Optical Coherence Tomography Angiography in Patients with Amblyopia

Abstract

Purpose: To determine the OCTA parameters including foveal avascular zone (FAZ) and vessel density (VD) in the amblyopic eyes compared with the fellow sound eyes and the eyes of the non-amblyopic subjects.Methods: In this case-control study, a total of 62 eyes from unilateral amblyopic children (n= 23) and the age-and sex-matched healthy children (n= 8) were included. The sound eye of the amblyopic children was considered as the internal control (n= 23) and the both eyes of the non-amblyopic children (n= 16) were considered as the external control. All participants underwent image recording with the optical coherence tomography angiography (OCTA) Results: The average age of 23 cases and 8 controls were 9.86±3.12 and 8.5±2.35 years, respectively.Twelve patients (52.2 %) in the case group and 8 subjects (50%) in the control group were female. Macular VD in different regions of super cial and deep capillary plexuses (SCP, DCP) were comparable amongst the case group and both the internal and the external control groups. The average FAZ area was 0.26±0.06 µm 2 in amblyopic eyes that was signi cantly larger than in the fellow eyes (0.21±0.06 µm 2 ; P=0.007) and was comparable to the healthy controls.Conclusion: Lack of signi cant difference of the macular vessel density between the amblyopic and nonamblyopic eyes of the both internal and external controls may be attributed to this fact that the changes of the retinal vascular density cannot be considered as the pathogenesis of amblyopia.

The Relationship between Fixation Stability and Retinal Structural Parameters in Children with Anisometropic, Strabismic and Mixed Amblyopia

“…No statistically significant differences were found in the FAZ area between amblyopic and control eyes, albeit a trend was observed in which anisometropic and mixed amblyopic eyes had larger FAZ areas than strabismic and control eyes. These findings would be in agreement with previous literature documenting larger FAZ areas in the SCP layer in anisometropic amblyopia [29,30], albeit other researchers have noted smaller FAZ areas in patients with anisometropic amblyopia, with or without strabismus [12], and in strabismic amblyopia [32].…”

“…However, the relationship between fixation stability and specific retinal anatomical features in various types of amblyopia is not conclusive. Similarly, several studies have investigated differences in the FAZ area between amblyopic and contralateral eyes, as well as healthy controls, reporting contradictory evidence [10,12,[29][30][31][32]. These discrepancies may be due to variations in sample demographics, such as age (adults or children) and distribution of amblyopia types, as well as differences in instrumentation, analysis software and methodology.…”

Evaluation of Foveal Avascular Zone After Strabismic and Anisometropic Amblyopia Therapy in Saudi Children Using Optic Coherence Tomography Angiography: A Cohort Study

“… 21 Nourinia et al in 2022 observed that the area of the FAZ was more extensive in eyes with amblyopia than in unaffected eyes. 10 Several studies have reported inconclusive variations in the FAZ area between amblyopic eyes and fellow eyes of children with unilateral amblyopia. 5 , 8 , 11 , 14 The FAZ biomarkers do not appear to have any correlation with the development of amblyopia or the health of the fellow eye.…”

“…12 However, our research conflicts with those of Nourinia et al and Yilmaz et al, who reported enlarged and reduced FAZ areas in amblyopic and fellow eyes, respectively. 10,11 These disparities underscore the need for additional controlled studies with adequate sample sizes to clarify the influence of amblyopia and its treatment on FAZ morphology and metrics derived from optical coherence tomographic angiography.…”

“…While some studies have reported inconclusive results regarding the differences in the foveal anterior zone (FAZ) between amblyopic and fellow eyes, other studies have found no such differences. 8 , 9 For example, Nourinia et al reported a larger FAZ in amblyopic eyes compared to unaffected eyes, 10 while Yilmaz et al noted a smaller FAZ in amblyopia versus fellow eyes. 11 Additionally, a study on Chinese children found that the perfusion parameters of the superficial retinal layer, such as the FAZ area, perimeter, and circularity, were significantly higher in amblyopic eyes compared to fellow eyes with anisometropic amblyopia.…”