Photodynamic therapy for age-related macular degeneration in a clinical setting: visual results and angiographic patterns

Impact of methylenetetrahydrofolate reductase C677T polymorphism on the efficacy of photodynamic therapy in patients with neovascular age-related macular degeneration

The most severe visual impairments due to age-related macular degeneration (AMD) are frequently caused by the occurrence of choroidal neovascularization (CNV). Although photodynamic therapy with verteporfin (PDT-V) is currently a second-line treatment for neovascular AMD, it can be conveniently combined with drugs acting against vascular endothelial growth factor (anti-VEGF) to reduce the healthcare burden associated with the growing necessity of anti-VEGF intravitreal re-injection. Because the common 677 C > T polymorphism of the methylenetetrahydrofolate reductase gene (MTHFR-C677T; rs1801133) has been described as predictor of satisfactory short-term responsiveness of AMD-related CNV to PDT-V, we retrospectively examined the outcomes of 371 Caucasian patients treated with standardized, pro-re-nata, photodynamic regimen for 24 months. Responder (R) and non-responder (NR) patients were distinguished on the basis of the total number of scheduled PDT-V (TN-PDT-V) and change of best-corrected visual acuity (∆-BCVA). The risk for both TN-PDT-V and ∆-BCVA to pass from R to NR group was strongly correlated with CT and TT genotypes of MTHFR-C677T variant resulting, respectively, in odd ratios of 0.19 [95% CI, 0.12-0.32] and 0.09 [95% CI, 0.04-0.21] (P < 0.001), and odd ratios of 0.24 [95% CI, 0.15-0.39] and 0.03 [95% CI, 0.01-0.11] (P < 0.001). These pharmacogenetic findings indicate a rational basis to optimize the future clinical application of PDT-V during the combined treatments of AMD-related CNV, highlighting the role of thrombophilia to be aware of the efficacy profile of photodynamic therapy.

The Nature and Frequency of Neovascular Age-Related Macular Degeneration

PURPOSE

This study was designed to evaluate the frequency and nature of neovascularization in age-related macular degeneration (ARMD) utilizing the combination of digital imaging techniques, fluorescein angiography (FA), indocyanine green (ICG) angiography, and optical coherence tomography (OCT).

METHODS

A complete clinical examination was performed on 100 eyes of 93 consecutive newly diagnosed patients with neovascular ARMD. Digital fluorescein angiography, ICG angiography, and OCT were also used in evaluating those patients. Comparison of the imaging techniques to determine their value in studying the nature of the lesions.

RESULTS

On the basis of existing fluorescein standards, 15 eyes were diagnosed with classic choroidal neovascularization (CNV), 15 with minimally classic CNV, and 70 with occult CNV. ICG angiography was superior for detecting the active vascular component in polypoidal CNV (16 eyes) and retinal angiomatous proliferation (14 eyes). OCT was more sensitive than FA for determining the presence of cystoid macular edema evident in the vast majority of eyes with retinal angiomatous proliferation (RAP).

CONCLUSIONS

These results suggest that FA, ICG angiography, and OCT, when used in combination, will assist clinicians in best determining the precise nature of the neovascular process in ARMD.

Factors Predictive of Visual Outcome 1 Year After Intravitreal Aflibercept Injection for Typical Neovascular Age-Related Macular Degeneration

PURPOSE

Several factors have been reported to be associated with visual outcomes after intravitreal ranibizumab treatment for neovascular age-related macular degeneration (AMD). In the present study, we investigated the factors associated with visual outcomes after intravitreal aflibercept injection (IAI) for typical neovascular AMD.

METHODS

We retrospectively studied the visual changes in 47 eyes of 51 patients with typical neovascular AMD, who had been initially treated with 3 monthly IAI followed by as-needed IAI.

RESULTS

Mean best-corrected visual acuity (BCVA) improved during the 12-month follow-up period in 40 eyes of 37 patients without reticular pseudodrusen (RPD) in both eyes, whereas it deteriorated in 11 eyes of 10 patients with RPD in either eye. Multiple regression analysis revealed that visual gain at 12 months after the first IAI positively correlated with worse baseline BCVA and thicker baseline subfoveal choroidal thickness (P = 0.018, P = 0.004, respectively), but not with absence of RPD (P = 0.13). Subfoveal choroidal thickness was significantly thinner in eyes with RPD compared with that in eyes without RPD (P = 0.003).

CONCLUSIONS

Visual gain after IAI in eyes with typical neovascular AMD appears to be limited in patients with RPD, which may reflect the poor visual outcome after IAI in eyes with a thinner subfoveal choroid that is seen predominately in patients with RPD.

Effect of Factor XIII-A G185T Polymorphism on Visual Prognosis after Photodynamic Therapy for Neovascular Macular Degeneration

Macular degenerations represent leading causes of central blindness or low vision in developed countries. Most of these severe visual disabilities are due to age-related macular degeneration (AMD) and pathologic myopia (PM), both of which are frequently complicated by subfoveal choroidal neovascularization (CNV). Photodynamic therapy with verteporfin (PDT-V) is still employed for CNV treatment in selected cases or in combined regimen. In Caucasian patients, the common polymorphism G185T of factor XIII-A gene (FXIII-A-G185T; rs5985) has been described as predictor of poor angiographic CNV responsiveness to PDT-V. Nevertheless, the prognostic implications of this pharmacogenetic determinant on long-term visual outcome after a PDT-V regimen have not been evaluated. We retrospectively selected Caucasian patients presenting with treatment-naive CNV and receiving standardized PDT-V protocol for two years. The study population included patients affected by subfoveal CNV secondary to AMD or PM. We assessed the correlations between the polymorphic allele T of FXIII-A-G185T and: (1) total number of photodynamic treatments; and (2) change in visual acuity from baseline to the end of the follow-up period. Considering a total study population of 412 patients with neovascular AMD or PM, the carriers of 185 T-allele of FXIII-A (GT or TT genotype) received a higher number of photodynamic treatments than patients without it (GG wild-type genotype) (p < 0.01; mean number of PDT-V: 5.51 vs. 3.76, respectively). Moreover, patients with 185 T-allele of FXIII-A had a more marked worsening of visual acuity at 24 months than those with the GG-185 wild genotype (p < 0.01; mean difference in logMAR visual acuity: 0.22 vs. 0.08, respectively). The present findings show that the G185T polymorphism of the FXIII-A gene is associated with significant differences in the long-term therapeutic outcomes of patients treated with standardized PDT-V protocol. The comprehensive appraisal of both anti-thrombophilic effects due to FXIII-A G185T variant and photo-thrombotic action of PDT-V toward CNV provides several clues about the rationale of this intriguing pharmacogenetic correlation. Further investigations are warranted to outline the appropriate paradigm for guiding PDT-V utilization in the course of the combined therapeutic protocol for neovascular macular degeneration.

Targeted radiotherapy with gold nanoparticles: current status and future perspectives

Radiation therapy (RT) is the treatment of cancer and other diseases with ionizing radiation. The ultimate goal of RT is to destroy all the disease cells while sparing healthy tissue. Towards this goal, RT has advanced significantly over the past few decades in part due to new technologies including: multileaf collimator-assisted modulation of radiation beams, improved computer-assisted inverse treatment planning, image guidance, robotics with more precision, better motion management strategies, stereotactic treatments and hypofractionation. With recent advances in nanotechnology, targeted RT with gold nanoparticles (GNPs) is actively being investigated as a means to further increase the RT therapeutic ratio. In this review, we summarize the current status of research and development towards the use of GNPs to enhance RT. We highlight the promising emerging modalities for targeted RT with GNPs and the corresponding preclinical evidence supporting such promise towards potential clinical translation. Future prospects and perspectives are discussed.

Thinner choroid and greater drusen extent in retinal angiomatous proliferation than in typical exudative age-related macular degeneration

PURPOSE

To compare choroidal thickness and extent and density of drusen between eyes with typical exudative age-related macular degeneration (AMD) and eyes with retinal angiomatous proliferation (RAP).

DESIGN

Observational case series.

METHODS

Twenty-four eyes with typical exudative AMD and 20 eyes with RAP were included. Subfoveal choroidal thickness was measured using enhanced depth imaging optical coherence tomography. Eyes were classified into 3 groups according to the extent of drusen distribution in the fundus photograph. Density of drusen was estimated based on optical coherence tomography images of the fellow eye. The proportion of the length beneath the drusen per the entire length of the Bruch membrane was defined as the density of drusen. Subfoveal choroidal thickness, extent of drusen distribution, and the density of drusen were compared between typical exudative AMD and RAP.

RESULTS

Mean ± standard deviation subfoveal choroidal thickness in eyes with typical exudative AMD and eyes with RAP was 184.9 ± 68.5 μm and 139.0 ± 65.5 μm, respectively (P = .035). The mean density of drusen was 0.06 ± 0.08 and 0.24 ± 0.12, respectively (P < .001). In the typical exudative AMD group, 19, 3, and 2 eyes were included in the small extent group (<one third), intermediate extent group (one third to two thirds), and large extent group (>two thirds), respectively. In the RAP group, 3, 14, and 3 eyes were included in each aforementioned group, respectively (P = .001).

CONCLUSIONS

The thinner subfoveal choroidal thickness and greater extent and density of drusen in RAP than the typical exudative AMD may suggest compromised choroidal perfusion in the development of RAP.

Gold nanoparticle enhancement of stereotactic radiosurgery for neovascular age-related macular degeneration

Age-related macular degeneration (AMD) is the leading cause of blindness in developed countries for people over the age of 50. In this work, the dosimetric feasibility of using gold nanoparticles (AuNP) as radiosensitizers to enhance kilovoltage stereotactic radiosurgery for neovascular AMD is investigated. Microdosimetry calculations at the sub-cellular level were carried out to estimate the radiation dose enhancement to individual nuclei in neovascular AMD endothelial cells (nDEF) due to photon-induced photo-/Auger electrons from x-ray-irradiated AuNP. The nDEF represents the ratio of radiation doses to the endothelial cell nuclei with and without AuNP. The calculations were carried out for a range of feasible AuNP local concentrations using the clinically applicable 100 kVp x-ray beam parameters employed by a commercially available x-ray therapy system. The results revealed nDEF values of 1.30-3.26 for the investigated concentration range of 1-7 mg g(-1), respectively. In comparison, for the same concentration range, nDEF values of 1.32-3.40, 1.31-3.33, 1.29-3.19, 1.28-3.12 were calculated for 80, 90, 110 and 120 kVp x-rays, respectively. Meanwhile, calculations as a function of distance from the AuNP showed that the dose enhancement, for 100 kVp, is markedly confined to the targeted neovascular AMD endothelial cells where AuNP are localized. These findings provide impetus for considering the application of AuNP to enhance therapeutic efficacy during stereotactic radiosurgery for neovascular AMD.

Anti-vascular endothelial growth factor for myopic choroidal neovascularization

Myopic choroidal neovascularization (CNV) is a vision-threatening complication in the eyes with pathological myopia, which is particularly prevalent among young and middle-aged Asians globally. To date, the verteporfin in photodynamic therapy study is the only randomized-controlled study in treatment of subfoveal myopic CNV. However, its long-term benefit is controversial. Recently, intravitreal injections of anti-vascular endothelial growth factors have shown promising results. In the absence of randomized-controlled trial comparing the efficacy of anti-vascular endothelial growth factors with photodynamic therapy and placebo, the purpose of this article is to review the current studies on functional and anatomical outcomes in both subfoveal and juxtafoveal myopic CNV. Furthermore, the influences of various doses and frequencies, as well as age and previous photodynamic therapy treatment on its effect are described.

LOC387715/HTRA1 variants and the response to combined photodynamic therapy with intravitreal bevacizumab for polypoidal choroidal vasculopathy

PURPOSE

To investigate whether there was an association with the LOC387715/HTRA1 variants and a response to combined photodynamic therapy with intravitreal bevacizumab for polypoidal choroidal vasculopathy.

METHODS

Combined photodynamic therapy with intravitreal bevacizumab was repeated every 3 months until the disappearance of angiographic signs in the active lesions of 51 eyes with polypoidal choroidal vasculopathy who were followed-up for at least 12 months. Patients were genotyped for LOC387715 and HTRA1 polymorphisms.

RESULTS

Although there was no significant difference in the baseline best-corrected visual acuity and fluorescein angiography-guided greatest linear dimension among the 3 genotypes in both genes, there was a significant difference at 12 months (P < 0.05, respectively). For LOC387715, the TT genotype showed greater fluorescein angiography-guided greatest linear dimension than the TG and GG genotypes (P = 0.035 and 0.006, respectively). The best-corrected visual acuity of the GG genotype was better than the TT and TG (P = 0.029 and 0.045, respectively). For HTRA1, the AA genotype showed greater fluorescein angiography-guided greatest linear dimension than AG and GG (P = 0.042 and 0.017, respectively). The best-corrected visual acuity of GG genotype was better than AA and AG (P = 0.018 and 0.040, respectively).

CONCLUSION

After combined photodynamic therapy with intravitreal bevacizumab treatment, LOC387715 TT and HTRA1 AA genotype had poorer outcomes at 12 months, suggesting a pharmacogenetic relationship.

Association of LOC387715 A69S genotype with visual prognosis after photodynamic therapy for polypoidal choroidal vasculopathy

PURPOSE

To investigate whether there is an association of the LOC387715 A69S genotype with visual prognosis after photodynamic therapy in eyes with polypoidal choroidal vasculopathy (PCV).

METHODS

Photodynamic therapy was repeated every 3 months until the disappearance of angiographic signs of active lesions in 71 eyes of 71 patients with PCV who were followed-up for at least 12 months. All patients were genotyped for LOC387715 A69S polymorphism (rs10490924, risk-allele T).

RESULTS

Although there was no statistically significant difference in the mean baseline visual acuity (P = 0.53) among the 3 genotypes, there was a statistically significant difference in the visual acuity both at the 12-month and final visits (P = 0.002 and P < 0.001, respectively) with the poorer acuity in patients with the higher "T-"allele frequency. "T" allele was more frequently observed in those with the recurred PCV lesions (odds ratio: 5.8, 95% confidential interval: 2.3-15.1, T vs. G).

CONCLUSION

There is a pharmacogenetic association between the LOC387715 A69S variant and the long-term results after photodynamic therapy in eyes with PCV. The LOC387715 A69S genotype is of clinical importance to predict the visual prognosis after photodynamic therapy in eyes with PCV. These results should be confirmed or refuted by replication studies.

Vascular endothelial growth factor gene variation and the response to photodynamic therapy in age-related macular degeneration

PURPOSE

To evaluate the role of vascular endothelial growth factor (VEGF) gene polymorphisms in exudative age-related macular degeneration (AMD).

DESIGN

Retrospective, comparative case series.

PARTICIPANTS

Patients with recent exudative AMD (n = 162) and age-matched subjects without AMD (n = 85).

METHODS

Fluorescein angiography (FA), clinical examination, and single nucleotide polymorphism (SNP) genotyping.

MAIN OUTCOME MEASURES

The frequencies of 3 VEGF gene SNPs were analyzed, 1 at the promoter site (rs699947, A-->C) and 2 intronic SNPs (rs2146323, A-->C, and rs3025033, A-->G), in relation to the risk of AMD, to choroidal neovascular (CNV) lesion size and configuration, and to the anatomic response to photodynamic therapy (PDT). These SNPs were chosen to cover all the haploblocks of the VEGF gene. The 86 patients who had undergone PDT were classified as either PDT responders or PDT nonresponders based on the outcome of PDT after the last treatment session. For the PDT responders, the treating physician had deemed the lesion to be clinically dry and without leakage from CNV in FA at a visit scheduled at least 12 weeks after the last PDT treatment. For the PDT nonresponders, the PDT sessions had been discontinued by the treating retina specialist because of an apparently poor response and a still exudative lesion after several PDT sessions.

RESULTS

The presence of exudative AMD or lesion size or configuration was not associated with the SNPs studied here. The frequencies of the rs699947 were significantly different in PDT nonresponders and PDT responders. The AA, AC, and CC genotypes were 14%, 39%, and 46%, respectively, in PDT nonresponders, compared with 40%, 48%, and 12%, respectively, in the PDT responders (P = 0.0008). The corresponding frequencies for the rs2146323 AA, AC, and CC genotypes were 4%, 32%, and 64%, respectively, in nonresponders and 24%, 38%, and 38%, respectively, in responders (P = 0.0369). The genotypes of the rs3025033 SNP were distributed evenly between the responders and nonresponders.

CONCLUSIONS

The VEGF gene polymorphic SNPs at rs699947 and rs2146323 are strong determinants of the anatomic outcome after PDT, but the SNPs studied were not associated with the presence of exudative AMD or with the CNV lesion size or configuration.

FINANCIAL DISCLOSURE(S)

The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Intravitreal bevacizumab vs sub-tenon triamcinolone acetonide for choroidal neovascularization attributable to pathologic myopia

PURPOSE

To compare the visual outcomes of intravitreal bevacizumab (Avastin; Genentech Inc, South San Franciso, California, USA) and sub-Tenon triamcinolone acetonide (TA) for choroidal neovascularization attributable to pathologic myopia (mCNV).

DESIGN

Retrospective, comparative, interventional case series.

METHODS

Fifty-four consecutive eyes of 53 patients with mCNV treated with either sub-Tenon TA or intravitreal bevacizumab in an institutional setting were included. Twenty eyes were treated with sub-Tenon TA and 34 eyes were treated with intravitreal bevacizumab. The main outcome measures included best-corrected visual acuity (BCVA) 12 months after the initial injection and logarithm of the minimum angle of resolution gain from baseline compared with analysis of covariance (ANCOVA).

RESULTS

At 12 months, the BCVA improved by 1.9 lines in the intravitreal bevacizumab group and worsened by 0.3 lines in the sub-Tenon TA group. Thus, the intravitreal bevacizumab group had significantly greater visual improvement than the sub-Tenon TA group (P < .01). Statistical analysis (ANCOVA) revealed that age (P = .01), pretreatment BCVA (P < .01), and the treatment choice (intravitreal bevacizumab or sub-Tenon TA; P < .01) correlated significantly with the BCVA and the BCVA gain at 12 months. The refractive error was of borderline significance (P = .06).

CONCLUSIONS

Although this study is limited because of its retrospective nature, intravitreal bevacizumab seems to result in a more favorable visual outcome than sub-Tenon TA in the treatment of mCNV. Patient age, the BCVA before treatment, and the refractive error must be considered to initiate the treatment.

Target-selective degradation of cancer-related proteins by novel photosensitizers for molecular-targeted photodynamic therapy

Proteins are key players in many biological events including cancers. The development of novel photosensitizers for the selective degradation of cancer-related proteins has attracted much attention in the fields of photodynamic therapy for various cancers. In this review article, several novel photosensitizers, which selectively degrade cancer-related proteins under photoirradiation and mild conditions without any further additives, are introduced. This novel class of photosensitizers promises bright prospects for finding molecular-targeted drugs for cancer photodynamic therapy in the near future.

Target-selective degradation of proteins and oligosaccharides by light-activated hybrid molecules for molecular-targeted photodynamic therapy

Proteins and oligosaccharides are key players in many biological events. The development of novel methods for the selective degradation of targeted proteins and oligosaccharides has attracted much attention in the fields of chemistry, biology and medicine. Target-selective degradations of proteins, such as estrogen receptor-α androgen receptor and HIV-1 protease, by light-activated 2-phenylquinoline-steroid hormone hybrids, porphyrin derivatives and fullerene-sugar hybrids, and target-selective degradation of oligosaccharides, such as a T-antigen disaccharide, by a light-activated anthraquinone-lectin hybrid have been achieved. This novel class of light-activated and molecular-targeted molecules, namely molecular-targeted photosensitizers, promise bright prospects for finding not only molecular-targeted bioprobes for future application in the life sciences but also molecular-targeted drugs for future photodynamic therapy.

Predictive role of C677T MTHFR polymorphism in variable efficacy of photodynamic therapy for neovascular age-related macular degeneration

Age-related macular degeneration (AMD) complicated by subfoveal choroidal neovascularization (CNV) is the leading cause of severe central blindness in developed countries. AMD-related CNVs are distinguishable in classic and occult subtypes, characterized by variable natural history and different responsiveness to therapeutic procedures. Combined and repeated use of photodynamic therapy with verteporfin (PDT-V) and antiangiogenic drugs represents the most promising strategy against neovascular AMD, but it is unavoidably associated with mounting health-resource utilization. Predictive correlations between peculiar coagulation-balance gene variants and different levels of post-PDT-V benefit have recently been documented in Caucasians with AMD-related CNVs. In particular, methylenetetrahydrofolate reductase C677T substitution, a common thrombophilic folate pathway genotypic polymorphism, influences a better CNV responsiveness to PDT-V in classic- but not in occult-CNV cases. These pharmacogenetic findings indicate the opportunities to optimize the eligibility criteria of PDT-V and/or to perform this intriguing therapy in a customized manner, for finally minimizing the socio-economic burden of neovascular AMD.

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

Photodynamic therapy (PDT) with verteporfin has been used less comprehensively in the treatment of exudative age-related macular degeneration (AMD), and specifically of choroidal neovascularization (CNV), since the advent of antiangiogenic therapies. Recently, there has been a renewed interest in PDT as an adjunct to these and other agents in the treatment of neovascular AMD. In light of this new development and the European Medicines Evaluation Agency's (EMEA) recent labelling decision to rescind approval for the use of PDT in occult CNV lesions, the present systematic review was undertaken to revisit the evidence supporting its clinical application. Photodynamic therapy provided the first pharmacological treatment for patients suffering from subfoveal CNV, the major cause of severe vision loss in AMD. Key clinical trials evaluating efficacy and safety have examined patients with all lesion subtypes, with the primary labelled indication (i.e. lesions containing a classic component of > or = 50% ) deriving from the results of the Treatment of Age-related Macular Degeneration with Photodynamic Therapy (TAP) Study. The subsequent TAP Study Group post hoc categorization of lesions as predominantly classic is open to question, however, as it appears that the overall efficacy in this group only may have reflected the especially strong response in 100% classic lesions. Based on a subgroup analysis of the Verteporfin in Photodynamic Therapy Study, the indication for PDT subsequently was expanded in some jurisdictions, including that of the EMEA, to include occult lesions with no classic component. However, the subsequent Visudyne in Occult Study found no benefit in 100% occult lesions, resulting in the EMEA rescinding its approval for this indication.

Lacquer crack formation and choroidal neovascularization in pathologic myopia

PURPOSE

To clarify the characteristics of choroidal neovascularization (CNV) due to myopic CNV (mCNV) and the relation to lacquer crack (LC) formation.

PATIENTS AND METHODS

Thirty-seven eyes with mCNV underwent fluorescein angiography (FA) and indocyanine green angiography (ICGA) using Heidelberg Retina Angiograph 2 (HRA2; Heidelberg, Germany). mCNV was detected by FA and ICGA; LCs were detected by late-phase ICGA.

RESULTS

Thirty-five eyes (95%) had classic mCNV, and 2 (5%) had occult CNV. LCs developed in 35 (95%) of 37 eyes. In 33 eyes (94%), classic mCNV originated from LCs; the 2 other eyes had small horizontal dotlike LCs, but mCNV originated from the adjacent area of LC. No occult CNV was associated with LCs. Two morphologic types of LCs were observed, linear (21 eyes [62%]) and stellate (12 eyes [32%]) from which mCNV originated, with no significant differences in parameters between the two types. Classic mCNV demonstrated well-delineated hyperfluorescence by late-phase ICGA in 10 eyes (29%), which was significantly correlated with absence of a dark rim (P = 0.022).

CONCLUSIONS

ICGA using HRA2 provides more detailed information on mCNV and LCs. LC formation is essential for classic mCNV to develop. Morphologic variations of LCs were not different clinically. Late-phase hyperfluorescence, probably due to the absence of pigment epithelium around the mCNV, may represent its activity.

Multifocal electroretinography as a predictor of maintenance of vision after photodynamic therapy for neovascular age-related macular degeneration

PURPOSE

To investigate the role of multifocal electroretinography (mfERG) in predicting the outcome of photodynamic therapy (PDT) for neovascular age-related macular degeneration (AMD).

METHODS

Participants underwent refraction protocol VA assessment using the ETDRS logMAR chart at 1 m, Contrast Sensitivity (CS) using the Pelli-Robson chart at 1 m, fundus fluorescein angiography (FA) and mfERGs in response to 19 segments. Response to PDT was binary (1 = the loss of less than 15 letters at 12 months, 0 = the loss of 15 letters or more) and was used as the dependent variable for logistic regression analysis.

RESULTS

Logistic regression modelling identified mfERG central segment amplitude, lesion size on FA, VA and CS as predictors of outcome (P = 0.05, 0.02, 0.01, 0.03). The model is stable and has excellent discriminability.

CONCLUSION

The outcomes of this study are particularly relevant to patients in the UK who are sometimes treated with PDT alone. A larger prospective study would facilitate development of an index to predict outcome of future treatments for AMD.

Photodynamic cell-kill analysis of breast tumor cells with a tamoxifen-pyropheophorbide conjugate

We hypothesized that estrogen receptor (ER) in hormone-sensitive breast cancer cells could be targeted for selective photodynamic killing of tumor cell with antiestrogen-porphyrin conjugates by combining the over-expression of ER in hormone-sensitive breast cancer cells and tumor-retention property of porphyrin photosensitizers. In this study we describe that a tamoxifen (TAM)-pyropheophorbide conjugate that specifically binds to ER alpha, caused selective cell-kill in MCF-7 breast cancer cells upon light exposure. Therefore, it is a potential candidate for ER-targeted photodynamic therapy of cancers (PDT) of tissues and organs that respond to estrogens/antiestrogens.

Nuclear estrogen receptor targeted photodynamic therapy: selective uptake and killing of MCF-7 breast cancer cells by a C17alpha-alkynylestradiol-porphyrin conjugate

We hypothesized that over-expression of estrogen receptor (ER) in hormone-sensitive breast cancer could be harnessed synergistically with the tumor-migrating effect of porphyrins to selectively deliver estrogen-porphyrin conjugates into breast tumor cells, and preferentially kill the tumor cells upon exposure to red light. In the present work we synthesized four (4) conjugates of C17-alpha-alkynylestradiol and chlorin e6-dimethyl ester with varying tether lengths, and showed that all these conjugates specifically bound to recombinant ER alpha. In a cellular uptake assay with ER-positive MCF-7 and ER-negative MDA-MB 231 human breast cancer cell-lines, we observed that one such conjugate (E17-POR, XIV) was selectively taken up in a dose-dependent and saturable manner by MCF-7 cells, but not by MDA-MB 231 cells. Furthermore, MCF-7 cells, but not MDA-MB 231 cells, were selectively and efficiently killed by exposure to red light after incubation with E17-POR. Therefore, the combination approach, including drug and process modalities has the potential to be applied clinically for hormone-sensitive cancers in organs where ER is significantly expressed. This could potentially be carried out either as monotherapy involving a photo-induced selective destruction of tumor cells and/or adjuvant therapy in post-surgical treatment for the destruction of residual cancer cells in tissues surrounding the tumor.

Photodynamic therapy with verteporfin for choroidal neovascularization due to age-related macular degeneration and other causes: a New Zealand outcomes study

PURPOSE

To assess the efficacy and safety of photodynamic therapy (PDT) for choroidal neovascularization (CNV) secondary to age-related macular degeneration (AMD) and other conditions by analysing visual acuity changes.

METHODS

A retrospective review of patients treated with PDT was conducted. CNV was confirmed on fluorescein angiography. Visual acuity outcomes were recorded at 3-monthly intervals to a maximum of 48 months. The primary outcome measure was the proportion of patients avoiding moderate visual loss (losing less than three lines of visual acuity relative to baseline) at 12 months.

RESULTS

A total of 343 patients receiving PDT were followed up for a mean of 14.9 months. Two hundred and eighty-five (83%) patients presented with CNV due to AMD and 58 patients (17%) due to other causes. Seventy per cent of patients with CNV secondary to AMD avoided moderate visual loss at both 12 and 24 months. Secondary outcomes (including mean change in visual acuity, proportion of patients with stable or improved vision and proportion of patients with severe vision loss) also compared favourably with the Treatment of Age-Related Macular Degeneration with Photodynamic Therapy (TAP) Investigation. Of patients with CNV secondary to causes other than AMD, 76% avoided moderate visual loss at both 12 and 24 months. The safety profile identified one severe adverse reaction, with development of a serous pigment epithelial detachment and subsequent rip.

CONCLUSION

The results of this present retrospective, open-label, clinical practice study in New Zealand are consistent with the findings of multicentre randomized, placebo-controlled trials and confirm the treatment benefit of PDT in a clinical setting.

[Photodynamic therapy of AMD for the first (better sight) and the second (worse sight) eyes]

BACKGROUND

Photodynamic therapy (PDT) is the standard treatment procedure for many forms of exudative and/or neovascular AMD. Despite therapy, visual acuity often drops to low vision levels. The cost efficiency of treating the eye in which vision is worse is therefore the subject of some controversy.

PATIENTS AND METHODS

A retrospective case-control study was conducted in all patients who were treated with PDT at the Universitätsspital Zürich between September 1999 and November 2004. Each patient's first (with worse vision) and second (with better vision) eyes were compared for situation on presentation and course during treatment.

RESULTS

In 117/228 cases (51.3%) visual acuity of the treated eye was better than (or identical to) that of the fellow eye at presentation. Visual acuity before therapy was an average of 0.58+/-0.27 logMAR [Snellen: 0.26 (0.14-0.49)] in the eyes with better visual acuity and 0.69+/-0.4 logMAR [Snellen 0.20 (0.08-0.51)] in the fellow eyes (p=0.015). After therapy there was no significant difference between the patient groups in visual acuity or in the magnitude of any change in visual acuity, or in lesion size or change in lesion size.

CONCLUSION

The outcome of PDT of a second eye (with better visual acuity) is not significantly better than the result obtained in the first eye (the one with worse visual acuity initially).

Verteporfin therapy for neovascular age-related macular degeneration in Indian eyes

PURPOSE

To determine visual outcome after a 12-month follow-up period of verteporfin therapy for subfoveal choroidal neovascularization (CNV) secondary to age-related macular degeneration (AMD) in Indian patients.

METHODS

Twenty-five patients (26 eyes) who completed a 12-month follow-up after photodynamic therapy for subfoveal CNV secondary to AMD were included in the study. The follow-up schedule was every month for 2 months and then every 3 months thereafter until 12 months. Improvement in visual acuity was defined as a >or=10-letter gain, and deterioration as a >or=10-letter loss in the Early Treatment Diabetic Retinopathy Study chart at 4 m.

RESULTS

The mean age of the 25 patients was 62.3 +/- 9 years. There were 17 male patients (68%). The mean initial letter acuity was 28. 4 +/- 14.1, and the final letter acuity was 25.5 +/- 18.4 at 12 months. Initial visual acuity was >or=20/40 in seven eyes, 20/50-20/80 in nine eyes, and 20/100-20/200 in ten eyes; seven eyes had a >or=10-letter gain, and three eyes had a >or=10-letter loss. At the end of 12 months, six eyes had a >or=10-letter gain and ten eyes had a >or=10-letter loss.

CONCLUSION

Photodynamic therapy appears to preserve the vision in subfoveal CNV secondary to AMD in the eyes of Indian patients.

Does lesion size determine the success rate of photodynamic therapy for age-related macular degeneration?

Photodynamic therapy (PDT) is a new evidence-based treatment modality available for choroidal neovascularisation (CNV) secondary to age-related macular degeneration (AMD). Eligibility for PDT is based on the morphological classification of the neovascular complex, the benefit being greater in classic with no occult lesions. Lesion size is also shown to be a predictive factor for treatment benefit. This retrospective case series looked at effect of initial and final lesion size on the visual outcome of patients with subfoveal classic with no occult CNV and found that increasing initial and final lesion size is associated with poorer visual outcome.

Combined Photodynamic Therapy and Intravitreal Triamcinolone Acetonide Injection for Neovascular Age-Related Macular Degeneration With Pigment Epithelium Detachment

BACKGROUND AND OBJECTIVE

To report the outcome of combined verteporfin photodynamic therapy (PDT) and intravitreal triamcinolone acetonide (IVTA) for the treatment of choroidal neovascularization (CNV) with serous pigment epithelium detachment (PED) due to age-related macular degeneration (AMD).

PATIENTS AND METHODS

The files of all consecutive patients with CNV and serous PED who received PDT and IVTA either primarily (primary treatment group) or following previous unsuccessful PDT (secondary treatment group) were reviewed for visual and angiographic results.

RESULTS

Ten patients (11 eyes) were included. Mean number of PDT sessions was 3.18; 8 eyes received one IVTA injection and 3 eyes received two IVTA injections. Thirty-six percent of patients retained their initial visual acuity after a mean follow-up of 15.3 months. Loss of 3 or more Snellen lines was noted in 2 of 3 eyes in the primary treatment group and 5 of 8 eyes in the secondary treatment group. Increased intraocular pressure developed in 3 patients and was controlled by topical medications.

CONCLUSIONS

Although combined PDT and IVTA may be considered for CNV with serous PED in patients with poor prognosis with PDT alone, the regimen as administered in this small series was not beneficial. Further studies are required to determine whether alternate sequences, timing, or doses would yield a better outcome.

One-year outcomes after photodynamic therapy in patients with age-related macular degeneration with poor baseline visual acuity

BACKGROUND

Photodynamic therapy with verteporfin (PDT) has been demonstrated in randomized controlled trials to be a safe and effective therapy for choroidal neovascular membranes (CNV) secondary to age-related macular degeneration (AMD). Limited information is available on the prognosis with PDT for patients who fell outside the inclusion criteria for the clinical trials, however. The purpose of this study is to describe the clinical course of patients with CNV lesions in AMD treated with PDT, with baseline visual acuities sufficiently poor to warrant exclusion from previous randomized trials.

METHODS

Retrospective case series. Ten consecutive patients with CNV secondary to exudative AMD treated with PDT with baseline visual acuity less than 34 ETDRS letters were followed for 1 year. The main outcome was median change in visual acuity on the ETDRS chart.

RESULTS

The median change in acuity over 12 months was + 13 letters. All patients lost <3 lines of ETDRS acuity, and eight of ten patients (80%) gained at least one line of vision, over 12 months.

CONCLUSIONS

In our series, patients with low visual acuity at baseline appeared to respond to PDT on both visual acuity and fluorescein angiographic measurements. PDT treatment may be considered for selected patients with these baseline characteristics.

Magnification requirement after photodynamic therapy with verteporfin for subfoveal predominantly classic choroidal neovascularization due to age-related macular degeneration

PURPOSE

To prospectively assess the magnification requirement after repeat photodynamic therapy (PDT) with verteporfin in patients with predominantly classic subfoveal choroidal neovascularization (CNV) due to age-related macular degeneration (AMD).

METHODS

A total of 103 patients were treated for the first time with PDT between November 1999 and September 2002. These patients were followed up at 3-month intervals for a minimum of 12 months. In addition to the usual investigations undertaken during PDT therapy, the magnification requirement was determined, under standardized conditions, using the SZB test developed by the Swiss Central Association for Blindness.

RESULTS

A stable lesion with a stable magnification requirement was achieved in 86 (83.5%) patients; these patients were followed up for 24.8 months (range 12 to 36 months). At the time of the last follow-up examination, the magnification requirement compared with baseline was < 3 log units higher in 46 patients (53.5%) and > or = 3 log units higher in the remaining 40 patients (46.5%). Seventy-four (86%) of these 86 patients had a magnification requirement of < or = 8x. Stability was not achieved in 17 (16.5%) patients; up to the last examination these patients had been followed up for 12 to 30 months (mean 20.8). At the time of the most recent examination, 7 (41.2%) patients had a higher magnification requirement of < 3 log units while 10 (58.8%) had changed by > or = 3 log units. Sixteen patients (94%) had a magnification requirement of < or = 8x.

CONCLUSIONS

PDT with verteporfin helps achieve stability without severe impairment in reading ability in most patients with predominantly classic subfoveal CNV due to AMD.

Photodynamic therapy for subfoveal choroidal neovascularization secondary to age-related macular degeneration

BACKGROUND

To evaluate the safety and efficacy of verteporfin photodynamic therapy (PDT) in patients with subfoveal choroidal neovascularization (CNV) secondary to age-related macular degeneration (AMD).

METHODS

We retrospectively reviewed the chart records and fluorescein angiography of patients with subfoveal CNV who were treated with verteporfin PDT between September 2001 and March 2003 and who completed at least 1 year of follow-up. The primary efficacy outcomes were the proportions of patients whose Snellen visual acuities had more than 1 line increase, no change or more than 1 line decrease 1 year after study entry compared with their baseline examinations. The secondary efficacy outcome was the changes in the logarithm of the minimum angle of resolution visual acuities at 1-year follow-up. Complications were monitored and tabulated.

RESULTS

Forty-eight eyes of 48 patients with subfoveal CNV secondary to AMD were enrolled in this study. The mean follow-up was 12.56 +/- 1.37 months. At their last visit, 10.4% of eyes had more than 1 line improvement in Snellen visual acuity, 72.9% of eyes had no change, and 16.7% experienced more than 1 line of visual acuity loss (7 eyes lost < 3 lines of Snellen visual acuity, 1 eye lost between 3 and 6 lines). None experienced more than 6 lines of visual loss. There was no statistically significant difference between baseline and final visual acuity for eyes with predominantly classic CNV, minimally classic CNV and occult without classic CNV (Wilcoxon Signed Rank test, p = 0.59 ). There was a positive correlation between baseline visual acuity and final visual outcome (Kruskal-Wallis test, p = 0.002). No severe systemic and ocular adverse events were encountered.

CONCLUSION

Of our patients with subfoveal CNV secondary to AMD, 83.3% could maintain or improve their visual acuity 1 year after verteporfin PDT. The risk of deterioration in visual acuity due to subfoveal CNV could be reduced by verteporfin PDT. Baseline visual acuity is significantly correlated with the final proportion of visual outcome.

Impact of lesion size on photodynamic therapy with verteporfin of predominantly classic lesions in age related macular degeneration

AIM

To determine if photodynamic therapy (PDT) outcomes are related to lesion size in patients with subfoveal predominantly classic choroidal neovascularisation (CNV) secondary to age related macular degeneration (AMD).

METHODS

According to greatest linear dimension (GLD) of the entire lesion determined with fluorescein angiography (FA) patients were divided into two groups. In the first group GLD was <3000 microm and in the second one GLD was 3000-5000 microm. All eyes were treated with standard PDT with the verteporfin protocol. The primary outcome was the proportion of eyes in both groups that did not show significant leakage in FA at the end of follow up. Secondary outcomes were changes in GLD and in best corrected visual acuity (BCVA).

RESULTS

64 patients (mean (SD) age, 76.7 (7.7) years; range 58-95 years) were recruited to participate in the study. All participants in the study completed the follow up time (mean 16.6 months). 24 patients (75%) in the group of smaller lesions (n = 32) compared with 15 patients (46.8%) in the group of larger lesions (n = 32) did not show significant leakage in FA at the end of follow up (p = 0.02). A GLD increase >1000 microm was recorded in nine eyes (28.1%) in the group of smaller lesions and in 16 eyes (50%) in the group of larger lesions (p = 0.07). 22 eyes (68.7%) in the group of smaller lesions compared with 19 eyes (59.3%) in the group of larger lesions lost less than three lines of vision (p = 0.06). Relevant side effects related to verteporfin therapy were not recorded, except for four patients (6.2%) with infusion related back pain.

CONCLUSIONS

These results suggest that lesion size at baseline may be a prognosis factor in PDT in patients with subfoveal predominantly classic CNV secondary to AMD. There are no relevant side effects or safety concerns derived from verteporfin therapy.

Loss of E-cadherin mediated cell-cell adhesion as an early trigger of apoptosis induced by photodynamic treatment

Photodynamic treatment with different photosensitizers (PSs) can result in the specific induction of apoptosis in many cell types. It is commonly accepted that this apoptotic response depends on the mitochondrial accumulation of the PS. Accumulation in other cellular organelles, such as lysosomes or the Golgi complex, and subsequent photodamage resulting in an apoptotic process has been also described. However, the role played by cell adhesion in apoptosis induced in epithelial cells after photodynamic treatment is not well characterized. Here, we have used a murine keratinocyte line, showing a strong dependence on E-cadherin for cell-cell adhesion and survival, to analyze the relevance of this adhesion complex in the context of zinc(II)-phthalocyanine (ZnPc) photodynamic treatment. We report that under apoptotic conditions, ZnPc phototreatment induces a rapid disorganization of the E-cadherin mediated cell-cell adhesion, which largely preceded both the detachment of cells from the substrate, via beta-1 integrins and the induction of apoptotic mitochondrial markers. Therefore, the alteration in E-cadherin, alpha- and beta-catenins adhesion proteins preceded the release of cytochrome c (cyt c) from mitochondria to the cytosol and the activation of caspase 3. In addition, blocking E-cadherin function with a specific antibody (Decma-1) induced apoptosis in this cell system. These results strongly suggest that the E-cadherin adhesion complex could be the primary target of ZnPc phototreatment, and that loss of E-cadherin mediated cell adhesion after early photodamage triggers an apoptotic response.

Photodynamic therapy with verteporfin for choroidal neovascularisations in clinical routine outside the TAP study. One- and two-year results including juxtafoveal and extrafoveal CNV

INTRODUCTION

The aim of this study was to analyse 1- and 2-year outcomes after photodynamic therapy (PDT) in clinical routine outside of the TAP [treatment of age-related macular degeneration (AMD) with PDT] study. We analysed the functional results, possible influencing factors and the rate of side effects.

METHODS

We analysed the medical records of 210 consecutive patients between 50 and 93 years of age (73+/-9 years) who had been treated with PDT for active > or =50% classic CNV resulting from AMD. Only patients with a minimum follow-up of 1 year (127) were included; 52 patients completed 2 years of follow-up. Juxta- and extrafoveal CNV were also analysed. Treatment was given in accordance with TAP parameters and regular follow-up examinations were performed with standardised ETDRS visual acuity (VA) measurements and fluorescein angiography.

RESULTS

In the subfoveal group, in 63.6% (70/110) a loss of VA > or =3 lines could be prevented after 1 year, and in 51.1% (23/45) after 2 years. An improvement of > or =1 line was found in 31.8% (1 year) and in 22.2% of eyes (2 years). Severe VA loss of > or =6 lines occurred in 10.9% of cases after 1 year and in 15.6% after 2 years. The mean change of VA was -1.7+/-3.4 lines (1 year) and -2.5+/-3.9 lines (2 years). For the group of CNV with juxta-/extrafoveal localisation, the mean change of VA was +0.8+/-2.5 lines after 1 year and +1.0+/-4.2 lines after 2 years. With regard to different CNV localisations, the results for juxta-/extrafoveal CNV are statistical significantly better (p=0.005 and p=0.035 after 1 and 2 years, respectively). A mean of 2.6 treatments were performed in the first year and 0.5 in the second year.

CONCLUSIONS

The results obtained in a single institution compare favourably with the results of the TAP study. The results regarding functional visual outcome could be obtained with a lower number of treatments in clinical practice. Juxta- and extrafoveal CNV showed significantly better results than a subfoveal localisation of the CNV. In this subgroup a mean improvement of VA could be obtained after 1 or 2 years.

Dose Response of Combination Photorejuvenation Using Intense Pulsed Light–Activated Photodynamic Therapy and Radiofrequency Energy

OBJECTIVE

To report the results of a dose-response study using a novel photorejuvenation regimen consisting of intense pulsed light-activated photodynamic therapy and radiofrequency energy in patients with Fitzpatrick skin types I through III.

METHODS

A combination intense pulsed light and radiofrequency device (Syneron Medical Ltd, Yokneam, Israel) was used in combination with the topical photosensitizer aminolevulinic acid (ALA) (Levulan Kerastick; DUSA Pharmaceuticals Inc, Wilmington, Mass). Duplicate titration trials were performed on the dorsal forearm skin of 3 patients with Fitzpatrick skin types I through III. Multiple treatments, with varying times of application of ALA (30 minutes and 1, 2, and 3 hours) and intense pulsed light fluence (24-30 J/cm(2)), were completed to determine a minimal erythema dose and a maximal tolerated dose based on epidermal reaction (erythema and crusting) and patient discomfort. Radiofrequency energy levels were constant in all treatment groups.

RESULTS

The ALA application time of 1 to 2 hours for all skin types and fluence levels of 26 to 28 and 24 to 26 J/cm(2) for Fitzpatrick skin types I/II and III, respectively, were determined to be the minimal erythema dose. The ALA application times of 2 to 3 hours and fluence levels of 28 to 30 and 26 to 28 J/cm(2) for skin types I/II and III, respectively, were determined to be the maximal tolerated dose and resulted in severe erythema and crusting. The presence of severe erythema and discomfort precluded longer ALA exposure and higher fluence levels. No epithelial breakdown was observed at any treatment levels.

CONCLUSION

The dose-response results defining the minimal erythema dose and the maximal tolerated dose of intense pulsed light-activated photodynamic therapy and radiofrequency energy have led to the development of 2 photorejuvenation protocols based on skin type and severity of photodamage.