EPL occurred within the first year and was maintained after four years. Based on these preliminary observations, EPL may be effective in the exudative forms of CSC.

Functional Outcomes and Safety Profile of Trans-Foveal Subthreshold Micropulse Laser in Persistent Central Serous Chorioretinopathy

Our study evaluated visual function changes after subthreshold micropulse laser (SML) treatment in persistent central serous chorioretinopathy (CSC) and SML safety profile. We conducted a prospective study including 31 fovea-involving CSC patients. The natural course was observed for the first 3 months, SML was performed at 3 months, and SML effectiveness was observed at 6 months. At all three clinical visits, optical coherence tomography (OCT), best corrected visual acuity (BCVA), contrast sensitivity (CS) in five spatial frequencies (1.5, 3.0, 6.0, 12.0, and 18.0 cycles per degree (cpd)), microperimetry (MP), and multifocal electroretinography (mfERG) were performed. The SML safety profile was evaluated with functional and morphological parameters. In the cohort of all CSC patients treated with SML, the statistically significant average improvement was observed in BCVA (p = 0.007), CS-1.5 (p = 0.020), CS-3.0 (p = 0.050), CS-12.0 (p < 0.001), CS-18.0 (p = 0.002), CS (CS-A) (p < 0.001), MP in the central ring (MP-C) (p = 0.020), peripheral ring (MP-P) (p = 0.042), and average retinal sensitivity (MP-A) (p = 0.010). After the SML treatment, mean changes in mfERG amplitudes and implicit times in our cohort were not statistically significant. No morphological or functional adverse effects of SML treatment were observed. SML treatment in persistent CSC episodes leads to significant functional improvement and has an excellent safety profile.

Yellow Subthreshold Micropulse Laser in Retinal Diseases: An In-Depth Analysis and Review of the Literature

Yellow subthreshold micropulse laser (YSML) is a retinal laser capable of inducing a biologic response without causing thermal damage to the targeted tissue. The 577-nm YSML is delivered to the retina abiding by different protocols in which wavelength, power, duration, spot size and number of spots can be properly set to achieve the most effective and safe treatment response in various chorioretinal disorders. The ultrashort trains of power modulate the activation of the retinal pigment epithelium cells and intraretinal cells, such as Müller cells, causing no visible retinal scars. Subthreshold energy delivered by YSML stimulates the production of the heat-shock proteins, highly conserved molecules that protect cells against any sort of stress by blocking apoptotic and inflammatory pathways that cause cell damage. YSML treatment allows resorption of the subretinal fluid in central serous chorioretinopathy and intraretinal fluid in various conditions including diabetic macular edema, postoperative cystoid macular edema and other miscellaneous conditions. YSML also seems to modulate the development and progression of reticular pseudodrusen in dry age-related macular degeneration. The aim of this review is to discuss and summarize the safety and efficacy of YSML treatment in retinal diseases.

Comparative efficacy of treatments for chronic central serous chorioretinopathy: A systematic review with network meta-analyses

Treatment of chronic central serous chorioretinopathy (cCSC) remains a topic of controversy. As cCSC is a disease that can wax and wane, treatment efficacy is difficult to assess especially when trials compare active treatments without any placebo/control group. In this study, we systematically reviewed short-term efficacies of any cCSC treatment tested in randomized controlled trials (RCT) and employed network meta-analyses to compare to non-treatment controls. We searched 11 literature databases on 20 March 2022 for RCTs of treatment of cCSC. We identified 17 RCTs including a total of 1172 eyes. Treatments included conventional laser (44 eyes), half-dose or half-fluence photodynamic therapy (PDT) (298 eyes), ranibizumab (16 eyes), antioxidants (50 eyes), mineralocorticoid receptor antagonists (187 eyes), rifampicin (91 eyes), selective retina therapy (SRT) (67 eyes) and subthreshold micropulse laser (192 eyes). Compared with controls, significant benefit on complete subretinal fluid resolution was only obtained from half-dose or half-fluence PDT (OR: 20.6; 95% CI: 6.3-66.7; p < 0.0001) and conventional laser (OR: 36.4; 95% CI: 2.0-655.7; p = 0.015), and at an order of magnitude lower degree from SRT (OR: 3.4; 95% CI: 1.7-6.8; p = 0.00075). Compared with controls and after sensitivity analyses, significant benefit in the change in best-corrected visual acuity was only obtained by half-dose/-fluence PDT (-0.13 logMAR; 95% CI: -0.20 to -0.06 logMAR; p = 0.00021). In conclusion, three treatment options provide significant improvement over no treatment: half-dose/-fluence PDT, conventional laser and to a much lesser degree SRT. Considering that conventional laser can only be applied for extrafoveal leaks, and the long-term data available for PDT-based treatments finding persisting treatment results, half-dose or half-fluence PDT is the only viable treatment option for patients with cCSC. Shortage issues with verteporfin should not lead to employment of ineffective treatment modalities, as they put patients at unnecessary risk of adverse events.

Effectiveness, Safety and Choroidal Changes of a Fovea-Sparing Technique for the Treatment of Chronic Central Serous Chorioretinopathy with Yellow Subthreshold Laser

The aim of this study was to evaluate the effectiveness and safety of a yellow subthreshold laser (STL) for the treatment of chronic central serous chorioretinopathy delivered in a fovea-sparing pattern and to analyze the post-laser changes in the choroidal structure by Swept-Source Optical Coherence Tomography. This study was a prospective case series of 43 eyes corresponding to 37 patients. Data were recorded at 6, 12 and 24 weeks after the STL treatment. The best-corrected visual acuity improved in 93% of the patients and remained stable in 7%. The subretinal fluid was completely reabsorbed in 27.9%, 32.6% and 69.8% of the patients at 6, 12 and 24 weeks, respectively. There were reductions in the choroidal thickness of 13.1% and 25.3% at 12 and 24 weeks, which corresponded to reductions of 17.5% and 45.9% in the choriocapillaris and Sattler layer and reductions of 12.2% and 21.2% in the Haller layer at 12 and 24 weeks, respectively (p < 0.05). This might account for the effect of the laser on the inner choroidal vasculature, the dysregulation of which is believed to be at the core of central serous chorioretinopathy. No laser-related complications were detected. Overall, the fovea-sparing STL was safe and effective in this series of patients.

Optical coherence tomography biomarkers as predictors of transition to chronic central serous chorioretinopathy after retinal laser photocoagulation

Objectives

To explore the optical coherence tomography (OCT) biomarkers to predict the transition to chronic central serous chorioretinopathy (cCSC) after retinal laser photocoagulation.

Methods

Patients enrolled in this study were from a 12-week clinical trial comparing the efficacy and safety of subthreshold micropulse laser (SML) with threshold conventional laser (TCL) for CSC and had extended follow-up for more than 1 year. They were divided into two groups, transited to cCSC group (cCSC group) and did not transited to cCSC group (non-cCSC group) according to fundus examination at the extended follow-up. Collect the best-corrected visual acuity (BCVA) and OCT characteristics of patients at baseline and 12 weeks after laser treatment.

Results

Twenty-seven patients were enrolled (42.6 ± 7.7 years old), and duration of follow-up was 178.9 ± 88.8 (57.0-312.0) weeks. Nine patients (33.3%) were assigned to cCSC group, and the other 18 patients (66.7%) were assigned to the non-cCSC group. Twelve weeks after the laser treatment, subretinal fluid (SRF) of 15 patients (83.3%) in non-cCSC group and 5 patients (55.6%) in cCSC group absorbed completely; the height of SRF had statistical difference between two groups (p = 0.035); rough RPE was less common in cCSC group (p = 0.030); hyper reflective mass (HRM) was more common in cCSC group (p = 0.024); more number of hyper reflective foci (HRF) in outer segment of photoreceptor layer were detected in cCSC group (p = 0.035). From baseline to 12 weeks after laser treatment, the number of HRF in outer segment photoreceptor layer did not change significantly in cCSC group (p = 0.665) but decreased significantly in non-cCSC group (p = 0.000). A total of five patients suffered binocular CSC, three of them in the non-cCSC group occurred later than the other two in the cCSC group (129.9-278.3 weeks vs 96.1-114.9 weeks after baseline).

Conclusion

SRF, rough RPE, HRM, and number of HRF in outer segment photoreceptor layer 12 weeks after laser treatment, and change in the number of HRF in outer segment photoreceptor layer from baseline to 12 weeks after laser treatment may predict the transition to cCSC.

Scanning Laser Ophthalmoscopy Retromode Imaging Compared to Fundus Autofluorescence in Detecting Outer Retinal Features in Central Serous Chorioretinopathy

Central serous chorioretinopathy (CSCR) is a retinal disease characterized by a heterogeneous clinical phenotype, depending on the influence of different factors in its pathogenesis, including the presence of subretinal fluid (SRF), trophism of the retinal pigmented epithelium (RPE) and choroidal hyper-permeability. Our study has the purpose of assessing the ability of scanning laser ophthalmoscopy (SLO) retromode imaging, compared to fundus autofluorescence (FAF), to identify outer retinal features in a cohort of patients with a diagnosis of CSCR. A total of 27 eyes of 21 patients were enrolled in our study. All patients underwent full ophthalmological examination, including fundus retinography, fundus fluorescein angiography, optical coherence tomography (OCT), FAF and SLO retromode imaging. For each patient, the following features were evaluated: SRF, the presence of pigmented epithelium detachment (PED), RPE dystrophy, and RPE atrophy. RPE dystrophy was further characterized according to the appearance in FAF of iso-, hyper- and hypo-autofluorescent dystrophy. The ability to identify each feature was evaluated for FAF and SLO retromode alone, compared to a multimodal imaging approach. FAF identified SRF in 11/14 eyes (78%), PED in 14/19 (74%), RPE dystrophy with iso-autofluorescence in 0/13 (0%), hyper-autofluorescence in 18/19 (95%), hypo-autofluorescence in 20/20 (100%), and RPE atrophy in 7/7 (100%). SLO retromode imaging identified SRF in 13/14 eyes (93%), PED in 15/19 (79%), RPE dystrophy with iso-autofluorescence in 13/13 (100%), hyper-autofluorescence in 13/19 (68%), hypo-autofluorescent in 18/20 (90%), and RPE atrophy in 4/7 (57%). SLO retromode imaging is able to detect retinal and RPE changes in CSCR patients with a higher sensitivity than FAF, while it is not able to identify the depth of lesions or supply qualitative information about RPE cells' health status, meaning that it is less specific. SLO retromode imaging may have a promising role in the assessment of patients with CSCR, but always combined with other imaging modalities such as OCT and FAF.

Short-term comparison between navigated subthreshold microsecond pulse laser and oral eplerenone for chronic central serous chorioretinopathy

To compare the anatomical/functional changes after navigated subthreshold pulse laser (SML) and oral eplerenone therapy for chronic central serous chorioretinopathy (cCSC). A total of 36 eyes of 36 patients suffering from cCSC treated with navigated SML (Navilas® 577s; OD-OS GmbH, near Berlin, Germany) (18 eyes, SML group) and oral eplerenone (18 eyes, eplerenone group) were enrolled in this retrospective study. Main outcome measures during a 3-month follow up period included changes of best corrected visual acuity (BCVA), central macular thickness (CMT), foveal subretinal fluid thickness (FSRFT), and subfoveal choroidal thickness (SFCT). At baseline average duration of symptoms was 6.8 ± 0.6 months in SML group and 6.4 ± 0.9 months in eplerenone group (p = 0.127). Mean BCVA, CMT and FSRFT changed significantly over time (p < 0.001). From baseline to 90 days the BCVA improved from 0.3 ± 0.1 to 0.1 ± 0.1 logMAR in SML group and from 0.3 ± 0. to 0.2 ± 0.1 logMAR in eplerenone group, CMT reduced from 357.1 ± 104.3 to 210.6 ± 46.7 μm and from 428.7 ± 107.7 to 332.5 ± 27.5 μm in SML group and eplerenone group respectively, FSRFT reduced from 144.4 ± 108.2 to 22.6 ± 37.2 μm and from 217.1 ± 105.9 to 54.4 ± 86.2 μm in SML group and eplerenone group. 55.6% of patients in SML group and 66.7% in eplerenone group showed a complete resolution of FSRFT during follow up. The interaction between group and time was statistically significant with greater absolute variation for CMT and FSRFT in SML group compared to eplerenone group (p < 0.001 and p = 0.043). SFCT did not change significantly during follow up (p = 0.083) for both groups. Both navigated SML and oral eplerenone were effective treatments showing recovery of retinal morphology and related visual acuity improvement in cCSC.

577 nm subthreshold micropulse laser treatment for acute central serous chorioretinopathy: a comparative study

BACKGROUND

To assess the efficacy of 577 nm subthreshold micropulse laser (SML) treatment for acute central serous chorioretinopathy (CSC).

METHODS

This retrospective comparative case-series included 34 eyes of 34 patients with acute CSC who received either 577 nm SML treatment (SML group, n = 16 eyes) or were only monitored (observation group, n = 18 eyes). Acute CSC was defined as disease course < 3 months. Eyes with any history of treatment in the past were excluded. Data were collected over a period of 6 months. The best corrected visual acuity (BCVA), central macular thickness (CMT), and subfoveal choroidal thickness (SFCT) were observed.

RESULTS

SML group showed significantly greater improvement in the BCVA (logMAR) compared to observation group at 1 month (0.20 ± 0.10 vs 0.30 ± 0.12, P < 0.01), 3 months (0.13 ± 0.06 vs 0.21 ± 0.06, P < 0.01) and 6 months (0.01 ± 0.06 vs 0.09 ± 0.66, P < 0.01). The CMT reduction was significantly greater in the SML group at 1 month (337.19 ± 62.96 µm vs 395.11 ± 91.30 µm, P < 0.05), 3 months (312.94 ± 49.50 µm vs 364.50 ± 70.30 µm, P < 0.05) and 6 months (291.38 ± 26.46 µm vs 348.56 ± 54.65 µm, P < 0.05). In the SML group, the SFCT did not show a significant decrease at 1 month (468.88 ± 42.19 µm, P > 0.05) but showed a significant reduction at 3 months (451.75 ± 39.36 µm, P < 0.05) and 6 months (450.50 ± 34.24 µm, P < 0.05) from baseline (489.94 ± 45.86 µm). In the observation group, there was no significant change in SFCF during follow-up. No adverse events occurred in the SML group.

CONCLUSIONS

Although some patients with acute CSC show spontaneous healing, timely intervention with 577 nm SML can shorten the disease course, improve visual acuity, and reduce the risk of chronic transformation without adverse events.

Safety of various parameter sets with navigated microsecond pulsing laser in central serous chorioretinopathy

Background

Subthreshold microsecond pulsing laser is an increasingly common treatment approach for central serous chorioretinopathy. However, there is no literature available on the safety of microsecond laser using different fluence settings in this disease. While many publications can be obtained from conventional microsecond pulsing lasers, few parameter sets are published with the navigated microsecond pulsing laser. Therefore, this study aims to investigate the safety of different parameter sets in subthreshold microsecond pulsing laser treatments.

Methods

In this retrospective chart review, consecutive patients with central serous chorioretinopathy (> 3 months duration of symptoms) treated with navigated subthreshold microsecond pulsing laser and a follow up of at least five months after microsecond laser application were included. For each patient, the treatment parameters, plan layout, and adverse events related to laser were evaluated. Secondary outcomes included best-corrected visual acuity and anatomical improvements (central retinal thickness).

Results

One hundred and one eyes were included in the observation and followed for a mean of 10 months (range 5–36). Although a larger range of parameter sets and fluence settings have been used, no patient demonstrated adverse events from navigated microsecond pulsing laser. While 88% of the cases demonstrated stability, 13 cases lost five or more letters due to the persistence of the subretinal fluid. In mean, a best-corrected visual acuity improvement of 0.07logMar (± 0.2) was seen (p = 0.02). In 51% of the patients, a statistically significant improvement of the central retinal thickness was noted at the last follow-up with a mean thickness reduction of 70 µm (± 143) (p < 0.01).

Conclusion

In conclusion, none of the used parameter sets lead to tissue damage (when using a cautious titration) and, in summary, lead to an improvement in subretinal fluid and improvement in visual acuity. However, further prospective studies are needed to correctly identify the dependency of the treatment strategy on the outcome criteria.

Retinal temperature determination based on photopic porcine electroretinogram

OBJECTIVE

Subthreshold retinal laser therapy (SLT) is a treatment modality where the temperature of the retinal pigment epithelium (RPE) is briefly elevated to trigger the therapeutic benefits of sublethal heat shock. However, the temperature elevation induced by a laser exposure varies between patients due to individual differences in RPE pigmentation and choroidal perfusion. This study describes an electroretinography (ERG)-based method for controlling the temperature elevation during SLT.

METHODS

The temperature dependence of the photopic ERG response kinetics were investigated both ex vivo with isolated pig retinas and in vivo with anesthetized pigs by altering the temperature of the subject and recording ERG in different temperatures. A model was created for ERG-based temperature estimation and the feasibility of the model for controlling SLT was assessed through computational simulations.

RESULTS

The kinetics of the photopic in vivo flash ERG signaling accelerated between 3.6 and 4.7%/C, depending on the strength of the stimulus. The temperature dependence was 5.0%/C in the entire investigated range of 33 to 44C in ex vivo ERG. The simulations showed that the method is suitable for determining the steady-state temperature elevation in SLT treatments with a sufficiently long laser exposure and large spot size, e.g., during > 30 s laser exposures with > 3 mm stimulus spot diameter.

CONCLUSIONS

The described ERG-based temperature estimation model could be used to control SLT treatments such as transpupillary thermotherapy.

SIGNIFICANCE

The introduced ERG-based method for controlling SLT could improve the repeatability, safety, and efficacy of the treatment of various retinal disorders.

Factors affecting resolution of subretinal fluid after selective retina therapy for central serous chorioretinopathy

The purpose of this study was to investigate the factors of clinical outcome of selective retina therapy (SRT) for central serous chorioretinopathy (CSC). This retrospective study included 77 eyes of 77 patients, who were treated with SRT for CSC and observed at least 6 months after the treatment. SRT laser (527 nm, 1.7 µs, 100 Hz) was used for treatment. The mean best-corrected visual acuity (logMAR), central macular thickness (CMT) and central choroidal thickness were changed from baseline to at 6-months follow-up with significant difference. The multivariate analyses found that the rate of change (reduction) in CMT was associated with focal leakage type on fluorescein angiography (FA) (p = 0.03, coefficient 15.26, 95% confidence interval 1.72–28.79) and larger baseline CMT (p < 0.01, coefficient − 0.13, 95% confidence interval − 0.13 to − 0.05). Complete resolution of subretinal fluid was associated with nonsmoking history (p = 0.03, odds ratio 0.276, 95% confidence interval 0.086–0.887) and focal leakage type on FA (p < 0.01, odds ratio 0.136, 95% confidence interval 0.042–0.437). These results may be useful for predicting the therapeutic effectiveness of SRT.

Central Serous Chorioretinopathy: Treatment with Laser

Currently, no general consensus exists regarding the management of central serous chorioretinopathy (CSC). Laser treatments include three different therapeutic approaches: conventional laser, subthreshold laser and photodynamic therapy. Conventional focal laser, addressed to seal the leaking points, as evidenced on fluorescein angiography, was largely used in the past, but now, it is almost completely abandoned, owing to the potential complications. Several studies confirmed the positive effects achieved by subthreshold laser treatment in CSC, even though its improper application in the PLACE trial has questioned the effectiveness.