Multimodal imaging in focal choroidal excavation secondary to blunt trauma

Author: Peter Garside (United Kingdom)

Co-authors: Amal Alomari, Guillermo DeLaMata

Purpose

To report an unusual case of extrafoveal conforming focal choroidal excavation (FCE) due to blunt trauma and discussion of its multimodal imaging findings.

Setting/Venue

Manchester Royal Eye Hospital, Manchester, United Kingdom

Methods

We report a 37 year old female who presented to our eye emergency department one month following blunt trauma to her left eye with flashes and floaters in her vision in association with an inferior visual field scotoma. She had been shot in the left eye by her child with a foam nerf gun pellet. She described pain at the time of the injury with visual symptoms developing one week later. She had no previous ocular or medical history of note.

Results

On presentation, visual acuity (VA) was -0.1logMar in both eyes. Left eye anterior segment examination was unremarkable with normal intraocular pressure and no signs of penetrating injury or hyphema. Posterior segment examination demonstrated an area of apparent mixed deep retinal and choroidal haemorrhage approximately 1 disc diameter in size, superior to the optic disc, with an otherwise flat retina. She was diagnosed with traumatic retinal/choroidal haemorrhage and managed conservatively. On subsequent follow-up she reported persistent scotoma albeit shrinking. Wide-field retinal imaging showed a circular, well demarcated red lesion at the same location, of two varying hues. Autofluorescence (AF) exhibited a three-way pattern with central marked hypoautofluorescence, an outer ring of less intense hypoautofluorescence and a transitional area of hyperautofluorescence. At her last attendance the hyperpigmented lesion had reduced in size, however persisted on autofluorescence with a reduction of hypoautofluorescence centrally. Enhanced depth imaging (EDI) - optical coherence tomography (OCT) was performed through the lesion which revealed a conforming FCE with associated scleral bowing. Based on these findings, a clinical diagnosis of traumatic retinal pigment epitheliopathy along with presumed underlying choroidal haemorrhage and secondary choroidal excavation was made. Conservative management and warning advice for potential rebleed or choroidal neovascularization was given.

Conlusions

FCE is an OCT based finding defined as an area of concavity in the choroid without accompanying scleral ectasia or posterior staphyloma. Different classifications have been suggested based upon location, morphology and cause. FCE in association with trauma has been rarely reported. The authors propose that the impact of the blunt trauma resulted in an area of traumatic pigment epitheliopathy with underlying choroidal haemorrhage. OCT imaging demonstrates photoreceptor atrophy and associated RPE damage at the lesion. The inner hyperpigmented hypoautofluorescent area seen on AF presumably corresponds to an area of more severe RPE damage with associated FCE. This RPE damage explains the patient’s persistent scotoma and fits with the multimodal imaging findings. The pathophysiology underlying FCE is not currently well understood. Whilst primary FCE cannot be excluded, the authors feel that this case represents secondary FCE. We propose that the impact from the blunt trauma resulted in choroidal haemorrhage, retinal pigment epitheliopathy and damage to Bruch’s membrane. On resorption of the haemorrhage, the stretched and damaged photoreceptor-RPE complex prolapsed posteriorly, corresponding to the area of FCE. To our knowledge, this is the first case reported of acquired extrafoveal conforming FCE secondary to blunt trauma.

Financial Disclosure

None

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