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 andcolleagues regarding our recent article “Recurrent optic dischemorrhage does not increase the rate of visual fieldprogression” [1]. It is gratifying to know that their studyconfirmed our results, and that they could not detect anydifference in the rate of visual field progression betweeneyes with a single detected disc hemorrhage and eyes withrecurrent disc hemorrhage.We would like to clarify several points raised byDr. Laemmer et al. There are significant differences inmethodologies between our two studies. We used atrend-based approach to investigate visual field pro-gression to provide an objective measure of thevelocity of progression, rather than the binary catego-rization into stable versus progressive eyes that isdetermined when using an event-based approach.Trend-analysis may be a more significant and usefultool for differentiating rapidly from slowly progressingeyes [2, 3], which may help tailor clinical managementmore objectively and, therefore, effectively.We look forward to learning more about their study afterpeerreviewandpublication.Thesamplesizedescribedintheirletter is relatively small (n=60) and may not have sufficientstatistical power to confirm or refute any differences betweengroups. Additional important missing information includesthe precise methodology for disc assessment and masking ofexaminers to disc and field results. The number of patientsremaining in each group at each year of follow-up willgreatly impact the survival curves and whether they are, infact, statistically different.