Reply to Grzybowski and Ascaso

Abstract

Sir, We thank Drs Grzybowski and Ascaso1 for their interest in and comments on our recent article.2 We agree that in our paper there is a lack of details concerning the statistical tests used (which were omitted for the sake of brevity). In the study, we proved that each variable group was normally distributed using the Kolmogorov-Smirnov normality test. Then we applied the ANOVA for repeated measures test, which best fitted for our analysis. Please note, the Kruskal-Wallis test is valuable only for a two-group comparison. We also agree that the lack of a control group is crucial, and this was acknowledged as a limitation of our study. We also acknowledged the unmasked design of the study as a limitation of our analysis. Regarding the evaluation of posterior hyaloid peeling, our method to describe the intrasurgical findings has been already published by Azzolini et al3 in a study investigating autologous plasmin enzyme for diabetic macular oedema, and, to our knowledge, no other classification systems are available in the literature. In the conclusion section, we stated that a single intravitreal autologous plasmin enzyme injection seemed to be insufficient to induce a complete posterior vitreous detachment in patients affected by focal vitreomacular traction syndrome, as in our case series, we did not obtain any complete posterior vitreous detachment with a single injection. We thank the authors for the opportunity to clarify this important aspect, which we do not find contradictory. As per our ethical committee approved protocol (reported in the Methods section), we were allowed to perform just one single intravitreal injection for each study patient, with a 24-hour waiting time before vitrectomy. Although we could not ascertain if a greater time gap could have influenced the rate of posterior vitreous detachment occurrence, we remarked that the single injection appeared as a useful tool in vitreoretinal surgery by obtaining an easier-to-peel posterior hyaloid. Finally, during the revision process of our paper, we preferred to exclude the comparison of our results with the MIVI-IIT study,4 as the MIVI-IIT study has a very different study design and uses a different drug. Particularly, we believe that our impossibility (per protocol) to re-inject patients preclude any comparison between the two studies.