TABLE 5.

GRADING SCHEME OF PHOTODYNAMIC THERAPY EFFECT ON RETINA AND CHOROID

GRADE	DAMAGED RETINAL/CHOROIDAL LAYERS
1	RPE only or RPE + slight photoreceptor changes + occasional pyknosis in the ONL; with or without choriocapillaris damage
2	Choriocapillaris closure + RPE + photoreceptors + 10%–20% pyknosis in the ONL
3	Choriocapillaris closure + RPE + photoreceptors + ONL pyknosis <50%
4	Choriocapillaris closure + RPE + photoreceptors + ONL pyknosis >50%
5	Choriocapillaris closure + RPE + photoreceptors + ONL pyknosis >50% + choroidal vessel damage or retinal vessel or inner retinal damage

ONL, outer nuclear layer; RPE, retinal pigment epithelium.

Adapted from Kramer M et al.⁸