We read with great interest the article by Lee and associates entitled “Microvascular changes on optical coherence tomography angiography after rhegmatogenous retinal detachment vitrectomy with silicone tamponade” [1]. We thank the authors for their remarkable work on silicone oil (SO) tamponade adverse effects, as it is a concerning topic in retinal detachment (RD) surgery and very few studies on this subject are available in the literature.
Forty-eight eyes operated on for RD with SO tamponade were included. Optical coherence tomography – angiography (OCT-A) measurements of vascular density (VD) and foveal avascular zone (FAZ) area in the superficial capillary plexus (SCP) and deep capillary plexus (DCP) were reported 3 months after SO removal. These data were compared to patients’ healthy fellow eyes. Results showed a lower VD in the DCP compared to control eyes (p=0.026), which was not the case in the SCP (p=0.504). Only VD of the nasal area of SCP was significantly lower compared to controls (p=0.028). FAZ areas in the SCP and DCP were both significantly larger in cases than controls (p=0.043 and p=0.002, respectively).

One recent study from Dormegny and associates reported vascular changes after SO removal in 43 eyes operated on for RD [2]. OCT-A was performed at least 3 months after SO removal. Measurements were compared with patients’ healthy fellow eyes. VD in the DCP and deep FAZ area were similar in operated and non-operated eyes (p>0.05). VD in the SCP was significantly higher in operated eyes compared to patients’ healthy fellow eyes (p=0.047) and superficial FAZ area was significantly smaller (p<0.0001). These results differ from Lee and associates’ ones, and it would be of great interest to discuss on these discrepancies.
We believe that the performance of peripheral retinectomy in many eyes from Dormegny and associates’ study (n=14) might have provoked some retinal vascular remodeling and could explain the above results. Could Lee and associates indicate if they also performed retinectomy in their operated eyes and what do they think about the possibility that this parameter might have led to diverging results between the two studies?
Finally, in Dormegny and associates’ study, twenty-five eyes developed macular cysts during the follow-up. In those eyes, VD in the DCP negatively correlated with MC area (p<0.001). Macular cysts were mostly located in the inner nuclear layer (60%). Retrograde maculopathy, with probable damage of retinal ganglion cells and degeneration of the Muller cells, was incriminated by the authors [3]. These damages could have resulted in impaired fluid absorption and retinal remodeling after SO removal, including decreased VD in the DCP. Did Lee and associates observe any macular cysts in their operated eyes and were these cysts located in the inner nuclear layer? Indeed, we believe that this parameter could explain the results obtained by Lee and associates in the DCP.


REFERENCES

1. Lee JH, Park YG. Microvascular changes on optical coherence tomography angiography after rhegmatogenous retinal detachment vitrectomy with silicone tamponade. PLoS One. 2021;16(3):e0248433. Epub 2021/03/13. doi: 10.1371/journal.pone.0248433. PubMed PMID: 33711059; PubMed Central PMCID: PMCPMC7954302.
2. Dormegny L, Jeanjean LC, Liu X, Messerlin A, Bourcier T, Sauer A, et al. Visual Impairment and Macular Vascular Remodeling Secondary to Retrograde Maculopathy in Retinal Detachment Treated with Silicon Oil Tamponade. Retina. 2021;41(2):309-16. Epub 2020/05/15. doi: 10.1097/IAE.0000000000002812. PubMed PMID: 32404843.
3. Abegg M, Dysli M, Wolf S, Kowal J, Dufour P, Zinkernagel M. Microcystic macular edema: retrograde maculopathy caused by optic neuropathy. Ophthalmology. 2014;121(1):142-9. doi: 10.1016/j.ophtha.2013.08.045. PubMed PMID: 24139122.