Sir,

This letter purports to attribute the late complications of unsuccessful surgery for the repair of retinal detachment due to trauma, to silicone oil. The eye in question is certainly unsightly, but there is no evidence from the report that the condition was progressive as implied in the title. The eye was said to have been more prominent only for 6 months, not progressively so. The title implies that the proptosis was due to the silicone; yet the CT scan shows a mass to the medial side of the eye, with limited spread more posteriorly. Had the proptosis been related to the extraocular movement to the silicone, there would have been evidence of a mass behind the eye.

The eye was reported as showing axial myopia as evidenced by an A-scan measurement. The authors should surely have known that ultrasound measurements in the presence of silicone oil always show an abnormal axial length owing to attenuation of the sound signal through the silicone. However, the CT scan does show an enlarged eye with some lateral displacement owing to a medially situated mass. It is highly probable that this previously traumatised eye had shown progressive enlargement due to glaucoma complicating unsuccessfully treated retinal detachment as evidenced by the appearance of the cornea. This would have led to a high risk of exposure and an unsightly eye. It is noteworthy that there appeared to be no history of pain from this eye.

It is also noteworthy that the histopathology showed only a relatively mild inflammatory reaction. This therefore could not be regarded as a granuloma. This term should be restricted to a mass involving chronic inflammation.

Silicone oil may leak from a glaucomatous eye, such as the one described in this letter. It is the result of scleral rupture, usually at one of the parsplanar sclerostomies used for vitrectomy. We have seen this in some patients where oil droplets leak slowly beneath the conjunctiva. It does not however cause such a red and unsightly eye unless other problems are present. In this case, it is highly likely to have been the result of corneal exposure and not oil ‘granuloma’.

The analogy with historic techniques for breast augmentation has been used by critics of the use of silicone oil for the treatment of complex retinal detachment. The comment in this letter begins with the statement that oil granuloma occurs when bulky mineral oils are injected into body tissues. It is true that serious problems did occur with the use of mineral oil for breast augmentation and was rapidly discontinued as a result. It is however highly misleading to use this analogy in any discussion regarding silicone oil. Silicone is not a mineral oil; it is not derived from petroleum and is never likely to be.