Editor's Note
In recent years, silicone oil has been a commonly used post-vitreous filler by domestic retinal surgeons. Long-term presence of silicone oil in the eye can cause emulsification, leading to a variety of serious complications, affecting the long-term efficacy after surgery. In addition to being familiar with the application of silicone oil, clinical ophthalmologists should also be familiar with silicone oil complications and their treatment. How should silicone oil emulsification be correctly understood and treated clinically? Professor Wang Fang of the Department of Ophthalmology of the Tenth People's Hospital Affiliated to Tongji University in Shanghai was invited to share an example of severe silicone emulsification and its experience and skills in dealing with silicone oil emulsification.
The focus of silicone oil removal surgery: remove small droplets of silicone oil emulsion
Silicone oil emulsification is one of the serious complications of silicone oil filler eye. The time of emulsification of the silicone oil-filled eye is affected by many factors, of which the viscosity of the silicone oil, the condition and condition of the affected eye, the surgical operation and the individual differences of the patient are the main factors. According to the literature, the incidence of silicone oil emulsification in silicone oil (5000cs) commonly used in clinical practice is 1% after one month of intraocular filling, the incidence of silicone oil emulsification is 11% when filling is 3 months, the incidence of silicone oil emulsification is as high as 85% when filling is 6 months, and the incidence of silicone oil emulsification is 100% in December. With the clinical popularity of SD-OCT, the discovery rate of silicone oil emulsification has been improved, and it has been reported that when the silicone oil remains in the vitreous cavity for 3 months, 21% of the silicone oil filler eyes are under the OCT, showing high reflection of small droplets of silicone oil on the retinal interface.
Intraocular silicone oil emulsification indicates the arrival of oil extraction time. Otherwise, as emulsification worsens, silicone oil emulsified droplets can lead to many potential complications, such as high intraocular pressure, inflammation, fibrous membrane formation, and retinal tissue atrophy. Therefore, an important purpose of clinical silicone oil removal surgery is to remove as many silicone oil emulsion droplets as possible in the eye. To achieve this, triple-fluid/air exchange, right after the removal of SO is usually used. Multiple gas-fluid exchanges do not necessarily completely remove emulsified droplets from the eye, especially after silicone oil emulsification has occurred for some time. The emulsified droplets remaining in the eye after the silicone oil is removed can cause inconvenience to the patient's life, such as a large number of black shadows fluttering in front of the patient's eyes, interfering with vision. Therefore, effectively removing small droplets of silicone oil emulsion and reducing postoperative eye retention is a major challenge for fundus surgeons.
Taking the clinical example as a lesson, the surgical treatment of severe silicone oil emulsifying eye is explained in detail
Professor Wang Fang shared a video of the surgical operation of a patient with severe silicone oil emulsified eye. The patient male, 21 years old, left eye RRD after the operation of silicone oil filling for more than 4 years, outpatient examination found that the patient's eye silicone oil is seriously emulsified, silicone oil droplets fill 70% of the anterior chamber. (See Figure 1)
Figure 1
Cleaning up the emulsified droplets in the anterior chamber is the first step. "See clearly" is one of the most basic surgical points of retinal surgeons, that is, the surgeon must see the instruments for surgical operations (such as vitreous cutting heads), and must not "see the flowers in the fog", and see clearly is the first guarantee and condition for safe retinal surgery. For this patient, only by cleaning the small droplets of silicone oil in the anterior chamber emulsion can the vitreous cavity silicone oil removal surgery be safely performed.
During surgery, vitreous cavity perfusion is placed in the flat part of the ciliary body, followed by anterior chamber puncture: most of the silicone oil emulsified droplets in the anterior chamber are discharged using aqueous humor; finally, the anterior chamber is rinsed to open the operator's visual path.
Removing emulsified droplets from the vitreous cavity after oil extraction is the focus of this procedure. Professor Wang Fang is accustomed to using "three so droplets by repetitive flushing using BSS and air in a procedure called triple-fluid/air exchange, right after the removal of SO). The principle of gas-liquid exchange is summarized by Mandelcorn (2016) as a "soup and sandwich technique", that is, the use of injected air to push the silicone oil (including silicone oil droplets) to the back pole, at this time the silicone oil is sandwiched between the air and BSS (see Figure 2), and the tip of the suction head (glass cutter or hose flute needle) is kept at the gas-liquid interface to effectively remove the silicone oil (including silicone oil emulsified droplets).
Figure 2
After the surface of the silicone oil droplets is stabilized by the active agent, the original hydrophobic silicone oil becomes amphiphilic( amphiphilic), that is, it has hydrophilic properties, resulting in the emulsified silicone oil droplets in the eye are difficult to remove. Biphilic silicone oil emulsified droplets easily adhere to the surface of hydrophilic tissues around the vitreous cavity (such as the retina) and are not easy to separate, making it difficult to remove completely. Using the "sandwich" gas-liquid exchange technology, the surface tension of the gas can be used to drive away the emulsified droplets adhering to the surface of the retina, and these droplets are relatively confined between the gas-liquid interface for easy removal.
Germany's fluoron company produces a semi-fluorinated alkane heavy water perfluorobutylpentane (F4H5), and 2008 reports showed that F4H5 can efficiently remove silicone oil droplets attached to the surface of intraocular lenses. F4H5® is a biocompatible solvent with unique amphiphilic properties that act as heavy water (specific gravity 1.28 g/cm3, 25 °C) to "dissolve" silicone oil emulsify droplets in it, effectively removing silicone cone oil residues. In 2015, Stalmans et al. applied F4H5 to evaluate the effect of removing silicone oil droplets in the silicone oil filled eye, and proved that the emulsified droplet clearance rate of the eyes receiving F4H5 irrigation was significantly better than that of the eyes that did not receive F4H5 treatment. In 2016, F4H5 was approved by CE, and Fluoron marketed F4H5® heavy water specifically as a wash out for oil residues in vitreoretinal surgery for flushing conventional silicone oil droplets, especially during the removal of silicone oil emulsified droplets.
Finally, Professor Wang concluded that the complications after emulsification of silicone oil directly endanger the visual function of patients. Therefore, an effective way to prevent complications of silicone oil emulsification is to remove the silicone oil from the vitreous cavity before silicone oil emulsification occurs. However, there has been a lack of definitive answers to the clinical question of the appropriate time for silicone oil removal. Because the time of emulsification of silicone oil in the eye is affected by multiple factors, among the four main factors (the viscosity of silicone oil, the condition and state of the affected eye, the surgical operation and the individual difference of the patient), the individual difference of the patient is a variable, which is a challenge for both the surgeon and the patient. As an surgeon, according to the patient's medical history, condition and intraoperative detailed lesion degree and characteristics, the appropriate viscosity of silicone oil should be selected as the postoperative vitreous cavity filler, and the time of silicone oil removal should be determined. All in all, the principle of silicone oil filling eye is to take oil as early as possible, avoid "dogmatic" thinking and extend the silicone oil eye oil extraction time without reason, and prevent silicone oil emulsification.
bibliography
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2.Marie-Hélène Errera. et al. Using spectral-domain optical coherence tomography imaging to identify the presence of retinal silicone oil emulsification after silicone oil tamponade. Retina, 2013; Sep; 33(8):1567-73.
3.Yau Kei Chan.et al. A Low-Molecular-Weight Oil Cleaner For Removal of Leftover Silicone Oil Intraocular Tamponade. Invest Ophthalmol Vis Sci, 2015; 56:1014–1022.
4.Mandelcorn ED. ‘Soup & sandwich’ silicone oil removal. Retina Specialist. 2016; November 15
5.Y Liang. et al. A cleaning solution for silicone intraocular lenses: “sticky silicone oil”. British Journal of Ophthalmology, 2008; 92: 1-1
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Expert Profiles
Professor Fang Wang
Ophthalmology Doctor of Medicine, Chief Physician
Director of the Department of Ophthalmology of the Tenth People's Hospital Affiliated to Tongji University
Doctoral supervisor of Tongji University
Vice Chairman of Shanghai Ophthalmology Branch
Vice President of Shanghai Ophthalmologists Branch
Member of the Standing Committee of the Chinese Association of Women Ophthalmologists
Member of the Chinese Ophthalmologists Branch
He has been practicing ophthalmology for 37 years. Main direction of attack: vitreoretinal disease. In recent years, the main contributions have been: the first in China to carry out 27G vitreous local resection treatment of idiopathic premacular membrane, macular interface disease navigation surgery, retinal detachment sclera reduction surgery under ceiling lights, refractory macular hiatus slit closure and ILM band stipen filling and other new treatments.
His research achievements have won the second prize of the 2012 Shanghai Medical Science and Technology Progress Award, the third prize of the 2014 Shanghai Municipal Science and Technology Commission Natural Science and Technology Award and the third prize of the National Huaxia Science and Technology Award, the second prize of the Science and Technology Progress Award of the Ministry of Education of the People's Republic of China in 2016, and the first Shanghai Female Physician "Medical Tree Award". He has published more than 80 academic papers. 40 graduate students were trained. In 2010, he was named the March 8th Red Banner Bearer of Shanghai and the pacesetter of "Jiangang Gang" in 2017.