Photodynamic therapy with verteporfin in age-related macular degeneration: a systematic review of efficacy, safety, treatment modifications and pharmacoeconomic properties

pH-Sensitive and Lysosome Targetable Photosensitizers Based on BODIPYs

Photodynamic therapy (PDT) is an effective and U.S. Food and Drug Administration (FDA) approved treatment for cancer and other diseases. Photosensitizer is one of the three key components that harvest the energy of light at a certain wavelength. Compared to the conventional fluorophores used as photosensitizers, boron dipyrromethene (BODIPY) derivatives have grown fast in recent years due to their low dark toxicity, versatile tunable sites, and easiness of being paired with other treatments. In this paper, two pH-sensitive BODIPY-based photosensitizers (BDC and BDBrC) were synthesized by adding carbazole moieties onto the BODIPY cores (BD and BDBr) through condensation reactions. BDBrC has two Br atoms at the BODIPY core that promote singlet oxygen generation and further red-shift the absorption maximum peak. Both compounds showed sensitivity toward pH change and generated more singlet oxygen under acidic conditions. The cellular uptake and cell imaging experiments showed that BDBrC can selectively target the lysosome organelle. The further dark cell viability and light cytotoxicity indicate the light triggered PDT treatment can be accomplished with BDBrC.

Verteporfin Exerts Anticancer Effects and Reverses Resistance to Paclitaxel via Inducing Ferroptosis in Esophageal Squamous Cell Cancer Cells

Esophageal squamous cell carcinoma (ESCC) is one of the most common malignant tumors. Ferroptosis is a new form of regulated cell death and targeting ferroptosis provides a novel therapeutic approach for human cancers. Verteporfin (VP) has been identified as a Yes-associated protein (YAP) inhibitor for treatment of several human cancers. However, it remains unclear whether VP exerts anticancer activity by inducing ferroptosis in ESCC cells. In the current study, we found that VP reduced cell viability and led to cell death in ESCC cell lines (KYSE150 and KYSE30) by inhibiting YAP expression. Subsequently, the findings revealed that VP treatment triggered significant ferroptosis events, including accumulation of Fe2+, reactive oxygen species (ROS) and malondialdehyde (MDA), reduction of mitochondrial membrane potential (MMP), glutathione (GSH) and glutathione peroxidase 4 (GPX4) expression. Further study showed that the effects of ESCC cell proliferation and death caused by VP could be reversed by ferroptosis inhibitor ferrostatin-1 (Fer-1). Moreover, VP enhanced the chemosensitivity of ESCC resistant cells to paclitaxel (PTX). And VP combined with PTX can synergistically inhibit cell proliferation and induce cell death by triggering ferroptosis of PTX-resistant cells. All these data suggested that VP suppressed ESCC cell survival and reversed resistance to PTX through inducing ferroptosis, which may provide a promising therapeutic strategy for ESCC.

A Trojan horse approach for efficient drug delivery in photodynamic therapy: focus on taxanes

Photodynamic therapy is an effective method for the treatment of several types of cancerous and noncancerous diseases. The key to the success of this treatment method is effective drug delivery to the site of action, for instance, a tumor. This ensures not only the high effectiveness of the therapy but also the suppression of side effects. But how to achieve effective targeted delivery? Lately, much attention has been paid to systems based on the so-called Trojan horse model, which is gaining increasing popularity. The principle of this model is that the effective drug is hidden in the internal structure of a nanoparticle, liposome, or nanoemulsion and is released only at the site of action. In this review article, we focus on drugs from the group of mitotic poisons, taxanes, and their use with photosensitizers in combined therapy. Here, we discuss the possibilities of how to improve the paclitaxel and docetaxel bioavailability, as well as their specific targeting for use in combined photo- and chemotherapy. Moreover, we also present the state of the art multifunctional drugs based on cabazitaxel which, owing to a suitable combination with photosensitizers, can be used besides photodynamic therapy and also in photoacoustic imaging or sonodynamic therapy.

Trial watch: an update of clinical advances in photodynamic therapy and its immunoadjuvant properties for cancer treatment

Photodynamic therapy (PDT) is a medical treatment used to target solid tumors, where the administration of a photosensitizing agent and light generate reactive oxygen species (ROS), thus resulting in strong oxidative stress that selectively damages the illuminated tissues. Several preclinical studies have demonstrated that PDT can prime the immune system to recognize and attack cancer cells throughout the body. However, there is still limited evidence of PDT-mediated anti-tumor immunity in clinical settings. In the last decade, several clinical trials on PDT for cancer treatment have been initiated, indicating that significant efforts are being made to improve current PDT protocols. However, most of these studies disregarded the immunological dimension of PDT. The immunomodulatory properties of PDT can be combined with standard therapy and/or emerging immunotherapies, such as immune checkpoint blockers (ICBs), to achieve better disease control. Combining PDT with immunotherapy has shown synergistic effects in some preclinical models. However, the value of this combination in patients is still unknown, as the first clinical trials evaluating the combination of PDT with ICBs are just being initiated. Overall, this Trial Watch provides a summary of recent clinical information on the immunomodulatory properties of PDT and ongoing clinical trials using PDT to treat cancer patients. It also discusses the future perspectives of PDT for oncological indications.

Two-year clinical outcomes of triple therapy with photodynamic therapy, anti-vascular endothelial growth factor agent, and triamcinolone acetonide for neovascular age-related macular degeneration

PURPOSE

To analyze the 2-year treatment outcomes of triple therapy with standard-fluence photodynamic therapy (PDT), intravitreal injection of ranibizumab (IVR)/aflibercept (IVA), and sub-tenon injection of triamcinolone acetonide (STTA) for neovascular age-related macular degeneration (nAMD) in Japanese patients.

STUDY DESIGN

A retrospective, clinical case-series study.

METHODS

Forty-four eyes of 44 patients with treatment-naïve nAMD followed for more than 24 months were evaluated. Initial treatment was given with triple therapy and retreatment with IVR/IVA as a pro re nata regimen. Best-corrected visual acuity (BCVA), central retinal thickness (CRT), the number of treatments, and intraocular pressure elevation were analyzed.

RESULTS

The mean age was 73.3 ± 10.0 years. The mean BCVA significantly improved from 0.61 ± 0.30 at baseline to 0.50 ± 0.46 at 24 months (p = 0.034). CRT significantly improved from 373 ± 162 μm at baseline to 200 ± 107 μm at 24 months (p < 0.001). The number of treatments given during the 2-year treatment period was 2.7 ± 1.8. No retreatments were necessary in 18 of 44 eyes (40.9%), with no significant difference between IVR (46.4%) or IVA (31.3%) used during the 2-year follow-up of triple therapy (p = 0.51). Four eyes (9.1%) temporarily required glaucoma eye drop treatments.

CONCLUSION

In nAMD patients, induction treatment with triple therapy resulted in approximately 40% of the patients requiring no retreatment for 2 years. The type of anti-VEGF agents used made no difference in the results.

Photosensitizer verteporfin inhibits the growth of YAP- and TAZ-dominant gastric cancer cells by suppressing the anti-apoptotic protein Survivin in a light-independent manner

Yes-associated protein (YAP) positivity indicates a poor prognosis in gastric cancer. Transcriptional co-activator with a PDZ-binding domain (TAZ), a YAP paralog, is highly expressed in gastric signet ring cell carcinoma. Verteporfin (VP), a clinical photosensitizer, was recently shown to inhibit YAP/TAZ. In the present study, the therapeutic potential of VP treatment was explored using two gastric cancer cell lines: MKN-45 (TAZ-dominant) and MKN-74 (YAP-dominant). Cell proliferation was evaluated by MTS assay. Vascular mimicry was evaluated by the tube formation assay. Gene and protein expression levels of YAP/TAZ downstream effectors [such as Survivin, Cysteine-rich angiogenic inducer 61 (CYR61), and connective tissue growth factor (CTGF)] were measured. YAP or TAZ localization was evaluated by immunofluorescence. Cell death was assessed by immunofluorescent staining of Annexin V. YAP and TAZ expression were knocked down by small interfering RNA. The current results demonstrate that MKN-45, a poorly differentiated TAZ-dominant gastric cancer cell line, was more sensitive to VP than MKN-74, a moderately differentiated YAP-dominant gastric cancer cell line. VP changed the localization of YAP/TAZ, promoted its degradation and significantly decreased the protein level of Survivin in both cell lines. Cell death was induced by VP treatment in a dose-dependent manner. Vascular mimicry was inhibited in both cell lines. Proliferation in both cell lines decreased in response to YAP/TAZ knockdown. The present study indicated that VP has potential as a therapeutic agent in YAP- and TAZ-dominant gastric cancers due to its ability to suppress the anti-apoptotic protein Survivin via inhibition of YAP and TAZ.

Proportion and Reasons for Ineligibility to Re-register for Extended Health Insurance in Neovascular Age-related Macular Degeneration

Purpose: To evaluate the proportion and reasons for ineligibility to re-register for extended health insurance at 5 years in patients diagnosed with neovascular age-related macular degeneration (AMD) and registered for extended health insurance. Methods: This retrospective study was performed in patients diagnosed with neovascular AMD and registered for extended health insurance with follow-up for at least 5 years. The criteria for re-registration for extended health insurance were determined along with the ineligibility for re-registration. Results: In total, 263 patients were included in the analysis. Of these, 148 (56.3%) did not satisfy the criteria for re-registration. No active treatment was performed in 98 patients during the last 6 months of the study period (no recurrence, 51 patients; additional treatment was not considered beneficial due to retinal damage even without disciform scar formation, 44 patients). Macular disciform scar formation was noted in 50 patients (33.8%). Older age (p = 0.013), poor visual acuity (p = 0.004), and retinal angiomatous proliferation (p < 0.001) were associated with ineligibility for re-registration due to severe retinal damage. Conclusions: Among the patients who were initially registered for extended health insurance, 56.3% failed to satisfy the re-registration criteria. The primary reason was advanced retinal damage. The results of this study provide useful information for patient education and to establish long-term treatment strategies.

Biophysical Characterization and Anticancer Activities of Photosensitive Phytoanthraquinones Represented by Hypericin and Its Model Compounds

Photosensitive compounds found in herbs have been reported in recent years as having a variety of interesting medicinal and biological activities. In this review, we focus on photosensitizers such as hypericin and its model compounds emodin, quinizarin, and danthron, which have antiviral, antifungal, antineoplastic, and antitumor effects. They can be utilized as potential agents in photodynamic therapy, especially in photodynamic therapy (PDT) for cancer. We aimed to give a comprehensive summary of the physical and chemical properties of these interesting molecules, emphasizing their mechanism of action in relation to their different interactions with biomacromolecules, specifically with DNA.

Oxime-based 19-nortestosterone-pheophorbide a conjugate: bimodal controlled release concept for PDT

Photodynamic therapy has become a feasible direction for the treatment of both malignant and non-malignant diseases. It has been in the spotlight since FDA regulatory approval was granted to several photosensitizers worldwide. Nevertheless, there are still strong limitations in the targeting specificity that is vital to prevent systemic toxicity. Here, we report the synthesis and biological evaluation of a novel bimodal oxime conjugate composed of a photosensitizing drug, red-emitting pheophorbide a, and nandrolone (NT), a steroid specifically binding the androgen receptor (AR) commonly overexpressed in various tumors. We characterized the physico-chemical properties of the NT-pheophorbide a conjugate (NT-Pba) and singlet oxygen generation. Because light-triggered therapies have the potential to provide important advances in the treatment of hormone-sensitive cancer, the biological potential of this novel specifically-targeted photosensitizer was assessed in prostatic cancer cell lines in vitro using an AR-positive (LNCaP) and an AR-negative/positive cell line (PC-3). U-2 OS cells, both with and without stable AR expression, were used as a second cell line model. Interestingly, we found that the NT-Pba conjugate was not only photodynamically active and AR-specific, but also that its phototoxic effect was more pronounced compared to pristine pheophorbide a. We also examined the intracellular localization of NT-Pba. Live-cell fluorescence microscopy provided clear evidence that the NT-Pba conjugate localized in the endoplasmic reticulum and mitochondria. Moreover, we performed a competitive localization study with the excess of nonfluorescent NT, which was able to displace fluorescent NT-Pba from the cell interior, thereby further confirming the binding specificity. The oxime ether bond degradation was assayed in living cells by both real-time microscopy and a steroid receptor reporter assay using AR U-2 OS cells. Thus, NT-Pba is a promising candidate for both the selective targeting and eradication of AR-positive malignant cells by photodynamic therapy.

Primary photodynamic therapy for small amelanotic choroidal melanomas: consecutive case series of 69 patients with at least 24-month follow-up

AIMS

To investigate the success and recurrence rates and visual outcomes in a large case series of amelanotic posterior choroidal melanomas treated by means of primary photodynamic therapy (PDT) with verteporfin.

METHODS

Retrospective case series from a single specialist ocular oncology centre. All patients had a clinical diagnosis of choroidal melanoma and were selected for PDT based on tumour characteristics. Included patients had at least 24 months of follow-up from initiation of treatment and all but one had not received treatment prior to PDT.

RESULTS

69 patients were included. Mean tumour thickness was 1.9 mm (range 0.5-4.4), while the mean basal diameter was 6.9 mm (range 2.4-11.0). Included lesions were stage cT1a (n=66) or cT2a (n=3). The mean duration of follow-up from treatment initiation was 57 months (range 24-116 months). Seven lesions (10%) failed to respond to PDT. 10 patients (16%) experienced recurrence during follow-up. Overall success rate in this series was 75% (n=52). 83% of successfully treated patients (n=43) maintained or gained vision by final follow-up. Visual outcomes were significantly better in those patients who received PDT therapy alone in comparison to those who needed other treatments for their melanoma (Fisher's exact test, p=0.004). Unfortunately, one patient (1.4%) in the series developed systemic metastases and died.

CONCLUSION

Selected amelanotic posterior uveal melanomas may be successfully treated with PDT with retention of good vision in the majority of cases, maintained with a mean of 57 months (minimum of 24 months) of follow-up.

Efficacy of ranibizumab combined with photodynamic therapy on wet age-related macular degeneration

Efficacy and safety of intravitreal ranibizumab (IVR) combined with photodynamic therapy (PDT) in treating wet age-related macular degeneration (wAMD) were studied. A total of 130 eyes were collected from 130 wAMD patients treated in Affiliated to Qingdao University Yuhuangding Hospital of Yantai, of which 65 were given IVR combined with PDT (combination therapy group) and the remaining 65 were treated with simple IVR (ranibizumab group). The differences in best corrected visual acuity (BCVA), central macular thickness (CMT), intraocular pressure, choroidal neovascularization (CNV) leakage, levels of serum vascular endothelial growth factor (VEGF) and transforming growth factor-β1 (TGF-β1) as well as complication rate were compared before and after treatment between the two groups. At 1, 3, 6 and 12 months after treatment, combination therapy group had remarkably better BCVA and notably smaller CMT than ranibizumab group. Fundus fluorescein angiography (FFA) showed that the area of macular degeneration was reduced markedly after treatment in both groups, and the area in combination therapy group was evidently smaller than that in ranibizumab group at 1, 3 and 6 months after treatment. At 3 months after treatment, the levels of serum VEGF and TGF-β1 declined obviously in the two groups compared with those before treatment. The IVR combined with PDT can effectively improve the visual acuity, decrease CMT and prominently reduce the area of macular degeneration of wAMD patients, and its therapeutic effects are long-standing and tolerable for the patients, so it is worthy of clinical popularization.

Porphyrin Derivative Nanoformulations for Therapy and Antiparasitic Agents

Porphyrins and analogous macrocycles exhibit interesting photochemical, catalytic, and luminescence properties demonstrating high potential in the treatment of several diseases. Among them can be highlighted the possibility of application in photodynamic therapy and antimicrobial/antiparasitic PDT, for example, of malaria parasite. However, the low efficiency generally associated with their low solubility in water and bioavailability have precluded biomedical applications. Nanotechnology can provide efficient strategies to enhance bioavailability and incorporate targeted delivery properties to conventional pharmaceuticals, enhancing the effectiveness and reducing the toxicity, thus improving the adhesion to the treatment. In this way, those limitations can be overcome by using two main strategies: (1) Incorporation of hydrophilic substituents into the macrocycle ring while controlling the interaction with biological systems and (2) by including them in nanocarriers and delivery nanosystems. This review will focus on antiparasitic drugs based on porphyrin derivatives developed according to these two strategies, considering their vast and increasing applications befitting the multiple roles of these compounds in nature.

Light Sources and Dosimetry Techniques for Photodynamic Therapy

Effective treatment delivery in photodynamic therapy (PDT) requires coordination of the light source, the photosensitizer, and the delivery device appropriate to the target tissue. Lasers, light-emitting diodes (LEDs), and lamps are the main types of light sources utilized for PDT applications. The choice of light source depends on the target location, photosensitizer used, and light dose to be delivered. Geometry of minimally accessible areas also plays a role in deciding light applicator type. Typically, optical fiber-based devices are used to deliver the treatment light close to the target. The optical properties of tissue also affect the distribution of the treatment light. Treatment light undergoes scattering and absorption in tissue. Most tissue will scatter light, but highly pigmented areas will absorb light, especially at short wavelengths. This review will summarize the basic physics of light sources, and describe methods for determining the dose delivered to the patient.

Negative Regulators of Angiogenesis, Ocular Vascular Homeostasis, and Pathogenesis and Treatment of Exudative AMD

Angiogenesis, the formation of new blood vessels from pre-existing capillaries, is very tightly regulated and normally does not occur except during developmental and reparative processes. This tight regulation is maintained by a balanced production of positive and negative regulators, and alterations under pathological conditions such as retinopathy of prematurity, diabetic retinopathy, and age-related macular degeneration can lead to growth of new and abnormal blood vessels. Although the role of proangiogenic factors such as vascular endothelial growth factor has been extensively studied, little is known about the roles of negative regulators of angiogenesis in the pathogenesis of these diseases. Here, we will discuss the role of thrombospondin-1 (TSP1), one of the first known endogenous inhibitors of angiogenesis, in ocular vascular homeostasis, and how its alterations may contribute to the pathogenesis of age-related macular degeneration and choroidal neovascularization. We will also discuss its potential utility as a therapeutic target for treatment of ocular diseases with a neovascular component.

The photodynamic therapy activity of 3-(1-hydroxylethyl)-3-devinyl-131-(dicyanomethylene) pyropheophorbide-a methyl ester (HDCPPa) against HeLa cell in vitro

Photodynamic therapy (PDT) has been a potential therapeutic method for the treatment of various cancers, with photosensitizer being the key component in photodynamic therapy. In this paper, we prepared a photosensitizer 3-(1-hydroxylethyl)-3-devinyl-131-(dicyanomethylene) pyropheophorbide-a methyl ester (HDCPPa), based on chlorophyll pyropheophorbide-a according to the previous report, and systematically investigated the fluorescence emission spectrum and ultraviolet absorption spectrum HDCPPa has long absorption in the near-infrared spectral region (around 695 nm). The excitation wavelength and the emission wavelength were 415 nm and 699 nm respectively in dichloromethane, 1O2 quantum yield was 63.5%. HDCPPa also had high stability in PBS solution, DMEM cell culture medium and normal saline (NS) in vitro. After irradiation by the light of 675 nm (10 J.cm[Formula: see text]) for 70 min the degradation rate of HDCPPa was 12.5%, which indicated that the target compound showed high stability under light. The in vitrophotodynamic therapy activities against HeLa cells were also studied, which showed that HDCPPa had extremely low dark toxicity but great phototoxicity, and the cell viability is lower than 10% under the light irradiation of 675 nm (10 J.cm[Formula: see text]). Moreover, HDCPPa can quickly enter the cell after being incubated with HeLa cells in less than 30 min. We also evaluated the mechanism of the photochemical reaction, which had proved that Type II is primarily responsible for the cell death. Therefore HDCPPa could serve as a very promising photosensitizer for photodynamic therapy.

Phthalocyanines and Tetrapyrazinoporphyrazines with Two Cationic Donuts: High Photodynamic Activity as a Result of Rigid Spatial Arrangement of Peripheral Substituents

High photodynamic activity was observed for hexadeca-cationic zinc, magnesium, and metal-free phthalocyanines (Pcs) and tetrapyrazinoporphyrazines with EC₅₀ values as low as 5 nM (MCF-7 cells) for the best compound; this activity was several times better than that of clinically established photosensitizers verteporfin, temoporfin, S₃AlOHPc, or protoporphyrin IX. This lead compound was characterized by low dark toxicity (TC₅₀ = 369 μM), high efficiency against other cell lines (HCT 116 and HeLa), and possible activation by light above 680 nm. The excellent photodynamic activity resulted from the rigid spatial arrangement of the quaternized triazole moieties above and below the Pc core, as confirmed by X-ray crystallography. The triazole moieties thus formed two "cationic donuts" that protected the hydrophobic core against aggregation in water. The lysosomes were found to be the site of subcellular localization and were consequently the primary targets of photodynamic injury, resulting in predominantly necrotic cell death.

OCT Angiography: An Upcoming Non-invasive Tool for Diagnosis of Age-related Macular Degeneration

PURPOSE

To review the most recent findings, characteristics, faults and future perspectives of optical coherence tomography angiography (OCTA) in age-related macular degeneration (AMD).

RECENT FINDINGS

In dry AMD, OCTA is useful on the evaluation of choriocapillaris perfusion and detection of naïve quiescent non-exudative choroidal neovascularization (CNV). In wet AMD, OCTA can provide detailed anatomic and morphologic information of CNVs, which may help to understand why and how they develop and become active. In other hand, the many artifacts present in OCTA images may lead to misinterpretation and misdiagnosis.

SUMMARY

OCTA is a still developing technology that is able to provide a large amount of anatomic, functional and morphologic information in macular diseases and, particularly, AMD. As the technology evolves, the need of dye-based modalities tends to decrease.

Tetra(3,4-pyrido)porphyrazines Caught in the Cationic Cage: Toward Nanomolar Active Photosensitizers

Investigation of a series of tetra(3,4-pyrido)porphyrazines (TPyPzs) substituted with hydrophilic substituents revealed important structure-activity relationships for their use in photodynamic therapy (PDT). Among them, a cationic TPyPz derivative with total of 12 cationic charges above, below and in the plane of the core featured a unique spatial arrangement that caught the hydrophobic core in a cage, thereby protecting it fully from aggregation in water. This derivative exhibited exceptionally effective photodynamic activity on a number of tumor cell lines (HeLa, SK-MEL-28, A549, MCF-7) with effective concentrations (EC₅₀) typically below 5 nM, at least an order of magnitude better than the EC₅₀ values obtained for the clinically approved photosensitizers verteporfin, temoporfin, protoporphyrin IX, and trisulfonated hydroxyaluminum phthalocyanine. Its very low dark toxicity (TC₅₀ > 400 μM) and high ability to induce photodamage to endothelial cells (EA.hy926) without preincubation suggest the high potential of this cationic TPyPz derivative in vascular-targeted PDT.

Syntheses and photodynamic activity of some glucose-conjugated BODIPY dyes

The syntheses of three water-soluble glucose-conjugated BODIPY dyes with different wavelength emissions and studies of their photodynamic therapeutic (PDT) action on human lung cancer A549 cell line are disclosed. Amongst the chosen compounds, the BODIPY dye 4 possessing a glycosylated styryl moiety at the C-3 position showed best PDT property against the A549 cell line. In particular, it induced reactive oxygen species-mediated caspase-8/caspase-3-dependent apoptosis as revealed from the increased sub G1 cell population and changes in cell morphology. These results along with its localization in the endoplasmic reticulum, as revealed by confocal microscopy suggested that mitochondria may not be directly involved in the photo-cytotoxicity of 4. Compound 4 did not induce any dark toxicity to the A549 cells, and was non-toxic to normal lung cells.

Photosensitizers binding to nucleic acids as anticancer agents

Cationic porphyrins (Prs) and phthalocyanines (Pcs) are strong photosensitizers that have drawn much attention for their potential in photodynamic therapy. These compounds have the interesting property of binding to nucleic acids, in particular G-rich quadruplex-forming sequences in DNA and RNA. In this review, we highlight their potential as anticancer drugs.

Interventions for Age-Related Macular Degeneration: Are Practice Guidelines Based on Systematic Reviews?

PURPOSE

Are existing systematic reviews of interventions for age-related macular degeneration incorporated into clinical practice guidelines?

DESIGN

High-quality systematic reviews should be used to underpin evidence-based clinical practice guidelines and clinical care. We examined the reliability of systematic reviews of interventions for age-related macular degeneration (AMD) and described the main findings of reliable reviews in relation to clinical practice guidelines.

METHODS

Eligible publications were systematic reviews of the effectiveness of treatment interventions for AMD. We searched a database of systematic reviews in eyes and vision without language or date restrictions; the database was up to date as of May 6, 2014. Two authors independently screened records for eligibility and abstracted and assessed the characteristics and methods of each review. We classified reviews as reliable when they reported eligibility criteria, comprehensive searches, methodologic quality of included studies, appropriate statistical methods for meta-analysis, and conclusions based on results. We mapped treatment recommendations from the American Academy of Ophthalmology (AAO) Preferred Practice Patterns (PPPs) for AMD to systematic reviews and citations of reliable systematic reviews to support each treatment recommendation.

RESULTS

Of 1570 systematic reviews in our database, 47 met inclusion criteria; most targeted neovascular AMD and investigated anti-vascular endothelial growth factor (VEGF) interventions, dietary supplements, or photodynamic therapy. We classified 33 (70%) reviews as reliable. The quality of reporting varied, with criteria for reliable reporting met more often by Cochrane reviews and reviews whose authors disclosed conflicts of interest. Anti-VEGF agents and photodynamic therapy were the only interventions identified as effective by reliable reviews. Of 35 treatment recommendations extracted from the PPPs, 15 could have been supported with reliable systematic reviews; however, only 1 recommendation cited a reliable intervention systematic review. No reliable systematic review was identified for 20 treatment recommendations, highlighting areas of evidence gaps.

CONCLUSIONS

For AMD, reliable systematic reviews exist for many treatment recommendations in the AAO PPPs and should be cited to support these recommendations. We also identified areas where no high-level evidence exists. Mapping clinical practice guidelines to existing systematic reviews is one way to highlight areas where evidence generation or evidence synthesis is either available or needed.

Trilobolide-porphyrin conjugates: on synthesis and biological effects evaluation

Trilobolide (Tb), a potent natural counterpart of thapsigargin, is a sesquiterpene lactone of guaianolide type isolated from horse caraway (Laser trilobum, L. Borkh). Tb exerts remarkable pharmacological properties based on irreversible inhibition of sarco/endoplasmic reticulum calcium ATPase (SERCA), thus being of increasing interest for cancer cure. Additionally, another pharmacological activity of Tb, as well as of thapsigargin, was reported in several studies, Tb as being an effective inductor of nitric oxide and cytokine production. These extraordinary biological properties move these molecules in further pre-clinical evaluation. Because of ubiquitous character of SERCA expression, development of specifically targeted bioactive molecules is inevitable. Since it is well known that porphyrins are preferentially taken up by cancer cells, we have designed and synthesized novel Tb-porphyrin conjugates. Copper-catalyzed azide-alkyne cycloaddition was used to link Tb with porphyrin at once. Two model conjugates of Tb and porphyrin were synthesized and properly characterized. Employing naturally occurring fluorescence properties of porphyrins, we investigated the intracellular localization of the conjugates employing fluorescence microscopy in living cells. Intriguingly, the prepared conjugates localized both in mitochondria and lysosomes of HeLa and LNCaP cells. Furthermore, the cytotoxicity of Tb-porphyrin conjugates was assessed in a number of human cancer cell lines and rat peritoneal cells. Likewise in cancer cell lines, viability of rat peritoneal cells was not affected by the tested conjugates. Interestingly, we observed dose-dependent nitric oxide (iNOS) production induced by the tested conjugates. The effect was related to the type of a linker used and the overall size of the molecule. Another potent immunobiological effects are under evaluation. In summary, the results presented here indicate notable immunobiological potential of the prepared Tb conjugates. Moreover, they could help to decipher the molecular mechanism of Tb for its possible biomedical applications.

Ranibizumab plus verteporfin photodynamic therapy in neovascular age-related macular degeneration: 12 months of retreatment and vision outcomes from a randomized study

PURPOSE

To investigate the injection frequency and visual acuity (VA) outcomes with combination therapy (ranibizumab plus verteporfin photodynamic therapy, PDT) versus monotherapy (ranibizumab).

METHODS

A total of 40 patients with exudative age-related macular degeneration were randomized 1:1 to ranibizumab 0.3 mg plus single standard verteporfin PDT or ranibizumab 0.3 mg plus sham PDT. Ranibizumab was administered 3 times monthly followed by 'as needed' to month 12 based on predetermined vision/anatomical criteria. Retreatment rates, VA outcomes and safety were assessed.

RESULTS

During months 3-12, combination therapy patients required fewer ranibizumab injections (mean 1.3) compared with monotherapy patients (2.8). Mean VA improved by 9.0 letters with combination therapy versus 7.5 letters in the monotherapy group at month 12. Both treatment regimens were well tolerated.

CONCLUSION

The need for ranibizumab retreatment might be reduced by administering a single verteporfin PDT on the same day as the first ranibizumab injection, without compromising VA outcomes or safety.

Age-related macular degeneration and changes in the extracellular matrix

Age-related macular degeneration (AMD) is the leading cause of permanent, irreversible, central blindness (scotoma in the central visual field that makes reading and writing impossible, stereoscopic vision, recognition of colors and details) in patients over the age of 50 years in European and North America countries, and an important role is attributed to disorders in the regulation of the extracellular matrix (ECM). The main aim of this article is to present the crucial processes that occur on the level of Bruch’s membrane, with special consideration of the metalloproteinase substrates, metalloproteinase, and tissue inhibitor of metalloproteinase (TIMP).

A comprehensive review of the literature was performed through MEDLINE and PubMed searches, covering the years 2005–2012, using the following keywords: AMD, extracellular matrix, metalloproteinases, tissue inhibitors of metalloproteinases, Bruch’s membrane, collagen, elastin.

In the pathogenesis of AMD, a significant role is played by collagen type I and type IV; elastin; fibulin-3, -5, and -6; matrix metalloproteinase (MMP)-2, MMP-9, MMP-14, and MMP-1; and TIMP-3. Other important mechanisms include: ARMS2 and HTR1 proteins, the complement system, the urokinase plasminogen activator system, and pro-renin receptor activation.

Continuous rebuilding of the extracellular matrix occurs in both early and advanced AMD, simultaneously with the dysfunction of retinal pigment epithelium (RPE) cells and endothelial cells. The pathological degradation or accumulation of ECM structural components are caused by impairment or hyperactivity of specific MMPs/TIMPs complexes, and is also endangered by the influence of other mechanisms connected with both genetic and environmental factors.

Treatment of posterior uveal melanoma with multi-dose photodynamic therapy

AIMS

To report on the use of multi-dose photodynamic therapy (PDT) in the treatment of posterior uveal melanoma.

METHODS

Prospective case series. 18 patients with posterior uveal melanoma were treated with a minimum of three sessions of PDT. Mean tumour thickness was 1.92 mm (median 1.75, range 0.5-4.4 mm) while the mean basal diameter was 7.1 mm (median 6.3, range 5.2-11 mm). Patients were assessed for visual acuity, complications, tumour status and systemic metastases.

RESULTS

In 16 cases, the tumour regressed with stable or improved vision in 15 patients (83%) over a mean follow-up period of 28 months (median 26.5, range 12-44 months). One patient developed an edge recurrence on two occasions ultimately requiring proton beam therapy while one patient showed no response to PDT before being successfully treated with proton beam therapy. Two patients developed scleritis requiring a short course of systemic steroids. No patient developed metastatic disease in the study period.

CONCLUSIONS

Posterior uveal melanomas may be successfully treated with high dose PDT with retention of good vision in the majority of cases, at least in the short-term. Longer follow-up is required to see if these encouraging results are maintained.

Preferred therapies for neovascular age-related macular degeneration

PURPOSE OF REVIEW

This report reviews the current treatment strategies and the most recent clinical trials in the treatment of neovascular age-related macular degeneration.

RECENT FINDINGS

The functional and anatomic outcomes achieved in the pivotal ranibizumab trials with monthly injections set the standard for comparison. Since then, various modified dosing regimens with the aim of lessening the treatment burden associated with monthly injections have been investigated. Additionally, level I evidence now exists for the noninferiority of bevacizumab, as compared to ranibizumab, in the treatment of neovascular age-related macular degeneration (AMD) through 1 year of follow-up. Aflibercept has emerged as a new anti- vascular endothelial growth factor (VEGF) therapy showing encouraging treatment results at 1 year. Novel treatments combined with anti-VEGF agents such as localized radiation are currently being investigated.

SUMMARY

Anti-VEGF monotherapy remains the preferred therapy for the management of neovascular AMD at the present time. Aflibercept is a new, FDA-approved, effective, anti-VEGF agent available for clinical use. Ongoing clinical trials will help determine the optimal dosing regimens for all of these agents, as well as the long-term efficacy and safety of combination therapy modalities.

Effect of virulence factors on the photodynamic inactivation of Cryptococcus neoformans

Opportunistic fungal pathogens may cause an array of superficial infections or serious invasive infections, especially in immunocompromised patients. Cryptococcus neoformans is a pathogen causing cryptococcosis in HIV/AIDS patients, but treatment is limited due to the relative lack of potent antifungal agents. Photodynamic inactivation (PDI) uses the combination of non-toxic dyes called photosensitizers and harmless visible light, which produces singlet oxygen and other reactive oxygen species that produce cell inactivation and death. We report the use of five structurally unrelated photosensitizers (methylene blue, Rose Bengal, selenium derivative of a Nile blue dye, a cationic fullerene and a conjugate between poly-L-lysine and chlorin(e6)) combined with appropriate wavelengths of light to inactivate C. neoformans. Mutants lacking capsule and laccase, and culture conditions that favoured melanin production were used to probe the mechanisms of PDI and the effect of virulence factors. The presence of cell wall, laccase and melanin tended to protect against PDI, but the choice of the appropriate photosensitizers and dosimetry was able to overcome this resistance.

Self-assembled liposomal nanoparticles in photodynamic therapy

Photodynamic therapy (PDT) employs the combination of non-toxic photosensitizers (PS) together with harmless visible light of the appropriate wavelength to produce reactive oxygen species that kill unwanted cells. Because many PS are hydrophobic molecules prone to aggregation, numerous drug delivery vehicles have been tested to solubilize these molecules, render them biocompatible and enhance the ease of administration after intravenous injection. The recent rise in nanotechnology has markedly expanded the range of these nanoparticulate delivery vehicles beyond the well-established liposomes and micelles. Self-assembled nanoparticles are formed by judicious choice of monomer building blocks that spontaneously form a well-oriented 3-dimensional structure that incorporates the PS when subjected to the appropriate conditions. This self-assembly process is governed by a subtle interplay of forces on the molecular level. This review will cover the state of the art in the preparation and use of self-assembled liposomal nanoparticles within the context of PDT.

BODIPY dyes in photodynamic therapy

BODIPY dyes tend to be highly fluorescent, but their emissions can be attenuated by adding substituents with appropriate oxidation potentials. Substituents like these have electrons to feed into photoexcited BODIPYs, quenching their fluorescence, thereby generating relatively long-lived triplet states. Singlet oxygen is formed when these triplet states interact with (3)O(2). In tissues, this causes cell damage in regions that are illuminated, and this is the basis of photodynamic therapy (PDT). The PDT agents that are currently approved for clinical use do not feature BODIPYs, but there are many reasons to believe that this situation will change. This review summarizes the attributes of BODIPY dyes for PDT, and in some related areas.

Denis TG, Hamblin MR. Photodynamic Therapy for Cancer and for Infections: What Is the Difference?

Photodynamic therapy (PDT) was discovered over one hundred years ago when it was observed that certain dyes could kill microorganisms when exposed to light in the presence of oxygen. Since those early days, PDT has mainly been developed as a cancer therapy and as a way to destroy proliferating blood vessels. However, recently it has become apparent that PDT may also be used as an effective antimicrobial modality and a potential treatment for localized infections. This review discusses the similarities and differences between the application of PDT for the treatment of microbial infections and for cancer lesions. Type I and type II photodynamic processes are described, and the structure-function relationships of optimal anticancer and antimicrobial photosensitizers are outlined. The different targeting strategies, intracellular photosensitizer localization, and pharmacokinetic properties of photosensitizers required for these two different PDT applications are compared and contrasted. Finally, the ability of PDT to stimulate an adaptive or innate immune response against pathogens and tumors is also covered.

Shining light on nanotechnology to help repair and regeneration

Phototherapy can be used in two completely different but complementary therapeutic applications. While low level laser (or light) therapy (LLLT) uses red or near-infrared light alone to reduce inflammation, pain and stimulate tissue repair and regeneration, photodynamic therapy (PDT) uses the combination of light plus non-toxic dyes (called photosensitizers) to produce reactive oxygen species that can kill infectious microorganisms and cancer cells or destroy unwanted tissue (neo-vascularization in the choroid, atherosclerotic plaques in the arteries). The recent development of nanotechnology applied to medicine (nanomedicine) has opened a new front of advancement in the field of phototherapy and has provided hope for the development of nanoscale drug delivery platforms for effective killing of pathological cells and to promote repair and regeneration. Despite the well-known beneficial effects of phototherapy and nanomaterials in producing the killing of unwanted cells and promoting repair and regeneration, there are few reports that combine all three elements i.e. phototherapy, nanotechnology and, tissue repair and regeneration. However, these areas in all possible binary combinations have been addressed by many workers. The present review aims at highlighting the combined multi-model applications of phototherapy, nanotechnology and, reparative and regeneration medicine and outlines current strategies, future applications and limitations of nanoscale-assisted phototherapy for the management of cancers, microbial infections and other diseases, and to promote tissue repair and regeneration.

The effect of the number of carbohydrate moieties on the azaphthalocyanine properties

A series of azaphthalocyanines (AzaPc) bearing one, two, four or eight isopropylidene-protected galactosyl units was prepared by azide-alkyne click reaction or by classical Pc template cyclotetramerization of the corresponding dicyanopyrazine and AzaPc properties important for photodynamic therapy were compared. All compounds absorbed at long wavelengths (above 650 nm) and belonged to strong singlet oxygen producers (Φ(Δ) = 0.58-0.64) retaining significant fluorescence emission (Φ(F) = 0.026-0.23). The only exception was the compound with four isopropyliden-protected galactosyl units where partial aggregation was observed. Removal of protecting groups increased the polar character of all AzaPc. However, only AzaPc bearing eight galactoses was found to be water-soluble (105 mg mL(-1)) but noticeably aggregated in water as well as in organic solvents (DMF, DMSO). Amphiphilic AzaPc bearing one deprotected galactose was incorporated into the lipidic bilayer of liposomes in a nonaggregated form. Liposomes may therefore be a suitable delivery system for this amphiphilic photosensitizer.

Ophthalmic transplantology: posterior segment of the eye--part II

Background

Transplants of the retina are among the new strategies being used in the treatment of genetic and degenerative macular diseases. Moreover, various cell cultures are being tested to treat retinal disorders.

Material/Methods

Literature dated from 2004 to 2011 was comprehensively examined via Medline and PubMed searches for the following terms: auto-, homo-, heterologous transplantation, retina, stem cells, cultivated cells.

Results

Tissue and cell therapy of retinal diseases are reviewed, including full-thickness retina/retinal pigment epithelium (RPE)/choroid graft; full and partial thickness RPE/choroid complex grafts; RPE/Bruch membrane complex graft; and RPE, iris pigment epithelium and stem cell grafts. Recommendations for transplants, as well as the benefits and weaknesses of specific techniques in retina transplants, are discussed.

Conclusions

Auto- and allogenic transplants of a full or partial thickness retina/RPE/Bruch membrane/choroid complex represent an alternative treatment offered to patients with some macular diseases. Stem cell transplantation to reconstruct and regenerate the macula requires further biomolecular and animal research studies.

Today and future of age-related macular degeneration

Age-related macular degeneration (AMD) is the leading cause of blindness in people over 50 in developed countries. Understanding of the pathologic process, genetic mechanisms, and risk factors of this disease has the benefit of seeking newer and more effective treatment options. Current clinical therapy for AMD shows a dramatic change from a decade ago. Anti-VEGF drug therapy is regarded as the more effective treatment for neovascular AMD now, especially combining PDT therapy. In the future, the genetic and biochemical therapies may be the promising treatments for AMD. This paper will focus on the progress of pathology, candidate genes of AMD, risk factors, and the existing drugs or surgical therapies available, in order to present some new directions of care with the prospect of improved vision in many patients suffered from AMD.

New Approach of Anti-VEGF Agents for Age-Related Macular Degeneration

Age-related macular degeneration (AMD) is the leading cause of visual loss in older population. Angiogenesis is an important factor associated with the development of CNV due to AMD. Treatment of CNV with intravitreal anti-VEGF monotherapy is currently the standard of care. However, not all patients respond to monotherapy, and modified anti-VEGF treatment regimen and combination therapy may target reducing treatment frequency or improving visual outcome. This paper reviews the many clinical trials that have been performed utilizing several treatment regimens. While many trials have shown that this variable therapy is justifiable, further study is required to determine correct regimens and dosage.

Intravitreal bevacizumab alone versus in combination with photodynamic therapy for the treatment of neovascular maculopathy in patients aged 50 years or older: 1-year results of a prospective clinical study

PURPOSE

To compare the outcomes of treatment with intravitreal bevacizumab alone (BEVA group) or in combination with photodynamic therapy (PDT) (COMB group), in patients aged at least 50 years with neovascular maculopathy.

METHODS

Forty-one patients with neovascular age-related macular degeneration (AMD) (n = 31) or polypoidal choroidal vasculopathy (PCV) (n = 10) were randomized to either the BEVA group (n = 18) or the COMB group (n = 23). A total of three intravitreal bevacizumab injections (1.25 mg/0.05 ml) were given at 6-week intervals. In the COMB group, PDT was included near the time of one injection. Patients underwent best-corrected visual acuity (BCVA) measurement and optical coherence tomography (OCT) at every visit. Fluorescein angiography and indocyanine green angiography were repeated every 3 months.

RESULTS

Overall BCVA (p = 0.001) and central foveal thickness (CFT) (p < 0.001) measured by OCT improved significantly at 12 months, and there was no between-group difference in BCVA or CFT between the BEVA and COMB groups. Whereas AMD patients showed significant improvement in BCVA (p = 0.001) and CFT (p = 0.004), PCV patients failed to improve. The effect of bevacizumab alone on neovascular AMD was similar to that of combination therapy, when measured by both BCVA and CFT. The total number of bevacizumab injections was not reduced when PDT was given, either among all patients or in a subgroup of naïve patients (p > 0.05). No serious complication was noted.

CONCLUSION

The results of our 12-month prospective study indicate that intravitreal bevacizumab alone has similar efficacy and safety to bevacizumab plus PDT for treatment of patients with neovascular AMD, even treatment-naïve patients. The addition of PDT did not assist in reducing the required total number of bevacizumab injections.

Effects of combination therapy with verteporfin photodynamic therapy and ranibizumab in patients with age-related macular degeneration

PURPOSE

This open-label, prospective, small-scale study investigated the benefits of same-day verteporfin and intravitreal ranibizumab in patients with predominantly classic, minimally classic or occult subfoveal choroidal neovascularization (CNV) secondary to age-related macular degeneration.

METHODS

Patients received verteporfin at baseline and at month 3, if leakage persisted. Ranibizumab (0.5 mg) was given at baseline and months 1, 2 and 3, and thereafter at monthly intervals if required. Same-day ranibizumab was given ≥ 1 hr after verteporfin.

RESULTS

Fifteen patients [11 male, four female; mean age 75.5 years (range 54-94 years)] were treated. At day 360, mean visual acuity (VA) had improved by 10.9 letters. An increase of ≥ 15 and ≥ 30 letters (i.e. ≥ 3 and ≥ 6 lines) was observed in seven (47%) patients and one patient (7%), respectively. Mean central retinal thickness (CRT) decreased by 85 μm. At days 7, 14 and 30, CNV perfusion was absent in 14/15 patients. Mean lesion area had reduced from baseline by 23.1% at day 120, 25.5% at day 180 and 23.6% at day 360. There were no visual safety concerns and intraocular pressures remained normal. Only two serious adverse events were recorded over the 12-month period, and neither was considered to be related to treatment.

CONCLUSION

Same-day verteporfin plus ranibizumab improved VA, reduced CRT, prevented CNV perfusion and reduced lesion area safely over 12 months. Further investigation is warranted to confirm whether this combination improves long-term vision and reduces the need for retreatment.

Influence of multidrug efflux systems on methylene blue-mediated photodynamic inactivation of Candida albicans

OBJECTIVES

To investigate whether the major fungal multidrug efflux systems (MESs) affect the efficiency of methylene blue (MB)-mediated antimicrobial photodynamic inactivation (APDI) in pathogenic fungi and test specific inhibitors of these efflux systems to potentiate APDI.

METHODS

Candida albicans wild-type and mutants that overexpressed two classes of MESs [ATP-binding cassette (ABC) and major facilitator superfamily (MFS)] were tested for APDI using MB as the photosensitizer with and without addition of MES inhibitors. The uptake and cytoplasm localization of photosensitizer were achieved using laser confocal microscopy.

RESULTS

ABC MES overexpression reduced MB accumulation and APDI killing more than MFS MES overexpression. Furthermore, by combining MB APDI with the ABC inhibitor verapamil, fungal killing and MB uptake were potentiated, while by combining MB APDI with the MFS inhibitor INF(271), fungal killing and MB uptake were inhibited. This latter surprising finding may be explained by the hypothesis that the MFS channel can also serve as an uptake mechanism for MB.

CONCLUSIONS

The ABC pumps are directly implicated in MB efflux from the cell cytoplasm. Both the influx and efflux of MB may be regulated by MFS systems, and blocking this gate before incubation with MB can decrease the uptake and APDI effects. An ABC inhibitor could be usefully combined with MB APDI for treating C. albicans infections.

Combination approaches to potentiate immune response after photodynamic therapy for cancer

Photodynamic therapy (PDT) has been used as a cancer therapy for forty years but has not advanced to a mainstream cancer treatment. Although it has been shown to be an efficient way to destroy local tumors by a combination of non-toxic dyes and harmless visible light, it is its additional effects in mediating the stimulation of the host immune system that gives PDT great potential to become more widely used. Although the stimulation of tumor-specific cytotoxic T-cells that can destroy distant tumor deposits after PDT has been reported in some animal models, it remains the exception rather than the rule. This realization has prompted several investigators to test various combination approaches that could potentiate the immune recognition of tumor antigens that have been released after PDT. This review will cover these combination approaches using immunostimulants including various microbial preparations that activate Toll-like receptors and other receptors for pathogen-associated molecular patterns, cytokines growth factors, and approaches that target regulatory T-cells. We believe that by understanding the methods employed by tumors to evade immune response and neutralizing them, more precise ways of potentiating PDT-induced immunity can be devised.

Microperimetric changes after photodynamic therapy for central serous chorioretinopathy

PURPOSE

To evaluate the effect of half-dose verteporfin photodynamic therapy (PDT) on macular function in cases of central serous chorioretinopathy (CSC).

DESIGN

Interventional case series.

METHODS

A total of 24 eyes from 24 cases of CSC were included in this study. In each eye, at baseline and 1, 3, and 6 months after half-dose PDT, logMAR best-corrected visual acuity (BCVA); central 10-degree, 20-degree, and paracentral 10-degree to 20-degree retinal sensitivity; and also mean retinal sensitivity results for each case over the area that was treated with half-dose PDT (PDT spot area) by MP-1 microperimetry and optical coherence tomography (OCT) foveal morphologic changes were assessed. The MP-1 microperimetry sensitivity map was overlaid onto an indocyanine green angiography image recorded on a Heidelberg scanning laser ophthalmoscope using dedicated MP-1 software to evaluate the PDT laser spot area.

RESULTS

After treatment, BCVA and central 10-degree, 20-degree, paracentral 10-degree to 20-degree, and PDT laser spot area retinal sensitivity were improved significantly. In OCT in 20 of 24 eyes (83%), subretinal fluid (SRF) was resolved 1 month after half-dose PDT. At 3 and 6 months after treatment, SRF was resolved at all eyes. None of the patients in this study developed any systemic or ocular adverse events associated with verteporfin treatment.

CONCLUSION

Half-dose verteporfin PDT induced a significant increase in central 10-degree, 20-degree, paracentral 10-degree to 20-degree, and also PDT laser spot area retinal sensitivity over 6 months in cases of CSC.

Verteporfin photodynamic therapy of six eyes with retinal capillary haemangioma

PURPOSE

Single-centre consecutive interventional case series by retrospective chart review to evaluate the efficacy of verteporfin (Visudyne™) photodynamic therapy (PDT) of retinal capillary haemangioma (RCH).

METHODS

Following an initial period of observation, six eyes of five patients with RCH (juxtapapillary 3 and extrapapillary (EP) 3) received 1-3 sessions of standard verteporfin PDT upon the development of progressive vision-threatening complications. Four of the five patients had von Hippel-Lindau (VHL) disease. Follow-up included documentation of best-corrected Snellen visual acuity (BCVA), tumour regression, and presence or absence of subretinal fluid (SRF) and/or lipid exudation as assessed by dilated fundus examination (DFE), fundus photos, and optical coherence tomography (OCT). These parameters were documented at 1 week, 1 month, and 3 months following each PDT session and up to 32 months following the first PDT.

RESULTS

All eyes showed favourable response to PDT as defined by tumour regression or stabilization as well as improvement of SRF and lipid exudation. BCVA improved or stabilized in three eyes. Three eyes required PDT retreatment for recurrent SRF. Epiretinal membrane (ERM) worsened in three eyes, requiring vitreoretinal surgery at a median of 6 months following PDT.

CONCLUSIONS

PDT is a moderately effective treatment for juxtapapillary and EP RCH. In this series, PDT resulted in tumour regression or stabilization as well as in the improvement of SRF and lipid exudation in all cases. However, stabilization or improvement of visual acuity was observed in only 50 per cent of the cases. The treatment benefits may be limited by pre-existing macular changes and worsening of ERM. A larger prospective study is necessary to validate these findings.

The potential of nanomedicine therapies to treat neovascular disease in the retina

Neovascular disease in the retina is the leading cause of blindness in all age groups. Thus, there is a great need to develop effective therapeutic agents to inhibit and prevent neovascularization in the retina. Over the past decade, anti-VEGF therapeutic agents have entered the clinic for the treatment of neovascular retinal disease, and these agents have been effective for slowing and preventing the progression of neovascularization. However, the therapeutic benefits of anti-VEGF therapy can be diminished by the need for prolonged treatment regimens of repeated intravitreal injections, which can lead to complications such as endophthalmitis, retinal tears, and retinal detachment. Recent advances in nanoparticle-based drug delivery systems offer the opportunity to improve bioactivity and prolong bioavailability of drugs in the retina to reduce the risks associated with treating neovascular disease. This article reviews recent advances in the development of nanoparticle-based drug delivery systems which could be utilized to improve the treatment of neovascular disease in the retina.

Combined intravitreal bevacizumab and triamcinolone in exudative age-related macular degeneration

PURPOSE

We report on the combined application of intravitreal bevacizumab and triamcinolone acetonide for treatment of exudative age-related macular degeneration (AMD).

METHODS

 The clinical interventional case-series study included 16 patients (16 eyes) with exudative AMD who had previously received 3.5±1.8 mono-injections of bevacizumab (1.5mg) without significant improvement in visual acuity (VA) or reduction in macular exudation. All patients underwent a combined intravitreal injection of bevacizumab (1.5mg) and triamcinolone acetonide (about 20mg). Main outcome measures were VA and macular thickness as determined by optical coherence tomography. All patients were re-examined at 2-3months after the intervention.

RESULTS

Visual acuity improved significantly (p=0.03) from 0.80±0.40 logMAR prior to the combined injection to 0.65±0.42 logMAR at 3 months after the injection. An improvement of ≥1Snellen line was found in eight subjects, an increase of ≥2lines in five subjects, and an improvement of ≥3lines in two subjects. One patient lost 1line and one patient lost 3lines. Central retinal thickness decreased significantly from 272±62μm to 220±47μm (p=0.03). At the 6-month follow-up examination, central retinal thickness had increased again to 319±142μm, which was not significantly (p=0.30) different from baseline measurements.

CONCLUSIONS

The combined intravitreal application of bevacizumab and triamcinolone may temporarily be helpful in the treatment of exudative AMD if previous intravitreal bevacizumab mono-injections have failed to improve vision and reduce macular oedema.