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Abstract
BACKGROUND Radiotherapy has been proposed as a treatment for new vessel growth in people with neovascular age-related macular degeneration (AMD). OBJECTIVES To examine the effects of radiotherapy on neovascular AMD. SEARCH METHODS We searched CENTRAL, MEDLINE, Embase, LILACS and three trials registers and checked references of included studies. We last searched the databases on 4 May 2020. SELECTION CRITERIA: We included all randomised controlled trials in which radiotherapy was compared to another treatment, sham treatment, low dosage irradiation or no treatment in people with choroidal neovascularisation (CNV) secondary to AMD. DATA COLLECTION AND ANALYSIS We used standard procedures expected by Cochrane. We graded the certainty of the evidence using GRADE. We considered the following outcomes at 12 months: best-corrected visual acuity (BCVA) (loss of 3 or more lines, change in visual acuity), contrast sensitivity, new vessel growth, quality of life and adverse effects at any time point. MAIN RESULTS: We included 18 studies (n = 2430 people, 2432 eyes) of radiation therapy with dosages ranging from 7.5 to 24 Gy. These studies mainly took place in Europe and North America but two studies were from Japan and one multicentre study included sites in South America. Three of these studies investigated brachytherapy (plaque and epimacular), the rest were studies of external beam radiotherapy (EBM) including one trial of stereotactic radiotherapy. Four studies compared radiotherapy combined with anti-vascular endothelial growth factor (anti-VEGF) with anti-VEGF alone. Eleven studies gave no radiotherapy treatment to the control group; five studies used sham irradiation; and one study used very low-dose irradiation (1 Gy). One study used a mixture of sham irradiation and no treatment. Fifteen studies were judged to be at high risk of bias in one or more domains. Radiotherapy versus no radiotherapy There may be little or no difference in loss of 3 lines of vision at 12 months in eyes treated with radiotherapy compared with no radiotherapy (risk ratio (RR) 0.82, 95% confidence interval (CI) 0.64 to 1.04, 811 eyes, 8 studies, I2 = 66%, low-certainty evidence). Low-certainty evidence suggests a small benefit in change in visual acuity (mean difference (MD) -0.10 logMAR, 95% CI -0.17 to -0.03; eyes = 883; studies = 10) and average contrast sensitivity at 12 months (MD 0.15 log units, 95% CI 0.05 to 0.25; eyes = 267; studies = 2). Growth of new vessels (largely change in CNV size) was variably reported and It was not possible to produce a summary estimate of this outcome. The studies were small with imprecise estimates and there was no consistent pattern to the study results (very low-certainty evidence). Quality of life was only reported in one study of 199 people; there was no clear difference between treatment and control groups (low-certainty evidence). Low-certainty evidence was available on adverse effects from eight of 14 studies. Seven studies reported on radiation retinopathy and/or neuropathy. Five of these studies reported no radiation-associated adverse effects. One study of 88 eyes reported one case of possible radiation retinopathy. One study of 74 eyes graded retinal abnormalities in some detail and found that 72% of participants who had radiation compared with 71% of participants in the control group had retinal abnormalities resembling radiation retinopathy or choroidopathy. Four studies reported cataract surgery or progression: events were generally few with no consistent evidence of any increased occurrence in the radiation group. One study noted transient disturbance of the precorneal tear film but there was no evidence from the other two studies that reported dry eye of any increased risk with radiation therapy. None of the participants received anti-VEGF injections. Radiotherapy combined with anti-VEGF versus anti-VEGF alone People receiving radiotherapy/anti-VEGF were probably more likely to lose 3 or more lines of BCVA at 12 months compared with anti-VEGF alone (RR 2.11, 95% CI 1.40 to 3.17, 1050 eyes, 3 studies, moderate-certainty). Most of the data for this outcome come from two studies of epimacular brachytherapy (114 events) compared with 20 events from the one trial of EBM. Data on change in BCVA were heterogenous (I2 = 82%). Individual study results ranged from a small difference of -0.03 logMAR in favour of radiotherapy/anti-VEGF to a difference of 0.13 logMAR in favour of anti-VEGF alone (low-certainty evidence). The effect differed depending on how the radiotherapy was delivered (test for interaction P = 0.0007). Epimacular brachytherapy was associated with worse visual outcomes (MD 0.10 logMAR, 95% CI 0.05 to 0.15, 820 eyes, 2 studies) compared with EBM (MD -0.03 logMAR, 95% CI -0.09 to 0.03, 252 eyes, 2 studies). None of the included studies reported contrast sensitivity or quality of life. Growth of new vessels (largely change in CNV size) was variably reported in three studies (803 eyes). It was not possible to produce a summary estimate and there was no consistent pattern to the study results (very low-certainty evidence). For adverse outcomes, variable results were reported in the four studies. In three studies reports of adverse events were low and no radiation-associated adverse events were reported. In one study of epimacular brachytherapy there was a higher proportion of ocular adverse events (54%) compared to the anti-VEGF alone (18%). The majority of these adverse events were cataract. Overall 5% of the treatment group had radiation device-related adverse events (17 cases); 10 of these cases were radiation retinopathy. There were differences in average number of injections given between the four studies (1072 eyes). In three of the four studies, the anti-VEGF alone group on average received more injections (moderate-certainty evidence). AUTHORS' CONCLUSIONS The evidence is uncertain regarding the use of radiotherapy for neovascular AMD. Most studies took place before the routine use of anti-VEGF, and before the development of modern radiotherapy techniques such as stereotactic radiotherapy. Visual outcomes with epimacular brachytherapy are likely to be worse, with an increased risk of adverse events, probably related to vitrectomy. The role of stereotactic radiotherapy combined with anti-VEGF is currently uncertain. Further research on radiotherapy for neovascular AMD may not be justified until current ongoing studies have reported their results.
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Affiliation(s)
- Jennifer R Evans
- Cochrane Eyes and Vision, ICEH, London School of Hygiene & Tropical Medicine, London, UK
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Rice SR, Katz MSJ, Mehta MP. Context for Protons as Adjunctive Therapy in Neovascular Age-Related Macular Degeneration: A Review. Int J Part Ther 2016; 2:555-569. [PMID: 31772967 PMCID: PMC6871634 DOI: 10.14338/ijpt-15-00019.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Accepted: 12/04/2015] [Indexed: 11/21/2022] Open
Abstract
In the last few years we have witnessed increasing availability of proton therapy in the United States and worldwide. As a result, proton therapy is considered as either a primary or adjunctive approach for numerous indications where conventional radiation therapy shows promise but is accompanied by toxicities. Age-related macular degeneration (AMD) remains the leading cause of adult blindness in industrialized nations, and third worldwide, following cataract and glaucoma. Current standard therapy is intravitreal injection of anti-vascular endothelial growth factor agents. While this treatment shows improvement and stabilization in visual acuity for 40% of patients, 60% still experience disease progression. These injections are costly, necessitate repeated office visits, and carry the risk of endophthalmitis. The pathophysiology underlying neovascular AMD (nAMD) underscores the need to simultaneously target multiple pathways to retain useful vision. Radiation can be antiangiogenic, anti-inflammatory, and antiproliferative. Early photon therapy clinical trials were heterogeneous, and a Cochrane review of data demonstrated usefulness in treatment of nAMD but recommended further studies. Advantages of proton therapy over photon therapy include the ability to deliver a focal dose to the target while minimizing dose to normal structures, which is enhanced by unique treatment planning software that uses fluorescein angiography to verify target location and allows conformation of dose to the irregular shape and thickness characteristic of choroidal neovascular membranes, the pathognomonic finding in nAMD. Preliminary data suggest a potential role for proton therapy in the treatment of nAMD. In this article we review previous treatments for AMD, including those with both photon and proton radiation, and recommend future directions for clinical investigations to evaluate the role of proton therapy as an adjunct to antiangiogenic therapy, the current standard of care in this challenging setting.
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Affiliation(s)
- Stephanie R. Rice
- Department of Radiation Oncology, University of Maryland Medical Center, Baltimore, MD, USA
| | | | - Minesh P. Mehta
- Department of Radiation Oncology, University of Maryland Medical Center, Baltimore, MD, USA
- Department of Ophthalmology, National Retina Institute, Towson, MD, USA
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Kishan AU, Modjtahedi BS, Morse LS, Lee P. Radiation therapy for neovascular age-related macular degeneration. Int J Radiat Oncol Biol Phys 2012; 85:583-97. [PMID: 22975610 DOI: 10.1016/j.ijrobp.2012.07.2352] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2012] [Accepted: 07/15/2012] [Indexed: 12/29/2022]
Abstract
In the enormity of the public health burden imposed by age-related macular degeneration (ARMD), much effort has been directed toward identifying effective and efficient treatments. Currently, anti-vascular endothelial growth factor (VEGF) injections have demonstrated considerably efficacy in treating neovascular ARMD, but patients require frequent treatment to fully benefit. Here, we review the rationale and evidence for radiation therapy of ARMD. The results of early photon external beam radiation therapy are included to provide a framework for the sequential discussion of evidence for the usage of stereotactic radiation therapy, proton therapy, and brachytherapy. The evidence suggests that these 3 modern modalities can provide a dose-dependent benefit in the treatment of ARMD. Most importantly, preliminary data suggest that all 3 can be used in conjunction with anti-VEGF therapeutics, thereby reducing the frequency of anti-VEGF injections required to maintain visual acuity.
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Steinle N, Barakat M, Moshfeghi D, Kaiser PK. Radiation therapy in the treatment of exudative age-related macular degeneration. EXPERT REVIEW OF OPHTHALMOLOGY 2011. [DOI: 10.1586/eop.11.27] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Abstract
BACKGROUND Radiotherapy has been proposed as a treatment to prevent new vessel growth in people with neovascular age-related macular degeneration (AMD). OBJECTIVES The aim of this review was to examine the effects of radiotherapy on neovascular AMD. SEARCH STRATEGY We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (which contains the Cochrane Eyes and Vision Group Trials Register) in The Cochrane Library Issue 3, 2010, MEDLINE (January 1950 to March 2010), EMBASE (January 1980 to March 2010), Latin American and Caribbean Health Sciences Literature Database (LILACS) (January 1982 to March 2010), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com) (March 2010) and ClinicalTrials.gov (http://clinicaltrials.gov) (March 2010). There were no language or date restrictions in the search for trials. The electronic databases were last searched on 23 March 2010. We also wrote to investigators of trials included in the review to ask if they were aware of any other studies. SELECTION CRITERIA We included all randomised controlled trials in which radiotherapy was compared to another treatment, sham treatment, low dosage irradiation or no treatment in people with choroidal neovascularisation secondary to AMD. DATA COLLECTION AND ANALYSIS Two review authors independently extracted the data. We combined relative risks using a random-effects model. We estimated the percentage of the variability in effect estimates that was due to heterogeneity, rather than sampling error, using I(2). MAIN RESULTS Thirteen trials (n=1154) investigated external beam radiotherapy with dosages ranging from 7.5 to 24 Gy; one additional trial (n=88) used plaque brachytherapy (15Gy at 1.75mm for 54 minutes/12.6 Gy at 4mm for 11 minutes). Most studies found effects (not always significant) that favoured treatment. Overall there was a small statistically significant reduction in risk of visual acuity loss in the treatment group. There was considerable inconsistency between trials and the trials were considered to be at risk of bias, in particular because of the lack of masking of treatment group. Subgroup analyses did not reveal any significant interactions, however, there were small numbers of trials in each subgroup (range three to five). There was some indication that trials with no sham irradiation in the control group reported a greater effect of treatment. The incidence of adverse events was low in all trials; there were no reported cases of radiation retinopathy, optic neuropathy or malignancy. Three trials found non-significant higher rates of cataract progression in the treatment group. AUTHORS' CONCLUSIONS This review currently does not provide convincing evidence that radiotherapy is an effective treatment for neovascular AMD. If further trials are to be considered to evaluate radiotherapy in AMD then adequate masking of the control group must be considered.
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Affiliation(s)
- Jennifer R Evans
- London School of Hygiene & Tropical MedicineCochrane Eyes and Vision Group, ICEHKeppel StreetLondonUKWC1E 7HT
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TWELVE-MONTH SAFETY AND VISUAL ACUITY RESULTS FROM A FEASIBILITY STUDY OF INTRAOCULAR, EPIRETINAL RADIATION THERAPY FOR THE TREATMENT OF SUBFOVEAL CNV SECONDARY TO AMD. Retina 2009; 29:157-69. [DOI: 10.1097/iae.0b013e3181985915] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Donati G. Emerging Therapies for Neovascular Age-Related Macular Degeneration: State of the Art. Ophthalmologica 2007; 221:366-77. [DOI: 10.1159/000107495] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2006] [Accepted: 12/15/2006] [Indexed: 11/19/2022]
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Goverdhan SV, Gibbs FA, Lotery AJ. Radiotherapy for age-related macular degeneration: no more pilot studies please. Eye (Lond) 2006; 19:1137-41. [PMID: 15543181 DOI: 10.1038/sj.eye.6701744] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Hori K, Saito S, Tamai M. Effect of irradiation on neovascularization in rat skinfold chambers: implications for clinical trials of low-dose radiotherapy for wet-type age-related macular degeneration. Int J Radiat Oncol Biol Phys 2005; 60:1564-71. [PMID: 15590188 DOI: 10.1016/j.ijrobp.2004.06.208] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2004] [Revised: 06/21/2004] [Accepted: 06/28/2004] [Indexed: 11/19/2022]
Abstract
PURPOSE Wet-type age-related macular degeneration is a refractory eye disease that involves choroidal neovascularization. Randomized controlled trials of low-dose radiotherapy for this disease performed in Japan showed that, at 12 months of follow-up, visual acuity was significantly well preserved and the neovascular membrane size decreased. Because understanding the effect of irradiation on new vascular networks is an important prerequisite for clinical trials, we used a rat skinfold chamber technique to investigate X-ray-induced changes in neovasculature microcirculation. METHODS AND MATERIALS Neovascularization was induced in rat skinfold chambers via polyvinyl chloride resin plates. Neovessels were irradiated in a single 10-Gy dose, after which, changes in vascular density, blood velocity, tissue blood flow, and interstitial fluid pressure (IFP), were measured. RESULTS Vascular density, tissue blood flow, and IFP measurements in resin-induced inflammatory tissue were much higher than those measurements in normal tissue. Although overall blood velocity was low and sluggish or blood-flow stasis occurred in the neovascular network, after a single 10-Gy dose of radiation, the velocity increased, stasis improved markedly, and many dilated vessels narrowed. Thereafter, vascular density, blood flow, and IFP significantly decreased and approached normal values. CONCLUSION These findings may help explain clinical results related to radiotherapy-induced changes in neovascular membranes in age-related macular degeneration. Both vascular morphology and vascular function in inflammatory tissue returned to normal, without vessel destruction, after an appropriate radiation dose.
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Affiliation(s)
- Katsuyoshi Hori
- Department of Vascular Biology, Division of Cancer Control, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan.
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Marcus DM, Peskin E, Maguire M, Weissgold D, Alexander J, Fine S, Followill D. The age-related macular degeneration radiotherapy trial (AMDRT): one year results from a pilot study. Am J Ophthalmol 2004; 138:818-28. [PMID: 15531318 DOI: 10.1016/j.ajo.2004.06.081] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/23/2004] [Indexed: 11/28/2022]
Abstract
PURPOSE To assess the short-term safety and efficacy of treating subfoveal choroidal neovascularization (CNV) with external beam radiation delivered in 5 x 4 Gy fractions among patients having age-related macular degeneration (AMD). DESIGN A multicenter prospective randomized controlled pilot study. METHODS Eighty-eight patients were enrolled through 10 sites and were randomized to radiotherapy (20 Gy delivered in 5 daily fractions of 4 Gy each; 6 MV [N = 41]) or no radiotherapy (sham radiotherapy [N = 22] or observation [N = 25]). Eligibility criteria included visual acuity of at least 20/320 and subfoveal CNV not amenable to treatment. Randomization was stratified by lesion type (new or recurrent CNV) and blood (<50% or >/=50% of the lesion [N = 13]). The primary outcome measure was loss of >/=3 lines of visual acuity. Secondary outcome measures were angiographic response and side effects. RESULTS At baseline, patient and ocular characteristics were similar between treatment groups. At six months, 9 radiated eyes (26%) and 17 eyes not radiated (49%) lost >/=3 lines of visual acuity (P = .04; stratified chi(2) test). At 12 months, 13 radiated eyes (42%) and 9 observed eyes (49%) lost >/=3 visual acuity lines (P = .60). The radiated group demonstrated smaller lesions and less fibrosis than the nonradiated group (P = .05 and .004, respectively) at 12 months. Radiation-induced complications were not observed except for one radiated eye with numerous cotton wool spots and possible radiation retinopathy. CONCLUSIONS External beam radiation at 5 x 4 Gy may have a modest and short-lived (six month) benefit in preserving visual acuity.
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Affiliation(s)
- Dennis M Marcus
- University of Pennsylvania, Department of Ophthalmology, Philadelphia, Pennsylvania, USA
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Hoeller U, Fuisting B, Schwartz R, Roeper B, Richard G, Alberti W. Results of radiotherapy of subfoveal neovascularization with 16 and 20 Gy. Eye (Lond) 2004; 19:1151-6. [PMID: 15543182 DOI: 10.1038/sj.eye.6701743] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
PURPOSE In a nonrandomized, prospective study the efficacy of radiotherapy with 16 and 20 Gray (Gy) for subfoveal neovascularization in age-related macular degeneration (ARMD) was analysed. MATERIAL AND METHODS From 1996 to 1998, 63 eyes were irradiated with 16 Gy and 38 eyes with 20 Gy for exudative ARMD. A total of 12 eyes had classic ARMD, 89 eyes occult ARMD, median baseline visual acuity (VA) was 6/30 (range: 3/60-6/9.5), median age was 78 years. Risk factors (type of ARMD, baseline VA) were evenly distributed in both groups. Median follow-up was 1.3 years (range: 4 months-4.7 years). VA of +/-1 line or better and unchanged size and activity of the membrane in fluorescein angiography were defined as stable. Actuarial methods were used. RESULTS Median loss of VA was -3 lines (range: -14 to +5), neovascularization remained unchanged or decreased in size and activity in 35 eyes. At 18 months, the probability of stabilized VA was 0.4 (95% confidence interval (CI): 0.3-0.5), at 24 months 0.3 (95% CI: 0.2-0.4). Radiation dose, type of ARMD or baseline VA had no significant impact on outcome of VA and membrane size and activity (P>0.05). Side effects were mild and transient increased tearing. CONCLUSION In this study, the results after radiotherapy were comparable to the natural course of the disease. An impact of radiation dose (16 vs 20 Gy) on stabilizing visual acuity and subfoveal neovascularization could not be shown. The results of studies on dose escalation using very small fields and high radiation doses should be awaited.
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Affiliation(s)
- U Hoeller
- Department of Radiotherapy and Radiooncology, University Hospital, Hamburg-Eppendorf, Germany.
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Sivagnanavel V, Evans JR, Ockrim Z, Chong V. Radiotherapy for neovascular age-related macular degeneration. Cochrane Database Syst Rev 2004:CD004004. [PMID: 15495075 DOI: 10.1002/14651858.cd004004.pub2] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND Radiotherapy has been proposed as a treatment to prevent new vessel growth in people with neovascular age-related macular degeneration (AMD). OBJECTIVES The aim of this review was to examine the effects of radiotherapy on neovascular AMD. SEARCH STRATEGY We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (which contains the Cochrane Eyes and Vision Group trials register) on The Cochrane Library Issue 2, 2004, MEDLINE (1966 to May 2004), EMBASE (1980 to June 2004) and LILACS (Latin American and Caribbean Health Sciences Literature Database) (May 2004). We also wrote to investigators of trials included in the review to ask if they were aware of any other studies. SELECTION CRITERIA We included all randomised controlled trials in which radiotherapy was compared to another treatment, sham treatment, low dosage irradiation or no treatment in people with subfoveal choroidal neovascularisation secondary to AMD. DATA COLLECTION AND ANALYSIS Two reviewers independently extracted the data. Relative risks were combined using a random effects model. The percentage of the variability in effect estimates that was due to heterogeneity, rather than sampling error, was estimated using I2. MAIN RESULTS Eleven trials randomising a total of 1078 people were included in this review. All trials used a similar method of delivering the radiotherapy treatment (external beam). Dosage ranged from 7.5 to 24 Gy. Most trials found effects (not always significant) that favoured treatment. However, there was considerable inconsistency in the results between trials (I2 > 50%). As only 11 trials were included in the review and only some of these trials provided data for each outcome our ability to determine the causes of the heterogeneity between trials was limited. Subgroup analyses did not reveal any statistically significant interactions although with small numbers of trials in each subgroup (range two to four) this was not surprising. There was some indication that trials with no sham irradiation reported a greater effect of treatment as did trials with a greater percentage of participants with classic choroidal neovascularisation. REVIEWERS' CONCLUSIONS This review currently does not provide evidence that external beam radiotherapy is an effective treatment for neovascular AMD. If further trials are to be considered to evaluate radiotherapy in AMD then adequate masking of the control group must be considered. Given the recent evidence that most lesions are amenable to treatment with photodynamic therapy if identified at a small lesion size, trials evaluating radiotherapy against photodynamic therapy are warranted.
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Marcus DM, Sheils WC, Young JO, McIntosh SB, Johnson MH, Alexander J, Samy CN. Radiotherapy for recurrent choroidal neovascularisation complicating age related macular degeneration. Br J Ophthalmol 2004; 88:114-9. [PMID: 14693787 PMCID: PMC1771925 DOI: 10.1136/bjo.88.1.114] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
AIMS To report the safety and visual outcome data of external beam irradiation for recurrent choroidal neovascularisation complicating age related macular degeneration. METHODS Eighteen consecutive eyes received external beam irradiation with seven fractions of 2 Gy (total dose 14 Gy). The next 16 consecutive eyes received external beam irradiation with five fractions of 3 Gy (total dose 15 Gy). Main outcome measure was change in visual acuity. Secondary outcome variables were contrast sensitivity and fundus photographic/fluorescein angiographic progression. RESULTS The 3 Gy fraction group lost fewer lines of distance visual acuity at the three and six month follow up. At one year follow up, this difference was not maintained with 2 Gy fraction and 3 Gy fraction eyes. At one year follow up a decrease in visual acuity of three or more lines (moderate visual loss) occurred in 58% of 2 Gy and 42% of 3 Gy fraction eyes (p<0.36). At one year follow up a decrease in visual acuity of six or more lines (severe visual loss) occurred in 41% of 2 Gy eyes and 17% of 3 Gy eyes (p<0.23). At three months follow up, 3 Gy eyes were less likely (0%) than 2 Gy eyes (47%) to show moderate visual loss (p<0.003). However, Kaplan Meier curves estimate a significantly lower rate of severe visual loss in the 3 Gy group (p = 0.02). There were no significant differences in contrast sensitivity loss or fluorescein angiographic stabilisation rates. No evidence of radiation toxicity was observed. CONCLUSION Our results are consistent with trends for a palliative benefit with higher fraction sizes and doses. The radiobiologic differences between low and high fraction size groups in this study are modest and correlate with the modest and short term difference in visual outcomes. These trends support further investigation of radiotherapy using fraction sizes of 4 Gy or higher.
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Affiliation(s)
- D M Marcus
- Department of Ophthalmology, Medical College of Georgia, 1120 15th Street, Augusta, GA 30912, USA.
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Abstract
Age-related macular degeneration (AMD) is the leading cause of legal blindness in individuals 50 years and older in the developed world. Choroidal neovascularization (CNV) in exudative AMD is responsible for the majority of severe vision loss. Until recently, laser photocoagulation was the only well-established and widely accepted treatment for CNV. However, it is beneficial only for a small subset of patients, has a high rate of CNV persistence and recurrence and results in iatrogenic, collateral damage to the overlying retina. These issues make it difficult to recommend in the case of subfoveal lesions. Consequently, numerous experimental therapeutic interventions are under investigation with the common objective of destroying the CNV but leaving the foveal neurosensory retina intact. Treatment modalities can be grouped into five major categories: photodynamic therapy; radiotherapy; transpupillary thermotherapy; anti-angiogenic and angiostatic agents; and surgical intervention. The present review aims to explain the rationale behind these new treatments, analyse the evidence for their safety and efficacy, determine their stage of development and indicate in which patients they are potentially useful.
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Affiliation(s)
- Claire Y Hooper
- Centre for Eye Research Australia, University of Melbourne, Department of Ophthalmology, Melbourne, Victoria, Australia
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Valmaggia C, Ries G, Ballinari P. Radiotherapy for subfoveal choroidal neovascularization in age-related macular degeneration: a randomized clinical trial. Am J Ophthalmol 2002; 133:521-9. [PMID: 11931786 DOI: 10.1016/s0002-9394(02)01336-3] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
PURPOSE To report results of 18-month follow up of external beam radiation therapy with photons for subfoveal classic or occult choroidal neovascularization (CNV) in age-related macular degeneration (ARMD). DESIGN Randomized clinical trial. METHODS A total of 161 patients with subfoveal CNV in ARMD were recruited in a prospective double-masked study. The posterior pole of the afflicted eye was given 1 Gy (4 x 0.25 Gy) in the control group and 8 Gy (4 x 2 Gy) or 16 Gy (4 x 4 Gy) in the treatment groups. At the time of treatment, and 6, 12, and 18 months post treatment, best-corrected visual acuity (BCVA), reading ability, and CNV size were measured. RESULTS At the completion of the study 150 (93.2%), 139 (86.3%), and 137 (85.1%) patients were followed for 6, 12, and 18 months, respectively. The mean number of lines lost in the BCVA was -1.69, -2.2, and -3.23 in the 1 Gy group; -0.94, -1.25, and -1.73 in the 8 Gy group; -0.51, -0.67, and -1.93 in the 16 Gy group. The difference was significant after 12 months (P =.016 for 8 Gy vs. 1 Gy; P =.006 for 16 Gy vs. 1 Gy), and 18 months (P =.011 for 8 Gy vs. 1 Gy; P =.05 for 16 Gy vs. 1 Gy). The patients with classic CNV, or with an initial distance visual acuity >or=20/100, benefited more from treatment. A significant difference was not found between control group and treatment groups in the reading ability and in the CNV size. No radiation-associated side effects were reported thus far. CONCLUSION The number of lines lost in the BCVA was less in the 8 Gy and 16 Gy treatment groups than in the control group during the complete follow up examination. Radiation therapy with 8 Gy and 16 Gy, without showing any difference in efficacy, resulted in a near stabilization of the BCVA in patients with subfoveal classic or occult CNV in ARMD. Further studies are necessary to determine the significance of repeated radiotherapy series with a dose of 8 Gy to improve the effect on the CNV size and thereby to prolong stabilization of distance visual acuity.
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Valmaggia C, Ries G, Ballinari P. A 5-year follow-up study for distance visual acuity after low dose radiation on subfoveal choroidal neovascularization in age-related macular degeneration. Doc Ophthalmol 2001; 103:201-9. [PMID: 11824657 DOI: 10.1023/a:1013047722865] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
In a prospective study with a 5-year follow-up, we assessed the effect of a single series of low-dose radiation on the distance visual acuity in eyes with angiographically confirmed subfoveal choroidal neovascularization (CNV) in age-related macular degeneration (ARMD). The posterior pole of 12 eyes was treated with 5 Gy (4 x 1.25 Gy), and 34 eyes treated with 8 Gy (4 x 2 Gy). The best corrected distance visual acuity was measured at the time of treatment, and annually thereafter for 5 years. The study obtained complete follow-up for 11 patients in the 5-Gy group (nine classic, two occult CNVs), and 29 patients in the 8-Gy group (12 classic, 17 occult CNVs). At baseline, the mean distance visual acuity of the treated eyes was 0.16 (20/125) in the 5-Gy group, and 0.2 (20/100) in the 8-Gy group. Five years later, an average loss of 3.2 lines was present in the 5-Gy group, and 4 lines in the 8-Gy group. After 5 years, an average loss of 2 lines was found in a control group consisting of 18 second eyes with low stage dry ARMD, with a mean distance visual acuity of 0.5 (20/40) at baseline. Statistical analyses with Wilcoxon and Mann-Whitney U-tests showed that a single series of low dose radiation with either 5 Gy or 8 Gy was not able to stabilize the distance visual acuity of eyes with subfoveal CNV in ARMD during a 5-year follow-up.
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Affiliation(s)
- C Valmaggia
- Department of Ophthalmology, Kantonsspital St. Gallen, Switzerland.
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Chakravarthy U. Radiotherapy for choroidal neovascularisation of age-related macular degeneration: a fresh perspective. Eye (Lond) 2000; 14 ( Pt 2):151-4. [PMID: 10845008 DOI: 10.1038/eye.2000.45] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
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Abstract
Age-related macular degeneration (AMD), while rapidly becoming more prevalent due to an aging population, is still poorly understood and treatment modalities are limited. Fortunately, advances are being made in the treatment of AMD that may greatly alter the outcome of this debilitating disease. Treatments for both wet and dry AMD are reviewed.
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Chakravarthy U, MacKenzie G. External beam radiotherapy in exudative age-related macular degeneration: a pooled analysis of phase I data. Br J Radiol 2000; 73:305-13. [PMID: 10817048 DOI: 10.1259/bjr.73.867.10817048] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
In recent years external beam radiotherapy (EBRT) has been proposed as a treatment for the wet form of age-related macular degeneration (AMD) where choroidal neovascularization (CNV) is the hallmark. While the majority of pilot (Phase I) studies have reported encouraging results, a few have found no benefit, i.e. EBRT was not found to result in either improvement or stabilization of visual acuity of the treated eye. The natural history of visual loss in untreated CNV of AMD is highly variable. Loss of vision is influenced mainly by the presenting acuity, and size and composition of the lesion, and to a lesser extent by a variety of other factors. Thus the variable outcome reported by the small Phase I studies of EBRT published to date may simply reflect the variation in baseline factors. We therefore obtained information on 409 patients treated with EBRT from eight independent centres, which included details of visual acuity at baseline and at subsequent follow-up visits. Analysis of the data showed that 22.5% and 14.9% of EBRT-treated eyes developed moderate and severe loss of vision, respectively, during an average follow-up of 13 months. Initial visual acuity, which explained 20.5% of the variation in visual loss, was the most important baseline factor studied. Statistically significant differences in loss of vision were observed between centres, after considering the effects of case mix factors. Comparisons with historical data suggested that while moderate visual loss was similar to that of the natural history of the disease, the likelihood of suffering severe visual loss was halved. However, the benefit in terms of maintained/improved vision in the treated eye was modest.
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Kanai M, Obana A, Gohto Y, Nagata S, Miki T, Kaneda K, Nakajima S. Long-term effectiveness of photodynamic therapy by using a hydrophilic photosensitizer ATX-S10(Na) against experimental choroidal neovascularization in rats. Lasers Surg Med 2000; 26:48-57. [PMID: 10637003 DOI: 10.1002/(sici)1096-9101(2000)26:1<48::aid-lsm8>3.0.co;2-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
BACKGROUND AND OBJECTIVE We previously demonstrated that a hydrophilic photosensitizer ATX-S10 had a potent photodynamic effect. This study was designed to reveal the long-term effectiveness of photodynamic therapy (PDT) with this agent in occluding choroidal neovascularization (CNV) and its selectivity in the neovascular tissue. STUDY DESIGN/MATERIALS AND METHODS Experimental CNV was induced by intense photocoagulation in rat eyes. Immediately or 2 hours after intravenous injection of 8 mg/kg body weight of ATX-S10(Na), a cis isomer of ATX-S10, eyes were irradiated by a diode laser at the radiance of 3.25-65.3 J/cm(2) Vascular occlusion was identified by fundus photography, fluorescein angiography, and histology at 1, 3, 7, 14, and 28 days after PDT. As controls, non-neovascular eyes were subjected to PDT and similarly analyzed. RESULTS By using the following treatment parameters, PDT with ATX-S10(Na) successfully occluded CNV without causing occlusion of retinal capillaries for 28 days; 7.4 and 19.6 J/cm(2) immediately after dye injection and 36.7 and 65.3 J/cm(2) 2 hours after injection. Although these conditions also caused occlusion of normal choriocapillaries and mild injuries of retinal vessels, retinal pigment epithelium, and photoreceptors at 1 day, retinal vessels and pigment epithelial cells recovered from damages by 28 days. No injuries were found in the inner retina. CONCLUSION In optimal treatment conditions, PDT with ATX-S10(Na) can induce long-term, selective occlusion of CNV without causing irreversible damages in the inner retina.
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Affiliation(s)
- M Kanai
- Department of Ophthalmology, Osaka City University Medical School, Osaka 545-8585, Japan
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Char DH, Irvine AI, Posner MD, Quivey J, Phillips TL, Kroll S. Randomized trial of radiation for age-related macular degeneration. Am J Ophthalmol 1999; 127:574-8. [PMID: 10334351 DOI: 10.1016/s0002-9394(99)00038-0] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE To assess external beam radiation efficacy for subfoveal neovascularization associated with age-related macular degeneration. METHODS All patients were evaluated in the same institution. In this prospective trial, 27 eyes (27 patients) with subfoveal neovascularization associated with age-related macular degeneration were randomized to either single fraction radiation (750 centigray) or observation. Endpoints were assessed by fluorescein angiography and Early Treatment Diabetic Retinopathy Study (ETDRS) visual acuity. Examiners were masked to patient treatment status. Parametric and nonparametric statistical analyses were performed. RESULTS Twenty-seven patients were entered into the trial with a mean age of 76 years (range, 64 to 89) and a mean follow-up of 17 months (range, 7 to 32). The visual acuity loss was slightly less in the irradiated group, a finding of borderline significance (P < .046). There was no significant difference in fluorescein angiographic evidence of subretinal neovascular membrane change in the control group vs the irradiated group. CONCLUSIONS External beam radiation, at this dose and fractionation, did not appear harmful. There was slightly less visual loss in irradiated eyes. No difference in fluorescein angiographic characteristics of subfoveal neovascularization size or progression in eyes with age-related macular degeneration was noted.
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Affiliation(s)
- D H Char
- Tumori Foundation, California Pacific Medical Center, San Francisco, USA
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