Outer Retinal Structure After Closed-Globe Blunt Ocular Trauma

Abstract

Purpose To evaluate outer retinal structural abnormalities in patients with visual deficits following closed globe blunt ocular trauma (cgBOT). Methods Nine subjects with visual complaints following cgBOT were examined between 1 month post-trauma and 6 years post-trauma. Spectral domain optical coherence tomography (SD-OCT) was used to assess outer retinal architecture, while adaptive optics scanning light ophthalmoscopy (AOSLO) was used to analyze photoreceptor mosaic integrity. Results Visual deficits ranged from central scotomas to decreased visual acuity. SD-OCT defects included focal foveal photoreceptor lesions, variable attenuation of the interdigitation zone, and mottling of the outer segment band, with one subject having normal outer retinal structure. AOSLO revealed disruption of the photoreceptor mosaic in all subjects, variably manifesting as foveal focal discontinuities, perifoveal hyporeflective cones, and paracentral regions of selective cone loss. Conclusions We observe persistent outer retinal disruption in subjects with visual complaints following cgBOT, albeit to a variable degree. AOSLO imaging allows assessment of photoreceptor structure at a level of detail not resolvable using SD-OCT or other current clinical imaging tools. Multimodal imaging appears useful for revealing the cause of visual complaints in patients following cgBOT. Future studies are needed to better understand how photoreceptor structure changes longitudinally in response to various trauma.

Assessing Photoreceptor Structure Associated With Ellipsoid Zone Disruptions Visualized With Optical Coherence Tomography

“…The split-detector AOSLO images revealed a mosaic of enlarged photoreceptors in the area of EZ and IZ disruption, surrounded by apparently normal cone and rod photoreceptors. Notably, the disruption size on confocal AOSLO more closely mirrors the size of the IZ disruption as previously reported 20 (Figure 5); whereas split-detector AOSLO demonstrates there is not complete loss of the photoreceptor mosaic as the EZ disruption might suggest. The dark vertical stripes in the confocal image are likely vessel shadows, which appear as a blur in the split-detector image.…”

“…20 Briefly, subject WW_0923 (22-year-old male) was an unrestrained driver in a motor vehicle collision in which airbags were deployed. Clinical evaluation on post-trauma day 2 revealed commotio retinae and RPE changes within the macula, as well as wide-spread hemorrhaging in the posterior pole OU.…”

“…To date, en face OCT has been utilized to evaluate photoreceptor structure in macular telangiectasia (MacTel) type 2, 15 diabetic retinopathy, 12 macular hole, 12, 16 macular degeneration 12, 17–19 and ocular trauma. 20 Quantification of EZ disruption with en face OCT was recently approved as the primary outcome measure for a therapeutic clinical trial in MacTel, 21 yet little is known about the in vivo cellular anatomy within and at the margins of these disruptions.…”

“…22, 23 The spatial correlation of disruptions as per confocal AOSLO imaging and en face OCT in closed globe blunt ocular trauma (cg-BOT) revealed photoreceptor cell disruption in the vicinity of EZ disruptions in OCT images. 20 Despite increased resolution, confocal AOSLO is also limited, as the technique does not visualize photoreceptors with abnormal outer segment morphology or alignment. 31 Since many retinal diseases are known to cause loss of the photoreceptor outer segment before loss of the remainder of the cell, 24–29 this limitation could prevent the accurate interpretation of the photoreceptor mosaic in the vicinity of such disruptions.…”

High-Resolution Imaging of Photoreceptors in Macular Microholes

“…Thus, the combination of fundus examination, SD-OCT, and AO-SLO may be useful in accurately diagnosing macular microholes and for monitoring patients with the disease. Recently Flatter et al 40 reported the SD-OCT and AO-SLO findings of photoreceptor damage after blunt trauma, which are similar to those of macular microholes. In both conditions, the lesions were very small, and AO-SLO is useful for evaluating and monitoring patients.…”