Comparison of OCT angiography in children with a history of intravitreal injection of ranibizumab versus laser photocoagulation for retinopathy of prematurity

Purpose To compare the foveal microvascular structure characteristics in children with a history of intravitreal injection of ranibizumab (IVR) versus laser photocoagulation (LP) for retinopathy of prematurity by optical coherence tomography angiography (OCTA). Methods In this cross-sectional study, a total of 17 children (28 eyes) underwent IVR and 20 children (37 eyes) underwent LP were recruited. The age of doing OCTA examination of the two groups are 5.4 +/- 1.1 years and 6.3 +/- 1.8 years, respectively (p=0.07). Spectral-domain OCTA was performed for all the eyes with a scan size of 3x3 mm. The data of the superficial retinal layer were analysed. The foveal avascular zone (FAZ) and vessel density (including vessel length density (VLD) and perfusion density (PD)) were measured using the software of OCTA (Cirrus AngioPlex 5000, Carl Zeiss, Meditec, Dubin, California, USA). The central foveal thicknesses (CFT) were measured by cross-sectional OCT. Results In the central fovea, the retinal VLD and PD of patients with IVR were 13.82 +/- 2.99 mm/mm(2) and 0.25 +/- 0.05 mm(2)/mm(2), respectively, which were significantly lower than those of the LP group (15.64 +/- 2.71 mm/mm(2) and 0.28 +/- 0.05 mm(2)/mm(2), p=0.01 and p=0.006). The FAZ area of patients with IVR and LP were 0.13 +/- 0.09 mm(2) and 0.09 +/- 0.07 mm(2), respectively (p=0.048). The CFT of patients with IVR and LP were 200.7 +/- 16.7 mu m and 220.9 +/- 22.7 mu m, respectively (p<0.01). The logarithm of the minimal angle of resolution best-corrected visual acuity of patients with IVR and LP were 0.2 +/- 0.1 and 0.1 +/- 0.1, respectively (p=0.01). There was no significant difference in the parafoveal and foveal VLD and PD, FAZ morphological index and spherical equivalent refraction (SER) between the two groups. Conclusion The IVR might contribute to microvascular changes in the macular zone, such as reducing the central foveal VLD and PD, while the LP might contribute to microstructural changes, such as smaller FAZ and thicker CFT.