|Year : 2015 | Volume
| Issue : 4 | Page : 914-917
Comparison between the tamponading effect of silicone oils with different viscosities in retinal surgery
Abdel Khalek E Elsaadany, Amin F Ellakwa, Sherif M Raafat MBBCh
Department of Ophthalmology, Menoufia University Hospitals, Menoufia University, Shebin El Kom, Egypt
|Date of Submission||16-Jan-2015|
|Date of Acceptance||07-Apr-2015|
|Date of Web Publication||12-Jan-2016|
Sherif M Raafat
Zagazig Ophthalmic Hospital, Sharkia Governorate
Source of Support: None, Conflict of Interest: None
The aim of this study is to determine the differences between silicone oils 1000, 2000, and 5000 cs in retinal reattachment, visual acuity, and complications.
Each of the silicone oils 1000, 2000, and 5000 cs has its own advantages and complications.
Patients and methods
This study included 42 eyes that were subjected to vitreoretinal surgeries with a silicone oil injection. Patients were divided into three groups: group A included 14 eyes injected with silicone oil 1000 cs, group B included 14 eyes injected with silicone oil 2000 cs, and group C included 14 eyes injected with silicone oil 5000 cs; injections were administered through the pars plana approach.
Silicone oil 5000 cs showed the best visual outcome and resulted in more complications (except emulsification as it emulsified less).
Silicone oil 1000 cs showed the less visual outcome and fewer complications.
Silicone oil 2000 cs showed good visual outcome and resulted in many complications that were intermediate between the other two viscosities.
Silicone oil 5000 cs is considered the most successful retinal tamponade. However, low-viscosity silicone oils are preferred sometimes because surgical injection and removal from the vitreous cavity are easier, and fewer complications are caused by these oils, such as cataract and increased intraocular pressure.
Keywords: silicone oils, retinal tamponade, vitrectomy, emulsification, retinal reattachment
|How to cite this article:|
Elsaadany AE, Ellakwa AF, Raafat SM. Comparison between the tamponading effect of silicone oils with different viscosities in retinal surgery. Menoufia Med J 2015;28:914-7
|How to cite this URL:|
Elsaadany AE, Ellakwa AF, Raafat SM. Comparison between the tamponading effect of silicone oils with different viscosities in retinal surgery. Menoufia Med J [serial online] 2015 [cited 2020 Apr 2];28:914-7. Available from: http://www.mmj.eg.net/text.asp?2015/28/4/914/173616
| Introduction|| |
The use of silicone oil as a long-acting retinal tamponade has improved the chances of reattachment of the retina in complicated cases of retinal detachment  .
Silicone oil can be used in the surgical management of proliferative vitreoretinopathy (PVR), severe diabetic tractional retinal detachment, giant retinal tears, eyes with large and multiple or posterior breaks, retinal detachments caused by macular holes, and macular translocation procedures  .
The highly purified polydimethylsiloxane, with a viscosity of 5000 centistokes (cs), is the preferred silicone oil endotamponade in vitreoretinal surgery (20 G) and shows high stability. In contrast, in transconjunctival minimally invasive surgery (23 G), the application of 5000 cs silicone oil results in many disadvantages because of a time-consuming and difficult application procedure owing to the small lumen of the surgical equipment used. Consequently, silicone oils with lower viscosity such as the 2000 cs silicone oil are increasingly being used in transconjunctival surgery  .
Despite the progress in vitreoretinal surgery and the importance of silicone oil as an adjunct for the treatment of complex forms of retinal detachment, controversy still exists on the issue of selection of the proper oil viscosity for clinical use. In complicated retinal detachment surgery, the use of 5000 cs silicone oil may be associated with a poorer anatomic and visual outcome compared with 1000 cs silicone oil. However, there was no difference between the two viscosities in intraocular pressure (IOP) elevation. A randomized-controlled study is necessary to further evaluate such a possibility  .
Pars plana vitrectomy with intravitreal silicone oil tamponade has been recognized as a successful mode of treatment in cases of complicated retinal detachments that lead to blindness almost without exception before the introduction of this operative method in routine clinical practice  .
Visual acuity improved significantly in the group with vitrectomy without scleral buckling, which was found to be effective in the repair of primary retinal detachment, compared with combined vitrectomy with scleral buckling  .
Some eyes sustaining gunshot injury with perforating ocular injuries retain some vision with this surgical sequence and phthisis may be prevented in others. Many of these eyes gain useful vision  .
Anatomic and visual acuity outcomes, as well as complication rates, retinal reattachment, and ambulatory vision were achieved in most eyes irrespective of oil viscosity  .
Several factors have improved the success of retinal detachment, and PVR surgery for eyes previously considered unsalvageable because of significant PVR now has a relatively good prognosis for the recovery of functional vision. The ability to provide prolonged intraocular tamponade with silicone oil has contributed considerably toward this success  .
Silicone oil tamponade may suppress anterior segment neovascularization by impeding the movement of vasoproliferative factors from the posterior segment to the anterior segment or by increasing oxygen tension in the aqueous by preventing diffusion of oxygen‐enriched aqueous to the posterior segment  .
Silicone oil tamponade has been used in the repair of macular holes in several settings: retinal detachment caused by idiopathic macular holes, myopic macular holes, and traumatic macular holes  .
This study aimed to clarify the differences between silicone oils 1000, 2000, and 5000 cs as retinal tamponades.
| Patients and methods|| |
The study was a retrospective one that included 42 eyes that were subjected to vitreoretinal surgeries with silicone oil injections. Patients were divided into three groups: group A included 14 eyes injected with silicone oil 1000 cs, group B included 14 eyes injected with silicone oil 2000 cs, and group C included 14 eyes injected with silicone oil 5000 cs. Injections were administered through the pars plana approach.
Patients with rhegmatogenous retinal detachment, tractional retinal detachment, PVR, proliferative diabetic retinopathy, vitreous hemorrhage, macular hole, and double perforation were included.
Patients with visual acuity, no perception of light were excluded. Participants in the study were subjected to an assessment of history, systemic evaluation, and an ophthalmic examination (visual acuity, slit-lamp examination, applanation tonometry, and indirect ophthalmoscopy); B-scan ultrasonography was performed under conditions with ocular media opacification. Optical coherence tomography and fluorescein angiography were also performed. Vitreoretinal surgery was performed with injection of silicone oil and follow-up was performed.
| Results|| |
The mean preoperative value of visual acuity was 0.025 ± 0.003 in group A (silicone 1000), 0.029 ± 0.006 in group B (silicone 2000), and 0.017 ± 0.002 in group C (silicone 5000) (P = 0.791, which is not significant, as we can expect the visual acuity of retinal detachment eyes in the three groups is nearly equal; hand motion to counting fingers).
The mean preoperative value of visual acuity of group A was 0.025 ± 0.003 and the mean postoperative value was 0.027 ± 0.001 (P = 0.695, nonsignificant).
The mean preoperative value of vision acuity was 0.029 ± 0.006 in group B and the mean postoperative value was 0.098 ± 0.007 (P = 0.001, significant, with improvement 237.9%).
The mean preoperative value of vision acuity of group C was 0.017 ± 0.002 and the mean postoperative value was 0.104 ± 0.01 (P = 0.009, significant, with improvement 511.8%).
The mean postoperative values of visual acuity of group A (silicone 1000) was 0.02 ± 0.001, group B (silicone 2000) was 0.098 ± 0.007, and group C (silicone 5000) was 0.104 ± 0.01 (P = 0.044, significant) [Figure 1].
|Figure 1 Postoperative mean values of vision acuity in the three groups studied.|
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The mean preoperative value of IOP of group A (silicone 1000) was 14.9 ± 4.6, that of group B (silicone 2000) was 15.8 ± 3.9, and that of group C (silicone 5000) was 13.6 ± 2.9 (P = 0.308, nonsignificant).
The mean preoperative value of IOP levels of group A was 14.9 ± 4.6 and the mean postoperative value was 16.00 ± 8.3 (P = 0.074, nonsignificant).
The mean preoperative value of IOP levels of group B was 15.8 ± 3.9 and the mean postoperative values was 22.7 ± 8.1 (P = 0.007, significant, with IOP elevation percentage 43.7%).
The mean preoperative value of IOP levels of group C was 13.6 ± 2.9 and the mean postoperative value was 23.4 ± 10.1 (P = 0.004, significant, with IOP elevation percentage 72.1%) [Figure 2].
|Figure 2 Preoperative and postoperative mean values of intraocular pressure levels of group C.|
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The mean postoperative value of IOP levels of group A (silicone 1000) was 22.3 ± 8.3, that of group B (silicone 2000) was 22.7 ± 8.1, and that of group C (silicone 5000) was 23.4 ± 10.1 (P = 0.956, nonsignificant).
The mean preoperative value of cataract grades in group A was 2.1 ± 0.09 and the mean postoperative value was 2.6 ± 0.8 (P = 0.078, nonsignificant).
The mean preoperative value of cataract grades in group B was 1.4 ± 0.6 and the mean postoperative value was 2.4 ± 0.8 (P < 0.001, highly significant, with cataract development percentage 71.4%).
The mean preoperative value of cataract grades in group C was 1.5 ± 0.7 and the mean postoperative value was 2.6 ± 0.6 (P = 0.001, highly significant, with cataract development percentage 73.3%).
The mean postoperative value of cataract grades in group A (silicone 1000) was 2.6 ± 0.8, that of group B (silicone 2000) was 2.4 ± 0.8, and that of group C (silicone 5000) was 2.6 ± 0.6 (P = 0.594, nonsignificant).
| Discussion|| |
Silicone oil 5000 cs showed the best visual outcome with P value of 0.009, which was significant, and vision improvement of 511.8%. Thus, silicone oil 5000 cs showed the best retinal tamponading effect, and is more resistant to emulsification. Shah et al.  reported that all patients who received 5000-cs silicone oil achieved attachment after retinal detachment repair. Also, Fernando Arevalo  reported that a complete fill of the vitreous cavity with silicone oil is easier to achieve with 5000-cs silicone oil.
Chong  reported that higher viscosity oil should be used because it is considered to cause less emulsification.
In contrast, Soheilian et al.  reported higher rates of retinal redetachment and poorer visual outcome with the use of 5000-cs silicone oil than with the use of 1000-cs silicone oil.
ElHabbak and Nagy  reported that, after 6 months of follow-up, there was almost no difference in efficacy between silicone 5000, 2000, and 1000 cs.
Silicone oil 1000 cs is easier to inject and remove, the least induction for cataract (P = 0.078, nonsignificant), but has a high ability to emulsify as reported by Shlomit Schaal in 2013  (lower-viscosity silicone oil was found to have a higher tendency to emulsify).
Silicone oil 2000 cs has an intermediate way by gathering benefits of high and low oil viscosities for example: the vision outcome has improved by 237.9% (P = 0.001, significant) resembling silicone 5000 cs.; on the other hand, handling and removal is easy and has less induction for cataract and glaucoma resembling silicone 1000 cs.
| Conclusion|| |
Each silicone oil viscosity has some or a part of the advantages but not the whole. Silicone oil with high viscosity, 5000 cs, was superior in terms of the results of visual acuity improvement and also showed the most resistance to emulsification; thus, it is considered the most successful retinal tamponade. However, low-viscosity silicone oils are preferred sometimes because of greater ease of surgical injection and removal from the vitreous cavity, and the fewer complications caused by these oils, such as cataract and increased IOP.
| Acknowledgements|| |
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2]