Abstract
Purpose :
To compare size and appearance of the foveal avascular zone (FAZ) in optical coherence tomopraphy angiography (OCTA) with foveal classic OCT and handheld OCT images in young children with a history of treated (tROP) or spontaneously resolved retinopathy of prematurity (ROP) (srROP).
Methods :
We investigated 5 children with tROP (mean age 5.85 years; range 4.6-7.08 years), and 5 children with srROP (mean age 5.8 years; range 4.5-6.7 years), and compared them to 10 healthy term-born age-matched children (Term; mean age 5.87 years; range 4.2-7.5 years). OCTA and classic volume OCT-Scans were performed using DRI OCT Triton (Swept Source OCT, Topcon, Netherlands). Handheld OCT was performed using Bioptigen Envisu C2300 (Leica, USA). The level of macular developmental arrest (MDA) (1), defined as a disproportion of the outer nuclear layer to inner retinal layers in the fovea, was analyzed with a custom made automated layer segmentation tool (DiOCTA) (2) and with the automated segmentation tool embedded in DRI OCT Triton. All children underwent visual acuity testing with Landolt-C.
Results :
OCTA clearly showed a narrowed FAZ in both tROP and srROP children. While the FAZ is assumed to be nearly circular in Term, the FAZ in tROP and srROP was significantly reduced in horizontal scale and only slightly reduced in vertical scale (elliptical shape). The overall area of the FAZ was significantly reduced (two fifths of the mean area of Term) and correlates with the MDA-Index – the smaller the area, the smaller the MDA-Index (narrow outer nuclear layer, wide inner retinal layers). At the same time visual acuity was significantly reduced in tROP and srROP and correlated with both reduced FAZ and reduced MDA-Index. Both layer analysis methods (handheld OCT with DiOCTA and classic OCT with Triton segmentation tool) showed consistent and reliable results and only small deviations in the calculation of the MDA-Index.
Conclusions :
OCTA allows detecting a downsized foveal avascular zone in young children with a history of ROP. The area of superficial FAZ and the reduced MDA-Index are correlated with best-corrected visual acuity in these children. OCTA and classic or handheld OCT are valuable diagnostic tools in young children because of their high accuracy and speed.
(1) Bowl et al.; Invest Ophthalmol Vis Sci 2016 1;57(9): OCT235-41.
(2) Ehnes et al.; Transl Vis Sci Technol 2014 11;3(1): 1.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.