¡¡¡¡DISCUSSION

¡¡¡¡Transpupillary thermotherapy for ageª²related macular degeneration was introduced by Reichel et al[6].Since that time, several laser surgeons have also investigated its utility in the treatment of primarily occult choroidal neovascularization [11ª²14]. While none of these studies was a randomized controlled trial, the general results of these studies indicate that TTT treatment appears to be associated with the stabilization of visual acuity Figure1 Macular nonª²perfusion immediately after TTT¡¡at six to nine months in about 2/3 to 3/4 of the cases with reduction of subretinal fluid. A pilot study by Reichel and colleagues using TTT for occult CNV has shown stabilization of vision in this group [6]. Sixteen eyes of 15 patients with occult CNV were treated with TTT and followed for 6 to 25 months. This study showed that vision improved or stabilized in 75% of eyes and subretinal fluid decreased in 94% of eyes. Another study by Newsom and colleagues studied the effect of TTT on 32 eyes with occult CNV followed for a mean of 7.2 months [10]. Stabilization or improvement of vision was obtained in 72% and reduction of exudation in 78% of the eyes. Kim and colleagues[12] evaluated the efficacy of TTT in 48 eyes with occult CNV. Visual acuity was stable or improved in 62.5% and subretinal fluid reduced in 61% of the eyes in their study. The prospective study on predominantly occult subfoveal CNV done by Algvere and colleagues [15] indicated that, visual acuity could be stabilized or improved by TTT in 74% of patients at 6ª²month followª²up. The results of our study on classic and predominantly classic CNV indicate that TTT effectively stabilizes CNV process in the long term. The majority of the patients treated with TTT maintained or gained visual acuity (93%).

¡¡¡¡Patients with classic CNV in our trial had average 1.4 treatments in 28.6 months compared with 2.3 treatments in 28 months for 10 patients with classic CNV in Newsom and colleagues¬ð study [16]. Twentyª²eight patients with occult, classic and mixed CNV in Agarwal et al ¬ðs study, had an average of 1.86 treatments in 15.3 months [17].

¡¡¡¡Several complications have been reported following TTT for uveal tumors, including branch retinal vein and artery occlusions and retinal and choroidal hemorrhage. However, low power settings used in TTT for CNV have meant that complications are rare and patient tolerance is good. TTT treatment has been well tolerated in the initial series of reports [4ª²6]. One eye in our study had a unique complication of macular nonª²perfusion immediately after treatment. The patient noted an immediate drop in vision with the clinical findings of retinal whitening and attenuation of the perifoveal retinal arteriols. A similar complication was observed in one of the 81 eyes treated with TTT in Ahuja et al ¬ðs study [11]. Their patient had preª²existing areas of geographic RPE atrophy in the macular region adjacent to the zone of treatment, which could have diminished the heat sink role of the choroid and potentiated the hyperthermic effect. We did not observe a similar finding in our patient.

¡¡¡¡In this study the 28ª²month results for patients treated with TTT for classic and predominantly classic CNV show good visual stability with little visual loss and few complications.

¡¡¡¡¡¾²Î¿¼ÎÄÏס¿

¡¡¡¡1 Macular Photocoagulation Study Group. Argon laser photocoagulation for neovascular maculopathy: five year results from randomized clinical trials. Arch Ophthalmol1991;109:1109ª²1114

¡¡¡¡2 Zhang X, Ren BC. Recent advance of the study on treatment for ageª²related macular degeneration. Int J Ophthalmol(Guoji Yanke Zazhi)2007;7(6):1674ª²1676

¡¡¡¡3 Macular Photocoagulation Study Group. Laser photocoagulation for juxtafoveal choroidal neovascularization: five year results from randomized clinical trials. Arch Ophthalmol1994;112:500ª²509

¡¡¡¡4 Macular Photocoagulation Study Group. Laser photocoagulation of subfoveal neovascular lesions in ageª²related macular degeneration: results of a randomized clinical trial. Arch Ophthalmol1991;109:1220ª²1231

¡¡¡¡5 Li WS, Zhao XY, Jiang DY. Transpupillary thermotherapy for ageª²related macular degeneration. Int J Ophthalmol(Guoji Yanke Zazhi)2002;2(4):24ª²27

¡¡¡¡6 Reichel E, Berrocal AM, Ip M, Kroll AJ, Desai V, Duker JS, Puliafito CA. Transpupillary thermotherapy of occult subfoveal choroidal neovascularization in patients with ageª²related macular degeneration. Ophthalmology 1999;106:1908ª²1914

¡¡¡¡7 Millerª²Rivero NE, Kaplan HJ. Transpupillary thermotherapy in the treatment of occult and classic choroidal neovascularization. Invest Ophthalmol Vis Sci2000;41:179

¡¡¡¡8 Petrone S, Staurenghi G, Migliavacca L, Ottochian M, Orzalesi N. Transpupillary thermotherapy for subfoveal choroidal neovascularization in ageª²related macular degeneration. Invest Ophthalmol Vis Sci2000;41:320

¡¡¡¡9 Fu T, Zhang P, Hu D, Bai JW, Hui YN. Transpupillary thermotherapy for occult choroidal neovascularization. Int J Ophthalmol
(Guoji Yanke Zazhi)2007;7(6):1636ª²1638

¡¡¡¡10 Newsom RS, McAlister JS, Saeed M, McHugh JD. Transpupillary thermotherapy (TTT) for the treatment of choroidal neovascuª²larization. Br J Ophthalmol2001;85:173ª²178

¡¡¡¡11 Ahuja RM, Benner JD, Schwartz JC, Butler JW, Steidl SM. Efficacy of transpupillary thermotherapy (TTT) in the treatment of occult subfoveal choroidal neovascularization in ageª²related macular degeneration. Semin Ophthalmol2001;16(2):81ª²85

¡¡¡¡12 Kim JE, Perkins SL, Schwiesow T, Connor TB, Han DP. Transpupillary thermotherapy of occult choroidal neovascularization in ageª²related macular degeneration. Semin Ophthalmol2001;16(2):86ª²89

¡¡¡¡13 Fuisting BH, Richard G. Transpupillary thermotherapy (TTT) of occult choroidal neovascularization in ageª²related macular degeneration. Invest Ophthalmol Vis Sci2001;42:443

¡¡¡¡14 Auer C, Tran VT, Chiou AGY, Herbort CP. Transpupillary thermotherapy (TTT) for occult subretinal neovessels: importance of patient pigmentation in adjusting diode laser power setting. Invest Ophthalmol
Vis Sci 2001;42:442

¡¡¡¡15 Algvere PV, Libert C, Seregard S. Transpupillary thermotherapy of occult CNV with no or minimally classic CNV in ageª²related macular degeneration. Semin Ophthalmol2001;16(2):90ª²96

¡¡¡¡16 Newsom RS, McAlister JC, Saeed M, Elª²Ghonemy K, McHugh JD. Results 28 months following transpupillary thermotherapy for classic and occult choroidal neovascularization in patients with ageª²related macular degeneration. Ophthalmic Surg Lasers Imaging2005;36:94ª²102

¡¡¡¡17 Agarwal M, Shanmugam MP, Gopal L, Shetty N, Bhende M, Sharma T, Thakur S, Raman R, Nizamuddin SH, Moorthy KR. Transpupillary thermotherapy for choroidal neovascular membrane in ageª²related macular degeneration. Indian J Ophthalmol2004;52:45ª²49

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