Indian Journal of Ophthalmology

LETTER TO THE EDITOR
Year
: 2019  |  Volume : 67  |  Issue : 10  |  Page : 1784-

Reply: The role of posterior vitreous detachment on the efficacy of anti–vascular endothelial growth factor intravitreal injection for treatment of neovascular age-related macular degeneration


Meira Neudorfer, Audelia E Fuhrer, Dinah Zur, Adiel Barak 
 Division of Ophthalmology, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel

Correspondence Address:
Dr. Meira Neudorfer
Division of Ophthalmology, Tel Aviv Sourasky Medical Center, 6 Weizman Street, Tel Aviv - 6423906
Israel




How to cite this article:
Neudorfer M, Fuhrer AE, Zur D, Barak A. Reply: The role of posterior vitreous detachment on the efficacy of anti–vascular endothelial growth factor intravitreal injection for treatment of neovascular age-related macular degeneration.Indian J Ophthalmol 2019;67:1784-1784


How to cite this URL:
Neudorfer M, Fuhrer AE, Zur D, Barak A. Reply: The role of posterior vitreous detachment on the efficacy of anti–vascular endothelial growth factor intravitreal injection for treatment of neovascular age-related macular degeneration. Indian J Ophthalmol [serial online] 2019 [cited 2019 Nov 20 ];67:1784-1784
Available from: http://www.ijo.in/text.asp?2019/67/10/1784/267372


Full Text



Sir,

This letter is in response to the letter by Awasthi et al. in which they note that “The authors have mentioned incomplete PVD as their exclusion criteria but patients with VMA on OCT were included in primary analysis as PVD+. This could have resulted in similar outcomes in both groups.”

Reply: Indeed, VMA is a misnomer: it refers to incomplete PVD and was indeed included in our group. This limitation was noted in the “Discussion” section.

Comment: “The authors have included patients with cataract surgery but have not mentioned time duration. A study by Mirshahi et al. reported 1 year incidence of PVD after cataract surgery as 58.6% with 82.4% within 1 month. A study by Sponer et al. termed the word RELEASE for the patients who developed PVD during the follow-up. They reported that RELEASE and VMA groups needed more injections. It would have been better if authors also have analyzed this as a separate group.”

Reply: We agree that such information is important, and we may in the future reanalyze our data to include the missing information. Currently, we do not have these data.

Comment: “In [Figure 4], CRT had increased in the PVD + group from 6 months to 12 months but no P value was given for the same. It would have been better if reasons would have been discussed. A study by Liu et al. has reported transient regression of CNVM after PPV and recurrence at 12 months. They postulated that vitrectomy may block pathogenic process at preretina level but cannot eliminate the existent, subretinal-level pathologic changes of RPE cells.”

Reply: The decrease of CRT from baseline to the 12-month endpoint was statistically significant for each group (the specifics are in the “Results” section). We did not delineate the complete within-group analyses since our focus was the between-group comparisons. Despite an upward trend of CRT between the 6- and 12-month follow-up among the PVD + eyes, the median CRT did not change significantly. Nonetheless, we believe it will be interesting to investigate this trend and test the mentioned hypothesis in a larger longitudinal study.

Comment: “The authors stated that 37 patients were required for the power of 80% but this number of patients should be in each group to keep this power. Therefore, the power of the study cannot be 80% with a subgroup analysis within 37 patients and, hence, the results should be interpreted with caution.”

Reply: According to the formal sample size calculation, a total of 34 patients with 17 patients in each arm were required. Due to the prospective nature of the study, we assumed a 10% dropout rate due to noncompliance and reported the final calculated recruitment requirements. Still, our sensitivity analysis including only a subset of patients was indeed underpowered to detect differences between the groups. We pointed out this limitation of the study in the “Discussion” section.

Comment: “It would have better for our understanding if authors have shared the sequential OCT raster scans.”

Reply: Indeed, it would have been interesting to present the raster scans of our patients. We did, however, present the progression in thickness map measurements in graphic form in the supplement section of the article.

Thank you once again for your comments on our study.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.