C ORRESPONDENCE Selective Occlusion of Subfoveal Choroidal Neovascularization in Pathologic Myopia Using a New Technique of Ingrowth Site Treatment EDITOR: IN THE ARTICLE BY COSTA AND ASSOCIATES (AM J OPH- thalmol 2003;135:857– 866), the authors reported success- ful indocyanine green (ICG)-mediated photothrombosis of subfoveal choroidal neovascularization (CNV) in patho- logic myopia by a new technique of ingrowth site treat- ment. There are, however, several issues that we would like to address. First, it has been shown previously that high myopia associated CNV do exhibit age-dependent biological dif- ferences with more aggressive behavior and poorer visual prognosis commonly seen in older patients. 1 In the present study, five out of six patients (83%) may be reckoned as younger age group with presumably better visual and angiographic outcomes with or even without any treat- ment. 1 Moreover, subfoveal CNV with feeder vessels or fibrovascular stalks located at juxtafoveal or extrafoveal areas are known to have a better prognosis. 2 These poten- tial sources of selection bias may lead to more favorable outcome observed with the new treatment modality. Second, dye-enhanced photo thrombosis using a lower dose of laser energy has been shown experimentally to dissipate less thermal energy into surrounding retinal pigment epithelium and neurosensory retina. 3 Neverthe- less, it should be noted that total laser energy and the laser irradiance delivered in the present study were 96 times and 50 times more than those offered by photodynamic therapy (PDT) using verteporfin. 5 Even the low energy level used in PDT is not without undesirable consequences and occasional retinal pigment epithelium damages have been reported. 4 This higher than expected amount of energy may actually account for the “blanching” phenomenon of the CNV complex observed during laser application and the post-procedure hypo fluorescence seen in ICG angiog- raphy. Accordingly, the treated areas are prone to develop atrophic scars with late-onset scar creeping, frequently compromising long term visual function in the second year after treatment. 5 We are so eager to learn the long term visual outcomes for those patients. Third, ICG has only 4% fluorescence efficacy of sodium fluorescein. 6 Therefore, it may not precisely discern feeder vessels of myopic CNV that are usually predominantly classic, small in size, and frequently encroached by thick layer of hyperplastic retinal pigment epithelium. More- over, the authors have adopted conventional ICG fundus camera instead of dynamic videoangiography and scanning laser ophthalmoscopes. We are interested to know about the sensitivity of their described method in picking up the feeder vessels and how many patients have been excluded from the study because of undetermined feeder vessels. This piece of information is crucial in evaluating the effectiveness of any new treatment modality. DAVID T.L. LIU, MRCS DENNIS S. C. LAM, FRCS, FRCOPHTH WAI-MAN CHAN, MRCP, FRCS Kowloon, Hong Kong REFERENCES 1. Yoshida T, Ohno-Matsui K, Ohtake Y, et al. Long-term visual prognosis of choroidal neovascularization in high myopia: a comparison between age groups. Ophthalmol 2002;109:712– 719. 2. Chan WM, Lam DSC, Wong TH, et al. Photodynamic therapy with verteporfin for subfoveal idiopathic choroidal neovascularization - one-year result from a prospective case series. Ophthalmology 2003; Forthcoming. 3. Flower RW. Experimental studies of indocyanine green dye- enhanced photocoagulation of choroidal neovascularization feeder vessels. Am J Ophthalmol 2000;129:501–512. 4. Treatment of age-related macular degeneration with photody- namic therapy (TAP) study group. Photodynamic therapy of subfoveal choroidal neovascularization in age-related macular degeneration with verteporfin. Arch Ophthalmol 1999;117: 1329 –1345. 5. Ruiz-Moreno JM, Montero JA. Long-term visual acuity after argon green laser photocoagulation of juxtafoveal choroidal neovascularization in highly myopic eyes. Eur J Ophthalmol 2002;12:117–122. 6. Hayashi K, Hasegawa Y, Tokoro T. Indocyanine green angiog- raphy of central serous chorioretinopathy. Int Ophthalmol 1986;9:37–41. AUTHOR REPLY WE THANK DR. LIU AND ASSOCIATES FOR THEIR INSIGHT- ful comments about our article on neovascular ingrowth site photothrombosis as an alternative new treatment for © 2004 BY ELSEVIER INC.ALL RIGHTS RESERVED. 0002-9394/04/$30.00 383