Retinal "sweet spot" for myopia treatment

Area of Science:

• Ophthalmology
• Vision Science
• Retinal Physiology

Background:

• Understanding the specific retinal areas responsible for detecting optical defocus is key to comprehending eye growth regulation.
• Previous research has implicated various retinal regions in visual processing, but their distinct roles in refractive development remain under investigation.

Purpose of the Study:

• To identify the specific retinal area that controls short-term axial eye shortening in response to positive monocular defocus.
• To investigate the contribution of the fovea and different peripheral retinal zones to the eye's response to defocus.

Main Methods:

• Human subjects viewed a movie with a custom infrared eye tracker monitoring fixation.
• Real-time software applied controlled positive defocus (+3.0D) to specific retinal areas: foveal (0-3°), annular (3-9°), combined foveal/annular, and near-peripheral (6-10°).
• Axial eye length changes were measured using the eye tracker during these defocus conditions.

Main Results:

• Positive defocus elicited axial eye shortening similarly with full-field and foveal defocus, indicating a minor foveal contribution.
• Patching annular areas (3-9° or 6-9°) significantly suppressed the eye shortening response compared to full-field defocus.
• The near-peripheral retina (6-10°) alone effectively regulated the eye growth control mechanism, showing a response comparable to full-field defocus.

Conclusions:

• The fovea has a limited role in short-term axial eye shortening induced by positive defocus.
• The near-peripheral retina (6-10°) is a critical 'sweet spot' for detecting positive defocus and initiating regulatory responses.
• These findings suggest the near-peripheral retina plays a significant role in controlling eye growth and potentially long-term refractive development.