Silicone oil (SO) has been used as an endotamponade in complex retinal detachment surgery for decades.1 Its use has been associated with high rates of retinal reattachment.1 Unlike intraocular gas, SO remains in the vitreous cavity, allowing for a long-term tamponade. The timing of surgical removal of SO is surgeon dependent, and varies from case to case.
A variety of complications, both short term and long term, have been described with intraocular SO.2 One such complication is migration of SO into the anterior chamber (AC).2 Silicone oil in the AC can cause secondary cataracts, corneal decompensation, and glaucoma.3 In situations where SO has migrated into the AC soon after surgery, it would be ideal to have it removed without returning to the operating room (OR) and without further SO prolapsing forward into the AC from the vitreous cavity.
There are few publications detailing SO removal from the AC. In these reports, SO removal is predominantly conducted in the OR. In these cases, air or an ophthalmic viscosurgical device is used to push SO out of the eye while simultaneously acting to barricade SO migration into the AC from the vitreous cavity.3,4 Returning to the OR to remove SO from the AC may be a less desirable option for the surgeon and patient because of scheduling issues. Furthermore, with the patient positioned in the supine position, as is the case in the OR, there is a chance of additional SO from the posterior segment migrating into the AC during removal. If the patient were in an upright position at the slit lamp, however, SO would not spontaneously drift toward the AC, lowering this risk.
To our knowledge, only one publication has described SO removal from the AC in an outpatient setting.5 In this work, Soliman et al removed SO via a temporal paracentesis with a 19-G needle. The needle functioned as a conduit by which the SO passively egressed out of the AC. In this study, we describe an alternative surgical technique to removing SO from the AC that is also suitable for use in an outpatient setting.
Once patient consent is obtained, the procedure is performed under topical anesthesia in the outpatient clinic. With the patient sitting upright at the slit lamp, the affected eye is anesthetized using topical 0.5% tetracaine eye drops. Two drops, 30 seconds apart, of povidone iodine 5% is instilled into the palpebral fissure for antisepsis. A wire eyelid speculum is inserted into the fornix for optimal exposure. Another drop of Povidone Iodine 5% is instilled.
A paracentesis is created at 12 o'clock through clear cornea (Figure 1). The paracentesis is made using a 1.0-mm angled sideport knife (Alcon Laboratories, Fort Worth, TX) in a shelved fashion, facilitating a self-sealing wound. The wound may be slightly enlarged to ensure an adequate size that allows for SO egression. Next, a viscoelastic cannula is inserted through the corneal wound (Figure 2), and dispersive viscoelastic (VISCOAT; Alcon Laboratories) is injected slowly. The cannula is advanced toward the inferior angle, instilling small amounts of viscoelastic while placing gentle pressure with the cannula on the posterior lip of the corneal wound, making it gape slightly. Silicone oil subsequently egresses from the depression of the corneal wound (see Video, Supplemental Digital Content 1, http://links.lww.com/IAE/A646, which demonstrates technique of SO removal from AC). In cases where residual SO remains, the procedure may be repeated several days later.
Prophylactic antihypertensive drops and next day follow-up are recommended. Depending on the amount of dispersive viscoelastic placed in the AC, an intraocular pressure rise may occur. In most cases, this is controlled with topical drops, however, in certain situations, oral carbonic anhydrase inhibitors, or an AC paracentesis of viscoelastic may be required.
We have performed this procedure to remove SO that has migrated into the AC approximately 30 times over the last 20 years. After SO has been removed (which may take a few sessions) we have not experienced significant recurrence.
This approach has several advantages: The ability to perform this procedure in the outpatient setting is convenient as it does not require coordinating OR time. As well, by performing this procedure in the clinic rather than the OR, there are likely significant cost savings for the health care system.
With the patient positioned upright at the slit lamp, there is a lower likelihood of SO prolapsing from the vitreous cavity anteriorly into the AC, as compared to if the patient was supine (as would be the case in the OR). A shelved incision created with a blade facilitates a self-sealing wound, with a lower risk of wound leak and associated complications than a large bore needle tract.
The use of ophthalmic viscosurgical device allows the procedure to be conducted in a controlled fashion. The small amount of viscoelastic that is placed in the AC maintains space as SO is evacuated. Without this, there is a risk of sudden hypotony once AC oil has been evacuated. Sudden hypotony could lead to iris prolapse, additional SO migration from the posterior segment into the AC, and choroidal hemorrhage.
Lastly, our procedure uses a superior incision to vent SO. Because of the low density of SO, upright positioning of the patient will automatically move SO toward the top of the eye. The 12 o'clock position of the corneal paracentesis is thus logical, and facilitates complete removal of SO.
In summary, we have described a novel and reproducible approach to removing SO from the AC in an outpatient setting.
1. Silicone Study Group. Vitrectomy
with silicone oil
or sulfur hexafluoride gas in eyes with severe proliferative vitreoretinopathy: results of a randomized clinical trial: Silicone Study Report 1. Arch Ophthalmol 1992;110:770–779.
2. Federman JL, Schubert HD. Complications associated with the use of silicone oil
in 150 eyes after retina-vitreous surgery. Ophthalmology 1988;95:870–876.
3. Kirkby GR, Gregor ZJ. The removal of silicone oil
from the anterior chamber in phakic eyes. Arch Ophthalmol 1987;105:1592.
4. Mandelcorn MS, Mandelcorn ED, Emanuelli A, Albini TA. The silicone sandwich technique. Retina Today 2011:46–48.
5. Soliman IAM, Smiddy WE. Silicone oil
removal from the anterior chamber. Retina 2016;36:2031–2032.
elevated intraocular pressure; postoperative complications; retinal detachment; silicone oil; vitrectomy
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