Photodynamic Therapy vs. Bevacizumab for Choroidal Neovascularisation
Photodynamic Therapy vs. Bevacizumab for Choroidal Neovascularisation
Aim To compare the long-term outcome of photodynamic therapy (PDT) with that of intravitreal bevacizumab (IVB) for myopic choroidal neovascularisations (mCNVs).
Methods 24 eyes were selected from 40 consecutive patients with mCNV, and the patients were divided into Group A, consisting of 12 eyes treated by PDT, and Group B, consisting of 12 eyes treated by 1.25 mg IVB. The age and best-corrected visual acuity (BCVA) were matched between the two groups. The BCVA, size of the chorioretinal atrophy surrounding the CNV (CRA), central foveal thickness (CFT) and CNV thickness were determined before and at 12 and 24 months after the treatment.
Results The BCVA did not change after PDT but was significantly improved from 0.75±0.25 to 0.49±0.42 logMAR units at 12 months and to 0.50±0.38 logMAR units at 24 months after IVB. The CFT were significantly reduced in both groups at 12 and 24 months. The CRAs were larger in group A than in group B at 12 and 24 months, and their sizes were correlated with the BCVA.
Conclusion At 24 months, IVB is more effective than PDT in treating mCNV. The enlargement of the CRA might be related to the incomplete visual recovery after PDT.
A myopic CNV (mCNV) is one of the major causes of legal blindness in developed countries. The natural course of mCNV has been studied, and in almost 95% of the patients, the vision decreases to 0.1 in 10 years. Although a variety of treatment protocols have been tried, the treatment of mCNVs is still not satisfactory. For example, direct photocoagulation of the mCNV can stop the exudations, but an atrophic creep can invade the fovea after several years. Macular translocation has also been widely used, but the unfavourable aspects of translocation, for example, proliferative vitreoretinopathy and cyclodeviations, has limited its use. Surgical removal of a CNV has been reported to result in higher recurrence rates and poorer visual outcomes than macular translocation.
A sub-Tenon or intravitreal injection of triamcinolone acetonide has also been reported, but the results have not been completely satisfactory.
Photodynamic therapy (PDT) with verteporphin, a photosensitiser and a low-intensity laser can occlude the CNV. The VIP Study (Verteporphin in photodynamic therapy) reported that eyes treated with PDT had a slightly better visual prognosis than the placebo-treated eyes after 2 years. However, PDT has also reported to have some post-treatment complications that led to visual decreases.
Intravitreal injections of bevacizumab (IVB) have been recently tried, and their effectiveness for mCNV has been confirmed for up to 12 months. Although both PDT alone and IVB alone have been reported to be effective, there has been only one long-term (1 year) follow-up study comparing the outcome of PDT with IVB for mCNV.
Thus, the purpose of this study was to compare the effectiveness of PDT or IVB for treating mCNVs for up to 24 months. We also examined whether either of these treatments will result in a greater postoperative chorioretinal atrophy (CRA) surrounding the mCNV, and the relationship between CRA formation and visual function after treatment.
Abstract and Introduction
Abstract
Aim To compare the long-term outcome of photodynamic therapy (PDT) with that of intravitreal bevacizumab (IVB) for myopic choroidal neovascularisations (mCNVs).
Methods 24 eyes were selected from 40 consecutive patients with mCNV, and the patients were divided into Group A, consisting of 12 eyes treated by PDT, and Group B, consisting of 12 eyes treated by 1.25 mg IVB. The age and best-corrected visual acuity (BCVA) were matched between the two groups. The BCVA, size of the chorioretinal atrophy surrounding the CNV (CRA), central foveal thickness (CFT) and CNV thickness were determined before and at 12 and 24 months after the treatment.
Results The BCVA did not change after PDT but was significantly improved from 0.75±0.25 to 0.49±0.42 logMAR units at 12 months and to 0.50±0.38 logMAR units at 24 months after IVB. The CFT were significantly reduced in both groups at 12 and 24 months. The CRAs were larger in group A than in group B at 12 and 24 months, and their sizes were correlated with the BCVA.
Conclusion At 24 months, IVB is more effective than PDT in treating mCNV. The enlargement of the CRA might be related to the incomplete visual recovery after PDT.
Introduction
A myopic CNV (mCNV) is one of the major causes of legal blindness in developed countries. The natural course of mCNV has been studied, and in almost 95% of the patients, the vision decreases to 0.1 in 10 years. Although a variety of treatment protocols have been tried, the treatment of mCNVs is still not satisfactory. For example, direct photocoagulation of the mCNV can stop the exudations, but an atrophic creep can invade the fovea after several years. Macular translocation has also been widely used, but the unfavourable aspects of translocation, for example, proliferative vitreoretinopathy and cyclodeviations, has limited its use. Surgical removal of a CNV has been reported to result in higher recurrence rates and poorer visual outcomes than macular translocation.
A sub-Tenon or intravitreal injection of triamcinolone acetonide has also been reported, but the results have not been completely satisfactory.
Photodynamic therapy (PDT) with verteporphin, a photosensitiser and a low-intensity laser can occlude the CNV. The VIP Study (Verteporphin in photodynamic therapy) reported that eyes treated with PDT had a slightly better visual prognosis than the placebo-treated eyes after 2 years. However, PDT has also reported to have some post-treatment complications that led to visual decreases.
Intravitreal injections of bevacizumab (IVB) have been recently tried, and their effectiveness for mCNV has been confirmed for up to 12 months. Although both PDT alone and IVB alone have been reported to be effective, there has been only one long-term (1 year) follow-up study comparing the outcome of PDT with IVB for mCNV.
Thus, the purpose of this study was to compare the effectiveness of PDT or IVB for treating mCNVs for up to 24 months. We also examined whether either of these treatments will result in a greater postoperative chorioretinal atrophy (CRA) surrounding the mCNV, and the relationship between CRA formation and visual function after treatment.
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