Triple therapy for choroidal neovascularization due to age-related macular degeneration: verteporfin PDT, bevacizumab, and dexamethasone

Combination of photodynamic therapy and immunomodulation: current status and future trends

Photodynamic therapy (PDT) has been used for the treatment of nonmalignant and malignant diseases from head to toe. Over the last decade its clinical application has gained increasing acceptance around the world. Pre-clinical studies demonstrate that, in addition to the direct local cytotoxicity and vascular effects, PDT can induce various host immune responses. Recent clinical data also show that improved clinical outcomes are obtained through the combination of PDT and immunomodulation. This review will summarize and discuss recent progress in developing innovative regimen of PDT combined with immunomodulation for the treatment of both nonmalignant and malignant diseases.

Applying the CONSORT and STROBE statements to evaluate the reporting quality of neovascular age-related macular degeneration studies

PURPOSE

To evaluate the quality of reporting in the neovascular age-related macular degeneration (nvAMD) literature by applying the Consolidated Standards for Reporting Trials (CONSORT) and Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) statement writing standards.

DESIGN

CONSORT and STROBE impact analysis; literature review.

PARTICIPANTS

Phase III randomized controlled trials (RCTs) of verteporfin photodynamic therapy, pegaptanib, and ranibizumab, and interventional case studies of bevacizumab for nvAMD.

METHODS

A literature search identified eligible articles published before October 31, 2007. We assessed the report quality of Phase III RCTs using the CONSORT statement and case series publications using the STROBE statement, both with indicators relevant to nvAMD.

MAIN OUTCOME MEASURES

Presence or absence of CONSORT or STROBE statement indicators.

RESULTS

Seven publications of Phase III RCTs and 29 publications on bevacizumab interventional case studies for nvAMD met our inclusion criteria. Of 37 possible CONSORT writing guideline items, the mean report quality for RCTs was 30.6 (83%), with a range from 23 to 35 (65%-95%). Of 35 possible STROBE writing guideline items, the mean report quality grade for intravitreal bevacizumab case series was 23 (70%), with a range from 16 to 31 (46%-94%). Among the bevacizumab studies, more than 90% reported scientific background, drug dose and administration, baseline characteristics, unadjusted results, and adverse events. Fewer than 20% reported study size calculations, handling of missing data, or a discussion of bias.

CONCLUSIONS

Since the adoption of the CONSORT standards by Ophthalmology and other journals in 1996, the reporting quality for RCTs has further improved among this cohort of nvAMD articles. On the other hand, no reporting standards for case series have existed until the recent publication of the STROBE statement. In this first application of the STROBE standards to ophthalmology, we found that the small interventional studies in our series had an average reporting score lower than the RCTs, but also that some individual scores were higher than the RCTs. This outcome demonstrates that good, useful articles can be written about small studies. Although not a direct measure of the quality of a study, good reporting allows a reader to assess the validity and applicability of the study's findings.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found after the references.

Relationships between clinical measures of visual function and anatomic changes associated with bevacizumab treatment for choroidal neovascularization in age-related macular degeneration

PURPOSE

This pilot study was undertaken to examine the relationships between clinical measures of visual function and anatomic changes occurring in the eyes treated with bevacizumab for choroidal neovascularization (CNV) due to age-related macular degeneration (AMD).

METHODS

A retrospective review was conducted for 50 eyes that had been treated with at least three injections of bevicizumab for CNV due to AMD, and followed for at least 6 months. Vision outcomes included best-corrected ETDRS chart acuity, scored by best-line read (ETDRS line) and by total letters read (ETDRS letter), and two measures obtained from central acuity perimetry with 98% Michelson contrast targets, the best acuity within 6 degrees of fixation (BA6 degrees ), and global macular acuity (GMA), representing a weighted average of the acuities thresholded at all intercepts within a 10 degrees radius of fixation. Assessment of anatomic outcomes included fibrosis, atrophy, and subretinal hemorrhage grading on fundus photography, CNV size, pigment epithelial detachment (PED) size and grading of CNV leakage on fluorescein angiography, and central retinal PED, and subretinal fluid (SRF) thickness on optical coherence tomography.

RESULTS

Logistic regression analysis showed an association between the vision outcomes of EDTRS letter and BA6 degrees with the change in SRF thickness (R (2): 0.47 and 0.35, respectively). The outcome of the vision measurement of GMA was associated with the change in SRF thickness, in CNV thickness, and in CNV fibrosis grade (R (2): 0.34). No association was noted between the outcomes of ETDRS line with the change in any anatomic outcomes.

CONCLUSION

Acuity perimetry outcomes in this study seemed to offer improved understanding of the relationship between the vision outcomes and the measured anatomic changes. It seemed that neither ocular coherence tomography nor fluorescein angiography alone offered sufficient morphologic markers for prediction of functional outcomes.

Anti-vascular endothelial growth factor pharmacotherapy for age-related macular degeneration: a report by the American Academy of Ophthalmology

OBJECTIVE

To examine the evidence about the safety and efficacy of anti-vascular endothelial growth factor (VEGF) pharmacotherapies for the treatment of neovascular age-related macular degeneration (AMD).

DESIGN

Literature searches were conducted in May and October 2007 in PubMed with no date restrictions, limited to articles published in English, and in the Cochrane Central Register of Controlled Trials without a language limitation and yielded 310 citations. The first author reviewed the abstracts of these articles and selected 73 articles of possible clinical relevance for review by the panel. The panel deemed 64 of these articles sufficiently clinically relevant to review in full text and assigned ratings of level of evidence to each of the selected articles with the guidance of the panel methodologists.

RESULTS

Eleven studies provided level I evidence for intravitreal pegaptanib and ranibizumab for neovascular AMD; there were no studies rated level I for bevacizumab for neovascular AMD. Five studies were rated as level II, which included studies of ranibizumab and bevacizumab, and the remaining 38 articles retrieved were rated as level III. The studies do not provide information about long-term results or the value (comparative effectiveness) and cost-effectiveness of combined therapies.

CONCLUSIONS

Review of the available literature to date suggests that anti-VEGF pharmacotherapy, delivered by intravitreal injection, is a safe and effective treatment for neovascular AMD for up to 2 years. There is level I evidence to support this conclusion for pegaptanib and ranibizumab, but none for bevacizumab at this time.

Relationship between optical coherence tomography retinal parameters and visual acuity in neovascular age-related macular degeneration

PURPOSE

To investigate the relationship between optical coherence tomography (OCT)-derived measurements of retinal morphology and visual acuity in patients with neovascular age-related macular degeneration (AMD).

DESIGN

Retrospective cross-sectional study.

PARTICIPANTS

A total of 216 consecutive patients (216 eyes) newly diagnosed with neovascular AMD who underwent StratusOCT imaging at the time of diagnosis.

METHODS

Best-corrected Snellen visual acuity was recorded for each patient. Raw exported StratusOCT images for each patient were analyzed using publicly available custom software entitled "OCTOR," which allows the precise positioning of prespecified boundaries on individual B-scans. Thickness and volume were calculated for morphologic parameters of interest: neurosensory retina, subretinal fluid, subretinal tissue (SRT), and pigment epithelial detachment.

MAIN OUTCOME MEASURES

OCT-derived measurements of retinal morphology and visual acuity.

RESULTS

An increased total volume of SRT was correlated with decreased visual acuity (r = 0.370, P<0.0001). Decreased visual acuity was also modestly correlated with increased thickness of the neurosensory retina at the foveal center point (r = 0.245, P = 0.0004). No statistically significant association was detected between visual acuity and the total volume of subretinal fluid or pigment epithelial detachment. The association between visual acuity and both the neurosensory retina and the SRT was stronger for lesions classified as minimally classic or occult on fluorescein angiography. For occult lesions, 20% of the variation in visual acuity could be predicted by a multiple regression model that incorporated age and SRT volume, whereas, for minimally classic lesions, 62% of the variation in visual acuity could be predicted by a multiple regression model that incorporated age, total neurosensory retinal volume, and total SRT volume.

CONCLUSIONS

The presence of increased SRT thickness and volume on OCT, and to a lesser extent increased neurosensory retinal thickness and volume, is associated with decreased visual acuity in neovascular AMD. However, because of the complex pathophysiology of neovascular AMD and, in part, the limitations of StratusOCT, these factors only account for a small degree of the variation in visual acuity that these patients exhibit. The detection of stronger correlations between retinal anatomy and visual acuity is likely to require the use of more advanced imaging modalities.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found after the references.

Pharmacokinetic study of dexamethasone disodium phosphate using intravitreal, subconjunctival, and intravenous delivery routes in rabbits

Dexamethasone is a corticosteroid with proven efficacy for treating both anterior- and posterior-segment ocular diseases. Delivery of drugs to the back of the eye has always been a challenge, with dexamethasone being no exception. There are multiple delivery routes to the retina, with each exhibiting different pharmacokinetics, depending on the drug molecule and specific route of administration. In this study, we used intravenous (IV), subconjunctival (SC), and intravitreal (IVT) injections in rabbits to determine the pharmacokinetics of dexamethasone phosphate and its metabolic product, dexamethasone, at low (25 microg/kg) and high (250 microg/kg) doses. Plasma samples were collected from each group of animals at different time points up to 24 h after the injection. Using a liquid chromatographic mass spectrometric method with a limit of detection of 0.5 ng/mL, the plasma concentration for dexamethasone and its prodrug compound were quantified. IV delivery showed the fastest plasma elimination, followed by SC delivery. IVT delivery exhibited a depot effect, with very low plasma levels throughout the 24-h time course. At 24 h postinjection, only the high-dose IVT and low- and high-dose SC dexamethasone injections were still detectable in the plasma.

Verteporfin therapy in occult with no classic CNV due to AMD: results of the Photodynamic Therapy in Occult-Only Lesions study

PURPOSE

To provide further information on verteporfin photodynamic therapy in occult with no classic choroidal neovascularization (CNV) secondary to age-related macular degeneration (AMD).

METHODS

Verteporfin therapy was administered at baseline and then at months 3, 6, and 9, if fluorescein leakage from CNV was evident on angiography.

RESULTS

Of 202 patients enrolled, 184 completed 12 months. Each patient was treated in one eye only. All study eyes received verteporfin therapy at baseline, with a progressive decrease in the number treated at subsequent visits (mean 2.5 treatments during 12 months). The mean change in visual acuity letter score from baseline to month 12 was -11.9. At month 12, 164 eyes (82.4%) had lost <30 letters of visual acuity, 123 eyes (61.8%) had lost <15 letters, 78 eyes (39.2%) had lost <5 letters, 31 (15.6%) had >5-letter increase, and 7 (3.5%) had >15-letter improvement. The percentage of eyes with fluorescein leakage from CNV decreased from 75.5% at month 3 to 25.1% at month 12. Adverse events were documented for 54% patients. Few patients had treatment-associated adverse events (7%). Acute severe visual acuity decrease occurred in two eyes (1%), one of which had visual acuity that returned to baseline by the next follow-up visit.

CONCLUSIONS

This study provides additional evidence that over 12 months, verteporfin is generally well tolerated and maintains or improves visual acuity in over one-third of eyes containing occult-only CNV. Verteporfin also improved anatomical outcomes by reducing leakage from CNV in at least two-thirds of eyes.

Intravitreal bevacizumab (Avastin) for primary treatment of diabetic macular oedema

BACKGROUND

To evaluate the effectiveness of intravitreal bevacizumab injection as primary treatment of diabetic macular oedema.

MATERIAL AND METHODS

Thirty eyes of 30 diabetic patients were treated with 2.5 mg of intravitreal bevacizumab injection as the primary therapy for diabetic macular oedema. The main outcome measures included best-corrected visual acuity, fundus fluorescein angiography, and macular oedema map values of Heidelberg retinal tomograph II (HRT II) before and after intravitreal injection.

RESULTS

The visual acuity increased in 24 of 30 eyes (80%) during a mean follow-up time of 5.6 months. The mean baseline best-corrected LogMAR value for visual acuities of the patients before intravitreal bevacizumab injection was 1.09+/-0.23. After treatment, it was 0.90+/-0.17 at the 1-month, 0.81+/-0.24, at 3-month, and 0.77+/-0.26 at the last visit examinations and the differences were significant when compared with baseline values (for each, P<0.001). The mean oedema map values significantly decreased by 33.3% at the last visit examination when compared with preinjection values (P<0.001). Mild anterior chamber inflammation was observed in four eyes (13.3%), which resolved in a week with topical corticosteroid. No other injection- or drug-related complications were observed.

CONCLUSION

Intravitreal bevacizumab application provides significant improvement in visual acuity of diabetic patients and clinical course of macular oedema, and may therefore be a promising approach in the primary treatment of diabetic macular oedema.

Intravitreal bevacizumab and triamcinolone acetonide combination therapy for exudative neovascular age-related macular degeneration: short-term optical coherence tomography results

PURPOSE

The aim of this study to describe the short-term anatomical results after an intravitreal injection of bevacizumab and triamcinolone acetonide in patients with foveal edema and/or subfoveal fluid associated with neovascularization (NV) due to age-related macular degeneration (AMD).

METHODS

A retrospective, noncomparative case series was conducted in patients with foveal edema and/or subfoveal fluid associated with NV due to AMD during a 3-month period. Patients were treated with intravitreal injections of bevacizumab (1.25 mg/0.05 mL) and followed immediately with triamcinolone acetonide (2 mg/ 0.05 mL) in separate syringes. Ophthalmoscopic examination with optical coherence tomography analysis of foveal edema and subfoveal fluid volume was performed at baseline and follow-up visits.

RESULTS

There were 30 consecutive eyes of 27 patients who received a short-term follow-up between 1 and 8 weeks after injection. Foveal thickness and subfoveal fluid volume were each statistically significantly reduced in the short term (paired Student t test; P < 0.01). No complications of intraocular pressure greater than 30 mmHg, endophthalmitis, retinal detachment, or vitreous hemorrhage developed.

CONCLUSIONS

Reduction of foveal edema and subfoveal fluid in patients with NV due to AMD suggests that combination treatment with intravitreal bevacizumab and triamcinolone merits further investigation.

The evolving role of vascular endothelial growth factor inhibitors in the treatment of neovascular age-related macular degeneration

Age-related macular degeneration (AMD) is the leading cause of blindness among the ageing population. The introduction of molecular inhibitors of vascular endothelial growth factor (VEGF), such as pegaptanib, ranibizumab, and bevacizumab, as treatments for exudative AMD has provided new hope for affected patients and has transformed the practices of retina specialists. Phase III clinical trials have demonstrated the efficacy and safety of monthly ranibizumab for the preservation as well as improvement of visual acuity in patients with exudative AMD. Ongoing trials are evaluating the effectiveness of different dosing regimens, monitoring strategies, and combination therapies to determine the optimal niche for this new class of drugs in AMD management. Based on emerging evidence, most clinicians are now adopting a variable VEGF inhibitor dosing strategy guided by serial diagnostic re-evaluation by optical coherence tomography. Some are also finding benefit through the addition of photodynamic therapy and steroids to the treatment regimen. The results of current and upcoming trials systematically addressing these issues are expected to establish new guidelines for the management of AMD. Indeed, a new paradigm may emerge wherein numerous modular therapeutic modalities are administered in customized combinations based on specific clinical and diagnostic findings.

Bevacizumab: off-label use in ophthalmology

Bevacizumab is a full-length, humanized monoclonal antibody directed against all the biologically active isoforms of vascular endothelial growth factor (VEGF-A). The antibody was initially designed and studied as an anti-angiogenic strategy to treat a variety of solid tumors. After approval by the US Food and Drug Administration, bevacizumab gained access into ophthalmology to treat various types of neovascular diseases. Since the first report in 2005 more than 100 publications share the experience with bevacizumab in ophthalmology. Two authors independently assessed the research results from Pubmed to April 2007. The reference list is a selection of key publications related to the issue. Currently, there is no well-designed randomized controlled trial yet to establish the efficacy and safety of intraocular bevacizumab for any ocular disease in spite of its assumed characteristics representing the most cost-effective VEGF inhibitor.

One-year results of photodynamic therapy for small predominantly classic choroidal neovascular membranes secondary to age-related macular degeneration

PURPOSE

To determine the visual and angiographic outcomes of patients with small predominantly classic choroidal neovascular membranes (CNV) undergoing photodynamic therapy (PDT).

METHODS

The subjects were a cohort of patients with age-related predominantly classic CNV with lesion size of greatest linear diameter of 2000 microm or less treated with PDT. Lesion size and visual acuity were recorded at baseline and at 3-month intervals. Visual treatment failure was defined as either loss of at least 15 letters or visual acuity less than 35 letters on a modified Early Treatment Diabetic Retinopathy Study chart. Lesion treatment failure was defined as increase in greatest linear diameter (GLD) of at least 500 microm.

RESULTS

Twenty-five eyes of 25 patients were included. Visual treatment failure occurred in 16 and mean visual acuity dropped from 58 letters to 34 letters (p<0.0001). In 11 of these patients this occurred within the first 3 months. Lesion treatment failure occurred in 18 patients. Mean GLD increased from 1331 to 2935 microm (p<0.0001). Early growth of the lesion was associated with poor visual outcome with growth in GLD in the first 3 months of 310 microm in patients without eventual visual treatment failure and 1131 microm in patients with eventual visual failure (p=0.027).

CONCLUSIONS

Small predominantly classic lesions commonly cause visual deterioration if treated with PDT alone. In the first year over 50% may lose at least 15 letters or drop below 35 letters, with most visual loss occurring in the first 3 months. Visual loss is associated with early lesion growth.

Current Treatment of Age-Related Macular Degeneration

PURPOSE

To review proved and experimental treatments for exudative and nonexudative complications of age-related macular degeneration (AMD), to consider the impact of current therapy on the structure of future clinical trials, and to consider the role of improved diagnostic imaging techniques on the effectiveness of current therapy as well as the structure of future clinical trials in AMD patients.

RESULTS

Defining the cell biology of choroidal new vessel (CNV) formation and geographic atrophy will lead to identification of different biochemical pathways that are the target of AMD treatment. Many treatments and treatment combinations are under study for AMD, but all work through a finite number of pathways. Currently, the most effective proved therapy for AMD-associated CNVs is administered by repeated intravitreal injection of agents that inhibit vascular endothelial growth factor, e.g., ranibizumab. Improved drug delivery will enhance patient satisfaction and possibly will enhance the effectiveness and reduce the risk of current pharmacotherapy for AMD-associated CNVs. Combination therapy (e.g., verteporfin-photodynamic therapy + ranibizumab) appears to reduce the risk and enhance the effectiveness of CNV treatment compared with monotherapy with currently available agents. Improved noninvasive diagnostic imaging may lead to better visual outcomes with existing therapeutic modalities. Improved imaging also may alter favorably the design of future clinical trials for AMD-associated CNVs and thus reduce cost and increase the diversity of sight-saving treatments.

CONCLUSIONS

Delineation of the biochemical basis for CNV formation has led to development of pathway-based pharmacotherapy for AMD patients. Areas of investigation that will advance the field further include combination therapy, improved drug delivery, and improved noninvasive, high-resolution diagnostic imaging. The logistics of future clinical trials will be complicated by the need for an active treatment control group, more stringent definition of successful treatment, and the increased numbers of patients required for combination therapy studies.

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

Background

To evaluate the efficacy of triple therapy consisting of single-session photodynamic therapy (PDT), intravitreal bevacizumab (IVB) and intravitreal triamcinolone (IVT) as initial pulse therapy followed by repeat intravitreal bevacizumab injections for maintenance treatment in neovascular age-related macular degeneration (AMD).

Methods

In a prospective interventional case series, patients with subfoveal choroidal neovascularization (CNV) secondary to AMD underwent pulse therapy with single-session PDT according to the standard protocol followed by 1.25 mg IVB and 2 mg IVT 48 hours later. Best corrected visual acuity (BCVA) was assessed and optical coherence tomography (OCT) and fluorescein angiography (FA) were performed prior to treatment. BCVA and OCT measurements were repeated at 6 week intervals and FA was obtained after 12 weeks and when necessary thereafter. Repeat injections of IVB were performed based on fluorescein angiographic evidence of CNV leakage.

Results

This series included 17 eyes of 17 patients with mean age of 67.6 ± 7.2 years. Mean follow up duration was 50.4 ± 15.5 weeks. Mean BCVA prior to treatment was 0.74 ± 0.33 logMAR which improved to 0.52 ± 0.36 logMAR after 12 weeks (P = 0.012) and 0.41 ± 0.38 logMAR after 24 weeks (P = 0.001). Mean pretreatment central macular thickness (CMT) was 395 ± 181μ which was significantly reduced to 217 ± 69μ (P = 0.005), 231 ± 79μ (P = 0.028) and 221 ± 87μ (P = 0.05) six, twelve and twenty-four weeks after initial treatment respectively. Visual acuity improvement and CMT reduction was maintained during the follow-up period. IVB injections were repeated once, twice and three times in 10, 7 and 2 eyes at a mean interval of 20.2 ± 10.1, 19 ± 13.7 and 15 ± 1.4 weeks after initial therapy, respectively.

Conclusion

Initial pulse triple therapy consisting of single-session PDT combined with IVB and IVT improves vision and reduces CMT in neovascular AMD. Repeat IVB injections maintain the visual gain from the initial combination therapy.