Abstract
Purpose :
To investigate the cause of persistent visual disturbance following Terson syndrome, defined as intraocular hemorrhage associated with subarachnoid hemorrhage.
Methods :
Retrospective analysis of multimodal retinal imaging in five patients who developed sub-internal limiting membrane (ILM) or vitreous hemorrhage as part of Terson syndrome. Retinal imaging included standard or wide-field fundus photography, confocal near-infrared (NIR) reflectance imaging, optical coherence tomography (OCT), fundus autofluorescence (FAF) and OCT angiography (OCTA, Heidelberg Engineering, Heidelberg, Germany). Where possible, comparisons were made between images obtained before and after vitrectomy with ILM peeling for sub-ILM hemorrhage.
Results :
Six eyes of five patients had macula-involving sub-ILM hemorrhage as part of Terson syndrome. At the last follow-up (median 11 weeks, range 6-150), findings on fundal examination did not explain persistent reduced visual acuity in some eyes. However, macular OCT revealed ellipsoid zone disruption and partial thinning of the photoreceptor layer in 7 eyes, which accounted for the vision loss. Notably, there was no correspondence between the size and locations of the outer retinal atrophy and the previous or partially persistent sub-ILM hemorrhages. All 10 eyes demonstrated variable degrees of disturbed NIR reflectance. These appeared as well-circumscribed hypo-reflective areas (median diameter 1.1 mm, range 0.6–2.1) over the posterior pole, which are also detectable as areas of hypo-autofluorescence by FAF imaging. In cases where these lesions involved the central macula, their extent showed correlation with the areas of outer retinal disruption and thinning on the OCT. OCTA was available in one eye 40 months after the acute sub-ILM hemorrhage and showed no obvious altered perfusion of the retina, choriocapillaris or choroid.
Conclusions :
These observations suggest that the outer retinal damage seen following Terson syndrome is unlikely to be directly linked to sub-ILM hemorrhage. OCT imaging may identify the functionally relevant structural changes and inform visual prognosis. While the exact pathophysiology remains unclear, the patchy partial photoreceptor atrophy may be explained by transient ischemia of choriocapillaris lobules, which are known to lack functional anastomosis between neighbouring units of arteriolar perfusion.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.