Photodynamic Therapy for Chorioretinal Diseases: A Practical Approach

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.

Perspectives and Update on the Global Shortage of Verteporfin (Visudyne®)

An ongoing global shortage of verteporfin (Visudyne®) limits the treatment possibilities for several chorioretinal diseases, including central serous chorioretinopathy, choroidal hemangioma, and polypoidal choroidal vasculopathy. Verteporfin is required to perform photodynamic therapy in these ocular diseases. Therefore, the current situation has a substantial impact on eye care worldwide. The worldwide supply of verteporfin appears to be manufactured by a single factory, which is situated in the United States. The distribution of verteporfin is done by different companies for different regions of the world. Official communication on the shortage by the responsible companies has been scarce and over the past years several promises with regards to resolution of the shortage have not been fulfilled. The delivery of new batches of verteporfin is at irregular intervals, unpredictable, and may not be fairly balanced between different regions or countries in the world. To ensure a fair distribution of available verteporfin within a country, several measures can be taken. In the Netherlands, a national committee, consisting of ophthalmologists, is in place to arrange this. On the European level, the European Union and European Medicine Agency have plans to monitor medicine shortages more closely and to intervene if necessary. With a more intensified monitoring and regulation of medicine supplies, future impending shortages may be prevented. Remarkably, the amount of medicine shortages is increasing, having a significant and sometimes irreversible impact on patient care. Thus, efforts should be undertaken to minimize the consequences and, whenever possible, to prevent future medicine shortages.

Verteporfin Photodynamic Therapy for the Treatment of Chorioretinal Conditions: A Narrative Review

Photodynamic therapy (PDT) with verteporfin involves intravenous administration of a photosensitizer followed by its laser light activation at the target site to inhibit aberrant choroidal vascularization. This narrative review provides an overview of the role verteporfin PDT plays in the management of chorioretinal conditions. A PubMed literature review of all English-language articles published through October 19, 2023, was conducted to identify relevant references. Verteporfin PDT has been shown to be safe and effective for the treatment of patients with choroidal neovascularization (CNV) due to neovascular age-related macular degeneration and is often used in combination with a vascular endothelial growth factor (VEGF) inhibitor. Additionally, patients with polypoidal choroidal vasculopathy, a subtype of neovascular age-related macular degeneration, also benefit from verteporfin PDT combined with a VEGF inhibitor for improving visual acuity. Verteporfin PDT has also been effective in treating patients with peripapillary CNV, as well as eyes with CNV due to ocular histoplasmosis and pathologic myopia. Reduced dose and/or fluence PDT protocols have been effective in patients with central serous chorioretinopathy while reducing adverse effects. In eyes with choroidal hemangioma, tumor regression and visual outcomes have been improved with verteporfin PDT treatment. Photodynamic therapy with verteporfin continues to play an important role in the management of chorioretinal conditions.

Research Progress of Natural Product Photosensitizers in Photodynamic Therapy

Photodynamic therapy is a noninvasive cancer treatment that utilizes photosensitizers to generate reactive oxygen species upon light exposure, leading to tumor cell apoptosis. Although photosensitizers have shown efficacy in clinical practice, they are associated with certain disadvantages, such as a certain degree of toxicity and limited availability. Recent studies have shown that natural product photosensitizers offer promising options due to their low toxicity and potential therapeutic effects. In this review, we provide a summary and evaluation of the current clinical photosensitizers that are commonly used and delve into the anticancer potential of natural product photosensitizers like psoralens, quinonoids, chlorophyll derivatives, curcumin, chrysophanol, doxorubicin, tetracyclines, Leguminosae extracts, and Lonicera japonica extract. The emphasis is on their phototoxicity, pharmacological benefits, and effectiveness against different types of diseases. Novel and more effective natural product photosensitizers for future clinical application are yet to be explored in further research. In conclusion, natural product photosensitizers have potential in photodynamic therapy and represent a promising area of research for cancer treatment.

Topical non-steroidal anti-inflammatory drugs for central serous chorioretinopathy: A systematic review and meta-analysis

Central serous chorioretinopathy (CSC) is a prevalent exudative maculopathy and the ongoing verteporfin shortage restricts current treatment possibilities. Topical non-steroidal anti-inflammatory drugs (NSAID) have previously been proposed as a treatment for CSC, although its exact efficacy remains unclear. In this systematic review and meta-analysis, we outlined the efficacy of topical NSAIDs for the treatment of CSC. We searched 11 literature databases on 13 December 2022, for any study describing topical NSAID treatment for CSC. Thirteen eligible studies were included with a total of 1001 eyes of 994 patients with CSC. Six studies were case reports, two were cohort studies and five were non-randomized comparative studies. Where specified, topical NSAIDs used were bromfenac 0.09%, diclofenac 0.1%, ketorolac 0.4% and 0.5%, pranoprofen 0.1%, and nepafenac 0.1% and 0.3%. Studies were predominantly of cases with acute CSC and several case studies reported treatment outcomes simultaneously with discontinuation of corticosteroid use, which complicated treatment evaluation. Meta-analyses of comparative studies revealed a statistically significant but clinically irrelevant best-corrected visual acuity improvement of -0.04 logMAR (95% CI: -0.07 to -0.01 logMAR; p = 0.01) at 1-month follow-up, which became statistically insignificant at 3-month follow-up (-0.03 logMAR; 95% CI: -0.06 to 0.003 logMAR; p = 0.08). Further, we found no benefit in complete subretinal fluid resolution at 1-month follow-up (OR: 1.20; 95% CI: 0.81-1.76; p = 0.37) or 3-month follow-up (OR: 1.17; 95% CI: 0.86 to 1.59; p = 0.33). Taken together, available evidence does not support the use of topical NSAIDs for the treatment of CSC.

Evaluating photodynamic therapy versus brolucizumab as a second-line treatment for polypoidal choroidal vasculopathy

BACKGROUND

To compare the one-year outcomes between intravitreal brolucizumab (IVBr) monotherapy and photodynamic therapy (PDT) as a second-line treatment in patients with polypoidal choroidal vasculopathy (PCV) who did not respond to first-line therapy.

METHODS

This case-control study included eyes with PCV that do not respond to aflibercept or ranibizumab. The patients were retrospectively registered. We compared outcomes, including best-corrected visual acuity (BCVA), anatomical results, and the need for additional treatments, between IVBr and a combination therapy using PDT as second-line treatments for refractory PCV, after adjusting for potential confounders. We analyzed E-values to evaluate the robustness of the results against unmeasured confounders.

RESULTS

Twenty-two eyes received IVBr, and twenty-four underwent PDT. No apparent differences were observed in BCVA and central macular thickness (CMT) changes from baseline between the groups (IVBr vs. PDT: BCVA, 0.01 ± 0.47 logMAR vs. 0.04 ± 0.18 logMAR, P-value = 0.756; CMT: - 36.3 ± 99.4 μm vs. - 114.7 ± 181.4 μm, P-value = 0.146). Only in the PDT group, five eyes (20.8%) did not require additional treatment after the second-line treatment, the adjusted odds ratio indicating no further treatment needed was 11.98 (95% confidence interval: 1.42-2070.07, P-value = 0.019). The E-value for the adjusted odds ratio was 23.44.

CONCLUSIONS

Both second-line treatments for PCV exhibited similar visual and anatomical outcomes. Only in the PDT-treated eyes were there some patients who did not require further treatment after second-line therapy.

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.

Clinical and multimodal imaging findings in a case of serous maculopathy with absence of retinal pigment epithelium (SMARPE)

INTRODUCTION

The differential diagnosis for serous SRF can involve diseases with widely different pathogenic mechanisms that can range from vascular ocular diseases to ocular tumours and paraneoplastic syndromes. Recently, van Dijk et al. have described in three patients a new entity which they have called serous maculopathy with an absence of retinal pigment epithelium (SMARPE). We hereby describe a case of this infrequent macular disease and report its characteristic findings on multimodal imaging.

CASE DESCRIPTION

We present the case of a 65-year-old hyperopic woman with a three-year history of visual acuity (VA) loss in her left eye. Prior optical coherence tomography (OCT) had revealed the presence of serous subretinal fluid that had shown no response to treatment with intravitreal injections. On swept source OCT angiography scan, no macular alterations in the retinal vascular plexus structure were noted and there was no evidence of choroidal neovascularization. Ultra-widefield fluorescence angiography of the left eye revealed an early hyperfluorescent macular spot corresponding to the area of absent RPE and late fluorescein pooling. On ultra-widefield indocyanine green angiography there were no central or peripheral abnormalities of choroidal vascularization.

CONCLUSION

This recently described entity should be considered as a differential diagnosis in persistent serous subretinal fluid. Multimodal imaging helps differentiate SMARPE from its main differential diagnoses, and care should be taken to identify and differentiate it from similar conditions to avoid unnecessary treatment with its possible side effects and complications.

Fluorescein versus Indocyanine Green Angiography Guided Half-Dose Photodynamic Therapy for Chronic Central Serous Chorioretinopathy

Purpose

To compare the outcomes of fluorescein angiography (FA)-guided and indocyanine green angiography (ICGA)-guided half-dose photodynamic therapy (PDT) in patients with chronic central serous chorioretinopathy (CSC).

Methods

In this retrospective comparative study, medical records of eyes with chronic CSC who underwent half-dose PDT were reviewed. A retina specialist performed FA-guided half-dose PDT, and the other performed ICGA-guided treatment. The success of applying PDT in the resolution of subretinal fluid was compared between the FA- and ICGA-guided methods.

Results

Eighty-two eyes of 73 patients (41 eyes in each group) received half-dose PDT. After half-dose PDT, a significant improvement in the best-corrected visual acuity (BCVA) was found at the time of the last follow-up in both groups (both P < 0.001), with no significant intergroup difference. Central subfield and subfoveal choroidal thicknesses decreased significantly in both groups at the last follow-up (all P < 0.05), with no significant differences between the groups. Subretinal fluid (SRF) resolved in all eyes, and no persistent SRF was detected during the follow-up period.

Conclusion

FA-guided and ICG-guided half-dose PDT may have similar efficacy for the treatment of chronic CSC.

Characteristics Related to Visual Acuity Loss After Successful Photodynamic Therapy for Eyes With Central Serous Chorioretinopathy

PURPOSE

This study aimed to examine baseline characteristics for identifying factors associated with vision loss (VL) in patients with central serous chorioretinopathy (CSC) who successfully responded to photodynamic therapy (PDT).

DESIGN

A retrospective, clinical case-control study.

METHODS

This study included 85 eyes with CSC, which underwent PDT, and resolved serous retinal detachment. These eyes were classified into 2 groups: the VL group (best-corrected visual acuity 6 months after PDT was worse than that at baseline) and the vision maintenance or improved group (the others). Baseline factors were analyzed to determine the characteristics of the VL group and assess the diagnostic potential of these factors.

RESULT

Seventeen eyes were included in the VL group. The mean values of the neurosensory retinal (NSR) thickness, the internal limiting membrane-external limiting membrane thickness (IET), and the external limiting membrane-photoreceptor outer segment thickness (EOT) in the VL group were significantly thinner than those in the vision maintenance or improved group (NSR thickness, 123.2 ± 39.7 µm vs 166.3 ± 49.6 µm, P < .001; IET, 63.1 ± 17.0 µm vs 88.0 ± 25.4 µm, P < .001; EOT, 60.1 ± 28.6 µm vs 78.3 ± 33.1, P = .041). The sensitivity, specificity, and positive and negative predictive values for predicting VL were 94.1%, 50.0%, 32.0%, and 97.1% for NSR thickness; 94.1%, 51.5%, 32.7%, and 97.2% for IET; and 94.1%, 30.9%, 25.4%, and 95.5% for EOT, respectively.

CONCLUSIONS

Pretreatment sensory retinal layer thickness could predict VL after PDT for CSC and may be a helpful reference for PDT.

A Photodynamic Therapy Index for Central Serous Chorioretinopathy to Predict Visual Prognosis Using Pretreatment Factors

PURPOSE

This study aimed to establish a treatment index based on functional outcomes of photodynamic therapy (PDT) for central serous chorioretinopathy (CSC).

DESIGN

A retrospective clinical case-control study.

METHODS

This was a single-institute study. Eighty (80) eyes with CSC, who were treated by PDT and whose subretinal fluid resolves within 6 months were divided into two groups: those with poor visual outcome (PVO) (best-corrected visual acuity [BCVA] ≤ 0.5 6 months post-PDT), and the remaining eyes (better visual outcome [BVO]). The areas under the curve (AUC) and cutoff values from receiver operating characteristic curves were examined. These was used to predict the groups using pretreatment BCVA and the thickness of each retinochoroidal layer.

RESULT

Twenty-one (21) eyes were in the PVO group and 59 eyes in the BVO group were included. The AUCs were 0.959 for BCVA, 0.959 for the thickness from the internal limiting membrane to the external limiting membrane (IET), 0.820 for the thickness from the external limiting membrane to the photoreceptor outer segment layer, 0.715 for the subfoveal retinal thickness, and 0.515 for the subfoveal choroidal thickness. The BCVA and IET cut-off values were 0.267 logMAR and 71.5 µm, respectively. Using the combination of the cutoff values of BCVA and IET, the highest values for the sensitivity, specificity, positive predictive value, and negative predictive value were 95.2%, 94.9%, 85.0%, and 98.0%, respectively.

CONCLUSION

The combination of pre-PDT BCVA and IET in CSC can accurately predict the post-treatment visual prognosis. These values could be used as a treatment index of PDT for CSC.

Scientific Literature Database Coverage of Randomized Clinical Trials for Central Serous Chorioretinopathy

BACKGROUND

Systematic literature searches are the cornerstone of systematic reviews. In this study, we evaluated database coverage of randomized clinical trials for central serous chorioretinopathy (CSC).

METHODS

We searched 12 databases (BIOSIS Previews, CINAHL, the Cochrane Central, Current Contents Connect, Data Citation Index, Derwent Innovations Index, EMBASE, KCI-Korean Journal Database, MEDLINE, PubMed, SciELO Citation Index, and Web of Science Core Collection) on 10 April 2023 for randomized clinical trials for CSC. After identifying all eligible studies across all databases, we investigated the coverage of these studies within each database, including the coverage of any combination of two databases.

RESULTS

The 12 databases yielded 848 records for screening, of which 76 were randomized clinical trials for CSC. No single database provided full coverage. The most comprehensive coverage was provided by EMBASE (88%), the Cochrane Central (87%), and PubMed (75%). A combined search in the Cochrane Central and PubMed led to complete coverage (100%) while reducing the number of records for screening from 848 to 279.

CONCLUSIONS

Systematic review search design should include multiple databases. For randomized clinical trials for CSC, the combination of the Cochrane Central and PubMed provides an excellent balance between coverage and workload.

Risk of Central Serous Chorioretinopathy in Male Androgen Abusers

INTRODUCTION

Male gender is an important risk factor of central serous chorioretinopathy (CSC), and studies have explored the pathophysiological role of androgens in CSC with conflicting results. In this study, we shed light on this hot topic by exploring the risk of CSC in a large cohort of male androgen abusers.

METHODS

This study included male androgen abusers identified through a nationwide anti-doping test program across Danish fitness centers from January 3 2006 to March 1 2018. For each case, we randomly sampled ten male controls using Danish nationwide registries. These controls were matched in age and date. Cases and controls were followed until May 16 2018. Data on diagnoses were extracted using the Danish National Registry of Patients using ICD-10 codes to identify cases with CSC.

RESULTS

We included 1189 cases and 11,890 controls. Mean age at the time of doping sentence was 27.4 ± 6.9 years, and mean length of follow-up was 15.8 ± 3.6 years. We identified no cases of CSC in androgen abusers, and five cases of CSC in the control cohort. The difference between groups was not statistically significant (P = 1.0).

CONCLUSIONS

Male androgen abusers were not at increased risk of CSC. Considering the lack of any signal in this large study, we speculate that if male androgen plays any direct role in the pathophysiology of CSC, its role may be subtle at best.

Half-Fluence, Half-Dose Photodynamic Therapy: Less Direct Damage but More Inflammation?

Objective: To present clinical findings and multimodal imaging of three patients who developed bacillary layer detachments (BALADs) shortly after half-fluence, half-dose (HFHD) verteporfin photodynamic therapy (PDT). Methods: Retrospective observational case series. Three patients were treated with HFHD-PDT for (1) macular neovascularisation five years after resolved central serous chorioretinopathy (CSC), (2) persistent serous retinal detachment (SRD) from chronic CSC, and (3) neovascular age-related macular degeneration with persistent SRD despite intravitreal anti-VEGF therapy. Results: Each patient developed a BALAD after HFHD-PDT. Acute fulminant exudation caused subretinal fluid expansion into the inner photoreceptor layer, cleaving myoid from ellipsoid zones in the central macula. Subretinal fluid and the BALADs subsequently resolved over 6–8 weeks. Conclusions: The subretinal fluid and BALAD following HFHD-PDT were transient and did not cause photoreceptor damage over a 6-month follow-up period. We speculate that the reduced-impact HFHD protocol decreases direct tissue damage but increases proinflammatory cytokines. The long-term pathophysiological consequences of the resolved BALADs are unknown.

Cupric-ion-promoted fabrication of oxygen-replenishing nanotherapeutics for synergistic chemo and photodynamic therapy against tumor hypoxia

Mixing a glutathione (GSH)-responsive carboxy zinc(II) phthalocyanine (ZnPc*) and CuSO₄·5H₂O in water with or without the presence of the anticancer drug SN38 resulted in the formation of self-assembled nanotherapeutics labeled as ZnPc*/Cu/SN38@NP and ZnPc*/Cu@NP, respectively. The Cu²⁺ ions not only promoted the self-assembly of the carboxy phthalocyanine through metal complexation, but also catalyzed the transformation of H₂O₂ to oxygen via a catalase-like reaction, rendering an oxygen-replenishing property to the nanosystems. Both nanosystems exhibited high stability in aqueous media, but the nanoparticles disassembled gradually in an acidic or GSH-enriched environment and inside human colorectal adenocarcinoma HT29 cells, releasing the encapsulated therapeutic components. The disassembly process together with the activation by the intracellular GSH led to relaxation of the intrinsic quenching of the nanophotosensitizers and restoration of the photoactivities of ZnPc*. Under a hypoxic condition, ZnPc*/Cu/SN38@NP could attenuate the intracellular hypoxia level and maintain the photodynamic activity due to its Cu²⁺-promoted oxygen-replenishing ability. The photodynamic effect of ZnPc* and the anticancer effect of SN38 worked cooperatively, causing substantial apoptotic cell death. The dual therapeutic actions could also effectively inhibit the tumor growth in HT29 tumor-bearing nude mice without initiating notable adverse effects to the mice. STATEMENT OF SIGNIFICANCE: The oxygen-dependent nature of photodynamic therapy generally reduces its efficacy against tumor hypoxia, which is a common characteristic of advanced solid tumors and usually leads to resistance toward various anticancer therapies. We report herein a facile approach to assemble a glutathione-responsive carboxy phthalocyanine-based photosensitizer and an anticancer drug in aqueous media, in which Cu(II) ions were used to promote the self-assembly through metal complexation and catalyze the conversion of H₂O₂ to oxygen through a catalase-like reaction, making the resulting nanoparticles possessing an oxygen-replenishing property that could promote the photodynamic effect against hypoxic cancer cells and tumors. The use of Cu(II) ions to achieve the aforementioned dual functions in the fabrication of advanced nano-photosensitizing systems has not been reported.

Long-term follow-up of chronic central serous chorioretinopathy patients after primary treatment of oral eplerenone or half-dose photodynamic therapy and crossover treatment: SPECTRA trial report No. 3

PURPOSE

Comparing anatomic and functional efficacy and safety of primary treatment with either half-dose photodynamic therapy (PDT) or oral eplerenone, or crossover treatment in chronic central serous chorioretinopathy patients.

METHODS

After the SPECTRA trial baseline visit, patients were randomized to either half-dose PDT or eplerenone and received crossover treatment if persistent subretinal fluid (SRF) on optical coherence tomography (OCT) was present at first follow-up (at 3 months). Presence of SRF and best-corrected visual acuity (BCVA) was evaluated at 12 months.

RESULTS

Out of the 90 patients evaluated at 12 months, complete SRF resolution was present on OCT in 43/48 (89.6%) of patients who were primarily randomized to half-dose PDT and in 37/42 (88.1%) who were primarily randomized to eplerenone. Out of the 42 patients that were primarily randomized to eplerenone, 35 received crossover treatment with half-dose PDT. The BCVA improved significantly more at 12 months in patients who had received primary half-dose PDT as compared to the primary eplerenone group (p = 0.030).

CONCLUSIONS

Twelve months after baseline visit, most patients treated with half-dose PDT (either primary or crossover treatment) still had complete SRF resolution. The long-term BCVA in patients who receive primary half-dose PDT is better than in patients in whom PDT is delayed due to initial eplerenone treatment with persistent SRF.

INCREASING EVIDENCE FOR THE SAFETY OF FOVEA-INVOLVING HALF-DOSE PHOTODYNAMIC THERAPY FOR CHRONIC CENTRAL SEROUS CHORIORETINOPATHY

PURPOSE

A retrospective study was performed with data from the prospective randomized controlled trials, PLACE and SPECTRA, assessing the risk of foveal atrophy and the likelihood of structural and functional improvement on optical coherence tomography, after foveal half-dose photodynamic therapy in chronic central serous chorioretinopathy.

METHODS

A total of 57 chronic central serous chorioretinopathy patients received a single half-dose photodynamic therapy with a treatment spot that included the fovea. Optical coherence tomography scans and fundus autofluorescence images were analyzed for structural improvement and possible atrophy development, at baseline and at several visits after treatment. Main outcome measures were integrity of the external limiting membrane and ellipsoid zone on optical coherence tomography and hypoautofluorescence on fundus autofluorescence.

RESULTS

The subfoveal external limiting membrane was graded as continuous in 21 of 57 of patients (36.8%) at baseline, and the subfoveal ellipsoid zone was graded as continuous in 5 of 57 patients (8.8%) at first visit, which improved to 50 of 51 (98.0%) and 32 out of 51 (62.7%) at the final visit at 2 years, respectively (both P < 0.001). Hypoautofluorescent changes on fundus autofluorescence were present in 25 of 55 patients (45.5%) at baseline and in 23 of 51 patients (45.1%) at the final visit ( P = 0.480).

CONCLUSION

In patients with chronic central serous chorioretinopathy who received a single, foveal, half-dose photodynamic therapy, a significant improvement in structure and function was seen at the final follow-up. None of the patients developed foveal atrophy.

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.

A Masquerade Case: Choroidal Hemangioma Misdiagnosed As Central Serous Retinopathy

Purpose

To report a case of misdiagnosed choroidal hemangioma, initially treated as central serous retinopathy (CSR) complicated by choroidal neovascularization (CNV), and to improve the proper identification of this disorder.

Observations

Fundus images revealed a subtle, elevated choroidal lesion with an associated exudative detachment and choroidal vascular lesion on indocyanine green (ICG) angiography. Combined treatment with photodynamic therapy (PDT) and anti-VEGF therapy led to resolution of fluid and improvement in VA from 20/50 to 20/25.

Conclusion

It is critical to understand the clinical features of choroidal hemangiomas and their physical presentation on retinal testing to diagnose and treat them in a timely and appropriate manner.

Clinical impact of the worldwide shortage of verteporfin (Visudyne®) on ophthalmic care

INTRODUCTION

Since July 2021, a worldwide shortage of verteporfin (Visudyne®) occurred: an essential medicine required for photodynamic therapy (PDT). PDT with verteporfin has a broad range of indications in ophthalmology, including chronic central serous chorioretinopathy, polypoidal choroidal vasculopathy and choroidal haemangioma. For these disorders, PDT is either the first-choice treatment or regarded as a major treatment option.

MATERIALS AND METHODS

A questionnaire was sent to key opinion leaders in the field of medical retina throughout the world, to assess the role of PDT in their country and the effects of the shortage of verteporfin. In addition, information on the application of alternative treatments during shortage of verteporfin was obtained, to further assess the impact of the shortage.

RESULTS

Our questionnaire indicated that the shortage of verteporfin had a major impact on ophthalmic care worldwide and was regarded to be a serious problem by most of our respondents. However, even though there is ample evidence to support the use of PDT in several chorioretinal diseases, we found notable differences in its use in normal patient care throughout the world. Various alternative management strategies were noted during the verteporfin shortage, including lowering the dose of verteporfin per patient, the use of alternative treatment strategies and the use of a centralized system for allocating the remaining ampoules of verteporfin in some countries.

CONCLUSION

The shortage of verteporfin has had a large effect on the care of ophthalmic patients across the world and may have resulted in significant and irreversible vision loss. Mitigation strategies should be developed in consultation with all stakeholders to avoid future medication shortages of verteporfin and other unique ophthalmic medications. These strategies may include mandatory stock keeping, compulsory licensing to an alternative manufacturer or incentivizing the development of competition, for example through novel public-private partnerships.

Novel Short PEG Chain-Substituted Porphyrins: Synthesis, Photochemistry, and In Vitro Photodynamic Activity against Cancer Cells

This work presents the synthesis and characterization of metal-free, zinc (II), and cobalt (II) porphyrins substituted with short PEG chains. The synthesized compounds were characterized by UV-Vis, ¹H and ¹³C NMR spectroscopy, and MALDI-TOF mass spectrometry. The origin of the absorption bands for tested compounds in the UV-Vis range was determined using a computational model based on the electron density functional theory (DFT) and its time-dependent variant (TD-DFT). The photosensitizing activity was evaluated by measuring the ability to generate singlet oxygen (ΦΔ), which reached values up to 0.54. The photodynamic activity was tested using bladder (5637), prostate (LNCaP), and melanoma (A375) cancer cell lines. In vitro experiments clearly showed the structure-activity relationship regarding types of substituents, their positions in the phenyl ring, and the variety of central metal ions on the porphyrin core. Notably, the metal-free derivative 3 and its zinc derivative 6 exerted strong cytotoxic activity toward 5637 cells, with IC₅₀ values of 8 and 15 nM, respectively. None of the tested compounds induced a cytotoxic effect without irradiation. In conclusion, these results highlight the potential value of the tested compounds for PDT application.

European Prevalence of Polypoidal Choroidal Vasculopathy: A Systematic Review, Meta-Analysis, and Forecasting Study

The purpose of this study was to provide an estimate of the number of current and future patients with polypoidal choroidal vasculopathy (PCV) in Europe. We systematically searched 11 literature databases on 18 May 2022 for studies on the prevalence of PCV among a consecutive and representative group of patients with suspected neovascular age-related macular degeneration (AMD). Prevalence of PCV in patients with suspected neovascular AMD was summarized and included in a prevalence meta-analysis. We then used current population data and population forecasts by Eurostat and the Office for National Statistics to determine current and future number of patients with neovascular AMD in Europe. Then, we calculated the number of patients with PCV with our calculated estimate of the prevalence of PCV among Europeans suspected with neovascular AMD. A total of five eligible studies were identified which included a total of 1359 patients. All these studies used the gold standard of indocyanine green angiography as a routine part of their diagnostic approach. Among patients undergoing detailed retinal examination for suspected neovascular AMD, our meta-analysis calculated the prevalence of PCV to be 8.3% (95% confidence interval: 6.8–9.8%). Our population estimates find that a total of 217,404 patients with PCV exist in Europe in the year 2022, which constitutes 0.04% of the entire population of Europe. This number is estimated to increase to 287,517 patients in the year 2040. Our estimates are important for different healthcare stakeholders, especially when planning and allocating expensive resources.

pH-Activatable Organic Nanoparticles for Efficient Low-Temperature Photothermal Therapy of Ocular Bacterial Infection

Low-temperature photothermal therapy (PTT) systems constructed by integrating organic photothermal agents with other bactericidal components that initiate bacterial apoptosis at low hyperthermia possess a promising prospect. However, these multicomponent low-temperature PTT nanoplatforms have drawbacks in terms of the tedious construction process, suboptimal synergy effect of diverse antibacterial therapies, and high laser dose needed, compromising their biosafety in ocular bacterial infection treatment. Herein, a mild PTT nanotherapeutic platform is formulated via the self-assembly of a pH-responsive phenothiazinium dye. These organic nanoparticles with photothermal conversion efficiency up to 84.5% necessitate only an ultralow light dose of 36 J/cm² to achieve efficient low-temperature photothermal bacterial inhibition at pH 5.5 under 650 nm laser irradiation. In addition, this intelligent mild photothermal nanoplatform undergoes negative to positive charge reversion in acid biofilms, exhibiting good penetration and highly efficient elimination of drug-resistant E. coli biofilms under photoirradiation. Further in vivo animal tests demonstrated efficient bacterial elimination and inflammatory mitigation as well as superior biocompatibility and biosafety of the photothermal nanoparticles in ocular bacterial infection treatment. Overall, this efficient single-component mild PTT system featuring simple construction processes holds great potential for wide application and clinical transformation.

Verteporfin Inhibits the Progression of Spontaneous Osteosarcoma Caused by Trp53 and Rb1 Deficiency in Ctsk-Expressing Cells via Impeding Hippo Pathway

Osteosarcoma is the most common primary malignancy of bone in children and adolescents. Others and our previous studies have shown that Yes-associated protein (YAP)/transcriptional coactivator with PDZ-binding motif (TAZ) as core components of the Hippo pathway are crucial regulators of osteosarcoma formation and progression. Recent studies demonstrated that verteporfin (VP) is an inhibitor of YAP/TAZ signaling in xenograft osteosarcoma. However, whether VP can inhibit primary osteosarcoma in mice is unknown. Mutations of Trp53 and Rb1 occur in approximately 50~70% of human osteosarcoma. In this study, we successfully generated the Ctsk-Cre;Trp53^f/f/Rb1^f/f mice in which Trp53/Rb1 was ablated in Ctsk-expressing cells and found that Ctsk-Cre;Trp53^f/f/Rb1^f/f mice spontaneously developed osteosarcoma with increased expansive osteoid lesions in the cortical bone with aging. Loss of Trp53/Rb1 in Ctsk-expressing cells significantly promoted the expression and nuclear translocation of YAP/TAZ. Micro-CT results showed that inhibition of YAP/TAZ by VP delays osteosarcoma progression and protected against bone erosion in Ctsk-Cre;Trp53^f/f/Rb1^f/f mice. Importantly, the Kaplan–Meier survival curves displayed a significantly longer survival rate after VP treatment in Ctsk-Cre;Trp53^f/f/Rb1^f/f mice compared to non-injected groups. In vitro studies further showed that VP inhibited the proliferation, migration and invasion in Trp53/Rb1-mutant Ctsk-expressing cells. Moreover, the results from promoter luciferase activity analysis showed that the transcriptional activity of YAP/TAZ was significantly increased in osteosarcoma tissue from Ctsk-Cre;Trp53^f/f/Rb1^f/f mice, which was attenuated by VP treatment. Overall, these findings suggest that targeting Hippo pathway by VP may be a potential therapeutic strategy for osteosarcoma.

Site-Specific Displacement-Driven Activation of Supramolecular Photosensitizing Nanoassemblies for Antitumoral Photodynamic Therapy

The delivery and activation of photosensitizers in a specific manner is crucial in photodynamic therapy. For an antitumoral application, it can confine the photodynamic action on the cancer cells, thereby enhancing the treatment efficacy and reducing the side effects. We report herein a novel supramolecular photosensitizing nanosystem that can be specifically activated in cancer cells and tumors that overexpress epidermal growth factor receptor (EGFR). It involves the self-assembly of the amphiphilic host-guest complex of a β-cyclodextrin-conjugated phthalocyanine-based photosensitizer (Pc-CD) and a ferrocene-substituted poly(ethylene glycol) (Mn = 2000) (Fc-PEG) in aqueous media. The resulting nanosystem Pc-CD@Fc-PEG with a hydrodynamic diameter of 124-147 nm could not emit fluorescence and generate reactive oxygen species due to the self-quenching effect and the ferrocene-based quencher. Upon interactions with molecules of adamantane substituted with an EGFR-targeting peptide (Ad-QRH*) in water and in EGFR-positive HT29 and A431 cells, the ferrocene guest species were displaced, resulting in disassembly of the nanoparticles and restoration of these photoactivities. The half-maximal inhibitory concentration values were down to 1.24 μM (for HT29 cells). The nanosystem Pc-CD@Fc-PEG could also be activated in an Ad-QRH*-treated HT29 tumor in nude mice, leading to increased intratumoral fluorescence intensity and effective eradication of the tumor upon laser irradiation. The results showed that this two-step supramolecular approach can actualize site-specific photosensitization and minimize nonspecific phototoxicity in a general photodynamic treatment.

Alkaloids as Photosensitisers for the Inactivation of Bacteria

Antimicrobial photodynamic therapy has emerged as a powerful approach to tackle microbial infections. Photodynamic therapy utilises a photosensitiser, light, and oxygen to generate singlet oxygen and/or reactive oxygen species in an irradiated tissue spot, which subsequently react with nearby biomolecules and destroy the cellular environment. Due to the possibility to irradiate in a very precise location, it can be used to eradicate bacteria, fungus, and parasites upon light activation of the photosensitiser. In this regard, natural products are low-cost molecules capable of being obtained in large quantities, and some of them can be used as photosensitisers. Alkaloids are the largest family among natural products and include molecules with a basic nature and aromatic rings. For this study, we collected the naturally occurring alkaloids used to treat microorganism infections using a photodynamic inactivation approach. We gathered their main photophysical properties (excitation/emission wavelengths, quantum yields, and oxygen quantum yield) which characterise the ability to efficiently photosensitise. In addition, we described the antibacterial activity of alkaloids upon irradiation and the mechanisms involved in the microorganism killing. This review will serve as a reference source to obtain the main information on alkaloids used in antimicrobial photodynamic therapy.

Therapeutic effect of a traditional Chinese medicine formulation on experimental choroidal neovascularization in mouse

AIM

To investigate therapeutic effects of traditional Chinese medicine formulations, Hexuemingmu (HXMM) on laser-induced choroidal neovascularization (CNV) and follow-up effect in mice.

METHODS

C57BL/6 mice of 8-week-old were used and CNV was induced with 577 nm laser photocoagulation. Animals were randomly divided into groups and different doses of HXMM were administered daily. One, four, and eight weeks after the intervention, the electroretinogram (ERG), fundus fluorescence angiography, choroidal flat mount and immunofluorescence staining were preformed to evaluate the function and CNV formation. The expression levels of angiogenic proteins were determined by Western blotting and immunofluorescence staining. An analysis of variance and Kruskal-Wallis test were used to test the differences among the groups.

RESULTS

The results showed that HXMM effectively increased amplitude of ERG of mice (P<0.05), alleviated fundus CNV leakage (P<0.05), and reduced the area of neovascularization and the expression of angiogenic proteins (P<0.05) after laser-induced CNV.

CONCLUSION

HXMM can protect the retinal function of mice after laser-induced CNV, and inhibit the CNV development.

Exploring the choroidal vascular labyrinth and its molecular and structural roles in health and disease

The choroid is a key player in maintaining ocular homeostasis and plays a role in a variety of chorioretinal diseases, many of which are poorly understood. Recent advances in the field of single-cell RNA sequencing have yielded valuable insights into the properties of choroidal endothelial cells (CECs). Here, we review the role of the choroid in various physiological and pathophysiological mechanisms, focusing on the role of CECs. We also discuss new insights regarding the phenotypic properties of CECs, CEC subpopulations, and the value of measuring transcriptomics in primary CEC cultures derived from post-mortem eyes. In addition, we discuss key phenotypic, structural, and functional differences that distinguish CECs from other endothelial cells such as retinal vascular endothelial cells. Understanding the specific clinical and molecular properties of the choroid will shed new light on the pathogenesis of the broad clinical range of chorioretinal diseases such as age-related macular degeneration, central serous chorioretinopathy and other diseases within the pachychoroid spectrum, uveitis, and diabetic choroidopathy. Although our knowledge is still relatively limited with respect to the clinical features and molecular pathways that underlie these chorioretinal diseases, we summarise new approaches and discuss future directions for gaining new insights into these sight-threatening diseases and highlight new therapeutic strategies such as pluripotent stem cell‒based technologies and gene therapy.

Photodynamic Therapy—An Up-to-Date Review

The healing power of light has attracted interest for thousands of years. Scientific discoveries and technological advancements in the field have eventually led to the emergence of photodynamic therapy, which soon became a promising approach in treating a broad range of diseases. Based on the interaction between light, molecular oxygen, and various photosensitizers, photodynamic therapy represents a non-invasive, non-toxic, repeatable procedure for tumor treatment, wound healing, and pathogens inactivation. However, classic photosensitizing compounds impose limitations on their clinical applications. Aiming to overcome these drawbacks, nanotechnology came as a solution for improving targeting efficiency, release control, and solubility of traditional photosensitizers. This paper proposes a comprehensive path, starting with the photodynamic therapy mechanism, evolution over the years, integration of nanotechnology, and ending with a detailed review of the most important applications of this therapeutic approach.

Serous business: Delineating the broad spectrum of diseases with subretinal fluid in the macula

A wide range of ocular diseases can present with serous subretinal fluid in the macula and therefore clinically mimic central serous chorioretinopathy (CSC). In this manuscript, we categorise the diseases and conditions that are part of the differential diagnosis into 12 main pathogenic subgroups: neovascular diseases, vitelliform lesions, inflammatory diseases, ocular tumours, haematological malignancies, paraneoplastic syndromes, genetic diseases, ocular developmental anomalies, medication-related conditions and toxicity-related diseases, rhegmatogenous retinal detachment and tractional retinal detachment, retinal vascular diseases, and miscellaneous diseases. In addition, we describe 2 new clinical pictures associated with macular subretinal fluid accumulation, namely serous maculopathy with absence of retinal pigment epithelium (SMARPE) and serous maculopathy due to aspecific choroidopathy (SMACH). Differentiating between these various diseases and CSC can be challenging, and obtaining the correct diagnosis can have immediate therapeutic and prognostic consequences. Here, we describe the key differential diagnostic features of each disease within this clinical spectrum, including representative case examples. Moreover, we discuss the pathogenesis of each disease in order to facilitate the differentiation from typical CSC.

Long term outer retinal changes in central serous chorioretinopathy submitted to half-dose photodynamic therapy

PURPOSE

To evaluate long-term changes in the foveal and parafoveal outer retina after half-dose photodynamic therapy (HD-PDT) in central serous chorioretinopathy (CSC).

METHODS

Retrospective study including CSC patients submitted to HD-PDT. Best corrected visual acuity (BCVA) was evaluated. Spectral-domain optical coherence tomography automatic segmentation algorithm was used and data on retinal, inner retinal, outer retinal and outer nuclear layers (ONL) in both foveal 1 mm (C) and parafoveal 3 mm ETDRS circles for the superior, nasal, inferior and temporal sectors, were obtained at baseline and 3, 12 and 24 months post-treatment. Subfoveal choroidal thickness, photoreceptors' outer segment thickness, subretinal fluid (SRF) height and width were also measured.

RESULTS

Twenty-one eyes of 15 patients were included. At baseline, the mean ONL thickness in the foveal area was significantly thinner in affected eyes compared to their fellow unaffected ones (55,50 ± 32,75 μm vs 93,00 ± 17,0 μm; p = 0,011), and was negatively correlated to logMAR BCVA (R=-0,601, p = 0,008) ONL thickness increased by 10,94 ± 11,88 μm at 24 months in the foveal area, and all the parafoveal sectors presented a similar increase. Baseline SRF width was significantly correlated with baseline BCVA (R1 = 0,483, p = 0,036), and with ONL thickness in all sectors.

CONCLUSION

In our study we found a significant long-term increase in foveal and parafoveal ONL thickness in CSC after HD-PDT, suggesting that this seems to be a safe treatment for the outer retina. This is the first study mapping the outer retinal changes in the macular area to 24 months follow up.

Plasma Levels of Matrix Metalloprotease MMP-9 and Tissue Inhibitor TIMP-1 in Caucasian Patients with Polypoidal Choroidal Vasculopathy

BACKGROUND

Matrix metalloproteinase 9 (MMP-9) and tissue inhibitor of metalloproteinases 1 (TIMP-1) are regulating enzymes of the extracellular matrix. A systemic imbalance of MMP-9 and TIMP-1, thought to reflect an imbalance of the extracellular matrix homeostasis, is previously associated with polypoidal choroidal vasculopathy (PCV) in Asian patients. Previous studies suggest inter-ethnical differences in the genetic background and etiology of PCV. To further explore this issue, we studied the plasma levels of MMP-9 and TIMP-1 in Caucasian patients with PCV and compared to healthy age-matched controls.

METHODS

For this prospective case-control study, 60 participants were recruited who were either patients with PCV (n = 26) or healthy controls (n = 34). All participants underwent detailed clinical examination. We sampled fresh venous blood, isolated plasma, and quantified plasma concentrations of the extracellular matrix regulators MMP-9 and TIMP-1 using electrochemiluminescence immunoassays.

RESULTS

Plasma levels of MMP-9 (p = 0.4), TIMP-1 (p = 0.9), and MMP-9/TIMP-1 ratio (p = 0.4) did not differ significantly between patients with PCV and healthy controls. No differences appeared after adjusting for influencing co-variates in multivariate analyses.

CONCLUSION

We demonstrate that Caucasian patients with PCV do not have altered levels of plasma MMP-9 or plasma TIMP-1. These findings suggest no strong evidence of a systemic imbalance of the extracellular matrix homeostasis in Caucasian patients with PCV. Our findings are in line with studies of other aspects of PCV that are also subject to significant inter-ethnical differences.