Verteporfin Therapy Combined with Intravitreal Triamcinolone in All Types of Choroidal Neovascularization due to Age-Related Macular Degeneration

Replicating endothelial shear stress in organ-on-a-chip for predictive hypericin photodynamic efficiency

Photodynamic therapy using Hypericin (Hy-PDT) is an alternative non-invasive treatment that enables selective tumor inhibition and angiogenesis derived from the differential recruitment of endothelial cells in the tumor microenvironment. Most PDT studies were performed on in vitro models without vascular biomechanical simulation. Our work strives to develop a microchip that generates a constant shear stress force to investigate the Hy-PDT efficiency on human umbilical vein endothelial cells (HUVECs). The microchip with a single straight microchannel was composed of the bottom layer (polystyrene), the middle layer (double-sided biocompatible adhesive tape), and the top layer (polyester film) and could produce shear stress in the range of 1.4 - 7.0 dyn cm^-2. The quantification of vascular endothelial growth factor (VEGF), cell viability, and activities of caspases 3 and 7 were assayed to validate the microchip and Hy-PDT efficacy. After the endothelization, static and dynamic cell incubations with Hy were conducted in microchips. Compared to static systems, the shear stress displayed its effect on the increasing release of VEGF and promoted more cell damage and cell death via necrosis during Hy-PDT. In conclusion, the expressive shear stress-dependent manner during PDT treatments suggests that the microchip could be an essential approach in preclinical tests to evaluate the therapeutic outcome considering the endothelial shear stress microenvironment.

Novel Approaches in the Drug Development and Delivery Systems for Age-Related Macular Degeneration

The number of patients with ocular disorders has increased due to contributing factors such as aging populations, environmental changes, smoking, genetic abnormalities, etc. Age-related macular degeneration (AMD) is one of the common ocular disorders which may advance to loss of vision in severe cases. The advanced form of AMD is classified into two types, dry (non-exudative) and wet (exudative) AMD. Although several therapeutic approaches are explored for the management of AMD, no approved therapy can substantially slow down the progression of dry AMD into the later stages. The focus of researchers in recent times has been engaged in developing targeted therapeutic products to halt the progression and maintain or improve vision in individuals diagnosed with AMD. The delivery of anti-VEGF agents using intravitreal therapy has found some success in managing AMD, and novel formulation approaches have been introduced in various studies to potentiate the efficacy. Some of the novel approaches, such as hydrogel, microspheres, polymeric nanoparticles, liposomes, implants, etc. have been discussed. Apart from this, subretinal, suprachoroidal, and port delivery systems have also been investigated for biologics and gene therapies. The unmet potential of approved therapeutic products has contributed to several patent applications in recent years. This review outlines the current treatment options, outcomes of recent research studies, and patent details around the novel drug delivery approach for the treatment of AMD.

The YAP signaling pathway promotes the progression of lymphatic malformations through the activation of lymphatic endothelial cells

BACKGROUND

To investigate whether the YAP/TAZ (Yes-associated protein/transcriptional coactivator with PDZ binding motif) pathway contributes to the pathogenesis of lymphatic malformations (LMs).

METHODS

YAP, TAZ, CTGF (connective tissue growth factor), and Ki-67 were detected in LMs by immunohistochemistry. The colocalization of YAP and Ki-67 was analyzed by double immunofluorescence. Pearson's correlation and cluster analyses were performed to analyze the relationships between these proteins. Human dermal lymphatic endothelial cells (HDLECs) were used for mechanistic investigation. Rat models of LMs were established to investigate the role of the YAP pathway in LM development.

RESULTS

Compared with those in normal skin, the expression levels of YAP, TAZ, CTGF, and Ki-67 were significantly upregulated in lymphatic endothelial cells (LECs) of LMs. Interestingly, YAP and CTGF presented much higher expression levels in infected LMs. In experiments in vitro, lipopolysaccharide (LPS) enhanced the expression of YAP in a concentration- and time-dependent manner via the increased phosphorylation of Erk1/2 (extracellular signal-regulated kinase 1/2). Moreover, the proliferation, invasion, and tubule formation of HDLECs increased significantly in accordance with the activation of the YAP signaling pathway. Furthermore, LM rat models validated that LPS facilitated the development of LMs, which was dependent on the activation of YAP.

CONCLUSIONS

The data reveal that activation of the YAP signaling pathway in LECs may play a crucial role in the progression of LMs.

IMPACT

Compared with that in normal skin, the YAP signaling pathway was activated in LECs of LMs. Inhibiting the YAP signaling pathway attenuated the proliferation, invasion, and tubule formation of HDLECs. Additionally, the activation of the YAP signaling pathway could promote LM development in a rat model. Activation of the YAP signaling pathway in LECs may play a crucial role in the progression of LMs. The YAP signaling pathway was activated in LMs. Inhibition of the YAP signaling pathway could promote regression of the lesions.

Evolution of Intravitreal Therapy for Retinal Diseases-From CMV to CNV: The LXXIV Edward Jackson Memorial Lecture

PURPOSE

To present the evolution of intravitreal therapy for retinal diseases and its impact on clinical practice.

DESIGN

Retrospective literature review and personal perspective.

METHODS

Retrospective literature review and personal perspective.

RESULTS

Pharmacotherapeutic advances in retinal disease have been remarkable over the last 25 years. Almost all of the new drugs developed have required intravitreal administration to be highly effective, leading to an exponential increase in the annual number of intravitreal injections given. The use of intravitreal antibiotic injections to treat endophthalmitis, usually on a one-time basis, first familiarized ophthalmologists with this method of drug delivery. Ganciclovir was the first widely available, relatively inexpensive compounded drug that was used for repeat intravitreal injection to treat a chronic retinal disease, followed by triamcinolone for diabetic macular edema and bevacizumab for neovascular age-related macular degeneration. Ganciclovir was formulated for sustained-release drug delivery to avoid frequent intravitreal injections, a goal that has been more elusive for anti-VEGF drugs. Political obstacles encountered while conducting some of the trials to evaluate these treatments were substantial. Addressing the issues they raised led to important national policy changes that will impact the conduct of future clinical trials. The first comparative efficacy trial of intravitreal therapies was the Comparison of AMD Treatments Trials (CATT). The primary results from CATT and the many publications that followed continue to shape the use of intravitreal therapy today.

CONCLUSION

Intravitreal therapy has proven highly effective for the treatment of many retinal diseases. The treatment burden for patients from numerous injections, the cost to health care systems, and the impact on workflows in clinical practice have been substantial. Efforts to develop effective intravitreal therapies with reduced treatment burden and cost are ongoing.

Glucocorticoid receptor signaling in the eye

Glucocorticoids (GCs) are essential steroid hormones that regulate numerous metabolic and homeostatic functions in almost all physiological systems. Synthetic glucocorticoids are among the most commonly prescribed drugs for the treatment of various conditions including autoimmune, allergic and inflammatory diseases. Glucocorticoids are mainly used for their potent anti-inflammatory and immunosuppressive activities mediated through signal transduction by their nuclear receptor, the glucocorticoid receptor (GR). Emerging evidence showing that diverse physiological and therapeutic actions of glucocorticoids are tissue-, cell-, and sex-specific, suggests more complex actions of glucocorticoids than previously anticipated. While several synthetic glucocorticoids are widely used in the ophthalmology clinic for the treatment of several ocular diseases, little is yet known about the mechanism of glucocorticoid signaling in different layers of the eye. GR has been shown to be expressed in different cell types of the eye such as cornea, lens, and retina, suggesting an important role of GR signaling in the physiology of these ocular tissues. In this review, we provide an update on the recent findings from in vitro and in vivo studies reported in the last 5 years that aim at understanding the role of GR signaling specifically in the eye. Advances in studying the physiological effects of glucocorticoids in the eye are vital for the elaboration of optimized and targeted GC therapies with potent anti-inflammatory potential while minimizing adverse effects.

Verteporfin Therapy and Triamcinolone Acetonide: Convergent Modes of Action for Treatment of Neovascular Age-Related Macular Degeneration

PURPOSE

Choroidal neovascularization associated with age-related macular degeneration is the primary cause of blindness in the elderly in developed countries, due to a number of pathogenic effects, including angiogenesis, cell-mediated inflammation, leukocyte adhesion and extravasation, and matrix remodeling.

METHODS

By producing photochemical effects at the site of target tissue (lesion), photodynamic therapy (PDT) can induce vascular damage and blood flow stasis, leading to occlusion of vascularization and lesion leakage.

RESULTS

PDT with verteporfin (Visudyne, Novartis) has been shown to be safe and effective in reducing the risk of vision loss in patients with classic containing subfoveal CNV and occult with no classic CNV. However, in predominantly occult CNV, the treatment may be most effective in smaller lesions, and less in larger lesions. Most important, visual acuity rarely is improved.

CONCLUSIONS

Pilot studies and large case series suggest that a combination of PDT and intravitreal triamcinolone acetonide has the potential to improve visual outcomes and reduce the need for additional treatments. Randomized, prospective clinical trials are underway to confirm the efficacy and safety of this novel treatment modality.

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.

25th RCOphth Congress, President's Session paper: 25 years of progress in medical retina

The quarter century since the foundation of the Royal College of Ophthalmologists has coincided with immense change in the subspecialty of medical retina, which has moved from being the province of a few dedicated enthusiasts to being an integral, core part of ophthalmology in every eye department. In age-related macular degeneration, there has been a move away from targeted, destructive laser therapy, dependent on fluorescein angiography to intravitreal injection therapy of anti-growth factor agents, largely guided by optical coherence tomography. As a result of these changes, ophthalmologists have witnessed a marked improvement in visual outcomes for their patients with wet age-related macular degeneration (AMD), while at the same time developing and enacting entirely novel ways of delivering care. In the field of diabetic retinopathy, this period also saw advances in laser technology and a move away from highly destructive laser photocoagulation treatment to gentler retinal laser treatments. The introduction of intravitreal therapies, both steroids and anti-growth factor agents, has further advanced the treatment of diabetic macular oedema. This era has also seen in the United Kingdom the introduction of a coordinated national diabetic retinopathy screening programme, which offers an increasing hope that the burden of blindness from diabetic eye disease can be lessened. Exciting future advances in retinal imaging, genetics, and pharmacology will allow us to further improve outcomes for our patients and for ophthalmologists specialising in medical retina, the future looks very exciting but increasingly busy.

Differential flow rate of commercially available triamcinolone with and without preservative through small-gauge needles

OBJECTIVE

To compare the flow rate through different gauge needles of triamcinolone acetonide with benzyl alcohol (TABA) versus preservative-free triamcinolone acetonide injectable suspension (TAIS).

MATERIALS AND METHODS

Experimental injections of 1 mL of TABA or TAIS were performed through a 27-, 30-, or 32-gauge needle. A piezoelectric pressure transducer connected to a personal computer was placed between the syringe and needle to record the force-time relationship and assess the flow rate (mL/s). Measurements were performed in triplicate.

RESULTS

Flow rates were similar between preparations using a 27-gauge needle. Using a 30-gauge needle, the flow rate was 0.058 mL/s for TABA and 0.178 mL/s for TAIS. Using a 32-gauge needle, no flow was sustained by TABA, whereas the flow rate of TAIS was 0.114 mL/s (P < .05).

CONCLUSION

TAIS can be injected through a 32-gauge needle without the risk of obstruction. Occlusions were seen with TABA using the 30- and 32-gauge needles.

Assessment of the differences in pharmacokinetics and pharmacodynamics between four distinct formulations of triamcinolone acetonide

PURPOSE

To compare the durability of Kenalog, Trivaris, Triesence, and compounding pharmacy preservative-free triamcinolone acetonide in pigmented rabbits with syneretic vitreous using direct visualization, pharmacodynamics, and pharmacokinetics.

METHODS

Twenty-five Dutch-belted rabbits were used. Pharmacokinetic experiment: Rabbits were intravitreally injected with one of four 4-mg triamcinolone acetonide formulations. Wide-field imaging was serially performed to document residual drug mass. Pharmacodynamics experiment: Four triamcinolone acetonide groups and one control group received intravitreal recombinant human vascular endothelial growth factor 165 every 2 weeks and were followed with fluorescein angiography to assess vascular endothelial growth factor retinal vasculopathy as a measure of residual steroid effect. Particle size of the formulations was measured with Mastersizer 2000.

RESULTS

Remaining triamcinolone acetonide mass after 19 weeks: 12,091 ± 2,512 pixels for the Kenalog group, 1,307.36 ± 695.57 for Trivaris, 5577 ± 1477 for Triesence, and 1,535 ± 329 for compounded preservative-free triamcinolone acetonide. Kenalog suppressed recombinant human vascular endothelial growth factor-induced retinopathy more effectively than the other triamcinolone acetonide groups at Week 39, the final time point assessed. Particle size (90th percentile) was 47 μm for Kenalog, 26 μm for Triesence, and 22 μm for both compounded preservative-free triamcinolone acetonide and Trivaris.

CONCLUSION

Triamcinolone acetonide formulations do not have the same pharmacokinetics/pharmacodynamics. Kenalog has the longest vitreous visibility and durability. Particle size appears to correlate with efficacy and durability.

Intraocular corticosteroids for posterior segment disease: 2012 update

INTRODUCTION

Diabetic macular edema (DME), cystoid macular edema (CME), age-related macular degeneration (AMD), retinal vascular occlusion (RVO) and uveitis are responsible for severe visual impairment worldwide. In some patients with these conditions, treatment with intraocular corticosteroids may be beneficial. Although off-label use of these agents has occurred for many years, novel agents including preservative-free and sustained-release intravitreal implants are currently being studied in clinical trials (CTs).

AREAS COVERED

This paper reviews the use of CTs for vitreoretinal (VR) diseases including choroidal neovascularization, CME, DME, RVO and posterior uveitis. It also discusses the use of corticosteroids for treating VR disease, including dexamethasone, fluocinolone acetonide, intravitreal implants and triamcinolone acetonide.

EXPERT OPINION

Used alone, intravitreal corticosteroids may benefit disorders such as DME, RVO and uveitis compared with standard therapy. Cases of exudative AMD non-responsive to standard treatment may benefit from combination therapy, including usage of intravitreal corticosteroid injections. Intraoperative use of these agents may aid visualization of retinal structures. Sustained-release intraocular implants have been approved for posterior uveitis and RVO associated with macular edema. In spite of this, most intraocular corticosteroids have a limited duration of action along with significant side effects, including cataract and glaucoma. Currently, intravitreal corticosteroid usage for DME is considered off-label.

Low-fluence photodynamic therapy combinations in the treatment of exudative age-related macular degeneration

AIM

To compare the efficacy of low-fluence photodynamic therapy (PDT) combinations in the treatment of age-related macular degeneration (AMD).

METHODS

Forty-five previously untreated eyes of 45 patients with exudative AMD whose best-corrected visual acuity (BCVA) was ≥0.3 (Snellen) were enrolled. 15 patients in Group I underwent low-fluence PDT (25J/cm(2)-300mW/cm(2)-83sec) and intravitreal pegaptanib combination, 15 patients in Group II underwent PDT (50J/cm(2)-600mW/cm(2)-83sec) and intravitreal pegaptanib combination while, 15 patients in Group III underwent intravitreal pegaptanib monotherapy. Complete ophthalmologic examinations were performed in pre and post treatment visits, and the results were statistically analised. A clinical activity score (CAS) was calculated by using changes in lesion size, amount of hemorrhage, staining pattern in FA and OCT measurement of intra/subretinal fluid. ≤ 3 logMAR lines of decrease in BCVA and decrease in CAS were considered as successful treatment.

RESULTS

The mean age of 19 female (42.2%) and 26 male (57.8%) patients was 72.82±8.02 years. Mean follow-up was 13.93±5.87 months. Lesion type was occult in 28 eyes (62.2%). Treatment success rates according to BCVA assessments were 86.7%, 80%, 60% and mean BCVA decrease were 0.3, 1.0, 2.2 logMAR lines in Group I, II and III, respectively (P>0.05). According to the changes in central macular thickness and CAS, no difference was found among the study groups (P=0.850 and P=0.811, respectively). Patients treated with combination regimens had lower intravitreal injection frequencies (P=0.015).

CONCLUSION

Combination regimen with intravitreal pegaptanib and low-fluence PDT seems to be safe and effective in stabilizing the clinical activity and BCVA in exudative AMD.

Review of combination therapies for neovascular age-related macular degeneration

While angiogenesis is one of the factors associated with the development of CNV due to age-related macular degeneration (AMD), inflammation and oxidative stress also appear to play a role. Treatment of CNV with intravitreal anti-vascular endothelial growth factor monotherapy is currently the standard of care. However, not all patients respond to monotherapy, and combination therapy may target the CNV through multiple mechanisms, thus reducing treatment frequency or improving visual outcome. Photodynamic therapy (with regular or reduced fluence), as well as intravitreal steroids are used in combination with anti-VEGF therapy. This paper reviews the many clinical trials that have been performed utilizing several combinations of double and triple therapy. While combination therapy is biologically justifiable, further study is required to determine correct combinations and dosage.

Combined treatment of exudative age related macular degeneration with photodynamic therapy and intravitreal triamcinolone

Choroidal neovascularization (CNV) secondary to age related macular degeneration is among the leading causes of legal blindness in developed countries. Photodynamic therapy (PDT) with verteporfin induces CNV closure causing little damage to healthy tissue, but the need to re-treat may lead to low final visual acuity at an unacceptable cost. The association of intravitreous triamcinolone or antiangiogenic drugs with PDT has been used in order to reduce these limitations of the therapy. The combination of PDT and intravitreous triamcinolone, its complications and outcome at one and two-year follow-up are discussed.

Changes in macular sensitivity after reduced fluence photodynamic therapy combined with intravitreal triamcinolone

PURPOSE

This study aimed to evaluate the course of macular sensitivity (MS) following treatment with reduced fluence photodynamic therapy (RPDT) versus standard photodynamic therapy (SPDT) in combination with intravitreal triamcinolone acetonide (IVTA) in patients with neovascular age-related macular degeneration, and to investigate the correlation between MS and angiographic outcomes.

METHODS

Forty eyes in 40 patients were included in this prospective, randomized clinical study. Group 1 patients received RPDT (n = 20, light dose of 25 J/cm(2) at 300 mW/cm(2)); group 2 patients received SPDT (n = 20, light dose of 50 J/cm(2) at 600 mW/cm(2)). All patients received 4 mg IVTA administered on the same day as RPDT or SPDT. Microperimetry, visual acuity testing (ETDRS) and fluorescein angiography (FA) were performed at baseline, and at months 3, 6, 9 and 12. Main outcome parameters were mean differential light threshold (DLT), and absolute and relative scotoma size.

RESULTS

Mean DLT decreased from 4.71 dB at baseline to 3.45 dB after 12 months in the SPDT + IVTA group (mean decrease 1.26 dB; p > 0.05) and from 5.42 dB to 4.92 dB in the RPDT + IVTA group (mean decrease 0.5 dB; p > 0.05). Absolute and relative scotoma sizes remained stable in both groups at 12 months (mean change 0 and -0.6 test-points; p > 0.05). Mean DLT values and absolute scotoma sizes correlated well with early and late leakage areas in FA (r = -0.45 to -0.80, p < 0.02).

CONCLUSIONS

With regard to MS, RPDT + IVTA did not show significant benefits over SPDT + IVTA at 12 months. Macular sensitivity correlated well with angiographic outcomes.

Destruction of amyloid fibrils of keratoepithelin peptides by laser irradiation coupled with amyloid-specific thioflavin T

Mutations in keratoepithelin are associated with blinding ocular diseases, including lattice corneal dystrophy type 1 and granular corneal dystrophy type 2. These diseases are characterized by deposits of amyloid fibrils and/or granular non-amyloid aggregates in the cornea. Removing the deposits in the cornea is important for treatment. Previously, we reported the destruction of amyloid fibrils of β(2)-microglobulin K3 fragments and amyloid β by laser irradiation coupled with the binding of an amyloid-specific thioflavin T. Here, we studied the effects of this combination on the amyloid fibrils of two 22-residue fragments of keratoepithelin. The direct observation of individual amyloid fibrils was performed in real time using total internal reflection fluorescence microscopy. Both types of amyloid fibrils were broken up by the laser irradiation, dependent on the laser power. The results suggest the laser-induced destruction of amyloid fibrils to be a useful strategy for the treatment of these corneal dystrophies.

Upcoming therapeutic advances in diabetic macular edema: an intravitreal dexamethasone drug delivery system

INTRODUCTION

Diabetes mellitus, through its ophthalmic complications diabetic retinopathy and diabetic macular edema (DME), is a leading cause of vision loss in industrialized countries.

AREAS COVERED

This review covers laser treatment, which is a standard treatment strategy that has proven efficacy and safety through large clinical trials in DME. Several intravitreal drug applications currently being investigated are also discussed.

EXPERT OPINION

First results suggest that the administration of anti-VEGF compounds is effective for DME. However, frequent injections may compromise safety. In order to enhance patient compliance, sustained delivery systems are being evaluated as potential treatment approaches. So far, only steroids have been included as active in such non-biodegradable or biodegradable delivery systems. Non-biodegradable systems are more complicated to administer as surgery is required and they need to be retrieved at the end of treatment. Also, in some cases safety issues have arisen, especially around intraocular pressure control. A new biodegradable dexamethasone delivery system seems to show promising efficacy results in addition to a more favorable safety profile, which will potentially improve patient compliance. All new therapeutic approaches, alone and in combination, will need to demonstrate their efficacy and safety in DME in future trials.

[Pigment epithelial detachment in exudative macular degeneration: clinical characteristics and therapeutic options]

Vascularized pigment epithelial detachment (PE detachment) can be viewed as a special form of occult choroidal neovascularization (CNV) owing to the natural course of the disease, its specific pathogenesis and its response to various forms of treatment. This applies to serous PE detachment associated with both occult CNV and also with retinal angiomatous proliferation (RAP). A tear in the retinal pigment epithelium (RIP) represents a serious complication of vascularized PE detachment and is often associated with acute vision deterioration that not uncommonly also involves massive subretinal hemorrhaging. The pathomechanism underlying the development of RIP has not yet been completely elucidated. The notion that the PED bursts as a result of the increased pressure stands in contrast to the theory that the CNV contracts and causes scarring which in turn causing secondary RIP. Anti-VEGF therapy is currently the preferred treatment. However, the initial stabilization of visual acuity after treatment could not be confirmed in long-term studies and after 2 years visual acuity deteriorated significantly. Furthermore, optimal VEGF treatment regimens have also not been defined and the criteria for repeated treatment have not been established as yet. Presently, visual deterioration and the presence of subretinal and intraretinal exudates seem to indicate that treatment will be effective. Here, high resolution OCT imaging should help to provide further insight into the matter.

Intravitreal triamcinolone, bevacizumab and pegaptanib for occult choroidal neovascularization

PURPOSE

To evaluate best-corrected visual acuity (BCVA) and foveal thickness (FT) changes in occult subfoveal choroidal neovascularization (CNV) from age-related macular degeneration (AMD) after intravitreal bevacizumab (IVB, 1.25 mg/0.05 ml), pegaptanib (IVP, 0.3 mg/0.09 ml) and triamcinolone acetonide (IVTA, 4 mg/0.1 ml) injected on an as needed basis.

METHODS

  Retrospective, interventional, comparative study. BCVA (Early Treatment Diabetic Retinopathy Study LogMAR) and FT by optical coherence tomography (OCT) were evaluated during 12 months from first treatment. Patients were retreated if signs of neovascular activity were still present on angiography or OCT.

RESULTS

Forty-eight eyes received IVB, 43 eyes received IVP, 52 eyes received IVTA. BCVA and FT at baseline were 1.22 ± 0.49 LogMAR and 410.2 ± 41.83 μm in the IVB group, 1.25 ± 0.43 LogMAR and 452.3 ± 44.83 μm in the IVP group and 1.31 ± 0.4 LogMAR and 456.6 ± 48.27 μm in the IVTA group. BCVA and FT improved in the three groups during follow-up. A significantly greater improvement of BCVA was present at month-3, month-6 and at month-12 in the IVB and IVP groups (p = 0.01). Improvement of FT was greater in the IVTA group at month-3 (p = 0.02), while it was greater in the anti-Vascular Endothelial Growth Factor (VEGF) groups at month-6 and month-12 (p = 0.01). A postoperative increase of intraocular pressure was detected in 9/52 (17.3%) eyes treated with IVTA, and in two cases it was resistant to topical therapy.

CONCLUSION

  Intravitreal injection of anti-VEGF drugs administered on an as needed basis for AMD-related occult CNVs provided functional and anatomic improvement during 12 months of follow-up.

Focal macular electroretinograms after photodynamic therapy combined with intravitreal bevacizumab

BACKGROUND

Retinal function is transiently depressed after photodynamic therapy (PDT) alone. One of the reasons for this functional impairment is a reduction of choroidal circulation caused by the PDT. The purpose of this study was to determine whether PDT combined with intravitreal bevacizumab (PDT+IVB) can reduce or prevent the transient impaired macular function. In addition, we examined whether a significant correlation existed between the changes in the focal macular electroretinograms (FMERGs), optical coherence tomography (OCT)-determined morphology, and changes in choroidal circulation.

METHODS

Thirty-eight eyes that were treated by full fluence PDT+IVB were studied. FMERGs, OCT, and indocyanine green angiography (ICGA) were performed before and after the PDT. The intensity of the diffuse fluorescence within the PDT site was measured by densitometry (I/N ratio).

RESULTS

The macula was significantly thinner 1 week after PDT+IVB (P < 0.01). The mean a- and b-wave amplitudes of the FMERGs were not significantly decreased 1 week after PDT+IVB. The mean b-wave amplitudes 3 months after PDT+IVB were significantly increased (P < 0.01). The I/N ratio of ICGA 3 months after PDT+IVB was 0.88 ± 0.1. The correlation between the FMERGs and I/N ratio was not significant.

CONCLUSION

The use of IVB with PDT mitigates the reduction of the FMERGs and reduces the macular thickness soon after PDT, regardless of the degree of impairment of choroidal circulation caused by PDT. Finally, the macular retinal function 3 months after PDT+IVB were better than that before the treatment.

Macular atrophy after combined intravitreal triamcinolone and photodynamic therapy to treat choroidal neovascularization

AIM

To report the appearance of choriocapillaris atrophy after combined high dose intravitreal triamcinolone acetonide (TA) and photodynamic therapy (PDT) to treat choroidal neovascularization (CNV) associated with age related macular degeneration (AMD).

METHODS

The present study was retrospective about non-randomized interventional case series. Fifty-one consecutive eyes with subfoveal (all types) CNV associated with AMD were treated by PDT and intravitreal (19.4±2.1)mg per 0.1mL TA at the Alicante Institute of Ophthalmology. The appearance of macular choriocapillaris and retinal pigment epithelium (RPE) atrophy was considered at two years follow-up. Thirty consecutive eyes treated by PDT alone, matched for age, sex, and type and size of CNV were considered as control group.

RESULTS

Twenty-one of 47 eyes in the study group (45%) and 7 of 30 eyes in the control group (23%) developed macular RPE and choriocapillaris atrophy in the treated area at month 24 (P=0.04, Chi-square test). The greatest diameter of the atrophic areas averaged (5044±1666)µm in the study group vs (4345±1550)µm in the control group. Mean final best corrected visual acuity (logarithm of minimal angle of resolution) was (0.87±0.33) in the cases with RPE atrophy vs (0.66±0.26) in the cases with no RPE atrophy in the study group (P=0.11, Mann-Whitney U test).

CONCLUSION

The association of high doses of intravitreal TA and PDT may increase the risk for RPE and choriocapillaris atrophy.

Effect of photodynamic therapy alone or combined with posterior subtenon triamcinolone acetonide or intravitreal bevacizumab on choroidal hypofluorescence by indocyanine green angiography

PURPOSE

Choroidal hypofluorescence has been reported beneath the photodynamic therapy (PDT) site in clinical studies. We evaluated the choroidal hypofluorescence after combined PDT with posterior subtenon injection of triamcinolone acetonide or PDT with an intravitreal injection of bevacizumab for age-related macular degeneration.

METHODS

Two hundred and forty-two eyes with a subfoveal choroidal neovascularization caused by age-related macular degeneration were studied. Ninety-two eyes underwent PDT alone, 90 eyes underwent PDT with sub-Tenon injection of triamcinolone acetonide, and 60 eyes underwent PDT with intravitreal injection of bevacizumab. Verteporfin-induced choroidal hypoperfusion was determined by indocyanine green angiograms. The intensity of the diffuse fluorescence within the PDT site away from the choroidal neovascularization lesion and from the normal retina just peripheral to the optic disk was measured by densitometry (Topcon IMAGEnet computer system, Topcon, Tokyo, Japan) in the indocyanine green angiogram images obtained at 10 minutes 3 months after the PDT. The ratio of the average brightness of the retina within the PDT area to that of the retina peripheral to the optic disk (irradiated/nonirradiated retinal brightness ratio) was calculated for each angiogram.

RESULTS

The irradiated/nonirradiated retinal brightness ratio of the angiograms was 0.96 in the PDT-alone group, 0.85 in the sub-Tenon injection of triamcinolone acetonide-PDT group, and 0.89 in the intravitreal injection of bevacizumab-PDT group (Kruskal-Wallis H test, P < 0.05).

CONCLUSION

The degree of choroidal hypofluorescence in the indocyanine green angiogram images 3 months after PDT in the sub-Tenon injection of triamcinolone acetonide and intravitreal injection of bevacizumab group was higher than that of PDT-alone group. Sub-Tenon injection of triamcinolone acetonide and intravitreal injection of bevacizumab can prolong the duration of the choroidal hypofluorescence after PDT.

Pharmacotherapeutic efficacy of preservative-free intravitreal triamcinolone acetonide

Preservative-free formulations of triamcinolone acetonide have recently been introduced to the market over concerns of local toxicity of the vehicle and preservatives, including benzyl alcohol in the original formulation, which was not designed for intraocular use. The pharmacokinetics and pharmacodynamics of intravitreal triamcinolone (IVTA) are discussed. The therapeutic effects of IVTA include improvement of visual acuity and reduction of macular edema. However, ongoing treatment is usually required to maintain its effects. The efficacy of IVTA for both FDA-approved and 'off-labeled' indications is reviewed. Elevation of intraocular pressure and cataract formation are the two major side effects of IVTA; these are manageable but require close long-term follow-up. More studies are required to determine the optimal dosage and treatment frequency in different posterior segment disease.

Combination therapy using verteporfin and ranibizumab; optimizing the timing in the CAM model

Combining photodynamic therapy (PDT) using verteporfin (Visudyne) with ranibizumab (Lucentis) can optimize the overall treatment outcome by providing more efficacy in vessel closure, and thus reduce the need for retreatment in patients with wet age-related macular degeneration. In this preclinical study in the chorioallantoic membrane (CAM) of the chicken embryo, we compare the vascular occlusion effects of verteporfin and ranibizumab as monotherapies with those observed in the combined therapy. In order to optimize the combination therapy, we varied the timing and sequence of the PDT and antivascular endothelial growth factor modalities. We observed that 1 day after PDT, the smaller blood vessels (Ø < 70 microm) of the CAM were selectively occluded, but as early as 2 days after PDT, both significant reperfusion and regrowth of new vessels were observed. Both these phenomena could be significantly delayed by application of ranibizumab. Ranibizumab itself did not induce any vascular occlusion. Under the applied conditions of combination therapy, the occlusion of the targeted blood vessels could be significantly extended to 3 days in this model compared with 1 day in the case of verteporfin monotherapy. Thus, in the present preclinical study, we demonstrate that for the applied conditions, the optimal time to administer ranibizumab is 24 h after PDT.

Photodynamic therapy with and without adjunctive intravitreal triamcinolone acetonide: a retrospective comparative study

BACKGROUND AND OBJECTIVE

To compare photodynamic therapy (PDT) with and without adjunctive intravitreal triamcinolone acetonide (IVTA) in the treatment of choroidal neovascularization secondary to age-related macular degeneration.

PATIENTS AND METHODS

Sixty-six eyes received PDT with IVTA and 73 eyes received PDT only. Outcome measures included changes in visual acuity and greatest linear dimension (GLD), the presence of angiographic leakage, the re-treatment rate, and adverse events.

RESULTS

Patients treated with PDT with IVTA had reduced mean GLD compared to patients treated with PDT only at all study time points (3 [P = .0049], 6 [P = .003], and 12 [P = .05] months). Forty-four percent of patients in the PDT with IVTA group and 22% of patients in the PDT only group achieved angiographic closure at 3 months (P = .027). There were no significant differences in the final visual acuity outcome or the re-treatment rate between the two groups.

CONCLUSION

PDT with IVTA therapy has a favorable outcome on GLD. There is a modest improvement in visual acuity with PDT with IVTA therapy, which diminishes over time.

Medical devices for the treatment of eye diseases

Development of intraocular drug delivery systems (DDSs) is urgently required for the treatment of eye diseases, especially in the posterior segment of the eye (the vitreous cavity, retina, and choroid), most of which are refractory to conventional pharmacologic approaches; eye drops and systemically administered drugs cannot achieve therapeutic drug concentrations in the posterior segment of the eye. Repeated intravitreal injections of anti-angiogenic agents are effective in the treatment of age-related macular degeneration, but there remain risks of serious side effects such as endophthalmitis associated with repeated injections. Intraocular DDSs may address these problems. Intraocular sustained drug release from implantable or injectable devices has been investigated to treat vitreoretinal diseases. A reservoir-type nonbiodegradable implant was first launched in the market in 1996 for the treatment of cytomegalovirus retinitis secondary to the acquired immunodeficiency syndrome, followed by clinical trials for a variety of potent devices to treat other challenging eye diseases. An injectable rod-shaped insert releasing a steroid is presently being assessed in a phase III trial to treat macular edema secondary to diabetic retinopathy or retinal vein occlusion. Thus various types of intraocular DDSs will be commercially available to treat vision-threatening intraocular diseases in the near future.

The use of intraocular corticosteroids

BACKGROUND

Diabetic macular edema (DME), cystoid macular edema (CME), age-related macular degeneration (AMD), retinal vascular occlusion (RVO) and uveitis are responsible for severe visual impairment worldwide. In some patients with these conditions, treatment with intraocular corticosteroids may be beneficial. Although off-label use of these agents has occurred for many years, novel agents including preservative-free and sustained-release intravitreal implants are currently being studied in clinical trials (CTs).

OBJECTIVE

To review the use of intraocular corticosteroids.

METHODS

Literature review.

RESULTS

Used alone, intravitreal corticosteroids may benefit disorders such as DME, RVO and uveitis compared with standard therapy or observation. Patients with AMD may benefit more from combination treatment with photodynamic therapy, intravitreal corticosteroid and intravitreal anti-VEGF injections. Intraoperative use of these agents may assist in visualization and manipulation of fine retinal structures. Sustained-release intraocular implants have been approved for severe posterior uveitis, and have shown benefits in ongoing CTs.

CONCLUSION

Although intraocular corticosteroid injections have a limited duration of action requiring frequent re-treatment, and significant side effects including cataract and glaucoma development, intraocular injections may be of benefit in certain ocular disorders. Corticosteroid implants are emerging as potential treatments for macular edema due to uveitis, DME or RVO.

Age-related macular degeneration: current treatments

Purpose:

Although important progress has been made in understanding age-related macular degeneration (AMD), management of the disease continues to be a challenge. AMD research has led to a widening of available treatment options and improved prognostic perspectives. This essay reviews these treatment options.

Design:

Interpretative essay.

Methods:

Literature review and interpretation.

Results:

Current treatments to preserve vision in patients with non-exudative AMD include antioxidant vitamins and mineral supplementations. Exudative AMD is currently most often treated monthly with anti-VEGF intravitreal injections. However, investigators are beginning to experiment with combination therapy and surgical approaches in an attempt to limit the number of treatment and reduce the financial burden on the health care system.

Conclusion:

By better understanding the basis and pathogenesis of AMD, newer therapies will continue to be developed that target specific pathways in patients with AMD, with the hoped for outcome of better management of the disease and improved visual acuity.

Triple therapy for neovascular age-related macular degeneration using single-session photodynamic therapy combined with intravitreal bevacizumab and triamcinolone

AIM

To evaluate the efficacy and safety of triple therapy consisting single-session photodynamic therapy (PDT), intravitreal bevacizumab (IVB) and intravitreal triamcinolone (IVTA) for treatment of neovascular age-related macular degeneration (AMD) METHODS: Consecutive patients with subfoveal choroidal neovascularisation (CNV) secondary to AMD were treated with PDT using a standard protocol immediately followed by 1.25 mg of IVB and 4 mg of IVTA. 1.25 mg of IVB was given at 3 months for residual leakage. Best-corrected Snellen visual acuity (BCVA) and fluorescein angiography (FA) were performed prior to treatment. BCVA, intraocular pressure (IOP) and presence of vitritis were documented at 1 and 6 weeks, 3 and 6 months. FA was repeated at 3 and 6 months. Outcome measures included visual improvement measured by logMAR equivalent, angiographic evident of leakage and safety profile.

RESULTS

36 eyes of 33 patients, aged 76.4 (SD 10.5) years with mean follow-up of 14.7 (6.9-19.2) months were analysed. Baseline logMAR acuity was 1.22 (0.71). The mean logMAR acuity was 1.14 (0.62) and 1.18 (0.63) at 3 and 6 months respectively. At 6 months, 61.1% (22/36) showed stable or gaining vision, and 27.8% (10/36) gained three or more lines. Twenty-eight eyes (77.8%) achieved CNV resolution by single session of triple therapy. One eye lost more than six lines due to retinal pigment epithelium rip, three eyes showed a significant cataract requiring surgery, and two showed persistent raised IOP at 6 months. None resulted in endophthalmitis or reported thromboembolic event.

CONCLUSIONS

Short-term results of single session triple therapy suggested that it might be a useful treatment option for neovascular AMD based on its low retreatment rates, sustainable CNV eradication result and visual gain achievement. However, the risk and benefits of using intravitreal triamcinolone in addition to combined PDT and IVB warrant further evaluation.

Photodynamic therapy with intravitreal application of triamcinolone acetonide in age-related macular degeneration: functional results in 54 patients

PURPOSE

This study aimed to investigate the functional results, efficacy and complications after photodynamic therapy (PDT) combined with intravitreal triamcinolone acetonide injection (IVTA) in patients with choroidal neovascularization (CNV) caused by age-related macular degeneration (AMD).

METHODS

A retrospective analysis of clinical data for 54 patients with CNV resulting from AMD was carried out. All patients had a follow-up of 12 months. The patients were treated with standardized PDT and IVTA (4 mg) as a first-line treatment or following PDT failure. Visual acuity (VA), greatest linear diameter (GLD) of the CNV and foveal thickness were evaluated.

RESULTS

Mean VA at baseline was 0.8 logMAR (0.4-1.4). After 12 months VA improved (> 2 lines) in 20.4% of patients and stabilized (+/- 2 lines) in 64.8%. There was no statistical significance in VA outcome between patients undergoing first-line treatment and patients with PDT failure; however, fewer PDT treatments were required to stop CNV activity in patients undergoing first-line treatment. At 12 months, a reduction in foveal thickness was seen in 67.7% of patients and a reduction in CNV GLD in 32.7%. Complications occurred in 22% of patients and included a transient rise in intraocular pressure, cataract and sterile hypopyon.

CONCLUSIONS

Our analysis shows that fewer PDT treatments were required to stop CNV activity when triamcinolone was used as first-line treatment. We can thus conclude that PDT combines synergistically with IVTA and the combination may lead to a cost reduction compared with PDT therapy alone. The overall complication rate of 22% is high and must be compared with complication rates caused by new intravitreal anti-VEGF (vascular endothelial growth factor) drugs in combination with PDT.

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.