Indian Journal of Ophthalmology

LETTERS TO THE EDITOR
Year
: 2019  |  Volume : 67  |  Issue : 10  |  Page : 1783-

Comment on: 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


Upma Awasthi, Rohini Grover, Chetan Videkar, Abhishek Varshney 
 Department of Vitreoretina, C L Gupta Eye Institute, Moradabad, Uttar Pradesh, India

Correspondence Address:
Dr. Upma Awasthi
C L Gupta Eye Institute, Ram Ganga Vihar Phase 2 (Ext.), Moradabad - 244 001, Uttar Pradesh
India




How to cite this article:
Awasthi U, Grover R, Videkar C, Varshney A. Comment on: 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;67:1783-1783


How to cite this URL:
Awasthi U, Grover R, Videkar C, Varshney A. Comment on: 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 2024 Mar 28 ];67:1783-1783
Available from: https://journals.lww.com/ijo/pages/default.aspx/text.asp?2019/67/10/1783/267392


Full Text



Sir,

We read the article by Neudorfer et al.[1] with great interest. However, we would like to comment upon few points. 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.

MIVI-TRUST study has shown that intravitreal saline injection can also lead to PVD induction in 10.1% of patients.[2] 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.[3] 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 number of injections.[4] It would have been better if authors also have analyzed this as a separate group.

[Figure 4]a shows change in CRT in both groups with time but authors have not mentioned whether increase in CRT from 6 months to 12 month was significant or not. Also the possible reasons for this increase would have been discussed. There is also discrepancy in the graph and its description; PVD- group has lower CRT at 12 months and similar MRT values as compared to PVD+ group. 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.[5]

The authors have stated that 37 patients were required for the power of 80% but this amount 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.

It would have been better for our understanding if authors have shared the sequential OCT raster scans.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

References

1Neudorfer M, Fuhrer AE, Zur D, Barak A. 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 2018;66:1802-7.
2Stalmans P, Benz MS, Gandorfer A, Kampik A, Girach A, Pakola S, et al. Enzymatic vitreolysis with ocriplasmin for vitreomacular traction and macular holes. N Engl J Med 2012;16;367:606-15.
3Mirshahi A, Höhn F, Lorenz K, Hattenbach LO. Incidence of posterior vitreous detachment after cataract surgery. J Cataract Refract Surg 2009;35:987-91.
4Sponer UM, Waldstein SM, Kundi M, Ritter M, Golbaz I, Heiling U, et al. Influence of the vitreomacular interface on outcomes of ranibizumab therapy in neovascular age related macular degeneration. Ophthalmology 2013;120:2620-9.
5Liu YL, Lin CP, Yang CM. Transient regression of choroidal neovascularization membrane after vitrectomy in age-related macular degeneration with vitreomacular traction syndrome. Acta Ophthalmol 2011;89:e291-3.