Polypoidal choroidal vasculopathy and treatments

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Th e size of the lesion seems to infl uence the reversal pattern. Th e lesions that are less than 0.5-disk diameter in size appear to have intense uniform fl uorescence, whereas internal details seem to be visible in larger polypoidal structures. Th ese fi ndings, in turn, suggest presence of an internal architecture. In the very late stages of ICG, the dye disappears from the lesions thus defi ning a phenomenon termed “washout”. Th e “washout” is only seen in non-leaking lesions; the leaking polypoidal lesions remain hyperfl uorescent throughout the late phases of the angiogram. Varying degrees of hypopigmentation of the RPE overlying an area involved in the disease process may enhance visualization of the abnormal vessels; yet, the late ICG staining results from the intrinsic characteristics of the lesion rather than the RPE alterations.

Differential Diagnosis8,9

Wet AMD: - Vascular proliferative changes associated with non-polypoidal type of CNV tend to produce small caliber vessels that are associated with a “dirty gray membrane” or a grayish discoloration of the overlying retina. On the contrary, the patients with vascular changes typical of PCV form a network of vessels ending with saccular polypoidal lesions that are red to orange in color and evident with slit-lamp biomicroscopy unless they are camoufl aged by overlying exudate or blood. Both fl uorescein and ICG angiography can be used to distinguish the two types of vascular abnormalities. In both of these studies, CNV is characterized by diff use late staining plaque. PCV is demonstrated by ICG angiography as a prominent vascular network in the early stages of the study and an area of clearing or so called “washout” of the dye in the late stage. Th e late phase of PCV is also distinguished by a characteristically appearing outline of the non-leaking large choroidal vessels. If the vessels are leaking, there

Photocoagulation10

Initially, laser photocoagulation was used in the treatment of polypoidal lesions. Photocoagulation is recommended only if the lesion is extrafoveal & if it is feasible to treat the entire polypoidal lesion.

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Anti-angiogenic drugs do not appear to work adequately as monotherapy, nor does PDT.

Th e current treatment regimen includes PDT followed by three intravitreal injections of ranibizumab. Th e patient is reassessed monthly with OCT & 6 monthly with ICGA. If polyps are found, even not active, reinjection of ranibizumab is recommended.

14. Kusashige Y, Otani A, Sasahara M, et al. Two-year results of photodynamic therapy for polypoidal choroidal vasculopathy. Am J Ophthalmol. 2008;146(4):513—9.

15. Otani A, Sasahara M, Yodoi Y, et al. Indocyanine green angiography: guided photodynamic therapy for polypoidal choroidal vasculopathy. Am J Ophthalmol. 2007; 144(1):7—14.