Purpose: To compare in vivo emulsification of silicone oil 1000 and 5000 centistokes (cs) after retinal detachment surgery. Design: Comparative non-interventional Retrospective study. Methods: Silicone oils from patients who underwent retinal detachment surgery were investigated using Spectrophotometer UV-Vis. Spectroscopically changes determine emulsification with the time of tamponade, inflammation, patients age and severity of retinal detachment. Results: We found significant difference on absorbance (p = 0.004) between used 1000 Centi stoke (cs) silicon oil (average wave length 2.51 nm; SD: 1.575 nm) and used 5000 cs silicon oil (average wave length 0.910 nm; SD: 0.564 nm). Conclusions: In vivo emulsification was higher in silicone oil 1000 compared to 5000 cs silicone oil after vitreoretinal tamponade 8 - 12 weeks due to retinal detachment surgery. Emulsification related to higher absorbance and lower transmittance in 1000 cs silicone oil. Inflammation may become a factor affecting this condition.
Silicone oils were used in retinal detachment surgery since 1962 and had been used increasingly especially in complicated cases such as retinal detachment with severe proliferative vitreoretinopathy, giant retinal tears, proliferative diabetic retinopathy, viral retinitis and ocular trauma [
Emulsification is the most common complication in silicone oil tamponade [
The most common used silicone oil in vitreoretinal surgery is 1000 and 5000 centi Stoke (cs). Silicone oil with viscosity 1000 cs is easier and faster to inject and remove but has limitation sooner to be emulsified compared to higher viscosity. Silicone oil 5000 cs has lower tendency to emulsify which may provide longer tamponade effect [
Although in vitro study showed that silicone oil with higher viscosity was more stable than lower viscosity, Soheilian et al. found that clinically, there was no difference in complications rates between 1000 vs. 5000 cs silicone oil after retinal detachment surgery [
The purpose of this study was to compare in vivo emulsification of silicone oil 1000 and 5000 cs after retinal detachment surgery.
This study non-randomized comparative study to 13 silicone oil 1000 cSt and nine silicone oil 5000 cs was taken from patients who underwent silicon oil tamponade for 8 - 12 weeks tamponade duration. The inclusions criteria are patient with primary vitrectomy due to Rhegmatogenous Retinal Detachment (RRD) who underwent vitrectomy with silicon oil endo tamponade. The exclusion criteria are combined endo tamponade with perfluorocarbon liquid; using perfluorocarbon liquid during vitrectomy surgery; patient using steroid or anti-inflammation therapy at least three months prior the surgery. All patients had undergone retinal detachment surgery at Cicendo Eye Hospital, Indonesia. Removal of silicone oil tamponade decision was based on the attachment of retina within 8 - 12 weeks of tamponade. The silicon oil removal was done by a single operator using vitrectomy machine (Alcon Constellation Vision System, Fort Worth Texas USA). As the normal control, we compared the samples with unused 1000 and 5000 cSt silicone oil from the same brand.
To perform Silicone oil evaluation, the samples were placed in an acrylic cuvet with dimension 4.5 cm × 1.425 cm × 1.425 cm and 1.5 cc volume. The Spectrophotometry UV-Vis T70+ (PG Instruments Ltd) was used to evaluate absorbance and transmittance changes in both groups. Assessment of silicon oil emulsification macroscopically was done by a single operator using criteria ‘fish egg’ appearance on silicon oil samples. The examiner was blinded to study subject. No interventions were given in this study. The statistical analysis was performed using Shapiro-Wilk test and Mann-Whitney test with p ≤ 0.05 is considered as significant.
We collected 13 samples from the eye that tamponade using 1000 cs silicon oil and nine samples from the eye that using 5000 cs oil. Detail of the clinical characteristics is shown in
Duration of tamponade on the two groups is between 8 - 12 weeks with average 9.9 weeks in group 1, and 10.6 weeks in group 2. There is no statistical difference between the two group on tamponade duration (p = 0.202)
Silicone oil is an important and widely used intravitreal tamponade in vitreoretinal
No | Age (years) | Sex | Diagnose | Time of Tamponade (weeks) |
---|---|---|---|---|
1 | 40 | M | RD + PVR grade B + Aphakia | 12 |
2 | 64 | M | RD + PVR grade B | 12 |
3 | 39 | F | RD (3 quadrants) | 8 |
4 | 47 | F | Total RD + SenileCataract | 8 |
5 | 48 | M | RD | 9 |
6 | 50 | F | RD | 12 |
7 | 31 | M | Total RD + Traumatic cataract | 12 |
8 | 47 | M | GRT | 8 |
9 | 61 | M | RD | 8 |
10 | 45 | F | RD (3 quadrants) | 12 |
11 | 50 | M | RD | 12 |
12 | 47 | M | RD + PVR | 8 |
13 | 64 | M | Total RD | 8 |
No | Age (years) | Sex | Diagnosis | Time of Tamponade (weeks) |
---|---|---|---|---|
1 | 39 | M | Total RD | 12 |
2 | 38 | M | RD (3 quadrants) | 12 |
3 | 30 | M | RD | 8 |
4 | 29 | M | RD | 8 |
5 | 58 | M | RD + Coloboma of Choroid | 12 |
6 | 33 | M | RD (2 quadrants) | 12 |
7 | 40 | M | Total RD | 12 |
8 | 36 | M | Total RD + PVR grade D | 8 |
9 | 62 | F | Total RD | 12 |
*RD = Retinal Detachments, PVR = Proliverative vitreoretinopathy, GRT = Giant Retinal Tears.
Patients Characteristics | Tamponade of Silicone Oil | |||
---|---|---|---|---|
1000 cs (n = 13) | 5000 cs (n = 9) | |||
Emulsification (+) | Emulsification (−) | Emulsification (+) | Emulsification (−) | |
1) Sex | ||||
Male | 4 | 5 | 0 | 8 |
Female | 3 | 1 | 0 | 1 |
2) Retinal Detachment (RD) | 2 | 4 | 0 | 3 |
Total RD | 2 | 0 | 0 | 4 |
RD | 0 | 1 | 0 | 2 |
RD with PVR | 1 | 1 | 0 | 0 |
GRT | 1 | 0 | 0 | 0 |
Total RD + History of Trauma | 1 | 0 | 0 | 0 |
3) Age (years) | ||||
<40 | 3 | 0 | 0 | 7 |
>40 | 4 | 6 | 0 | 2 |
4) Time of Tamponade (weeks) | ||||
<10 weeks | 4 | 3 | 0 | 3 |
>10 weeks | 5 | 1 | 0 | 6 |
*RD = Retinal Detachments, PVR = Proliverative vitreoretinopathy, GRT = Giant Retinal Tears.
surgery that is intended as a temporary tamponade for rhegmatogenous retinal detachment surgery. Based on the viscosity, there are several types of silicone oil that are used in vitreoretinal surgery. Selection of the type of silicone oil used is based on the patient’s clinical condition and estimated the duration of tamponade needed [
Absorbance | Group | |
---|---|---|
Silicon Oil 1300 cs (n = 13) | Silicon Oil 5500 cs (n = 9) | |
Wave length: 770 nm Mean (SD) Median Range | 0.059 0.148 (0.093) 0.131 0.049 - 0.357 | 0.111 0.103 (0.062) 0.096 0.024 - 0.176 |
Comparison of Wave length sample to unused silicon oil | p = 0.005 | p = 0.699 |
Absorbance | Group | p-value | |
---|---|---|---|
Silicon Oil 1300 cs (n = 13) | Silicon Oil 5500 cs (n = 9) | ||
Wave length: 770 nm Mean (SD) Median Range | 2.51 (1.575) 2.22 0.83 - 6.05 | 0.910 (0.564) 0.86 0.21 - 1.58 | 0.004 |
The 1000 cs and 5000 cs silicon oil are the two type of silicon oil most used in vitreoretinal surgery. The 1000 cSt silicone oils are easier to inject and remove from the eye but have less stable properties resulting in more frequent complications. Silicon 5000 cs oil has more stable properties when compared with 1000 cs silicone oil but is more difficult to inject and removal due to its viscosity [
Several factors are thought to affect changes in physical properties of silicone oils in the eyeballs such as the rheological properties of silicone oil itself, the saccadic movement of the eyes and the patient’s head, the length of tamponade, and the presence of blood and inflammation components in the vitreous cavity [
The presence of inflammatory cells released in the retinal detachment can diffuse into the silicone oil [
Silicone oil is widely used in surgery are trimethyl siloxy-terminated vitreoretinal SiO, poly-trifluoro propyl-methylsiloxane (FsiO) and the most rarely used polyphenylmethylsiloxane [
Vitreous samples examination of PVR patients showed an increased number of cytokines, such as interleukin-1 beta (IL-1β), TNF-α, and monocyte chemoattractant protein-1 (MCP-1). Study showed, growth factors, such as basic fibroblast Growth Factor (bFGF) in PVR patient is also higher when compared with patients with macular holes or idiopathic premacular fibrosis [
As a result, on the 1000 cs group showed a considerable increase in absorbance values (emulsification rates) in some samples taken from patients with rhegmatogenous retinal detachment with PVR, giant retinal tear, and total retinal detachment (samples 1, 4, 7, 8, 10, 13). Samples in the 5000 cs silicone oil group with retinal detachments, total retinal detachment and retinal detachment with PVR have increased absorbance value (emulsified). However, the increasing of absorbance value in the 5000 cs sample group did not exceed the absorbance value Silicone oil in the sample group 1000 cs. This suggests that with a risk factor of an inflammatory condition, 5000 cs silicone oil has a more stable properties compared with 1000 cs silicone oil.
Bleeding factor is one of the factors that can accelerate the silicone oil emulsification [
In this study the duration of tamponade in the two sample groups varied, ranging from 8 - 12 weeks on based on the patient clinical conditions. Tamponade on 1000 cs silicone oil samples performed over eight weeks resulted in higher absorbance values when compared to the 5000 cs sample group. Increased absorbance values in the 5000 cs sample group who had tamponade over eight weeks is not higher when compared to the 1000 cs sample group at the same tamponade duration.
The duration of tamponade is one of the factors that influence the damage of silicone oil [
Emulsification of silicone oil in the eyeball is also affected by the movement of the eyeball and the movement speed of silicone oil against the walls of the vitreous cavity. As the eye moves, the silicone oil inside the ball will also move [
Factors that may affect damage to silicone oils such as the saccadic movement of the eyeball and the patient’s head, the duration of tamponade and the presence of surfactants in the eyeballs are affected each other [
Absorbance 1000 cs silicon oil is greater when compared with 5000 cs silicone oil. Even though macroscopically there is no sign of silicone oil damage, but microscopically the physical and chemical structures changes may already there. This is evident from the increase in absorbance in both groups of samples with a larger increase occurring in the 1000 cs silicone oil sample group.
The inflammation and blood properties were not assessed in this study. This is considered as the limitation of this study. Further study involving more samples is suggested to confirm findings in this study.
Silicon oil with 5000 cs viscosity has better emulsification stability in tamponade to retinal detachment surgery comparing to 1000 cs Silicon oil. Although there was no emulsification of silicone oil clinically, there were some structural changes occurring in silicone oil which was higher in silicone oil 1000 cs compared to 5000 cs.
Kartasasmita, A., Kusdiono, W., Virgana, R. and Boesorie, S. (2017) In Vivo Emulsification Analysis of 1000 cs and 5000 cs Silicone Oil after Rhegmatogenous Retinal Detachment Vitrectomy Surgery. Open Journal of Ophthalmology, 7, 231-239. https://doi.org/10.4236/ojoph.2017.74031