IMAGE ANALYSIS OF OPTICAL COHERENCE TOMOGRAPHY SCANS TO EXPLORE ESTABLISHED AND NOVEL CHOROIDAL FEATURES IN PATIENTS WITH CENTRAL SEROUS CHORIORETINOPATHY.

PURPOSE: To explore the characteristics of choroidal tissue in patients with and without central serous chorioretinopathy (CSC) using an automated system of image analysis to determine known and novel metrics. METHODS: This was a retrospective case-control analysis of optical coherence tomography scans of patients seen at Manchester Royal Eye Hospital, UK, comparing patients with active CSC to an age-matched and gender-matched group with no CSC using a purpose-built automated system of image analysis. The expert system segments and measures established and novel features of choroid using a combination of thresholding, noise removal, and morphological techniques. RESULTS: A total of 72 patients were included in this study, with 40 included in the group with CSC and 32 patient controls with no CSC. There were significant increases from normal to CSC of median choroidal vascularity index, 54.7(median absolute deviation = 9.8) to 61.2(4.3), and all choroidal thickness indices including maximum depth, from 249.0(90.1) µm to 372.3(80.3) µm. For novel measures, there was a significant increase in tissue entropy from 6.68(0.28) to 6.95(0.17) and area of the largest five vessels from 6.28(3.04) mm2 to 9.10(3.49) mm2. The ratio of vessel lumen to stromal tissue intensity was conversely significantly reduced from 0.674(0.11) in normal patients to 0.59(0.06) in CSC. CONCLUSION: The automated system of choroidal analysis expands on the utility of known measures and introduces novel metrics. These findings contribute pathophysiological insights and metrics for further assessment and research on conditions affecting choroidal tissue.

Macular fibrosis in Coats' disease demonstrated by Optical Coherence Tomography Angiography - new data toward pathophysiology.

PURPOSE: To analyze if Segmented Swept-Source Optical Coherence Tomography Angiography (SS OCT-A) can provide additional information on morphology and pathophysiology of macular fibrosis in Coats' patients. METHODS: A consecutive case series of three male patients (5, 7 and 15 years old), with Coats' disease-related macular fibrosis (stage 2b-2 patients, 3b-1 patient). SS OCT-A 3×3 mm macular scans of affected eyes were performed. RESULTS: In all three cases the inner portion of macular fibrosis displayed a dense network of vessels, continuing into deeper layers. This structure was similar to that observed in retinal angiomatous proliferations (RAP). There was associated loss of the foveal avascular zone. In one case we observed evolution of the lesion. CONCLUSION: SS-OCT imaging of macular fibrosis in Coats' disease reveals a distinct intralesional vascular structure with elements resembling RAP, probably developing as a secondary process.

Electronic retinal prosthesis for severe loss of vision in geographic atrophy in age-related macular degeneration: First-in-human use.

BACKGROUND: To date there are yet no available approved therapies for Geographic Atrophy (GA) secondary to age-related macular degeneration (AMD). METHODS: Single site, non-randomized safety and efficacy study presenting the preliminary results in a cohort of five late stage AMD (GA) patients successfully implanted with the Argus II Retinal Prosthesis System (Second Sight Medical Products Inc., Sylmar, CA, USA). Extensive fundus imaging including retinal photographs from which the GA area was measured. A combination of custom and traditional tests designed for very low vision subjects assessed visual function in study subjects. A Functional Low-Vision Observer Rated Assessment was carried out to evaluate the impact of the system on the subject's daily life. In addition, a study to evaluate structural characteristics of the visual cortex of the brain was performed in one subject using magnetic resonance imaging. RESULTS: Seven device-related adverse events were reported, four of which were classed as serious adverse events. Retinal detachment was reported in three patients and was successfully treated within 12 months of onset. Testing showed an improvement in visual function in three of five patients with the system turned on. Magnetic resonance imaging assessed in one patient after implantation indicates a selective increase in cortical myelin and thickness in visual brain regions 1 year post implantation. CONCLUSIONS: Epiretinal prostheses can successfully be implanted in those affected by GA secondary to late-stage AMD and can elicit visual percepts by electrical stimulation of residual neuroretinal elements and improve basic visual function in those affected.