Impact of tamponade agent on retinal displacement following pars plana vitrectomy for rhegmatogenous retinal detachment repair: a computer simulation model

• Published in: Acta ophthalmologica (Oxford, England) Vol. 100; no. 7; pp. e1470 - e1478
• Main Authors: Farahvash, Armin, Marafon, Samara B., Juncal, Verena R., Figueiredo, Natalia, Ramachandran, Arun, Muni, Rajeev H.
• Format: Journal Article
• Language: English
• Published: England Wiley Subscription Services, Inc 01-11-2022
• Subjects: Computer simulation; Contact angle; gas tamponade; pars plana vitrectomy; Pressure; Retina; Retinal detachment; retinal displacement; silicone oil; Silicones; Tamponade; pars plana vitrectomy; silicone oil; retinal detachment; retinal displacement; gas tamponade
• ISSN: 1755-375X; 1755-3768
• DOI: 10.1111/aos.15118

Purpose
Rhegmatogenous retinal detachment (RRD) repair with silicone oil (SO) tamponade has been observed to cause less retinal displacement than gas tamponade. Here, we assessed the mechanism and theoretical extent of retinal displacement in SO versus air tamponade in pars plana vitrectomy (PPV).
Design
Computer simulation model.
Methods
Tamponade scale and subretinal scale simulation models previously developed were used to assess the physical forces, fluid dynamics and retinal deformations in SO versus air PPV.
Results
When comparing a SO tamponade and an air tamponade occupying 93% of the ocular cavity, the SO tamponade has a Bond number that is an order of magnitude smaller and has a much lower contact angle (99° versus 125°) and contact pressure (0.0230 versus 1.44 mmHg). With a greater contact area and contact pressure, an air tamponade squeezes subretinal fluid away from contact points, displacing the retina by a maximum length of approximately 700 μm in our model. In contrast, for a SO tamponade, the contact pressure is much lower with a very small magnitude of retinal displacement (~ 50 μm).
Conclusions
We showed that SO tamponade leads to significantly less retinal displacement than air tamponades. Although we do not recommend the routine use of primary SO because of its several disadvantages compared with gas, our findings can be further utilized to develop novel tamponade agents that minimize the risk of retinal displacement following RRD repair.