The effect of silicone oil tamponade on retinal layers and choroidal thickness in patients with rhegmatogenous retinal detachment: a systematic review and meta-analysis

Abstract

Background To evaluate the effects of intravitreal silicone oil (SO) on the retinal and choroidal thickness in eyes with rhegmatogenous retinal detachment (RRD). Methods A literature search was performed in Web of Science, Scopus, ProQuest, Embase, Clinical Key, Science Direct, Cochrane Library, and Springer, as well as Persian databases, including IranDoc, MagIran, SID, MOH thesis, and MOH articles until June 2020. Two reviewers independently searched and extracted the data. Results Sixteen studies (n = 391) met the inclusion criteria. The meta-analysis showed that the SO tamponade could significantly reduce the central macular thickness (CMT) in patients with RRD as compared to gas tamponade WMD = − 14.91; 95% CI: − 22.23, − 7.60; P < 0.001, I2 = 71%). No significant change was found in CMT between the eye with SO tamponade (after SO removal) and the fellow healthy eye in patients with RRD (WMD = − 3.52; 95% CI: − 17.63, 10.59; I2 = 68.6%). Compared to the preoperative stage, the SO tamponade could significantly reduce the subfoveal choroidal thickness in patients with RRD (WMD = − 18.67, 95% CI: − 30.07, − 1.28; I2 = 80.1%). However, there was no significant difference in the subfoveal choroidal thickness before and after SO removal (WMD = − 1.13, 95% CI: − 5.97, 3.71; I2 = 87.6%). Conclusion The SO tamponade had a significant effect on the reduction of retinal layers and the subfoveal choroidal thickness.

Impact of Silicone Oil Removal on Macular Perfusion

“…Our data on central retinal thickness changes were also in keeping with previous data, that have been reviewed by Ghanbari et al: While central macular thickness reduces due to SO filling after retinal detachment repair, this effect is reversible, and CRT increases after SO removal [5]. Our data support this as CRT increases significantly after SO removal in our cohort.…”

“…Central retinal thinning might be caused by various factors like mechanical stress on the inner retinal layers, inflammatory mechanisms, toxicity on the internal limiting membrane or hydrophobicity of the oil that alters the retinal environment. Luckily, these effects seem to be short term and reversible to a large extent and is dependent on the duration of SO filling [ 5 ].…”

“…Endotamponade with SO, as well as its removal from the vitreous cavity are known to impact retinal and choroidal microstructures [ 5 ]. Several studies with different methodological approaches attempted to examine vascular and perfusion alterations due to SO tamponade and its removal [ 6 , 7 , 8 ].…”

Anatomical and functional outcomes of short-term DensironXTRA heavy silicone oil for rhegmatogenous retinal detachments: a comparative case series

“…Our OCT imaging analysis showed that there is no evidence for central macular thinning with DensironXTRA compared to the contralateral eye without RRD as well as with DensironXTRA in situ versus after its removal. A meta-analysis conducted by Ghanabri et al suggested that retinal thinning occurs with silicone oil tamponade and that silicone oil is associated with a greater degree of thinning compared to gas tamponades 36 . There is conflicting evidence whether visual acuity is affected by retinal thinning 36 – 39 .…”

Macular Parameters Change during Silicon Oil Tamponade for Retinal Detachment Surgery

“…Retinal nerve fibre layers of the optic nerve head have also been described as prone to thinning during SO tamponade [ 8 ]. Changes have also been recorded in the choroid’s subfoveal region regarding its thickness reduction [ 9 ]. During silicon oil tamponade, perfusion is reduced in the macular area, and foveolar avascular zone (FAZ) extension occurs [ 10 ].…”