Interocular differences in choroidal thickness and volumen in healthy eyes

Abstract

 

Purpose

 

To analyze and establish the interocular limits in choroidal thickness (CT) and volume (CV) in a healthy young adult population.

 

Methods

 

One hundred and twenty eyes of 60 healthy subjects underwent optical coherence tomography (OCT) with enhanced depth imaging (EDI). CTs and CVs at the three rings (1, 3 and 6mm) of the defined areas of the Early Treatment Diabetic Retinopathy Study (ETDRS) were measured manually. Topographic variation and relative interocular differences in CT and CV were analyzed.

 

Results

 

The mean±SD subfoveal CT in the right eye (RE) and the left eyes (LE) were 338.33±73.82µm and 357.80±76.11µm respectively, with a high correlation between the two eyes (r=0.826). Subfoveal CV were respectively, 0.27±0.06mm³ and 0.28±0.06mm³ (r=0.821). In the 3mm and 6mm rings, mean CT (RE vs LE) were 332.08±69.41µm vs 346.90±70.73µm (r=0.860) and 306.28±58.30µm vs 313.90±58.93µm (r=0.901). Regarding CV, they were 2.37±0.52mm³ vs 2.46±0.50mm³ (r=0.855) and 8.84±1.72mm³ vs 9.12±1.74mm³ (r=0.894). Although relative interocular difference is not significant, absolute interocular differences in subfoveal CT and CV may reach 95µm and 0.07mm³ respectively, 74µm and 0.62mm³ in a 3mm ring and 59µm and 1.85mm³ in a 6mm ring.

 

Conclusions

 

In healthy eyes there was a no significant relative interocular difference in CT or CV but normal absolute interocular differences should be established to differentiate healthy eyes from its pathological fellows.