Name

Effet de la durée de tamponnement par huile de silicone sur les modifications de structure rétinienne des patients opérés de décollement de rétine rhegmatogène

To investigate the effect of tamponade duration on retinal changes induced by silicone oil (SO) in patients who underwent successful rhegmatogenous retinal detachment (RRD) surgery.

Retrospective comparative case series of 68 patients who underwent pars plana vitrectomy with SO tamponade for RRD. Patients were divided into two groups based on timing of SO removal: < 6 months (group 1, n = 34) versus ≥ 6 months (group 2, n = 34). The main outcome measure was the change in central, inner and outer retinal layer thickness (CMT, IRLT and ORLT) before and after SO removal (SOR). Eyes with epiretinal membrane (ERM), cystoid macular edema (CME) or persistent subfoveolar fluid (PSF) were not considered for this analysis. Secondary outcomes were macular microstructural changes, complications and final visual acuity.

Both groups were comparable with respect to baseline RRD characteristics and intraoperative data, except for lens status (p = 0.015). The median tamponade duration was 4 [3; 5] months in group 1 and 8 [7; 9] months in group 2 (p < 0.001). The mean CMT significantly increased from 245.3 ± 22.2 μm and 238.8 ± 41.6 μm under SO to 281.3 ± 60.2 μm and 259.0 ± 43.5 μm after SOR in group 1 (p = 0.009) and in group 2 (p = 0.007), respectively. Automated segmentation measurement revealed a significant increase in mean IRLT (p = 0.014 and p = 0.013) but no change in mean ORLT (p = 0.080 and p = 0.257) in both groups. After adjusting for pre-SOR values, there was no difference between the two groups in terms of mean final CMT, IRLT and ORLT (p = 0.303, p = 0.381 and p = 0.500) and mean retinal thickness changes after SOR (p = 0.303, p =0.381 and p = 0.500). The rate of ERM, CME and PSF was not found to increase with a longer period of SO tamponade, at any time prior to or after SOR. There was also no correlation between the tamponade duration and postoperative photoreceptor damage or visual recovery.

Our analysis confirms that SO induces substantial structural changes in the retina, as evidenced by the significant increase in CMT after SOR in both groups. This is consistent with two recent studies which demonstrated that SO tamponade caused a transient thinning of central retinal layers that resolved following SO extraction. By contrast, some authors reported that SO durably affected the retinal thickness, especially in eyes with macula-on RRD, suggesting a deleterious effect on retinal anatomy. Our results show that the degree of retinal thinning under SO and thickness changes following SOR are not affected by longer tamponade (over 6 months). Interestingly, we noted that the retinal thickness values collected immediately after RRD surgery, when available, were comparable to those measured at the end of the follow-up, with no apparent difference between the two groups. 

SO tamponade causes a thinning of all retinal layers, mainly affecting the inner retinal layer. However, these changes resolved following SO extraction and were not affected by longer tamponade duration. The tamponade period also had no impact on the microstructural changes occurring before or after SOR and final visual acuity.