Layer-by-layer analysis of macular diseases with objectively measured visual functions

Area of Science:

• Ophthalmology
• Neuroscience
• Biomedical Engineering

Background:

• Macular diseases significantly impact visual function, necessitating objective and quantitative assessment methods.
• Current diagnostic tools may lack the precision to evaluate layer-by-layer visual function in the macula.

Purpose of the Study:

• To develop and present novel, objective, and quantitative methods for assessing layer-by-layer visual function in macular diseases.
• To introduce a prototype apparatus for foveal cone densitometry and detail its application.

Main Methods:

• Assembly of a prototype apparatus combining a modified fundus camera, independent optic pathways, and a personal computer for foveal cone densitometry.
• Utilizing a two-way density technique to objectively measure foveal cone pigment density and regeneration time.
• Employing focal macular electroretinography (FMERG) to record a-wave, b-wave, and oscillatory potentials for layer-specific visual function analysis.
• Simultaneous recording of FMERG and visual evoked response (VER) to differentiate between retinal and broader visual pathway impairments.

Main Results:

• Demonstrated the capability to objectively measure foveal cone pigment density and regeneration time.
• Showcased how comparative analysis of FMERG components (a-wave, b-wave, oscillatory potentials) identifies specific macular layers affected by disease.
• Highlighted the potential of combined FMERG and VER recordings for precise localization of visual pathway dysfunction.

Conclusions:

• The developed methods provide objective and quantitative layer-by-layer assessment of visual function in macular diseases.
• The prototype apparatus and FMERG techniques offer valuable tools for diagnosing and understanding the progression of macular disorders.
• Simultaneous FMERG and VER recording enhances the ability to distinguish between retinal and central visual pathway abnormalities.