Grading is done according to a special grading system to evaluate photographs of the posterior pole and visual axis of the treated and control eyes at 3 months and 12 months after entry and randomization. This grading system has been specially developed for this study but elements of it correspond to the Reese Classification. The major features of the grading system are directly related to the final endpoints which will decrease visual acuity.
| Watzke, R C; Robertson Jr, J E; Palmer, E A et al. (1990) Photographic grading in the retinopathy of prematurity cryotherapy trial. Arch Ophthalmol 108:950-5 |
