J Korean Ophthalmol Soc.  2020 Dec;61(12):1507-1516. 10.3341/jkos.2020.61.12.1507.

Differences in Retinal and Choroidal Vessels between Dominant and Non-dominant Eyes in Intermittent Exotropia

• Kim JG
• Lee SY
• Lee DC

• KMID: 2511293
• DOI: http://doi.org/10.3341/jkos.2020.61.12.1507

Abstract

Purpose
To distinguish the dominant eye in patients with intermittent exotropia by comparing the width of the foveal avascular zone (FAZ), the vascular density (VD), and the choroidal thickness (CT) in both eyes.
Methods
A total of 34 subjects with intermittent exotropia were enrolled. Optical coherence tomography angiography (OCTA) was performed after discrimination of the dominant eye using a prism cover test (PCT). FAZ widths in the superficial capillary plexus (referred to here as superficial FAZ or SFAZ) and in the deep capillary plexus (deep FAZ or DFAZ); VDs of the 1-mm fovea and 3-mm parafovea, specifically the superficial capillary plexus density (SCPD); and CT measured by OCTA were compared between both eyes using a one-sample t-test. These abovementioned parameters were compared between dominant and non-dominant eyes through Pearson’s correlation analysis.
Results
The widths of SFAZ and DFAZ, the 1-mm fovea and 3-mm parafovea SCPDs, and CT of dominant eye showed positive correlations with respect to the non-dominant eye. Although there was no statistically significant difference in SFAZ and DFAZ widths, the 3-mm parafovea SCPD, or CT between eyes, the 1-mm fovea SCPD in the non-dominant eye showed a statistically significant higher density than that of the dominant eye (p = 0.039).
Conclusions
Our results suggest that the higher 1-mm fovea SCPD in the non-dominant eye is due to the secondary development of capillaries around the FAZ of the non-dominant eye after the retina of both eyes had developed to some extent.

Keyword

Choroid; Exotropia; Fovea centralis; Optical coherence tomography; Retinal vessels