Tamponades act as barriers to prevent fluid passage between the vitreous cavity and the subretinal space. Once adhesion between the retina and the retinal pigment epithelium (RPE) is established, this barrier is no longer needed. Gas tamponade agents, after a complete gas-fluid exchange, resorb spontaneously over different periods: air in 5–7 days, 20% SF6 in about 2 weeks, and 14% C3F8 in about 8 weeks. Unlike gases, silicone oils are permanent until surgically removed. Air and gases have higher surface tension and buoyancy than silicone oils, with the tension exerted by air or gas being approximately 30 times greater than silicone oil [5, 6].
Retina-RPE adhesion occurs theoretically within 24hours without subretinal fluid (SRF) [7]. Thus, the effectiveness of tamponade agents in closing retinal breaks is most critical within the first 24 hours post-surgery. Residual SRF around tears can interfere with adhesion. For superior tears, gravity helps isolate the tears from SRF, making long-acting tamponade excessive. Conversely, short-acting gases like air might be inappropriate for inferior breaks [8]. However, studies have shown that air can be as effective as long-lasting gases for inferior breaks [9, 10, 3, 11–14], given adequate SRF drainage [15].
Our SRF drainage technique includes thorough vitreous base shaving and around breaks, filling the eye with PFCL to push away SRF, and passive drainage through retinal tears. Drainage through a posterior retinotomy is avoided due to potential complications like PVR.
In a prospective series of 15 patients, Martínez-Castillo’s group first reported that PPV with air tamponade effectively managed pseudophakic RRDs with inferior breaks without postoperative facedown positioning [10, 15]. Singh et al. described 236 eyes treated for primary RD: one third receive SF6 gas tamponade and the others air tamponade. The authors demonstrated air's safety in treating RRDs with a success rate of 88.5% for superior, inferior, and multiple breaks [16]. Although our study did not include a gas tamponade control group, our data confirm the overall reported results in terms of retinal reattachment. We did not find any association between surgical failure and the number of quadrants involved in the RD, contrary to what was reported by Chuandi Zhou et al., although this association was independent of the choice of air or gas [9]Taken together, the reports above confirmed our results and suggest that air tamponade is generally adequate for both superior and inferior retinal detachments and is, at least, as effective as long-lasting gas tamponade, especially if complete removal of vitreous traction, aspiration of SRF, and sealing of all retinal breaks are routinely performed.
In addition, the use of SF6 and other fluorinated gases in RRD surgery poses significant environmental risks due to their high global warming potential. These gases are extremely stable and can persist in the atmosphere for thousands of years, thereby contributing to long-term climate change. Although the release of these gases during medical procedures is minimal compared to other industrial uses, it still adds to the overall environmental burden. In a retrospective analysis of 3,239 eyes treated for RRD, Moussa et al. evaluated the mass of gas used per operation and its CO2 equivalent across three different gas delivery systems (SF6, C2F6, and C3F8). Their study provides real-world data on the environmental impact of fluorinated gases and air tamponade in the management of RRDs, highlighting the potential benefits of utilizing air in the majority of cases to reduce the carbon footprint of vitreoretinal surgery [17].
Moreover, several cases of complications related to mistakes in the correct dilution of gas to achieve an isovolemic concentration have been reported recently at scientific conferences.
We also investigated the role of VCRs in influencing the outcomes of PPV and air tamponade for primary RRD. Several authors have suggested that VCRs, which can occur as a consequence of PVD with vitreoschisis [3], may contribute to PVR membrane formation, critical in retinal redetachment [2]. Sebag’s theories distinguish between full-thickness PVD, which does not involve VCRs, and partial-thickness PVD, which includes vitreoschisis with VCRs [3]. Van Overdam expanded on these theories by noting that anomalous PVD with vitreoschisis can result in VCRs over the retina, which can act as a scaffold for fibrocellular proliferation. In such cases, RPE cells from retinal tears and hyalocytes in VCRs, along with other known PVR risk factors, can combine to form PVR membranes [2]. Triamcinolone staining is used to reveal VCRs, which are often underestimated when not routinely used [2]. Van Overdam conducted a pilot study comparing two cohorts of patients who underwent PPV for RRD in 2016 and 2018. The 2018 group, which had more extensive triamcinolone staining and consequent VCR removal, showed a lower rate of RD relapse [18]. Recently, Rizzo et al. described a series of eyes that underwent PPV for RRD, with the presence of VCRs confirmed intraoperatively using triamcinolone acetonide (TA), observing that the presence of VCRs is associated with a higher incidence of PVR development [19].
In our study, we didn’t observe any significant association between VCR removal and RRD recurrence. A possible explanation could be that cases with a potential high risk of PVR were excluded from the study, having generally been operated using long-lasting tamponade. For this reason, we do not feel that TA staining and VCR removal are completely irrelevant for anatomical success: in fact, our surgical experience suggests that VCR presence is a relatively frequent finding in eyes treated for RRD recurrence with PVR development. However, VCR removal can sometimes be extremely time-consuming and does not represent a completely riskless procedure: iatrogenic retinal breaks can occur, and this can be a problem especially in case of posterior breaks due to their potential in PVR promoting.
In addition to RD relapse, other possible postoperative complications are represented by IOP rising, cataract development, macular edema, and retinal displacement. No differences in IOP rising between air and long-acting expansile gas were previously found, even if the air group had a lower IOP on the first postoperative day [9]. Another study reported about 11% of cases of early IOP rising (within 3 days after PPV and air tamponade), normalized by using anti-glaucoma medication within 3 days [20]. We reported similar results and no further surgeries for IOP rising were required.
Macular edema after RRD repair is believed to stem from subclinical low-grade inflammation that breaks down the blood-aqueous barrier [21]. Anti-inflammatory agents like corticosteroids and NSAIDs have been succesfully used for treatment [22, 23]. Chatziralli reported a 16.3% CME rate post-PPV for RRD [24]. Our previous study showed a 6.5% CME rate post-PPV with air tamponade, and this larger series observed an 8% rate [4]. No significant association was found between CME and any variables, including combined phacoemulsification. Discrepancies may be due to different sample sizes and exclusion of patients with preoperative PVR and long-standing RRD.
Retinal displacement is reported in about a third of RRD cases treated with PPV. Blue fundus autofluorescence identifies retinal displacement via lines of increased autofluorescence, which closely reflect the adjacent retinal vessels that occur in metamorphopsia and vertical diplopia [25]. Given the retrospective nature of our study, blue fundus autofluorescence images could not be acquired for all patients, and so it was not possible for us to describe the retinal displacement prevalence in our cohort.In conclusion, our data suggest that air represents a safe and effective tamponade for primary RRD treatment and is adequate for both superior and inferior retinal breaks. Accurate traction release through a complete vitreous base shaving and as complete as possible SRF drainage represent the key elements for a successful RRD surgical repair. A faster tamponade resorption compared to long-standing gas is associated with lower visual disturbance, quicker normal lifestyle recovery, and probably a lower inflammation grade without any impact on the environement.
VCR removal does not seem to affect anatomical results, even if its role should be better investigated, especially in cases with a higher PVR risk. A prospective randomized study on large multicentric series would likely clarify these aspects.