Silicone Oil Tamponade Hydrostatics and Technology for Additional Mechanical Support of Retina
Silicone oil tamponade is widely used in the surgical treatment of retinal detachments. The article provides analysis of mechanical forces exerted to the retina in various parts of the vitreous cavity. There are areas of tamponade effect insufficiency, in which it may be beneficial to create additional means which would support the retina keeping it attached to the pigment epithelium.
The aim of the study was to develop a new technique desired to keep the retina attached in the areas where retina lacks effective tamponade effect of silicone oil. The technology is desired to be implemented in challenging cases of retinal detachments caused by giant retinal breaks, retinodialysis, or in patients with hard-to-remove epiretinal membranes in proliferative vitreoretinopathy.
Materials and Methods. The proposed technique — magnetic scleral buckling — is able to exert pressure to the retina by the means of mutual magnetic attraction of the magnetic scleral buckle (outer buckle) sutured to the retina and endovitreal magnetic buckles (inner buckles) made of magnetoactive elastomer and placed onto the retina in the projection of the outer magnetic buckle. A series of ex vivo experiments was performed to elaborate the technique using isolated cadaver donor eyes: we performed magnetic scleral buckling and then subtotal vitrectomy with iatrogenic detaching of retina followed by implantation of endovitreal magnetic buckles (inner buckles) made of magnetoactive elastomers to provide additional mechanical support for the retina.
Results. Elastic properties of the magnetic scleral buckles didn’t differ from those of common scleral buckles. Endovitreal magnetic buckles fitted well onto the retina, smoothly, tightly and effectively held it pressing against the pigment epithelium. We tried buckles of various sizes and shapes and chose the best fitted for endovitreal manipulations. Endovitreal buckles securely supported the retina and could be easily removed with 25G vitreotome.
Conclusion. The developed technique of magnetic scleral buckling allowed to keep retina securely reattached with magnetic forces as was shown during ex vivo experiments. Further in vivo studies of the technique are required.
- Fawcett I.M., Williams R.L., Wong D. Contact angles of substances used for internal tamponade in retinal detachment surgery. Graefes Arch Clin Exp Ophthalmol 1994; 232(7): 438–444, https://doi.org/10.1007/bf00186587.
- Rush R., Sheth S., Surka S., Ho I., Gregory-Roberts J. Postoperative perfluoro-n-octane tamponade for primary retinal detachment repair. Retina 2012; 32(6): 1114–1120, https://doi.org/10.1097/iae.0b013e31822f56f6.
- Eames I., Angunawela R.I., Aylward G.W., Azarbadegan A. A theoretical model for predicting interfacial relationships of retinal tamponades. Invest Ophthalmol Vis Sci 2010; 51(4): 2243–2247, https://doi.org/10.1167/iovs.09-4442.
- Wong D., Cazabon S., Ali H., Kumar I., Valldeperas X., Groenewald C., Pearce I. Can the sequential use of conventional silicone oil and heavy oil be a strategy for the management of proliferative vitreoretinopathy? Ann Acad Med Singapore 2006; 35(3): 181–184.
- Schaal S., Sherman M.P., Barr C.C., Kaplan H.J. Primary retinal detachment repair: comparison of 1-year outcomes of four surgical techniques. Retina 2011; 31(8): 1500–1504, https://doi.org/10.1097/iae.0b013e31820d3f55.
- Mehta S., Blinder K.J., Shah G.K., Grand M.G. Pars plana vitrectomy versus combined pars plana vitrectomy and scleral buckle for primary repair of rhegmatogenous retinal detachment. Can J Ophthalmol 2011; 46(3): 237–241, https://doi.org/10.1016/j.jcjo.2011.05.003.
- Storey P., Alshareef R., Khuthaila M., London N., Leiby B., DeCroos C., Kaiser R.; Wills PVR Study Group. Pars plana vitrectomy and scleral buckle versus pars plana vitrectomy alone for patients with rhegmatogenous retinal detachment at high risk for proliferative vitreoretinopathy. Retina 2014; 34(10): 1945–1951, https://doi.org/10.1097/iae.0000000000000216.
- Rush R., Simunovic M.P., Sheth S., Chang A., Hunyor A.P. 23-gauge pars plana vitrectomy versus scleral buckling versus combined pars plana vitrectomy–scleral buckling for medium-complexity retinal detachment repair. Asia Pac J Ophthalmol 2014; 3(4): 215–219, https://doi.org/10.1097/apo.0000000000000013.
- Makarova L.A., Nadzharyan T.A., Alekhina Y.A., Stepanov G.V., Kazimirova E.G., Perov N.S., Kramarenko E.Yu. Magnetoactive elastomer as an element of a magnetic retina fixator. Smart Materials and Structures 2017; 26(9): 095054, https://doi.org/10.1088/1361-665x/aa82e9.
- Puustjärvi T.J., Teräsvirta M.E. Retinal fixation of traumatic retinal detachment with metallic tacks: a case report with 10 years’ follow-up. Retina 2001; 21(1): 54–56, https://doi.org/10.1097/00006982-200102000-00009.
- Burke J.M., McDonald H.R., Neuwirth J., Lewandowski M. Titanium retinal tacks with pneumatic insertion. Histologic evaluation in rabbits. Arch Ophthalmol 1987; 105(3): 404–408, https://doi.org/10.1001/archopht.1987.01060030124041.
- Ohira A., de Juan E., Tsai M. Long-term histologic and electrophysiologic evaluation of the alloy retinal tack. Graefes Arch Clin Exp Ophthalmol 1991; 229(1): 95–98, https://doi.org/10.1007/bf00172270.
- Tripathi R.C., Pon D.M., Levine R.A., Tripathi B.J., Falckh R.C., Moffat K.P. Retinal tacks: tolerance and tissue reaction in a human eye. Ophthalmic Surg 1989; 20(9): 658–662.
- de Juan E. Jr., McCuen B.W., Machemer R. Mechanical retinal fixation using tacks. Ophthalmology 1987; 94(4): 337–340, https://doi.org/10.1016/s0161-6420(87)33441-4.
- Takhchidi Kh.P., Kazaykin V.N. Suture fixation of the retina in giant tears and abruptions of retina from the dentate line with the use of perfluororganic compounds. Oftal’mokhirurgiya 1996; 4: 23–28.
- Pashtaev N.P., Grigorieva I.N. The first experience of microinvasive suture fixation of giant tears and abruptions of retina. Oftal’mokhirurgiya 2012; 1: 58–61.
