Choroidal Thickness Profile in Normal Iranian Eyes with Different Refractive Status by Spectral-Domain Optical Coherence Tomography

Abstract

Purpose: To investigate the choroidal thickness and its association with age, gender, spherical equivalent (SE), and axial length (AL) in a sample of Iranian population with different refractive status using spectral-domain optical coherence tomography (SD-OCT). Methods: In a cross-sectional study, a total of 469 right eyes of 469 healthy subjects comprising 194 (41.4%) males and 275 (58.6%) females were examined. The mean age was 32.76 ± 15.77 years (range, 4-60 years). All subjects were divided into different groups according to their refractive status, age, and AL. The choroidal thickness was evaluated through enhanced-depth imaging (EDI) modality at subfoveal (Sf), 1, and 3 mm nasal (N1 and N3, respectively), temporal (T1 and T3, respectively), superior (S1 and S3, respectively), and inferior (I1 and I3, respectively) to the foveal center. Results: In the whole population, the mean subfoveal choroidal thickness (SfChT) was 329.83 ± 70.33 μm, and the choroid was thickest at S1 (342.04 ± 71.28 μm) and thinnest at N3 (209.00 ± 66.0 μm). Our data indicated a significant difference in the mean choroidal thickness across all points in different age groups (P < 0.0001). For emmetropic, myopic, and hyperopic subjects, mean SfChT values were 346.64 ± 59.63, 319.66 ± 73.17, and 364.00 ± 74.54 μm, respectively. Linear regression estimated that SfChT decreased about 12.8 and 8.71 μm for every 10 years of aging and each diopter increasing in myopia, respectively. Additionally, the SfChT decreased as 13.48 μm per mm increase in AL. Conclusions: The mean SfChT of a sample of Iranian emmetropic subjects was 346.64 ± 59.63 μm. The choroidal thickness has a decreasing trend with increasing age, and the choroid is thinner in myopes and thicker in hyperopes compared with emmetropic subjects. In the whole participants, the thickest and thinnest points were S1 and N3, respectively.

Comparison of retinal and choroidal structures among three refractive groups

“…In a cohort study in China, patients with myopia had a lower CT compared with emmetropic patients, and patients with high myopia had the lowest CT values (14). In another study, Heirani et al (15) examined CT and refractive status and found that patients with myopia had a lower CT and patients with hyperopia had a greater CT. Similarly, we also found that myopic patients had a lower CT and hyperopic patients had a greater CT.…”

Choroidal features in flat irregular pigment epithelial detachment associated with Chronic central serous chorioretinopathy: Avascular versus vascularized

“…Choroidal thickness measurements vary among different studies, as this can be affected by factors such as patient’s ethnicity, age, refractive error, and axial length, the light source used in the OCT device, and software used to measure [ 13 , 14 ]. Although it has been shown that the Iranian population has a thicker choroid ranging from 329 to 363 μm compared to some other ethnicities [ 13 , 14 ]. The current study showed that patients with FIPED had a higher choroidal thickness compared to the fellow eye and also normal eyes.…”

Choroidal Remodeling Distribution Pattern in the Macular Region in Chinese Young Patients with Myopia

“…In both normal and highly myopic eyes, CT values vary among different regions in the macula, and CT is the thinnest at the nasal and inferior regions, followed by the superior and temporal regions (3,7,8). Several studies have demonstrated a decreased CT in highly myopic eyes (9)(10)(11). What is noteworthy is that Fang et al (12)reported a CT cut-off value of 56.5µm at 3mm nasally to the fovea, which is suggested as a diagnostic criterion of pathological myopia.…”