Microplasmin before Vitrectomy

Abstract

We read with interest the article by Benz et al.1Benz M.S. Packo K.H. Gonzalez V. et al.A placebo-controlled trial of microplasmin intravitreous injection to facilitate posterior vitreous detachment before vitrectomy.Ophthalmology. 2010; 117: 791-797Abstract Full Text Full Text PDF PubMed Scopus (107) Google Scholar We would like to congratulate the authors for describing a novel method of posterior vitreous detachment (PVD) induction. However, we would like to make a few observations. 1The authors mention the use of 3 different doses of microplasmin. The results show a continued improvement of PVD induction with dose escalation without any noted side effects. The rate of total PVD at the time of surgery increased significantly from 18% in the 75 μg group to 31% in the 125 μg group, which was the highest dose studied. It would be worthwhile testing further higher doses until a therapeutic ceiling is achieved in order to determine the maximal efficacious and safe dose.2The inclusion criteria consist of cases without evidence of a complete macular PVD on clinical, as well as on optical coherence tomography and ultrasound examination. But 36 of 54 patients with a macular hole had stage 3 and 4 macular hole, and stage 4 macular hole by definition would have a macular PVD.3The authors mention about the secondary end point in terms of PVD progression. Though there is a reference of Table 3 in the text, there is no description of the said secondary end point in the Table.It would be useful for the readers if the authors clarify these doubts We read with interest the article by Benz et al.1Benz M.S. Packo K.H. Gonzalez V. et al.A placebo-controlled trial of microplasmin intravitreous injection to facilitate posterior vitreous detachment before vitrectomy.Ophthalmology. 2010; 117: 791-797Abstract Full Text Full Text PDF PubMed Scopus (107) Google Scholar We would like to congratulate the authors for describing a novel method of posterior vitreous detachment (PVD) induction. However, we would like to make a few observations. 1The authors mention the use of 3 different doses of microplasmin. The results show a continued improvement of PVD induction with dose escalation without any noted side effects. The rate of total PVD at the time of surgery increased significantly from 18% in the 75 μg group to 31% in the 125 μg group, which was the highest dose studied. It would be worthwhile testing further higher doses until a therapeutic ceiling is achieved in order to determine the maximal efficacious and safe dose.2The inclusion criteria consist of cases without evidence of a complete macular PVD on clinical, as well as on optical coherence tomography and ultrasound examination. But 36 of 54 patients with a macular hole had stage 3 and 4 macular hole, and stage 4 macular hole by definition would have a macular PVD.3The authors mention about the secondary end point in terms of PVD progression. Though there is a reference of Table 3 in the text, there is no description of the said secondary end point in the Table. It would be useful for the readers if the authors clarify these doubts A Placebo-Controlled Trial of Microplasmin Intravitreous Injection to Facilitate Posterior Vitreous Detachment before VitrectomyOphthalmologyVol. 117Issue 4PreviewTo evaluate the safety and efficacy of a preoperative intravitreous injection of microplasmin in patients scheduled for vitreous surgery. Full-Text PDF Author replyOphthalmologyVol. 118Issue 2PreviewWe appreciate the interest in our paper from Drs. Narayanan and Dave.1 They bring up 3 separate points needing clarification. With respect to the first point, a separate previous clinical trial found no additional benefit when increasing the dose of microplasmin to 175 μg.2 The optimal dose was determined to be 125 μg, and that is the dose that has undergone further testing in this and in subsequent clinical trials. With respect to the second point, there were a very small number of macular holes enrolled in this trial that were classified by the individual investigator as stage IV, using the Gass classification. Full-Text PDF