Sir,

Ocular trauma is the leading cause of monocular blindness worldwide1 and intraocular foreign bodies (IOFBs) are a major contributor accounting for approximately 17–41% of cases.2 We present an unusual trauma case, whereby C3F8 gas escaped into the orbit resulting in surgical emphysema.

Case report

A 37-year-old man had an accidental perforating injury while using a pneumatic nail gun in the left eye. Examination revealed hand movement (HM) acuity, a 3.8 mm corneal laceration, shallow anterior chamber with hyphema (0.5 mm), iris sphincter tear, and anterior lens capsule disruption with temporal dislocation of the lens. Owing to vitreous haemorrhage, fundus examination was not possible but retinal detachment was excluded on orbital ultrasound. Figure 1a (X-ray) demonstrates the close proximity of the IOFB to the superior orbital roof.

Figure 1
figure 1

(a and b) Lateral orbital radiograph showing the nail in close proximity to the superior orbital roof (a) and surgical emphysema in the upper lid (b; arrow).

Full size image

The patient underwent a three port pars planar vitrectomy (PPV) with lensectomy. The nail had perforated the retina inferotemporal to the disc and was pulled out through the corneal wound revealing a gaping round hole at the posterior pole. During IOFB removal, a self-limiting suprachoroidal haemorrhage (SCH) developed inferiorly. The eye was subsequently filled with 14% C3F8 gas to tamponade the posterior retinal defect and the patient was asked to posture face down.

At the first postoperative day, 60% gas fill was detected but on the third day only 10% gas fill remained with surgical emphysema evident on the left upper lid (Figure 1b). The surgical emphysema and SCH gradually resolved and a month later, his best-corrected acuity was 10/200 and a retinal defect was evident with surrounding subretinal haemorrhage and retinal folds due to retinal incarceration (Figure 2).

Figure 2
figure 2

Fundus photograph showing a retinal defect inferotemporal to the disc with surrounding subretinal haemorrhage and retinal folds.

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Comment

Migration of silicone oil into the orbit has been previously reported resulting in blindness due to the blockage of Ahmed valve and rubeosis.3 Gas is less likely to escape compared with silicone oil in these circumstances due to its larger surface tension. However, once the defect is breached by the gas bubble, its surface tension forces are reduced resulting in gas escaping to the orbit. It is thus important to avoid raising the intraocular pressure postoperatively to limit gas escape.