Interobserver Agreement in Clinical Grading of Vitreous Haze Using Alternative Grading Scales

Both scales are sufficiently reproducible using clinical grading for clinical and research use with the appropriate threshold (≥2- and ≥3-step differences for the 6- and 9-step scales, respectively). The results suggest that more eyes are likely to meet eligibility criteria for trials using the 9-step scale. The 9-step scale appears to have higher reproducibility with Reading Center grading than clinical grading, suggesting that Reading Center grading may be preferable for clinical trials.