Response to: “Morphologic and functional glaucomatous change after occurrence of single or recurrent optic disc haemorrhages”

Abstract

Dear Editor:We read with interest the comments by Dr. Laemmer and colleagues regarding our recent article "Recurrent optic disc hemorrhage does not increase the rate of visual field progression" [1]. It is gratifying to know that their study confirmed our results, and that they could not detect any difference in the rate of visual field progression between eyes with a single detected disc hemorrhage and eyes with recurrent disc hemorrhage.We would like to clarify several points raised by Dr. Laemmer et al. There are significant differences in methodologies between our two studies. We used a trend-based approach to investigate visual field progression to provide an objective measure of the velocity of progression, rather than the binary categorization into stable versus progressive eyes that is determined when using an event-based approach. Trend-analysis may be a more significant and useful tool for differentiating rapidly from slowly progressing eyes [2,3], which may help tailor clinical management more objectively and, therefore, effectively.We look forward to learning more about their study after peer review and publication. The sample size described in their letter is relatively small (n=60) and may not have sufficient statistical power to confirm or refute any differences between groups. Additional important missing information includes the precise methodology for disc assessment and masking of examiners to disc and field results. The number of patients remaining in each group at each year of follow-up will greatly impact the survival curves and whether they are, in fact, statistically different.