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Orbital decompression is a common surgery performed to treat patients with thyroid related orbitopathy for functional or cosmetic indications.3,4 Many complications have been described with the surgery, but this surgery has never been associated with retinal haemorrhages.
We describe a case of a 70 year old woman, who developed bilateral retinal haemorrhages after staged bilateral orbital decompression surgeries.
A 70 year old woman with the diagnosis of euthyroid Graves’ disease was referred because of severe proptosis. Past ophthalmic history revealed two previous strabismus surgeries. Past medical history was unremarkable with no history of diabetes or cardiovascular disease, also she was not taking aspirin or any other blood thinning medications.
Ophthalmic examination showed visual acuity of 20/20 in each eye. Both orbits were moderately firm to retropulsion. IOP was within normal limits in primary gaze (14, 19 mm Hg) and slightly elevated in upgaze (17, 26 mm Hg). There were limitations in upgaze and lateral gaze in both eyes as well as upper and lower lids retractions. There was a mild degree of lagophthalmos with exposure keratopathy. Funduscopy was normal and did not show any evidence of microvascular disease or retinal haemorrhages. Hertel measurements were 22 mm on the right and 23 mm on the left. Computed tomography scan showed enlargement of the extraocular muscles.
She underwent balanced orbital decompression surgery on the left side, including deep lateral and medial wall decompression with intraconal fat removal. Three days after surgery she noted spots in front of her left eye. Visual acuity in that eye was 20/25. Funduscopic examination disclosed dot and blot haemorrhage with flame shaped haemorrhages in the posterior pole of the left eye (fig 1).
The patient was well informed of the complication in the first eye and the chance of developing retinal haemorrhages in the right eye after orbital decompression. She agreed to undergo surgery and 1 week later she underwent balanced orbital decompression on the right side. Three days later she again noted spots in front of her right eye. Best corrected visual acuity decreased to 20/160, and funduscopic examination revealed posterior pole retinal haemorrhages (fig 2).
Three months postoperatively IOP in primary gaze decreased to 12 mm Hg in both eyes, and 14 and 16 mm Hg in upgaze. Exophthalmos decreased to 18 mm on each side, and the lagophthalmos and exposure keratopathy resolved. Fluorescein angiography showed evidence of blocked fluorescence, suggestive of retinal haemorrhage. There was no evidence of neovascularisation, vasculopathy, or choroidal rupture. Visual acuity gradually improved over the course of 3 months and returned to 20/20 in both eyes.
Decompression retinopathy is a rare complication that may occur after glaucoma filtration surgery. It is associated with scattered retinal haemorrhages concentrated in the posterior pole. It may be more common in patients with marked elevated preoperative intraocular pressure and after acute decrease of IOP. The haemorrhages may be diffuse, both in deep and superficial layers of the retina, and may even show white centres when first observed.1,2
Retinal haemorrhages associated with ocular decompression appear to be relatively benign and usually resolve within weeks to months with no effect on visual acuity or intraocular pressure. A gradual decrease of IOP preoperatively and intraoperatively is recommended in order to avoid this complication.1,2
Decompression retinopathy has not previously been described as a complication of orbital decompression surgery. Our patient had a relatively tight orbit with restrictive strabismus and marked enlargement of the extraocular muscles. Significant force was required to retract the globe to achieve exposure of the medial and deep lateral orbital walls. Retraction was frequently relaxed to assure perfusion of the retina. We hypothesise that the marked intraocular pressure fluctuation that occurs during these surgical manoeuvres may have contributed to the retinal haemorrhages. It may also be that rapid decrease in retrobulbar pressure has caused ocular hypotony and retinal haemorrhage.4