Evaluating the causes of retinopathy of prematurity relapse following intravitreal bevacizumab injection.

BACKGROUND: Retinopathy of prematurity (ROP) is a proliferative disorder of the developing retina. Intravitreal bevacizumab injection (IVB) is an emerging treatment for severe forms of ROP, which does not restrict the visual field in comparison to laser therapy. The present study aimed to determine and evaluate the risk factors for ROP recurrence following IVB injection. MATERIALS AND METHODS: In this retrospective study, 98 eyes of 49 infants with ROP who had received IVB injections as the primary treatment for type 1 ROP are included. RESULTS: Fifty-four eyes (55.1%) had aggressive retinopathy of prematurity (A-ROP), and forty-four (44.9%) had Stage III Plus ROP in Zone II. ROP recurred in 13 eyes (13.26%) of 8 infants. The mean period between IVB and the ROP recurrence was 8.08 (95% CI:5.32-10.83) weeks. The infants who had ROP recurrence had lower birth weight (P value = 0.002), lower postmenstrual age at IVB injection (P value = 0.001), lower IVB injection gap period from birth (P value = 0.044), higher oxygen therapy requirement rate after IVB injection (P value < 0.001, OR:19.0) and higher oxygen therapy duration (P value = 0.006). The ROP severity, gestational age at birth, and diet were not statistically different between the recurrence and complete regression groups. Out of 13 eyes treated with laser photocoagulation because of ROP relapse, macula dragging occurred in one eye, and all the cases met the complete regression. CONCLUSION: Low birth weight and oxygen therapy are the most important risk factors for ROP relapse, which requires meticulous oxygen treatment guidelines for premature infants.

Analysis of Retinal Layers' Thickness and Vascular Density after Successful Scleral Buckle Surgery.

PURPOSE: To investigate retinal layers' thickness and vascular density after successful scleral buckle surgery using the optical coherence tomography angiography (OCTA) method. METHODS: In this prospective interventional case-control study, 24 patients with macular-off rhegmatogenous retinal detachment (RRD) were included after performing successful reattachment by scleral buckling. Retinal layers' thickness and vascular density were assessed in the patients using the OCTA method compared to normal fellow eyes as controls 10 months postoperation. RESULTS: Inner retinal layers showed no significant difference, but there was a significant reduction in outer central 1-mm retinal layers' thickness. Outer plexiform-Bruch's membrane (153.1 ± 24.3 µm vs. 166.2 ± 15.1 µm, P = 0.003) and ellipsoid zone to Bruch's membrane (51.25 ± 9.3 µm vs. 57.35 ± 3.8 µm, P = 0.009) were thinner in the operated eyes compared to fellow eyes. Vascular density within a 300 µm wide region around the foveal avascular zone (FAZ) (foveal density-300) was significantly lower in the detached eyes (46.28% ± 7.12% vs. 51.01% ± 4.73%, P = 0.016), however, there was no difference in superficial and deep vascular density at 1-mm central circle. Superficial parafoveal vascular density was lower in the operated eyes (46.24% ± 5.30% vs. 49.52% ± 5.93%, P = 0.026) with no significant difference in deep parafoveal vascular density (49.93 ± 4.29% vs. 51.88% ± 4.79%, P = 0.137). There was no difference in FAZ area and perimeter between the two groups. CONCLUSIONS: Complete recovery of retinal thickness and vascular density did not achieve in the patients with RRD even after 10 months of reattachment by scleral buckling surgery. Superficial capillary vascular density was more affected than deep vascular density almost in the parafoveal area.