Differences in retinal shape between East Asian and Caucasian eyes

Area of Science:

• Ophthalmology
• Human Anatomy
• Vision Science

Background:

• Retinal shape is a critical factor in visual function and refractive error development.
• Understanding ethnic variations in ocular anatomy can elucidate population-specific predispositions to eye conditions.
• Myopia prevalence varies significantly across different ethnic groups, with higher rates observed in East Asian populations.

Purpose of the Study:

• To investigate and compare the retinal shape of East Asian and Caucasian young adults.
• To determine if differences in retinal curvature correlate with refractive error (myopia) and ethnicity.

Main Methods:

• Peripheral eye lengths were measured in 36 East Asians and 40 Caucasians using a partial coherence interferometer.
• Retinal coordinates were estimated using ray-tracing through a theoretical eye model.
• Retinal shape was characterized by vertex radius of curvature (Rv) and equivalent radius of curvature (REq) along horizontal and vertical meridians.

Main Results:

• East Asians exhibited smaller Rv and REq values, indicating steeper retinas compared to Caucasians.
• Steeper retinal curvature was observed along the horizontal meridian versus the vertical meridian.
• Myopic individuals, irrespective of ethnicity, demonstrated steeper retinas than emmetropes, particularly along the horizontal meridian.

Conclusions:

• East Asians possess steeper retinas than Caucasians, with this difference being more pronounced horizontally.
• The observed racial and refractive differences in retinal shape suggest a potential role in the development of myopia.
• These findings contribute to understanding the high prevalence of myopia in East Asian populations.