Veränderungen neovaskulärer Membranen und normaler Aderhautgefäße nach mehrfacher photodynamischer Therapie

PURPOSE: ICG angiography (ICGA) was used to document the effect of repeated PDT (verteporfin) on size and leakage of choroidal neovascularisation in age-related macular degeneration (AMD) and treatment-related side effects on the choroid. METHODS: Forty-two patients were followed over 24 months in a clinical trial for PDT in AMD. The ICGAs were performed every 3 months with a confocal laser scanning system. Patients received repeated verteporfin treatment. At each control visit, the patients were retreated if leakage was present in fluorescein angiography (FA). RESULTS: A continuous, highly significant reduction in CNV size and leakage area was found over 24 months. The initial CNV size dropped by 23% from 3.86 mm2 to 2.98 mm2. The leakage area in the late phase of the angiogram decreased by 30.3% from 5.0 mm2 to 3.5 mm2. A significant side effect of PDT on the choroid was documented by an increased hypofluorescent area in ICGA. The maximum size of the hypofluorescent area was reached after 12 months. At month 24, the choroidal fluorescence showed recovery in respect to area and intensity of fluorescence. But hypofluorescence surrounding the CNV lesion was already present in 40 out of 42 eyes before treatment. CONCLUSION: The ICGA confirms that repeated PDT treatments lead to a significant reduction in CNV size and leakage area over as long as 2 years. CNV lesions are surrounded by choriocapillary hypofluorescence in ICGA. PDT causes further hypoperfusion of the choroid but in the long-term significant recovery of choroidal perfusion was shown.     

Angiographic features after photodynamic therapy for choroidal neovascularisation in age related macular degeneration and pathological myopia

AIM: To describe the angiographic features after photodynamic therapy (PDT) with verteporfin in choroidal neovascularisation (CNV) associated both with age related macular degeneration (AMD) and pathological myopia (PM). METHODS: 36 patients affected by subfoveal CNV in AMD and 25 patients with subfoveal CNV in PM underwent an ophthalmological examination including fluorescein angiography (FA) and indocyanine green angiography (ICGA) using the IMAGEnet System. Post-PDT examinations were performed 7, 30, and 90 days later. RESULTS: The typical angiographic aspect after PDT for AMD related CNV was a round hypofluorescence visible both on FA and on ICGA, which included both CNV and the surrounding tissues and corresponded to the area exposed to laser light. In PM the CNV appeared hypofluorescent during the early phases and gradually became hyperfluorescent during the late phases on FA, whereas on ICGA it was detectable in its whole extension as a hyperfluorescent lesion since the early phases. Differently from AMD, there was no round hypofluorescence surrounding the CNV on FA or on ICGA. Moreover, five patients in the AMD group showed hot spots on ICGA, which spontaneously disappeared during the follow up. Classic and occult components of the AMD related CNV revealed a different angiographic response to PDT, showing with the latter only a partial closure 1 week after PDT followed by a complete reopening at the first month in 100% of cases. CONCLUSION: The post-PDT hypofluorescence typical of AMD related CNV, especially visible on FA, might be secondary to a combination of choriocapillary occlusion and masking effect due to swelling of retinal pigment epithelium cells. Hot spots in the AMD affected patients could be interpreted as the expression of a non-thermal choroidal vasculitis secondary to PDT.     

Changes in confocal indocyanine green angiography through two years after photodynamic therapy with verteporfin

PURPOSE: To evaluate vascular changes documented by confocal indocyanine green angiography (ICGA) through 2 years after photodynamic therapy (PDT) with verteporfin of neovascular age-related macular degeneration (AMD). DESIGN: Single-center, 2-year, randomized, double-masked, interventional, placebo-controlled trial (subset from Treatment of AMD with PDT Study [TAP]). PARTICIPANTS: Sixty patients with subfoveal choroidal neovascularization (CNV) resulting from AMD. INTERVENTION: Patients were randomized in a ratio of 2:1 to a standard regimen using verteporfin therapy at a drug dose of 6 mg/m(2) body surface area and a light dose of 50 J/cm(2) or a sham treatment with placebo infusion and light exposure. Retreatments, if persistent fluorescein leakage from CNV was documented, were scheduled at 3-month intervals for up to 2 years. Confocal ICGA with tomographic sections was performed at baseline and continuously at the month 3, 6, 12, and 24 examinations using a standardized protocol. MAIN OUTCOME MEASURES: Analysis included the size of the neovascular net, the area of late hyperfluorescence, and choroidal hypofluorescence during early- and late-phase imaging. RESULTS: In the verteporfin-treated group, the mean size of the CNV and the mean area of late leakage consistent with active leakage or staining showed no further enlargement at month 12 and were reduced at month 24. In the placebo-treated group, new vessels grew threefold compared with baseline and exhibited persistent late hyperfluorescence resulting from leakage at 24 months. Associated choroidal hypofluorescence within the treated area was significantly increased in eyes treated with verteporfin PDT compared with the control group during the first year, persisted during all ICGA phases, and was irreversible during follow-up. Image analysis revealed choroidal hypoperfusion with choriocapillary dropout, which correlated with chorioretinal atrophy clinically. Progressive destruction of choroidal integrity by fibrosis in control eyes led to a similar extent of collateral hypofluorescence in both groups through the 24-month examination. CONCLUSIONS: Indocyanine green angiography is an important adjunct in the identification of vascular effects associated with verteporfin PDT. Repeated treatments effectively arrested CNV growth and reduced leakage activity. The collateral impairment of choroidal perfusion appears to influence the visual outcome of the treatment.     

Photodynamic therapy: ICG angiographic findings

Purpose: Photodynamic therapy (PDT) has been shown to provide immediate occlusion of choroidal neovascularization (CNV), followed by recurrent leakage after single PDT in the majority of the cases after 3 months. Indocyanine green angiography (ICG-A) was used to evaluate completeness of CNV occlusion, effects on physiological choroid and patterns of CNV recurrence. Methods: ICG-A was performed using a confocal laser scanning ophthalmoscope (HRA) before PDT at 1 week, 4 and 12 weeks following PDT. Twenty patients with single and 10 patients with repeated PDT treatments with administration of benzoporphyrin derivative and radiant exposures between 50 and 150 J/cm² were evaluated. Results: Before PDT well-defined CNV was detectable during early ICG-A in all lesions. Depending on the number of treatments, CNV was absent in early phase ICG-A in 46–83 %. CNV reappeared at week 4 in many and at 12 weeks in 77 (66 %) of the cases. The treated area regularly showed hypofluorescence, which persisted until week 12. The intensity of choroidal hypofluorescence showed wide interindividual variability. Recurrence may originate from persistent feeder vessels. Conclusion: With ICG-A we demonstrated that PDT induces hypofluorescence of CNV and choroid possibly due to perfusion changes or blockade phenomena. Recurrence may be due to reperfusion of the preexisting CNV or regrowth from feeder vessels.      

Influence of treatment parameters on selectivity of verteporfin therapy

PURPOSE: To improve selectivity of verteporfin therapy (PDT) in neovascular age-related macular degeneration (AMD) using modified treatment parameters. METHODS: Nineteen consecutive patients with predominantly classic choroidal neovascularization (CNV) in AMD were treated with 6 mg/m2 verteporfin given as bolus infusion. Patients received PDT with a fluence of either 25 or 50 J/cm2. Choroidal perfusion changes were evaluated by indocyanine green angiography (ICGA) at baseline, day 1, week 1, week 4, and month 3. Secondary outcomes were CNV closure rate and therapy-induced leakage documented by fluorescein angiography (FA). The safety of the treatment was assessed with ETDRS visual acuity. RESULTS: Complete CNV closure was achieved in all patients at day 1. Choroidal hypoperfusion was minimal in eyes treated with a reduced fluence of 25 J/cm2. Most patients treated with 50 J/cm2 showed significant choriocapillary nonperfusion at week 1, lasting as long as 3 months. A transient PDT-induced increase in leakage area in FA at day 1 was found to be more extensive in the 50-J/cm2 group. CONCLUSIONS: Bolus administration of verteporfin combined with a reduced light dose achieved improved selectivity of photodynamic effects, avoiding collateral alteration of the physiologic choroid while obtaining complete CNV closure. An increased selectivity with decreased effect on the surrounding choroid should be of advantage in verteporfin monotherapy as well as in combination strategies.     

Early vascular changes induced by transpupillary thermotherapy of choroidal neovascularization

OBJECTIVE: To study early direct effects of transpupillary thermotherapy (TTT) on choroidal neovascularization (CNV) and choroid. DESIGN: Retrospective, noncomparative interventional case series. PARTICIPANTS: Sixty-four eyes with subfoveal CNV. INTERVENTION: TTT was delivered using a diode laser at 810 nm through a contact lens. Exposure time was 60 seconds with a power/diameter ratio of 247 mW/mm. The end point was an invisible treatment with no color change at the retina level. MAIN OUTCOME MEASURES: Fluorescein and indocyanine green angiographic findings within 1 hour, and at 1, 2, and 4 weeks after TTT. RESULTS: Fluorescein angiography (FA) and indocyanine green angiography (ICGA) performed within 1 hour after TTT showed increased leakage of CNV and choroidal vessels. Follow-up at 1 and 2 weeks demonstrated a hypofluorescent area corresponding to the laser spot and absence of angiographic leakage seen on FA and ICGA. At 4 weeks after TTT, FA showed mottled hypofluorescence-hyperfluorescence of the TTT-treated area and absence of angiographic leakage. CONCLUSIONS: TTT induces a characteristic dynamic sequence of vascular changes. Treatment with TTT can lead to absence of angiographic (FA and ICGA) leakage for 4 weeks. Determination of the long-term efficacy and visual implications awaits the results of clinical trials.     

Immediate indocyanine green angiography and optical coherence tomography evaluation after photodynamic therapy for subfoveal choroidal neovascularization

PURPOSE: To better understand the mechanisms of action of photodynamic therapy (PDT) with verteporfin for subfoveal choroidal neovascularization (CNV), the authors evaluated the retinal and choroidal response immediately after treatment with serial optical coherence tomography (OCT) and indocyanine green angiography (ICGA). METHODS: This study was a prospective, noncomparative case series. PDT was performed on nine eyes of nine consecutive patients who presented with subfoveal CNV due to age-related macular degeneration, and serial evaluation with OCT as well as ICGA was performed at 20-minute intervals for the first 2 hours and then at 1 week, 1 month, and 3 months. RESULTS: In the first 2 hours after PDT, OCT showed an increase in the thickness of the retina in the treatment area due to fluid leakage from the neovascular complex as confirmed by ICGA. At 1 week, marked reduction of intraretinal/subretinal fluid was observed in all patients. Neovascular complex nonperfusion by ICGA was associated with some degree of choroidal hypoperfusion in the treatment area. Return of the foveal contour by OCT was optimal after 1 month of treatment. At 3 months, choroidal reperfusion by ICGA and recurrent intraretinal/subretinal fluid by OCT were observed. CONCLUSIONS: Serial OCT and ICGA evaluation after PDT suggests that the initial successful CNV nonperfusion as shown by fluorescein angiography at 1 week occurs by means of selective PDT damage to the lesion and/or reduced choroidal blood flow in the treatment area, thereby decreasing intraretinal/subretinal fluid and facilitating restoration of the retinal architecture.     

Chorioretinal anastomosis as unfavourable prognostic factor during photodynamic therapy

BACKGROUND: The aim of this study was the documentation of chorioretinal anastomosis in neovascular age-related macular degeneration (AMD) and correlation with functional and angiographic results following photodynamic therapy (PDT). METHOD: A total of 100 patients presenting with neovascular AMD and indication for PDT based on the presence of predominantly classic choroidal neovascularization (CNV), underwent ophthalmoscopic and angiographic screening for chorioretinal anastomosis. Conventional PDT using verteporfin was performed according to the recommended standard procedure.The pre- and post-treatment status at 3 and 6 months post-PDT in all patients and at 1 week in selected patients was documented with respect to the central visual acuity test (ETDRS), ophthalmoscopy as well as fluorescein (FA) and indocyanine green angiography (ICGA). RESULTS: A primary chorioretinal anastomosis was found in 6% ( n=12) of all eyes with CNV and classic PDT indication. Mean visual loss within the first 6 months after therapy was 3 lines indicating lack of visual stabilization according to the PDT study criteria.Furthermore, an increase in visual acuity could not be documented in any case.Angiography demonstrated continuous progression of CNV size although PDT had been uneventful. The characteristic initial occlusion of the CNV with homogeneous hypofluorescence was absent angiographically at 1 week post-PDT.The anastomosis was detected by ICGA in all eyes and by ophthalmoscopy or optical coherence tomography (OCT) in most eyes. DISCUSSION: Chorioretinal anastomosis is not a rare finding associated with predominantly classic CNV.The presence of anastomosis appears to be an unfavourable prognostic factor during PDT. If a chorioretinal shunt is suspected evaluation by ICGA and/or OCT should be performed and the indication for PDT should be rediscussed.     

Indocyanine green angiography in the juvenile haemorrhagic choroidopathy

Juvenile haemorrhagic choroidopathy (JHC) is an idiopathic syndrome marked by macular choroidal neovascularization (CNV) in patients under the age of 50. We used fluorescein angiography (FA) and indocyanine green angiography (ICGA) to examine 17 patients with macular CNV and JHC. CNV was always unilateral. On ICGA examination the CNV were weakly fluorescent in 59% of cases, hyperfluorescent in the remaining 41%.ICGA showed up the following alterations: a) areas with diffuse choroidal hyperfluorescence at the posterior pole or in the peripapillary region in 11 affected eyes (65%), in the fellow eye too in 5 patients; b) areas of choroidal hypofluorescence at the posterior pole but also outside the vascular arcades in 2 affected eyes (12%).In conclusion, ICGA does not appear indispensable for detecting CNV in JHC but this method does show up diffuse choroidal alterations not detectable with FA. The pathogenetic implications of the ICGA findings are discussed.     

Early angiographic changes after laser treatment of choroidal neovascularisation in age-related macular degeneration

PURPOSE: To describe angiographic features detectable on fluorescein angiography (FA) and indocyanine green angiography (ICGA) early after laser photocoagulation of choroidal neovascularisation (CNV) in age-related macular degeneration (AMD). METHODS: Thirty-five eyes of patients with AMD and juxtafoveal or extrafoveal CNV referred to the angiographic centre of the Eye Clinic of Trieste were considered. Ophthalmological assessment included FA and ICGA performed 2 days before and 30 min after laser treatment, and then 1, 2, 7, 14, 21 and 28 days after photocoagulation. Further clinical angiographic examinations were carried out 2, 3, 4 and 6 months after treatment. Photocoagulation was performed for classic CNV on FA and occult CNV on FA, appearing as well-defined focal spot on ICGA. RESULTS: Our results show that interpretation of early post-treatment angiographic examinations may be awkward because diffuse leakage on FA and hot spots on ICGA are normally detectable soon after laser treatment and thereafter during the first 2 weeks. Later, at the 3-week control, leakage on FA and hot spots on ICGA are visible in 62.8% and in 37% of cases respectively; they disappear completely by the 4-week control. CONCLUSION: Difficulty in analysing FA and ICGA in the early post-photocoagulation period underlines the importance of the decision regarding when to perform the first reliable post-laser control and how to improve its interpretation. We suggest that the first angiographic control be performed 3 weeks after treatment, strictly monitoring those eyes showing leakage or marginal hot spots over the following weeks. Overlapping the post-laser hypofluorescent area on the pre-laser lesion can ensure the complete coverage of CNV, and analysis of the retinal and choroidal vascular pattern inside and near the photocoagulated area during the different angiographic phases, albeit difficult, is essential for the interpretation of the angiographic lesions.     

光动力疗法治疗渗出性年龄相关性黄斑变性

目的观察光动力疗法(photodynamic therapy,PDT)治疗渗出性年龄相关性黄斑变性(age-related macular degeneration,AMD)的疗效。方法回顾分析经荧光素眼底血管造影(fundus fluorescein angiography,FFA)、吲哚菁绿血管造影(indocyanine green angiography,ICGA)以及光学相干断层扫描(optical coherence tomography,OCT)检查确诊的21例(31眼)渗出性AMD患者PDT治疗前及治疗后的临床资料,主要以视力、FFA及(或)ICGA、OCT的改变为观察指标,评价PDT对渗出性AMD的治疗效果。结果治疗后13眼视力明显改善(视力提高≥2行),占41.9%;14眼视力稳定不变(视力波动在1行以内),占45.2%;4眼视力下降2行,占12.9%。大部分患眼于PDT治疗后眼底出血和渗出减轻;ICGA检查显示:PDT治疗后1周,16眼CNV的渗漏明显减少或完全停止,8眼渗漏完全停止。OCT检查显示:CNV周围视网膜脉络膜水肿以及神经上皮脱离好转。5例6眼患者在PDT治疗过程中及治疗后发生视网膜神经上皮脱离范围变大,1例1眼发生黄斑部再次大面积出血,所有病例均未发生任何全身不良反应。结论单次和重复PDT治疗可以部分或完全封闭渗出性AMD的CNV,PDT治疗对病灶周围的正常视网膜和脉络膜组织短期内有轻度影响,对视力无损害。     

Effects of photodynamic therapy on the choriocapillaris and retinal pigment epithelium in the irradiated area

PURPOSE: To evaluate the effect of photodynamic therapy (PDT) on the choriocapillaris and retinal pigment epithelium (RPE) in the irradiated area surrounding choroidal neovascularization (CNV) during 12 months of follow-up. METHODS: We reviewed the medical records, and indocyanine green angiography (IA), fluorescein angiography (FA), and fundus photographic findings of 72 eyes (72 patients) with CNV associated with age-related macular degeneration (AMD) or polypoidal choroidal vasculopathy (PCV). Patients were divided into three groups based on the number of PDT sessions. Twelve months after PDT, we evaluated the relationship between the number of sessions and both the presence of hypofluorescence in the late phase of IA and window defects observed on FA in the irradiated areas. RESULTS: Twenty-three patients had one PDT session (group I), 25 had two (group II), and 24 had three or four (group III). IA revealed hypofluorescence indicating a choriocapillaris filling defect within the irradiated area in 11 eyes (48%) in group I, 18 (72%) in group II, and 22 (91%) in group III. The correlation between the number of PDT sessions and hypofluorescence in the irradiated areas was significant. FA showed window defects surrounding CNV in 26%, 52%, and 71% of eyes from groups I, II, and III, respectively. Subretinal hemorrhages had been present in 23 eyes (32%) and exudation in 13 (18%) prior to PDT. Areas without hemorrhages or exudation prior to PDT had a normal appearance within the irradiated area in all 72 eyes. CONCLUSIONS: Although the RPE in the irradiated area was preserved, 12 months after PDT, mild choriocapillaris occlusion was detected in the irradiated area in eyes that had undergone multiple PDT sessions.     

Acute visual loss and chorioretinal infarction after photodynamic therapy combined with intravitreal triamcinolone

PURPOSE: To report acute visual loss associated with dynamic vascular changes after photodynamic therapy (PDT) combined with intravitreal triamcinolone (IVTA) for the treatment of occult choroidal neovascularization (CNV). METHODS: An 86-year-old woman complained of visual loss in her left eye. Angiographic examination showed a serous pigment epithelium detachment complicated by CNV. She underwent combined treatment with IVTA (4 mg) followed by standard verteporfin PDT administered after a 5-day interval. RESULTS: The patient developed vision loss 1 day after PDT. Ophthalmoscopic examination disclosed an acute serous neurosensory retinal detachment. Fluorescein angiography showed a large area of early hypofluorescence in correspondence to and extending beyond the photodynamic spot. Neurosensory retinal vessels involvement with dilation of the retinal arterioles and capillary nonperfusion were also revealed. Indocyanine green angiography showed choroidal infarction within the collateral choroid included in the area of light exposure, with associated nonperfusion of medium and large choroidal vessels being revealed. Five days after PDT, spontaneous severe bleeding with breakthrough into the vitreous occurred, in addition to an RPE tear. CONCLUSIONS: Acute loss of vision associated with vascular changes in retinal and choroidal circulation represents an uncommon but serious complication following combined PDT and IVTA. These risks should be carefully considered in combination therapies.     

Fluorescein and indocyanine green angiography after transpupillary thermotherapy of choroidal neovascularization. Early vascular changes

Transpupillary thermotherapy (TTT) is currently being evaluated in clinical trials for the treatment of choroidal neovascularization (CNV). Preliminary results show that TTT achieves closure of CNV and reduction in subretinal exudation while preserving visual acuity. Fluorescein and indocyanine green angiography reveal increased leakage activity from CNV and collateral choroid within 1 hour after TTT and absence of dye leakage from CNV at 1 week after treatment. Optical coherence tomography confirms the angiographic findings. The early vascular changes after TTT of CNV are similar to those observed after PDT of CNV. Transpupillary thermotherapy and PDT might share common mechanisms of action. A placebo-controlled, multi-center trial (TTT4CNV) evaluating the long-term efficacy and visual implications of TTT in occult CNV is underway.     

中心性渗出性脉络膜视网膜病变的吲哚青绿造影特征

目的:分析中心性渗出性脉络膜视网膜病变(central exudative chorioretinopathy,CEC)吲哚青绿血管造影(indocyaninegreen angiography,ICGA)特点。方法:应用海德堡造影系统HRA2对24例24眼CEC患者进行荧光素、吲哚青绿眼底血管造影,并对ICGA与眼底荧光造影(fundus fluorescein angiography,FFA)结果进行对比分析。结果:CEC患者24眼FFA均证实为典型性脉络膜新生血管(choroidal neovascularization,CNV)。ICGA早期,24例CEC可见边界清晰的网状CNV。5例见CNV周围局限性脉络膜血管扩张。ICGA晚期可见CNV处染料渗漏或染色。20眼ICGA早期可见宽窄不一的暗环包绕CNV,4眼未见暗环。ICGA晚期,24眼CNV周围均可见暗环。1例患者光动力(photodynamic therapy,PDT)治疗后2mo,因视力继续下降复查ICGA,可见视网膜脉络膜血管吻合(retinal-choroidal anastomosis,RCA)。结论:由HRA2进行的ICGA对CEC的CNV的结构、边界、局部脉络膜静脉的改变、RCA的显示优于FFA。     

Marginal crack after intravitreal bevacizumab for myopic choroidal neovascularization

Purpose: To report new indocyanine green angiographic (ICGA) findings after intravitreal bevacizumab (IVB) for myopic choroidal neovascularization (mCNV). Cases report: Three eyes of three patients with mCNV were examined with fluorescein angiography (FA) and ICGA using Heidelberg Retinal Angiograph 2 and the conventional fundus camera before and after IVB. The cessation of angiographic leakage on FA was achieved in all eyes (100%) after IVB, however the hypofluorescent line delineating the margin of the neovascular tissue appeared in ICGA seemingly according to the contraction of mCNV. It was not detected either on FA or ICGA with the conventional camera. This hypofluorescence line enlarged over the time. Conclusion: The contraction‐associated hypofluorescence line, namely marginal crack line, indicates the early damage of retinal pigment epithelium and seems to lead to expanding macular chorioretinal atrophy typically seen in mCNV.     

Photodynamic therapy: ICG angiographic findings

Purpose: Photodynamic therapy (PDT) has been shown to provide immediate occlusion of choroidal neovascularization (CNV), followed by recurrent leakage after single PDT in the majority of the cases after 3 months. Indocyanine green angiography (ICG-A) was used to evaluate completeness of CNV occlusion, effects on physiological choroid and patterns of CNV recurrence.     

光动力疗法治疗老年性黄斑变性合并脉络膜新生血管的临床观察

目的 观察单次光动力疗法(photodynamic therapy, PDT)治疗渗出型老年性黄斑变性(age-related macular degeneration, AMD)合并脉络膜新生血管(choroidal neovascularization, CNV)的短期治疗效果。 方法 回顾分析经荧光素眼底血管造影(fundus fluorescein angiography, FFA)、吲哚青绿血管造影(indocyanine green angiography,ICGA)和光相干断层成像术(optic coherence tomography, OCT)等检查确诊的30例渗出型AMD患者的35只患眼行PDT治疗前和治疗后1周,1、3个月的临床资料，以视力、FFA、ICGA和OCT检查结果为观察指标，评价PDT对渗出型AMD的短期治疗效果。 结果 治疗后3 个月内有34只眼视力不变或提高，1只眼因出血而视力下降；FFA检查显示有19只眼荧光素渗漏减轻或完全消退；OCT检查显示视网膜水肿和浆液性脱离明显好转。全部患者治疗过程中未发生任何不良反应；治疗后3例患者主诉有一过性视物变暗，2例主诉轻微背痛。 结论 PDT治疗渗出型AMD时，可短期封闭CNV，使渗漏减轻或消退，对视力无损害。 (中华眼底病杂志, 2002, 18: 171-174)     

Fluorescein and indocyanine green angiography after transpupillary thermotherapy of choroidal neovascularization. Early vascular changes

Transpupillary thermotherapy (TTT) is currently being evaluated in clinical trials for the treatment of choroidal neovascularization (CNV). Preliminary results show that TTT achieves closure of CNV and reduction in subretinal exudation while preserving visual acuity. Fluorescein and indocyanine green angiography reveal increased leak-age activity from CNV and collateral choroid within 1 hour after TTT and absence of dye leakage from CNV at 1 week after treatment. Optical coherence tomography confirms the angiographic findings. The early vascular changes after TTT of CNV are similar to those observed after PDT of CNV. Transpupillary thermotherapy and PDT might share common mechanisms of action. A placebo-controlled, multi-center trial (TTT4CNV) evaluating the long-term efficacy and visual implications of TTT in occult CNV is underway.     

Photodynamic effects on choroidal neovascularization and physiological choroid

PURPOSE: To evaluate the effect of photodynamic therapy (PDT) on perfusion and vascular integrity of choroidal neovascularization (CNV) and collateral physiological choroid. METHODS: In a prospective clinical trial, patients with subfoveal CNV were treated with PDT and verteporfin. Indocyanine green angiography (ICG-A), using a confocal laser scanning system with tomographic sections, was performed continuously 1 week before and 1, 4, and 12 weeks after and a mean long-term follow-up of 16.5 months after the final PDT. Vascular changes were localized tomographically and quantified on the level of the CNV and collateral choroid according to early lesion size, late hyperfluorescence, and persistence or recurrence. Data were analyzed separately from 38 eyes in a single- and 12 eyes in a multiple-treatment regimen. RESULTS: CNV lesions were significantly reduced in size and late hyperfluorescence. However, 54% of lesions primarily demonstrated persistence, typically of the choroidal feeding complex, which was only detectable by ICG-A. Regrowth from the feeding vessel occurred regularly, but did not reach baseline dimensions. Collateral choroid exposed to photoactivation exhibited choriocapillary occlusion. Progressive recanalization was documented within 4 to 12 weeks after both single and multiple PDT. Residual changes in the choroidal filling pattern often persisted during long-term follow-up. CONCLUSIONS: Tomographic ICG-A after PDT reveals persistence of CNV and/or the feeder vessel and a reduction in perfusion within the entire photosensitized area, including the surrounding choroid. Repair mechanisms occur slowly in neovascular and normal choroidal structures.