Silicone oil migration presenting as an eyelid cyst
Reviewed by Annes Ahmeidat

The author presents a single case report of a rare complication of silicone oil tamponade, silicone oil migration, after pars plana vitrectomy. A seven-year-old female, with a history of vitrectomy one year prior for penetrating eye trauma, presented with a left upper eyelid mass. On examination there was mechanical ptosis, reduced visual acuity in the left eye with counting fingers from 20cm, and the retina was attached. This case was presented alongside two computed tomography (CT) scans in different planes and a histology specimen to demonstrate the silicone oil mass in situ and foreign body reaction respectively. An orbital CT scan localised the two masses to the intraconal space of the left orbit between the superior and lateral rectus muscles. Transcutaneous excisional biopsy of the upper eyelid masses revealed the masses to be translucent and cystic with the largest having dimensions of 10x18mm. Complete excision of the globules was performed followed by suturing of skin with nonabsorbable suture. At one week follow-up, sutures were removed, ptosis was noted to have improved, and there were no signs of recurrence. Silicone oils have a low specific gravity (lighter than water) and are commonly employed for intraoperative retinal manipulation and prolonged postoperative intraocular tamponade. They are used as either 1000cs which is easier to inject and remove or as 5000cs which is more viscous, but less prone to emulsification. The author of this case report did not specify the viscosity utilised. Silicone oil gives rise to complications because of its emulsification and dispersion and may affect nearly all ocular structures leading to complications such as glaucoma, cataract, chronic hypotony and band keratopathy. Silicone oil leakage is thought to be either through the vitrectomy port, or the posterior scleral and corneal wound which are aggravated by increased intraocular pressure postoperatively. Previous reports have highlighted silicone oil migration following vitrectomy for proliferative diabetic retinopathy, endogenous endophthalmitis and penetrating eye trauma. The authors conclude that patients with a history of silicone oil injection for surgery complaining of eyelid swelling, ptosis, or mass postoperatively should raise suspicions of silicone oil migration.

Migration of silicone oil into the orbit and eyelid as a cyst.
Sharifi M, Ansari Astaneh MR.
CASE REPORTS IN OPHTHALMOLOGY
2020;11:217-21.