Choroidal Structure after Half-Dose Photodynamic Therapy in Chronic Central Serous Chorioretinopathy

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.

Crossover to PDT after the unsuccessful micropulse laser treatment of central serous chorioretinopathy

Purpose

Subthreshold micropulse laser (SML) and photodynamic therapy (PDT) are among the most effective therapeutic modalities applied to central serous chorioretinopathy (CSCR). This study aimed to evaluate the efficacy and durability of PDT in CSCR cases unresponsive to at least two SML treatments.

Methods

The study included 26 consecutive eyes of 24 patients (21 males and three females) with chronic CSCR. In all cases, a lack of reduction in subretinal fluid (SRF) levels was noted after at least two consecutive SML sessions. The parameters of best corrected visual acuity (BCVA) and spectral domain optical coherence tomography (SD-OCT) were evaluated at baseline and 1, 3 and 12 months post-PDT.

Results

The mean duration of symptoms in the group was 53.81 ± 39.48 months, the mean age of the patients was 49.26 ± 12.91 years, and the mean subfoveal choroidal thickness (SFCT) was 572.11 ± 116.21 mm. Complete resorption of SRF was observed in 21 out of 26 eyes (80.77%) at 1 month and sustained in 18 cases (69.23%) at 12 months. At 12 months, in the sustained group, BCVA improved significantly from 0.39 ± 0.18 to 0.19 ± 0.2 logMAR (P = 0.01), central subfoveal thickness (CST) reduced from 316.44 ± 75.83 mm to 197.67 ± 22.99 mm (P < 0.0001), and SFCT reduced from 579.28 mm to 446.78 mm (P < 0.0001).

Conclusions

PDT provides the opportunity for the successful treatment of CSCR unresponsive to SML treatment. Improvements are possible even in cases with a long duration of symptoms and significant alterations in retinal morphology. Thus, PDT should be considered for patients with prominently increased choroidal thickness.

The Choroid after Half-Dose Photodynamic Therapy in Chronic Central Serous Chorioretinopathy

PURPOSE

To characterize choroidal structure and vasculature after half-dose verteporfin photodynamic therapy (hd-vPDT) in eyes with chronic central serous chorioretinopathy using Enhanced Depth Imaging Optical Coherence Tomography (EDI OCT) and Optical Coherence Tomography Angiography (OCT-A).

METHODS

This prospective case-control study included 10 eyes. Choroid was examined before and at 1 month following hd-vPDT. We measured choroidal thickness (CT) at subfoveal area and at 750 μm nasal and temporal of fovea and thickness of Haller and choriocapillaris/Sattler layers. Whole (WA), luminal (LA) and interstitial area (IA) at EDI-OCT, and perfusion density at OCT-A were analyzed. The unaffected fellow eyes were used for comparisons.

RESULTS

Mean CT at subfoveal area and at 750 μm nasal and temporal of fovea, values of Haller and choriocapillaris/Sattler layers and those of WA, LA and IA were reduced, while PD increased at 1 month after hd-vPDT (all p < 0.001). There was a significant (p < 0.05) negative correlation (ρ = -0.658) between PD and post-treatment logMARVA. None of analyzed parameters reached values of unaffected fellow eye.

CONCLUSION

Following hd-vPDT, choroidal thickness with both luminal and interstitial components markedly decreased, while perfusion of choriocapillaris improved.

Evaluation of the choriocapillaris after photodynamic therapy for chronic central serous chorioretinopathy. A review of optical coherence tomography angiography (OCT-A) studies

PURPOSE

Emerging evidence suggests that choroidal microcirculation and microstructural changes after verteporfin photodynamic therapy (vPDT) for chronic central serous chorioretinopathy (CSC) can be shown in detail using OCT-Angiography (OCT-A). The use of OCT-A for the examination of choriocapillaris (CC) has attracted significant attention as the technique offers potential explanations for the effects of vPDT on choroidal tissue.

METHODS

A meticulous literature search was performed in the PubMed database without restriction on year of publication until June 2021. The reference list of all electronically retrieved articles was carefully reviewed for potentially relevant articles that had not been identified.

RESULTS

We identified and reviewed 11 studies reporting a comprehensive update on microvasculature and morphologic changes of the CC layer as seen on OCT-A in chronic CSC. The reviewed articles extensively analyze both the qualitative and quantitative characteristics of the CC flow pattern after applying vPDT safety-enhanced protocols. The changes in the CC plexus indicate the potential of beneficial or deleterious treatment effect on choroidal tissue remodeling. The reviewed series have revealed variability of flow pattern, vessel density, and perfusion of the CC over time.

CONCLUSION

The CC plexus alterations during the post-vPDT period in chronic CSC may imply the treatment effect on choroidal tissue, indicating the potential of anatomical or functional recovery over time. The reviewed literature may confirm the diagnostic value of OCT-A in the assessment of the pathophysiology of eyes with CSC.

Evaluation of Choroidal Thickness Using Optical Coherent Tomography: A Review

The choroid is the main source of blood and nourishment supply to the eye. The dysfunction of the choroid has been implicated in various retinal and choroidal diseases. The identification and in-depth understanding of pachychoroid spectrum disorders are based on the tremendous progress of optical coherence tomography (OCT) technology in recent years, although visibility of choroid is challenging in the era of the time or spectral domain OCT. The recent rapid revolution of OCTs, such as the enhanced depth imaging OCT and the swept-source OCT, has greatly contributed to the significant improvement in the analysis of the morphology and physiology of the choroid precisely, especially to the choroid-scleral boundary and vasculature. The present review highlights the recently available evidence on the measurement methodology and the clinical significance of choroidal thickness in retinal or choroidal disorders.

Choroidal Volume Evaluation after Photodynamic Therapy Using New Optical Coherence Tomography Imaging Algorithm

To evaluate choroidal volume and thickness changes after photodynamic therapy (PDT) for chronic central serous chorioretinopathy (CSC). Chronic CSC eyes with a history of PDT were selected. Average choroidal volume, average choroidal thickness, the maximum and minimum choroidal thickness of the macula irradiated area and peripheral non-irradiated areas before and after one and three months of treatment were examined. A total of 14 patients with chronic CSC and 9 controls without any eye pathology were enrolled. The mean choroidal volume in CSC before and, and after one and three months of treatment were 2.36 (standard deviation: 0.70), 1.90 (0.69), 1.86 (0.66) mm³ for the central area, 1.25 (0.38), 1.14 (0.35), 1.13 (0.34) mm³ for superior nasal area, 1.47 (0.41), 1.28 (0.43), 1.26 (0.43) mm³ for superior temporal area, 1.07 (0.49), 0.95 (0.38), 0.93 (0.35) mm³ for inferior nasal area, 1.17 (0.38), 1.04 (0.32), 1.03 (0.33) mm³ for inferior temporal area. This study revealed the choroidal volume changes in a short period after PDT and a decrease in unirradiated choroidal volume was also shown after the treatment. The algorithm provided on the ARI Network enables to evaluate the choroidal changes quantitatively and qualitatively.

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

INTRODUCTION

Photodynamic therapy with verteporfin (vPDT) has been shown to be effective against central serous chorioretinopathy (CSC) and was the preferred therapeutic for CSC treatment. However, alterations in choroidal structure after PDT were reported, and these effects were dose-dependent. This study aimed to compare the changes in choroidal structure after PDT with different doses of verteporfin in rabbits and may provide individualized therapeutic guidance for patients who failed to respond to initial half-dose vPDT.

METHODS

The full dose of verteporfin used in CSC was 6 mg/m2, which was used in patients with neovascular age-related macular degeneration. Laser fluence was 50 J/cm2 (irradiance, 600 mW/cm2, 83 s). There were 4 different dose groups in this study (100%, 70%, 50%, and 30%). The alterations were examined at 1 day, 1 week, and 1 month after vPDT using color fundus imaging, indocyanine green angiography, and histopathology analysis.

RESULTS

Various degrees of choroidal alterations were demonstrated at different dose groups. Examinations on day 1 showed that gradually reduced verteporfin dose tended to decrease photochemical reactions to the choroid in terms of the number of occlusion vessels and area of the lesion. After 1 month, choroid vessel alteration persisted in high-dose groups (100% and 70%); nevertheless, alterations of low-dose groups (50% and 30%) returned to normal.

CONCLUSIONS

vPDT can induce photochemical reactions of the choroid, high dose causes permanent change, and low dose causes recoverable change. The dose-dependent alterations need to be considered for the individual therapeutic plan according to the situation of a patient with CSC.