Teletherapy for subfoveal choroidal neovascularisation of age-related macular degeneration: results of follow up in a non-randomised study

Context for Protons as Adjunctive Therapy in Neovascular Age-Related Macular Degeneration: A Review

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.

Is vitamin D status associated with open-angle glaucoma? A cross-sectional study from South Korea

OBJECTIVE

Open-angle glaucoma (OAG) is one of the major chronic diseases involving the optic nerve. However, little is known about the association between vitamin D and OAG. The present study was conducted to test the hypothesis that lower vitamin D status is associated with greater prevalence of OAG.

DESIGN

Cross-sectional study. Multivariable logistic regression was performed to examine the relationship between serum 25-hydroxyvitamin D (25(OH)D) and OAG after adjusting for traditional potential confounders. OAG was defined by the criteria of the International Society for Geographical and Epidemiological Ophthalmology.

SETTING

The Fifth Korean National Health and Nutrition Examination Survey conducted in 2010-2011.

SUBJECTS

Six thousand and ninety-four adult participants randomly selected from 192 surveys in 131 locations in South Korea.

RESULTS

Multivariable-adjusted odds ratios of OAG across quintiles of decreasing 25(OH)D were 1.26, 1.00 (reference), 1.31, 1.36 and 1.69 (P for quadratic trend <0.01). The odds ratio for the lowest 25(OH)D quintile was significantly higher than that for the second quintile (P < 0.01). In addition, we discovered that the predictors for worsening of OAG, such as intraocular pressure or vertical and horizontal cup-to-disc ratios, had a significant relationship with 25(OH)D level.

CONCLUSIONS

There was a reverse J-shaped association between 25(OH)D levels and the risk of OAG, with significantly elevated risk at lower 25(OH)D. The findings of this research suggest that vitamin D deficiency should be considered as a potential risk factor for the development of OAG. To our knowledge, the present study is the first one that shows an association between vitamin D status and OAG.

Current knowledge and trends in age-related macular degeneration: today's and future treatments

PURPOSE

To address the most dynamic and current issues concerning today's treatment options and promising research efforts regarding treatment for age-related macular degeneration. This review is aimed to serve as a practical reference for more in-depth reviews on the subject.

METHODS

An online review of the database PubMed and Ovid were performed, searching for the key words age-related macular degeneration, AMD, VEGF, treatment, PDT, steroids, bevacizumab, ranibizumab, VEGF-trap, radiation, combined therapy, as well as their compound phrases. The search was limited to articles published since 1985. All returned articles were carefully screened, and their references were manually reviewed for additional relevant data. The web page www.clinicaltrials.gov was also accessed in search of relevant research trials.

RESULTS

A total of 363 articles were reviewed, including 64 additional articles extracted from the references. At the end, only 160 references were included in this review.

CONCLUSION

Treatment for age-related macular degeneration is a very dynamic research field. While current treatments are mainly aimed at blocking vascular endothelial growth factor, future treatments seek to prevent vision loss because of scarring. Promising efforts have been made to address the dry form of the disease, which has lacked effective treatment.

Comparing the effects of three different intravitreal injection techniques on vitreous reflux and intraocular pressure

PURPOSE

To compare the effects of straight, oblique, and double-plane tunnel scleral intravitreal injection techniques, on short-term intraocular pressure (IOP) changes, occurrence of vitreous reflux (VR), and/or other complications.

METHODS

A total of 105 patients were included in this prospective study. Patients were assigned randomly to one of the straight injection group (SI; n=35), oblique injection group (OI; n=35), or double-plane tunnel injection group (DPTI; n=35). The occurrence of VR and preinjection and postinjection IOP at 2 and 6 h were compared between groups, and complications were assessed.

RESULTS

The mean patient age was 71.1±6.6 years (range 58 to 86 years; 50 women and 55 men). In the SI, OI, and DPTI groups, VR occurred in 18 (51.4%), 12 (34.3%), and 6 patients (17.1%), respectively. Mean preinjection IOPs were 15.4, 14.8, and 15.6 mmHg, and changed to 17.3, 18.0, and 20.0 mmHg at the second hour, and 15.7, 16.2, and 16.1 mmHg at the sixth hour, respectively. No significant differences among the groups were found in terms of complications such as transient mild uveitis or subconjunctival hemorrhage.

CONCLUSION

Double-plane tunnel injection prevents VR from the injection site and has no additional complications than other techniques.

Radiation therapy for neovascular age-related macular degeneration

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.

The Natural History and Prognosis of Neovascular Age-Related Macular Degeneration

PURPOSE

To describe the natural history and progression of visual loss in eyes with untreated neovascular age-related macular degeneration (AMD).

DESIGN

Systematic review and meta-analysis.

PARTICIPANTS

Four thousand three hundred sixty-two untreated neovascular AMD patients from published interventional studies.

METHODS

A systematic review of the literature from 1980 to August 2005 was performed. Studies reporting disease progression outcomes for untreated patients with neovascular AMD were included. Outcome measures were summarized using simple counts and means. Random effects meta-analyses were conducted and tests of heterogeneity were performed where appropriate.

MAIN OUTCOME MEASURES

Changes in visual acuity (VA) loss, development of comorbidities, and fellow eye involvement.

RESULTS

Fifty-three primary studies were included. Nearly half of the studies (28) were randomized clinical trials. The quality of the studies was high, with over 80% providing level I or II evidence. Mean baseline VA among study patients was 0.64 logarithm of the minimum angle of resolution (logMAR) (approximately 20/87 Snellen). The mean VA change in logMAR progressed from 0.1 (1 line lost) at 3 months to 0.3 (2.7 lines lost) after 12 months and 0.4 (4 lines lost) after 24 months. The proportion of patients who developed severe vision loss (>6 lines) from baseline increased from 21.3% at 6 months to 41.9% by 3 years. The proportion of patients with VA worse than logMAR 1.0 (20/200 Snellen) increased from 19.7% at baseline to 75.7% by 3 years. Neovascular AMD developed in the fellow eye in 12.2% of patients by 12 months and in 26.8% by 4 years. Meta-analyses of vision outcome by subtype of neovascular AMD were not possible.

CONCLUSIONS

A doubling of the visual angle of presenting VA may be expected to occur in the year after initial presentation in eyes with untreated neovascular AMD. No conclusions can be drawn as to the differences in rates of disease progression by neovascular AMD subtype. The diversity of reporting formats, paucity of long-term natural history data, and heterogeneity among the reported clinical studies impose limits to the clear understanding of long-term prognosis for visual function in neovascular AMD.

Age related macular degeneration

INTRODUCTION

Sight-threatening (late) age-related macular degeneration (AMD) occurs in 2% of people aged over 50 years in industrialised countries, with prevalence increasing with age. Early-stage disease is marked by normal vision, but retinal changes (drusen and pigment changes). Disease progression leads to worsening central vision, but peripheral vision is preserved.

METHODS AND OUTCOMES

We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of interventions to prevent progression of early- or late-stage age-related macular degeneration; and exudative age-related macular degeneration? We searched: Medline, Embase, The Cochrane Library and other important databases up to March 2006 (Clinical Evidence reviews are updated periodically, please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA).

RESULTS

We found 45 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions.

CONCLUSIONS

In this systematic review we present information relating to the effectiveness and safety of the following interventions: antiangiogenesis (using pegaptanib, ranibizumab, interferon alfa-2a, or anecortave acetate), antioxidant vitamins plus zinc, external beam radiation, laser treatment to drusen, photodynamic therapy with verteporfin, submacular surgery, thermal laser photocoagulation, transpupillary thermotherapy.

Therapeutic effect of diode laser photodynamic therapy with ICG dye in ARMD: a case report

PURPOSE

To evaluate the diode laser photodynamic therapy efficacy on choroidal neovascularization (CNV) in the treatment of three patients with age-related macular degeneration (ARMD).

METHODS

The authors selected three patients with ARMD whose vision has decreased due to CNV, and applied diode laser treatment after injecting an indocyanine green (ICG) solution. The patients were followed for at least three months after treatment, and examinations included evaluating vision changes and possible leakage on fluorescein angiography (FAG).

RESULTS

The final vision of two patients improved by more than one line on the Early Treatment Diabetic Retinopathy Study (ETDRS) chart after at least three months of follow-up. However, the final vision of the third patient decreased by one line on ETDRS chart. FAG was done in all patients, and in two of the patients, there was no evidence of leakage at the laser-applied site. In the other patient, there was evidence of minimal leakage, with the area of leakage decreasing by more than fifty percent. Side effects of ICG were not found during or after the photodynamic therapy sessions.

CONCLUSIONS

The photodynamic usage of ICG treatment of CNV in patients with ARMD, was effective in preventing or improving the visual outcome. Compared to the widely used verteporfin, ICG is more stable and is more cost effective. The authors therefore came to a conclusion that ICG can be very useful in the treatment of CNV. However, further studies are necessary.

Proton Beam Irradiation for Neovascular Age-Related Macular Degeneration

OBJECTIVE

To evaluate safety and visual outcomes after proton therapy for subfoveal neovascular age-related macular degeneration (AMD).

DESIGN

Randomized dose-ranging clinical trial.

PARTICIPANTS

One hundred sixty-six patients with angiographic evidence of classic choroidal neovascularization resulting from AMD and best-corrected visual acuity of 20/320 or better.

METHODS

Patients were assigned randomly (1:1) to receive 16-cobalt gray equivalent (CGE) or 24-CGE proton radiation in 2 equal fractions. Visual acuity was measured using standardized protocol refraction. Complete ophthalmological examinations, color fundus photography, and fluorescein angiography were performed before and 3, 6, 12, 18, and 24 months after treatment.

MAIN OUTCOME MEASURE

Proportion of eyes losing 3 or more lines of vision from baseline. Kaplan-Meier statistics were used to compare cumulative rates of vision loss between the 2 treatment groups.

RESULTS

At 12 months after treatment, 36 eyes (42%) and 27 eyes (35%) lost 3 or more lines of vision in the 16-CGE and 24-CGE groups, respectively. Rates increased to 62% in the 16-CGE group and 53% in the 24-CGE group by 24 months after treatment (P = 0.40). Radiation complications developed in 15.7% of patients receiving 16 CGE and 14.8% of patients receiving 24 CGE.

CONCLUSIONS

No significant differences in rates of visual loss were found between the 2 dose groups. Proton radiation may be useful as an adjuvant therapy or as an alternative for patients who decline or are not appropriate for approved therapies.

La radiothérapie des affections bénignes : quelles indications huit ans plus tard ?

The authors present an update version of the indications for radiotherapy in the management of benign diseases. This is based on available randomized trials and recent international meetings. Validated indications remain the prevention of resected heterotopic bone ossifications, keloïds scars and pterygium and also treatment of arteriovenous malformations; the place of radiotherapy for malignant exophtalmia is more and more restricted. Randomized trials have demonstrated the efficacy of endobrachytherapy in the prevention of restenosis after angioplasty but the use of embedded stent has replaced this indication. Macular degeneration is no more an indication of radiotherapy. Quality requirements for radiotherapy are identical for benign or malignant indications.

The age-related macular degeneration radiotherapy trial (AMDRT): one year results from a pilot study

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.

Results of radiotherapy of subfoveal neovascularization with 16 and 20 Gy

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.

Fluorescein angiography-guided indocyanine green angiography for the detection of feeder vessels in subfoveal choroidal neovascularization

AIMS

To compare the newly devised fluorescein angiography (FA) - guided indocyanine green angiography (ICGA) with conventional ICGA for detecting feeder vessels in subfoveal choroidal neovascularization (CNV).

METHODS

The detection of feeder vessels was attempted in 86 AMD patients with subfoveal CNV: 44 (age 70.4+/-4.5 years) underwent conventional ICGA (control group) and 42 (age 70.9+/-4.0 years) underwent an FA-guided ICGA (FA-guided group) using a double-detector scanning laser ophthalmoscope (SLO). In the control group, indocyanine green (ICG) was injected simultaneously with fluorescein. The patients were instructed to gaze forward localizing the fovea at the centre. In the FA-guided group, fluorescein sodium was injected a few minutes prior to ICG, and the patients were instructed to fixate in the appropriate direction by referring to the ongoing FA on the monitoring screen. In both groups, a 20 degrees visual angle was used to capture good images of feeder vessels in ICGA and, in case ICGA missed the first images of the entire CNV filling, an additional injection of ICG was given in the late phase to record the choroidal filling again. The overall detection rate, single-injection detection rate, double-injection rate and examination time were analysed using Fisher's direct exact probability test or Mann-Whitney's U-test.

RESULTS

There was no significant difference in the overall detection of feeder vessels between the two groups (50% in the control group and 52.3% in the FA-guided group; P=0.49 with Fisher's direct exact probability test). However, in the FA-guided group, the single injection detection rate was significantly higher (45.1 and 15.9%, respectively; P<0.001 with Fisher's direct exact probability test); significantly less double injections were required (7.1 and 50%, respectively; P=0.003 with Fisher's direct exact probability test); and significantly shorter examination times were needed (9.6+/-3.7 and 14.1+/-6.8 min, respectively; P=0.02 with Mann-Whitney's U-test).

CONCLUSION

FA-guided ICGA is effective for detecting feeder vessels of subfoveal CNV, minimizing the amount of ICG injected and the examination time compared to conventional ICGA.

Radiotherapy for recurrent choroidal neovascularisation complicating age related macular degeneration

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.

Palladium-103 plaque radiation therapy for macular degeneration: results of a 7 year study

AIM

To report 7 year results of ophthalmic plaque radiotherapy for exudative macular degeneration.

METHODS

In a phase I clinical trial, 30 patients (31 eyes) were treated with ophthalmic plaque irradiation for subfoveal exudative macular degeneration. Radiation was delivered to a mean 2 mm from the inner sclera (range 1.2-2.4) prescription point calculated along the central axis of the plaque. The mean prescription dose was 17.62 Gy (range 12.5-24) delivered over 34 hours (range 18-65). Early Treatment Diabetic Retinopathy Study (ETDRS) type standardised visual acuity determinations, ophthalmic examinations, and angiography were performed before and after treatment. Clinical evaluations were performed in a non-randomised and unmasked fashion.

RESULTS

At 33.3 months (range 3-4), 17 of 31 (55%) eyes had lost 3 or more lines of vision on the ETDRS chart, five (16%) had improved 3 or more lines, and the remaining nine (29%) were within 2 lines of their pretreatment visual acuity measurement. Overall, 45% of patients were within or improved more than 2 lines of their initial visual acuity. Five eyes developed macular scars, eight developed subsequent neovascularisation or haemorrhage, and three progressed through therapy. Two patients were lost to follow up. The most common finding of patients followed for 6 or more months (n=18 of 29 (62%)) was regression or stabilisation of the exudative process. No radiation retinopathy, optic neuropathy, or cataracts could be attributed to irradiation.

CONCLUSION

Ophthalmic plaque radiation can be used to treat exudative macular degeneration. At the dose and dose rates employed, most patients experienced decreased exudation or stabilisation of their maculas. No sight limiting radiation complications were noted during 7 year follow up. Owing to the variable natural course of this disease, a prospective randomised clinical trial should be performed to evaluate the efficacy of plaque radiation therapy for exudative macular degeneration.

Review Article. New treatments in age-related macular degeneration

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.

Clinicopathological correlation of choroidal neovascularization after external beam radiotherapy in age-related macular degeneration

PURPOSE

To analyze the histopathology of choroidal neovascularization after external beam radiotherapy in age-related macular degeneration.

METHODS

A retrospective non-case-matched comparative histopathologic study. The histoarchitecture of nine surgically removed subretinal specimens from nine patients that had undergone external beam radiotherapy for exudative age-related macular degeneration was studied. Seven patients had received 20 Gy in 10 fractions and two 15 Gy in 5 fractions with an average time interval between radiotherapy and surgical extraction of 14 months (range 3-28). A consecutive series of classic, mixed and occult choroidal neovascular membranes served as controls.

RESULTS

Clinical findings. Radiation-associated choroidal neovasculopathy was angiographically suspected in four patients: a coarse net of vessels on fluorescein angiography developing at the border of previously irradiated choroidal neovascularization was observed in three patients; blebs at the margin of a plaque on indocyanine green angiography were observed in two patients. Pathological findings. Diffuse drusen as well as intra-Bruch's fibrovascular tissue was found in all irradiated specimens. In four specimens an edematous vascularized layer was seen between diffuse drusen and normal-appearing intra-Bruch's fibrovascular tissue. This lesion was not found in the control specimens. A particular correlation for the bleb lesion was not recognized.

CONCLUSION

The appearance of an edematous subretinal pigment epithelial vascularized layer between diffuse drusen and normal-appearing fibrovascular tissue in four of nine irradiated membranes may be secondary to previous irradiation. It may correlate with the unusual exudative manifestations observed after external beam radiotherapy.

Age-related macular degeneration: epidemiology and optimal treatment

Age-related macular degeneration (AMD) is a common macular disease affecting elderly people in the Western world. It is characterised by the appearance of drusen in the macula, accompanied by choroidal neovascularisation (CNV) or geographic atrophy. The disease is more common in Caucasian individuals than in pigmented races. In predominantly Caucasian populations, the age-standardised prevalence of AMD in at least one eye is 7760 cases per million. The age-standardised cumulated 1-year incidence of AMD in at least one eye is 1051 cases per million individuals. AMD is the most important single cause of blindness among Caucasian individuals in developed countries. Blindness resulting from AMD rarely occurs before age 70, and most cases occur after age 80. The age-standardised 1-year incidence of legal blindness resulting from AMD is 212 cases per million. Two-thirds of AMD cases have CNV (exudative cases); the remainder has only geographic atrophy. In cross-sectional population-based studies about 45% of eyes with AMD have visual acuity reduced to 20/200 or worse. This is true both for exudative AMD and pure geographic atrophy. Age and genetic predisposition are known risk factors for AMD. Smoking is probably also a risk factor. Preventive strategies using macular laser photocoagulation are under investigation, but their efficacy in preventing visual loss is as yet unproven. There is no treatment with proven efficacy for geographic atrophy. Optimal treatment for exudative AMD requires a fluorescein angiographic study and a physician capable of interpreting it. For CNV not involving the foveal centre, the only evidence-based treatment is laser photocoagulation. For AMD cases with subfoveal CNV, good visual acuity, and predominantly classic fluorescence pattern on fluorescein angiography, photodynamic therapy with verteporfin is the treatment of choice. Photodynamic therapy is also effective in eyes with pure occult CNV and evidence of recent disease progression. For new subfoveal CNV with poor vision and recurrent CNV, laser photocoagulation can be considered.

Radiotherapy for age-related macular degeneration: is there a benefit for classic CNV?

AIM

To evaluate the efficacy of radiotherapy in the treatment of subfoveal classic and occult choroidal neovascularization (CNV) in age-related macular degeneration (AMD) under strict fixation control.

METHODS

Twenty-seven eyes of 27 patients with subfoveal CNV as a result of AMD were treated with a total dose of 20 Gy in 10 fractions (10 well-defined, 17 occult). Fixation monitoring was achieved by installing a TV camera with an attached fixation light 3 cm from the cornea of the eye being treated. Visual acuity and fluorescein angiography were obtained before and 6 months after treatment. Fifteen eyes of 15 patients served as controls (4 well-defined, 11 occult).

RESULTS

After 6 months the treated group showed an average decrease in visual acuity of 27%; the control group experienced a decrease of 31%. Membrane size increased by 56% in the treated group and by 28% in the control group. There was no statistically significant difference. Within the subgroup analysis, however, patients with classic CNV suffered significantly less visual loss than in the control group.

CONCLUSION

Radiation therapy under optimized treatment conditions by fixation monitoring failed to control further growth in membrane size in both classic and occult CNV. Regarding visual acuity, however, patients with classic CNV seem to benefit from radiation treatment compared to the natural course.

Radiotherapy in age-related macula degeneration

PURPOSE

To ascertain the benefit from radiotherapy in age-related macula degeneration in a single-arm longitudinal study.

METHODS AND MATERIALS

From 1997 to 1998, 39 patients with occult and 33 patients with classic choroidal neovascularization (CNV) were irradiated with 16 Gy. Fluorescein angiography and measurements of visual acuity were performed before and 3, 6, and 12 months after irradiation.

RESULTS

Complete follow-up data for 1 year were available from 69 patients. The mean patient age was 72 years (range 49-92). Vision decreased in 43, was stable in 18, and improved in 8 cases. The mean vision deteriorated significantly (p = 0.02, Wilcoxon test), particularly within the first 3 months. Patients with occult CNV did significantly better than did those with classic CNV (p = 0.03). The proportion of patients retaining vision > or = 0.2 fell from 65% to 42% (p <0.01), for classic and occult CNV from 50% to 23%, and for occult CNV from 77% to 56% (p < 0.02), respectively. CNV size increased in 30 patients and was stable in 38. Neither age (p = 0.17) nor gender (p = 0.21, chi-square test) influenced prognosis. Four patients reported transitional complaints.

CONCLUSION

Low-dose fractionated radiotherapy with 16 Gy is well tolerated. However, vision and reading ability were not preserved in most patients.

A 5-year follow-up study for distance visual acuity after low dose radiation on subfoveal choroidal neovascularization in age-related macular degeneration

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.

Dosimetric advantages of enhanced dynamic wedge in small field irradiation for the treatment of macular degeneration

Exudative macular degeneration is a process that affects the central retina and is the chief cause of blindness in people over 55 years old. Radiation appears to improve or stabilize visual acuity in some of these patients, although definitive clinical studies are ongoing. The delivery of radiation in patients with macular degeneration is unique and challenging because of the location of the surrounding structures, such as the lens and the opposite retina. The "standard" treatment technique has been an anterior oblique beam 20 degrees above lateral to limit dose to these structures. In preference to the undesirable hot spot caused by this single-beam technique, we have employed a superior and inferior oblique pair utilizing the Enhanced Dynamic Wedge (EDW). Couch rotation was used to establish the desired treatment angles. The anterior half of the fields were blocked with the asymmetric jaw (AJ). Studies were performed to determine the value of these methods in reducing lens dose. Although the peripheral dose measurements at Dmax using a 60 degrees metal wedge for > or = 10 cm square fields were higher than for an open field or the EDW, for the small retinal fields there was no lens-dose reduction attributable to the EDW. However, the steep wedge angles achievable with the EDW were useful for optimizing the dose distribution for the most desirable field angles. As expected, the independent collimator was more effective in reducing transmitted dose to the lens than a typical Cerrobend block. Measurements required to predict dose in and out of the field are discussed along with the dosimeters employed in evaluating small fields (less than 5 cm square) with the EDW. The technical challenges of positioning, immobilization, treatment planning and treatment delivery are presented.

Transpupillary thermotherapy (TTT) for the treatment of choroidal neovascularisation

AIM

To assess the effectiveness of transpupillary thermotherapy (TTT) for the treatment of classic and occult choroidal neovascularisation (CNV).

METHOD

In a retrospective, case selected, open label trial 44 eyes of 42 patients with CNV secondary to age related macular degeneration (ARMD) were studied. 44 eyes with angiographically defined CNV were treated with diode laser (810 nm) TTT. Laser beam sizes ranged between 0.8 and 3.0 mm and power settings between 250-750 mW. Treatment was given in one area for 1 minute, the end point being no visible change, or a slight greying of the retina. Outcome was assessed with Snellen visual acuity and clinical examination; in 24/44 patients angiographic follow up was available.

RESULTS

12 predominantly classic CNV and 32 predominantly occult membranes were followed up for a mean of 6.1 months (range 2-19). Mean change in vision for classic membranes was -0.75 (SD 1.75) Snellen lines and occult membranes was -0.66 Snellen lines (2.1) (p>0.05). Predominantly classic membranes were closed in 75% (95% CI: 62.5-87.5) of eyes, remained persistent in 25% (95% CI: 12.5-37.5); no recurrences occurred. Predominantly occult membranes were closed in 78% (95% CI: 70.1-85.3) of eyes, remained persistent in 12.5% (95% CI: 6.6-18.5), and were recurrent in 5.1% (95% CI: 4.2-14.3).

CONCLUSIONS

Transpupillary thermotherapy is a potential treatment for CNV. It is able to close choroidal neovascularisation while maintaining visual function in patients with classic and occult disease. Further trials of TTT are needed to compare this intervention with the natural history and other treatment modalities.

Age-related macular degeneration: long-term results of radiotherapy for subfoveal neovascular membranes

PURPOSE

To study results of 2-year follow-up of radiotherapy for subfoveal choroidal neovascular membrane associated with age-related macular degeneration.

METHODS

In a randomized prospective clinical study, 101 patients received a low-dose radiotherapy or no treatment. In the treatment group, subfoveal choroidal neovascular membranes were treated with 20 Gy of 6-MV photons to the macula of the affected eye.

RESULTS

The overall complete follow-up rate was 84.2% (85/101). No measurable treatment-related morbidity was seen during or after treatment. Mean changes in log of minimal angle of resolution (logMAR) of visual acuity and area of choroidal neovascular membrane for 2-year follow-up were +0.226 +/- 0.373 and 143.5 +/- 53.1% in the treatment group, and +0.563 +/- 0.370 and 190. 3 +/- 81.4% in the control group; a significant difference was found (P <.0001; P =.0008). In patients with smaller choroidal neovascular membrane (</=1.5 mm(2)) or better visual acuity (>/=60/200) at baseline, the treatment group showed a significantly smaller increase in area of choroidal neovascular membrane and a significantly smaller decrease in LogMAR visual acuity for 2 years, whereas there was no significant difference in patients with larger choroidal neovascular membrane (>1.5 mm(2)) or poorer visual acuity (<60/200).

CONCLUSIONS

Radiotherapy appeared to have a favorable treatment effect in eyes with subfoveal neovascular membrane associated with AMD. Favorable factors for radiotherapy were a smaller area of choroidal neovascular membrane and better visual acuity.

Radiotherapy for subfoveal neovascularisation associated with pathological myopia: a pilot study

BACKGROUND/AIM

Limited treatments are available for this disease process. A pilot study was performed to determine the toxicity and efficacy of external beam radiotherapy for subfoveal neovascular membranes and subretinal haemorrhage associated with pathological myopia.

METHODS

A randomised, prospective study was carried out on 39 patients with subfoveal neovascularisation associated with high myopia. 20 patients underwent radiotherapy and the remaining 19 were observed as a randomised comparison group. All patients were followed up for at least 24 months. Subfoveal choroidal neovascular membranes (CNVMs) were treated with a single lateral 6 MV photon beam to a dose of 10 Gy in five fractions over 5-7 days. Post-treatment measurements included corrected visual acuity, area of CNVM, and occurrence of radiotherapy related complications, and adverse reactions. To assess changes of area of CNVM, the initial (pretreatment) size of the CNVM was set to 100%, and all post-treatment measurements were normalised relative to the initial size.

RESULTS

No significant acute morbidity was noted. There was no significant difference in age, sex, refractive error, visual acuity, and area of CNVM at baseline between the treatment group and control group. The mean change of the size of the CNVM for 2 years was 155% (SD 156%) in the treatment group and 249% (124%) in the control group. The increase in the size of CNVM in the treatment group was significantly smaller than that in the control group (p = 0.0452). In the treated eyes, the visual acuity before and 1 and 2 years after radiotherapy were 0.111 (22.2/200), 0.091 (18.2/200), and 0.086 (19.2/200), respectively. In the control eyes, visual acuity before and 1 and 2 years after the start of the follow up were 0.141 (34.2/200), 0.089 (17.8/200), and 0.063 (12.6/200). The patients in the treatment group showed no significant change for 2 years, and those in the control group showed a significant decrease in the visual acuity (p = 0.0033). The changes of logMAR of visual acuity for 2 years after the start of the follow up were +0.019 (0. 443) in the treatment group and +0.347 (0.374) in the control group. There was a statistically significant difference between them (p = 0. 0173). Multiple regression analysis on the treatment group showed that the most significant predictive variable for the visual acuity 2 years after the treatment was the combination of pretreatment visual acuity and refractive error.

CONCLUSIONS

Radiotherapy appeared to have a favourable treatment effect in eyes with subfoveal neovascular membranes and haemorrhage associated with pathological myopia. Further investigation is needed to evaluate the efficacy of radiotherapy for subfoveal neovascularisation associated with pathological myopia.

Radiotherapy for age related macular degeneration causes transient lens transparency changes

AIM

Evaluation of potential side effects of photon radiotherapy on the transparency of the lens.

METHODS

The anterior segments of 14 phakic eyes from patients suffering from subfoveal neovascularisation as a result of age related macular degeneration (AMD) were documented by Scheimpflug photography (Topcon SL-45, Kodak Tmax 400) before the start of radiotherapy as well as 6 and 12 months afterwards. All negatives were evaluated by microdensitometry, and peak heights for distinct layers of the lens were used for statistical comparison. External beam radiotherapy (6 MeV photons) consisted of a total dose of 20 Gy, delivered as 10 fractions of 2 Gy.

RESULTS

Six and 12 months following irradiation statistical comparison of the ratios in density change of lenses from irradiated versus non-irradiated fellow eyes revealed statistically significant (p</=0.05) loss of transparency of layers 5 and 7 of the nuclear region. In layer 1 (capsuloepithelial complex) the changes were close to significance. At the 12 month examination, however, all of these significant changes had disappeared.

CONCLUSION

Six months following radiotherapy for AMD, both the anterior capsuloepithelial region and the nuclear layers showed precataractous changes. As most of these significant differences had disappeared after 12 months, it is obvious that these findings reflect acute radiation damage to the lens epithelial cells and an ionising effect on the proteins of the lens nucleus. Long term studies will have to be carried out to demonstrate whether or not this acute radiation damage, which is expressed as a transient increase in light scattering of some layers of the lens, actually does lead to permanent transparency changes, thus reflecting radiation cataractogenesis, and if so, after what time interval and to what extent cataract occurs.

Treatment of age-related macular degeneration

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.

External beam radiotherapy in exudative age-related macular degeneration: a pooled analysis of phase I data

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.

Radiation-associated choroidal neovasculopathy

PURPOSE

To characterize a newly discovered choroidal vascular abnormality in patients who have received radiation therapy for subfoveal choroidal neovascularization (CNV) secondary to age-related macular degeneration.

DESIGN

Two-center cross-sectional study.

PARTICIPANTS

In the United States, there were 95 patients who were treated with 10 or 12 Gy of external beam photons. In Belgium, 98 patients were treated with 20 Gy. These patients were examined retrospectively for the presence of a specific CNV abnormality.

RESULTS

During the follow-up period, an unusual vascular growth pattern was identified in 12 patients (12.6%) of those treated in the United States and in 7 (7.1%) of those treated in Belgium. These patients developed round or oval vascular blebs along the outer border of their neovascular lesions. These blebs profusely leaked fluorescein dye and could be imaged best by indocyanine green angiography. Patients with these blebs appeared to have a marked propensity for loss of visual acuity.

CONCLUSION

An unusual pattern of new vessel growth occurred in 19 of the 193 patients with CNV treated with radiation. This new entity, termed radiation-associated choroidal neovasculopathy, is a recognizable disorder that appears to have a particularly poor prognosis.

A prospective, randomized, double-masked trial on radiation therapy for neovascular age-related macular degeneration (RAD Study). Radiation Therapy for Age-related Macular Degeneration

OBJECTIVE

To determine the efficacy of external beam radiation therapy on choroidal neovascularization (CNV) secondary to age-related macular degeneration (ARMD).

DESIGN

Multicenter, parallel, randomized, double-masked clinical trial performed at nine ophthalmic and radiotherapeutic centers.

PARTICIPANTS

Two hundred five patients were randomly assigned either to treatment with 8 fractions of 2 Gy external beam irradiation (n = 101) or to control with 8 fractions of 0 Gy (sham treatment, n = 104). Both patients and ophthalmologists were masked with regard to applied treatment. Patients with subfoveal classic or occult CNV, visual acuity of 20/320 or greater on the Early Treatment Diabetic Retinopathy Study chart, lesion size of 6 disc areas or less, history of visual symptoms of 6 months or less, and absence of foveal hemorrhage were recruited.

INTERVENTION

In the treatment group, external beam irradiation with 8 fractions of 2 Gy was performed, whereas in the control group, sham treatment with 8 fractions of 0 Gy was applied.

MAIN OUTCOME MEASURES

Primary outcome measure was the difference in visual acuity between baseline and after 1 year of follow-up.

RESULTS

One hundred eighty-three patients (89.3%) completed the 1-year follow-up. The mean reduction in visual acuity was 3.5 +/- 4.7 lines in 88 patients of the 8- x 2-Gy treatment group and 3.7 +/- 3.8 lines in 95 patients of the 8- x 0-Gy control group. This difference was not statistically significant (P = 0.53, Mann-Whitney U test). At 1 year, 51.1% of treated patients and 52.6% of control subjects lost three or more lines (P = 0.88). Visual acuity in the presence of classic CNV dropped by 3.7 +/- 4.4 lines in 33 patients of the treatment group versus 4.3 +/- 3.9 lines in 36 patients of the control group (P = 0.47). Visual acuity in 114 patients with occult CNV dropped by 3.4 +/- 4.9 in the treatment group (55 patients) versus 3.4 +/- 3.8 lines in the control group (59 patients) (P = 0.80).

CONCLUSIONS

In this randomized study, radiation therapy at a dose of 16 Gy applied in 8 fractions of 2 Gy provided no benefit as a treatment for subfoveal CNV secondary to ARMD at 1 year.

External beam radiotherapy for subretinal neovascularization in age-related macular degeneration: is this treatment efficient?

PURPOSE

Control of the natural course of subretinal neovascularization (SRNV) in age-related macular degeneration (AMD) is difficult. Only a subset of patients is suitable for laser coagulation. This prospective study aimed to determine the efficacy and individual benefit of external beam radiotherapy (EBRT).

METHODS AND MATERIALS

The prospective trial included 287 patients with subfoveal neovascularization due to AMD which was verified by fluorescein angiography. Patients have been treated between January 1996 and October 1997. All patients received a total dose of 16 Gy in 2-Gy daily fractions with 5-6 MeV photons based on computerized treatment planning in individual head mask fixation. This first analysis is based on 73 patients (50 women, 23 men, median age 74.3 years), with a median follow-up of 13.3 months and a minimum follow-up of 11 months.

RESULTS

All patients completed therapy and tolerability was good. First clinical control with second angiography was performed 6 weeks after irradiation, then in 3-month intervals. Eighteen patients with SRNV refusing radiotherapy served as a control group and were matched with 18 irradiated patients. After 7 months median visual acuity (VA) was 20/160 for the irradiated and 20/400 for the untreated patients. One year after radiotherapy final median VA was 20/400 in both groups.

CONCLUSION

These results suggest that 16 Gy of conventionally fractionated external beam irradiation slows down the visual loss in exudative AMD for only a few months. Patients' reading vision could not be saved for a long-term run.

Long term results of radiotherapy for subfoveal choroidal neovascularisation in age related macular degeneration

BACKGROUND/AIMS

Radiotherapy has been proposed as an alternative treatment for patients with subfoveal choroidal neovascularisation (CNV) that is untreatable according to macular photocoagulation study guidelines. This prospective study was designed to evaluate whether radiotherapy may affect the functional and anatomical outcome in a large cohort of patients affected by subfoveal CNV, with a follow up period up to 24 months.

METHODS

212 patients (231 eyes) with newly diagnosed subfoveal CNV not amenable to laser therapy were included in this study. Two radiotherapy methods, the lateral beam technique (6 MV, 20 Gy in five fractions) and lateral arc therapy (25 MV, 16 to 20 Gy, in four or five fractions), were used. Comparisons of best corrected visual acuity (VA), fluorescein (FA) and indocyanine green (ICG) angiography, at inclusion and 6, 12, 18, and 24 months after radiotherapy were performed using univariate analysis.

RESULTS

A VA improvement of two or more lines was observed in 34% at 12 months, 31% at 18 months, and 32% of the eyes at 24 months. Paired comparisons of CNV areas in FA and ICG showed no significant change between baseline and each visit. However, 12 and 18 months after treatment, 47% of the eyes showed a decrease of 10% or more in CNV size both in ICG and FA. Radiation side effects included radiation retinopathy (eight eyes), optic neuropathy (four eyes), choroidal vasculopathy (five eyes), and branch retinal vein occlusion (three eyes).

CONCLUSION

Compared with the natural course of subfoveal CNV, the results of this prospective study suggest that radiotherapy could stabilise visual and anatomical outcome in selected cases.

Radiotherapy for isolated occult subfoveal neovascularisation in age related macular degeneration: a pilot study

BACKGROUND/AIMS

Teletherapy has been proposed as a possible treatment for choroidal neovascular membranes (CNV), secondary to age related macular degeneration (AMD) not amenable to laser photocoagulation. The aim of this prospective study has been to investigate the effect of teletherapy on isolated occult choroidal neovascular membranes of subfoveal location.

METHODS

28 AMD patients presenting with retrofoveal isolated occult CNV demonstrated by fluorescein angiography were treated by external beam radiation. A complete ophthalmological examination, fluorescein angiography, and indocyanine green angiography (ICG) were performed within 15 days before treatment and repeated at follow up. A total dose of 16 Gy was applied in four sessions of 4 Gy using a 4 MeV photon beam. Follow up ranged from 6 to 9 months (mean follow up 6.4 months).

RESULTS

Visual acuity was found to be stable in 68% of the cases. The decrease in visual acuity was of 3-6 lines in 18% and of more than 6 lines in 10% of the eyes at last examination. On fluorescein angiography the size of the lesion area was found to be stable in 67%, decreased in 13%, and increased in 20% of the cases. On ICG angiography the size of the CNV was stable in 93% and increased in 7% of the cases. All the eyes experiencing a visual acuity decrease showed either no change or an increase in size of the membrane on fluorescein angiography and/or on ICG.

CONCLUSION

According to this study with strict inclusion criteria, external beam radiotherapy seems to have a beneficial effect on the evolution of isolated occult subfoveal CNV.

Randomized trial of radiation for age-related macular degeneration

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.

Radiation therapy in exudative age-related macular degeneration

It has been suggested that ionizing radiation at doses relatively safe to the optic nerve and retina exert an inhibitory and occlusive effect on the endothelial proliferation of choroidal neovascularization (CNV) associated with age-related macular degeneration (AMD). The encouraging results of early studies in preservation or improvement of visual acuity and regression of the CNV gave rise to many clinical trials in different centers. Disparate radiation doses, dose fractions, type and rate of radiation administration have been used to determine the efficacy of radiotherapy in AMD. Conflicting treatment responses have been reported by different centers. Some studies provided evidence of beneficial treatment outcome in AMD, and others could not show any efficacy of ionizing radiation in the visual and morphological evolution of the disease. Data from the literature and our experience indicate that radiotherapy can be effective in regressing the leakage of the CNV in AMD. However, despite treatment visual deterioration continues and new CNV lesions develop. The observation of morphological progression in the disease process might be related to an unfavorable effect of radiation on the pathogenesis of AMD.

The use of confocal scanning laser tomography in the evaluation of retinal elevation in age-related macular degeneration

OBJECTIVE

To evaluate the feasibility of using confocal scanning laser tomography in the analysis of macular topography in patients with subfoveal choroidal neovascularization associated with age-related macular degeneration (AMD) and to analyze quantitatively the changes in topography after local strontium-plaque radiation therapy.

DESIGN

Prospective case series.

PARTICIPANTS

A total of 16 eyes with subfoveal choroidal neovascular membranes (CNVM) treated with strontium-90 (90Sr)-plaque radiation therapy and 16 fellow eyes of 16 patients were examined.

INTERVENTION

Confocal scanning laser analysis of macular surface topography before and after irradiation of the macula was performed.

MAIN OUTCOME MEASURES

Parameters describing the height and volume of the retinal elevation in the macula were measured.

RESULTS

The maximum height of the macular lesion at baseline was 0.25 mm (standard deviation [SD], 0.12 mm) in eyes showing regression of the CNVM during follow-up and 0.34 mm (SD, 0.19 mm) in eyes showing continued growth of the CNVM. During follow-up, a mean decrease in the maximum height of the macular lesion ranging from 0.03 to 0.10 mm occurred in eyes with regression of the CNVM, whereas the mean maximum height increased by 0.07 to 0.15 mm during follow-up visits in eyes with continued growth of the CNVM. All parameters describing the mean height and volume of the lesion also decreased significantly in patients showing angiographic regression, whereas they increased or remained unchanged in patients with continuous growth of the CNVM despite irradiation. The corresponding parameters also were higher in fellow eyes with untreated CNVM than in eyes without exudative AMD.

CONCLUSIONS

Confocal scanning laser tomography can be used to monitor the amount of the change in neurosensory detachment in AMD. The parameters obtained by confocal scanning laser tomography correlate with CNVM perfusion after 90Sr-plaque radiation therapy. This technology is a useful tool for objective evaluation of morphologic change after institution of new therapeutic methods for the treatment of AMD.

Ophthalmic plaque radiotherapy for age-related macular degeneration associated with subretinal neovascularization

PURPOSE

To evaluate ophthalmic plaque radiotherapy for the treatment of subretinal neovascularization associated with age-related macular degeneration.

METHODS

In a prospective phase I clinical trial, we treated 23 patients (23 eyes) with ophthalmic plaque radiotherapy for subfoveal exudative macular degeneration. Palladium 103 ophthalmic plaque brachytherapy was delivered to a retinal apex dose of 1,250 to 2,362 cGy (rad). Early Treatment Diabetic Retinopathy Study type visual acuity determinations, ophthalmic examinations, and angiography were performed before and after treatment. Clinical evaluations were performed in a nonrandomized and unmasked fashion.

RESULTS

Patients were followed up for a mean (+/-SD) of 19 +/- 10.7 months (range, 3 to 37 months). Six months after radiation therapy, three (16%) of 19 eyes had lost 3 or more lines of best-corrected visual acuity; 12 months after radiation therapy, four eyes (31% of 13 eyes), and 24 months after radiation therapy, only two (22% of nine eyes) lost 3 or more lines of visual acuity. No eye suffered sudden irreversible loss of central vision. No radiation retinopathy, optic neuropathy, or cataract could be attributed to radiotherapy within this follow-up period.

CONCLUSION

Ophthalmic plaque radiotherapy can be used to treat neovascular age-related macular degeneration. In contrast to external beam radiotherapy, ophthalmic plaque radiotherapy is a unilateral treatment, which allows a larger dose to be delivered to the macula with less irradiation of normal ocular structures. We have found no sight-limiting complications at the doses, dose rates, and follow-up evaluated in this study.

Age-related macular degeneration: a review of experimental treatments

Age-related macular degeneration (AMD) is the leading cause of irreversible visual loss in the USA. Laser photocoagulation of choroidal neovascular membranes (CNVMs) in exudative AMD is currently the only well-studied and widely accepted treatment modality. It is beneficial for only a small minority of patients who show well-demarcated "classic" CNVMs, and it destroys normal retinal tissue, creates a scotoma, and is associated with an unacceptably high CNVM persistence and recurrence rate. Consequently, investigators have attempted to develop new modalities for treatment of CNVMs. These treatment modalities can be grouped into four major categories: photodynamic therapy; pharmacologic inhibition of CNVM formation with antiangiogenic agents; surgical intervention, including excision of subfoveal CNVMs; and radiation therapy. All of these experimental treatment modalities are directed toward destroyiing CNVMs, the end result of the exudative process, and all have limitations. The ideal treatment of the future must be based on the pathogenesis of the disease at a stage well before CNVMs develop. Investigations in nonexudative AMD are currently focusing on several major areas. Epidemiologic factors, such as genetics, sunlight, and nutrition, are being evaluated in several large studies, including the Age-Related Eye Disease Study, with the possibility of ultimately limiting the risk of AMD through behavior modification. Laser treatment of drusen is being evaluated as a means of limiting the risk of CNVM formation, although mixed results have been reported in the small number of studies to date. Choroidal perfusion abnormalities have been described in AMD, and some investigators postulate that altering blood flow may limit the risk of CNVM formation. No perfusion-treatment trials have been completed to date.

Low dose radiation for subfoveal choroidal neovascularization in age-related macular degeneration. A pilot study: radiotherapy for age-related macular degeneration

The aim of our pilot study was to test the effect of low dose radiation on classic and occult subfoveal choroidal neovascularization (CNV) in age-related macular degeneration (AMD). The posterior pole of the afflicted eye of 12 patients was irradiated with 5 Gray (Gy), and that of 34 patients with 8 Gy. The radiotherapy was done by a linear accelerator (6 MV X-rays) during 4 consecutive days with daily doses of 1.25 Gy and 2 Gy respectively. At the time of treatment, and 6 weeks, 6 months and 1 year after, a simultaneous fluorescein and ICG angiography of both eyes were carried out, and the distance visual acuity was measured. In none of the cases were we able to note a reduction in the subfoveal membrane's size. With regards to the visual acuity, the evolution was slightly better than the spontaneous courses described in existing literature. Further prospective randomized studies with higher dose radiation are necessary in order to determine the significance of radiotherapy in the treatment of this pathology.

External beam radiotherapy in the management of subfoveal choroidal neovascular membranes of the eye: a new treatment for an old disease

Images

[Role of radiotherapy in benign diseases]

Radiation therapy of benign diseases represent a wide panel of indications. Some indications are clearly identified as treatment of arteriovenous malformations (AVM), hyperthyroid ophtalmopathy, postoperative heterotopic bone formations or keloid scars. Some indications are under evaluation as complications induced by neo-vessels of age-related macular degeneration or coronary restenosis after angioplasty. Some indications remain controversial with poor evidence of efficiency as treatment of bursitis, tendinitis or Dupuytren's disease. Some indications are now obsolete such as warts, or contra-indicated as treatment of infant and children.

Feeder vessel photocoagulation of subfoveal choroidal neovascularization secondary to age-related macular degeneration

PURPOSE

This study aimed to assess the feasibility of laser photocoagulation of feeder vessels of subfoveal choroidal neovascularization (CNV) secondary to age-related macular degeneration.

PATIENTS AND METHODS

Of 170 consecutive patients with subfoveal CNV secondary to age-related macular degeneration, feeder vessels were detected in 37 patients by means of indocyanine green videoangiography using a scanning laser ophthalmoscope. Dye laser photocoagulation was applied to extrafoveal feeder vessels, with the fovea spared.

RESULTS

Twenty-six (70%) of those 37 patients had complete resolution of exudative manifestations. Persistent or worsened manifestations were seen in 11 patients (30%) because of recurrent CNV or persistent CNV. The visual acuity improved or stabilized in 25 patients (68%). Ten patients (27%) had a final visual acuity of 20/40 or better and six patients (16%) had a final visual acuity of 20/50 to 20/100. Significant factors prognostic of the visual outcome of 20/100 or better were small CNV (2 disc areas or smaller, Fisher's exact probability test, P = 0.041), the absence of white, fibrous tissue in neovascular membranes (Fisher's exact probability test, P = 0.003), and the closest distance of laser burns to the center of the foveal avascular zone (Fisher's exact probability test, P = 0.049). Preoperative visual acuity had a significant positive correlation with final visual acuity (Spearman's rank correlation test, P = 0.0076).

CONCLUSION

Feeder vessel photocoagulation should be considered as a treatment option for subfoveal CNV secondary to age-related macular degeneration, because no other treatment method has a better visual outcome.