Session Title: Free Paper Session 2: Vascular Diseases & Diabetic Retinopathy I
Session Date/Time: Thursday 07/09/2017 | 09:00-10:30
Paper Time: 09:36
Venue: Room 117
First Author: : F.Romano ITALY
Co Author(s): : F. Stringa H. Ahmed E. Tsamis S. Ch'ng S. Biswas P. Stanga
Measure the size of the Foveal Avascular Zone (FAZ) area in the fellow and presumably healthy eye of paediatric patients (0-16 years old) affected by Coats’ Disease using Swept Source Optical Coherence Tomography Angiography (SS-OCT-A).
The study was designed as a Cross-Sectional and Observational Case Series. A total of nine patients, accounting for 9 normal looking on Dilated Fundoscopy fellow eyes were examined in our Paediatric Vitreoretinal Regional Service and prospectively recruited from September 2015 to December 2016.
All patients (9) underwent full ophthalmologic assessment including: Best Corrected Visual Acuity (BCVA), Slit lamp Biomicroscopy, Dilated Fundoscopy, Ultra Wide Field Multi-wavelength Imaging (UWF-MWI; California®, Optos plc.) and Swept Source Optical Coherence Tomography Angiography (SS-OCT-A) ((Topcon Corp., Japan) ). SS-OCT-A scans (6x6-mm ) were centred on the macula and acquired for each patient. All scans were automatically segmented using the proprietary analysis software Imagenet 6 (version 1.19) and the angiograms from the superficial (SCP) and the deep capillary plexus (DCP) vascularization were exported on to Image J software. The FAZ area was mapped by manually bordering its contours and converted from pixels to mm2 unit of measurement.
The cohort was composed of eight male and one female patients (5 white and 4 black) and with a mean age of 11.7 ± 3.7 years old (range: 6-16). The presumably unaffected fellow eye was the right one in five patients and the left in the remaining four. BCVA was unremarkable (-0.08 ± 0.11 LogMAR). While UWF-MWI did not reveal alterations in any fellow eye, six eyes (67%) showed a visibly enlarged FAZ, both on SCP and DCP on SS-OCT-A. Seven patients (78%) showed an FAZ of irregular contour in the plane of the SCP, whereas only two (22%) showed a normal shape. Quantitatively, the FAZ area measurement of these fellow eyes resulted to be significantly larger in the DCP than in the SCP (0.365 ± 0.130 vs. 0.247 ± 0.092 mm2 area; p = .02).
Despite Coats' Disease being considered a unilateral vascular disease of the retina in 90% of cases, SS-OCT-A assessment can show vascular alterations in the fellow and presumably unaffected eye. We therefore hypothesize that the enlarged and irregular FAZ noticed in the majority of fellow eyes might indicate previously clinically undetected alterations in the inner Blood Retinal Barrier (iBRB). These vascular alterations identified on SS-OCT-A may provide a new insight into the still elusive pathogenesis of Coats’ Disease. The limited size of our patient sample may indicate the need of a larger study of an age-matched control group in order to better explore and validate our hypothesis.