[Outcome of photodynamic therapy for subretinal neovascularization secondary to choroidal nevi]

Choroidal nevi are the most common benign intraocular tumors. However, the occurrence of subretinal neovascularization secondary to choroidal nevus is very rare. Our goal was to assess the efficacy and the safety of photodynamic therapy (PDT) for treatment of subretinal neovascularization related to choroidal nevi.

We conducted a retrospective study including subretinal neovascularization secondary to choroidal nevi treated by PDT from 1999 to 2005. PDT was performed according to the standard protocols used for treating neovascularization due to age-related macular degeneration (ARMD). Post-PDT follow-up was also done according to the guidelines used in ARMD. Moreover, tumors were followed up every 3 months.

Six subretinal neovascularizations secondary to choroidal nevi were included in our study. All nevi were localized in the posterior choroids. The median diameter of tumors was 3mm and their thickness was less than 2mm in all cases. Subretinal neovascularizations were classic in five cases. The last case was a small vascularized pigment epithelium detachment. Locations were subfoveal in two cases, juxtafoveal in three cases, and extrafoveal in one case. In half the cases, the size of subretinal neovascularization was 1-disk-diameter or less. A mean of 3.3 sessions of PDT were necessary to obtain the stabilization of subretinal neovascularization on both fluorescein angiography and OCT. The average follow-up period was 35 months with no patients lost to follow-up. Visual outcomes were extremely variable. Large or subfoveal neovascularization but also a history of atrophic ARMD were related to worse functional results. No growth of the nevi was observed.

Subretinal neovascularization is reassuring from the oncologist's point of view because it is considered a relative indicator of benignity of the nevus. However, it often marks a definitive turning point in visual function. PDT appears to be a safe and effective procedure for the treatment subretinal neovascularization secondary to choroidal nevus, with results similar to those observed in ARMD.