Parasympathetic innervation of emmetropization
Frances Rucker1, Chris Taylor1, Alexandra Kaser-Eichberger2
1New England College of Optometry, 424 Beacon St, Boston, MA, 02115, USA.
Experimental Eye Research
|February 5, 2022
Summary
Autonomic innervation and visual stimulation impact eye development. Parasympathetic lesions in chickens showed distinct effects on eye growth and anterior eye structures when exposed to specific light stimuli, suggesting antagonistic roles in emmetropization.
Area of Science:
- Ophthalmology
- Neuroscience
- Developmental Biology
Background:
- Emmetropization, the process of eye focusing, is influenced by visual stimuli and autonomic nervous system (ANS) input.
- Understanding the interaction between ANS and visual cues is crucial for deciphering eye growth regulation.
Purpose of the Study:
- To investigate how different types of visual stimulation interact with ocular innervation in emmetropization.
- To test the hypothesis that selective autonomic lesions modify the eye's response to light-induced emmetropization.
Main Methods:
- Selective parasympathetic denervation of the eye in chickens: ciliary ganglion (CGX) or pterygopalatine ganglion (PPGX).
- Exposure to modulated achromatic (RGB, RG) and chromatic (B/Y, R/G) light stimuli.
- Ocular biometry measurements (Lenstar, refractometer) post-stimulation.
Main Results:
- CGX lesions affected anterior and vitreous chamber depths under RGB stimulation.
- CGX eyes showed increased eye length with R/G chromatic light, while PPGX eyes showed decreased length with B/Y chromatic light.
- PPGX lesions did not alter responses to achromatic stimulation.
Conclusions:
- Two distinct parasympathetic innervations exhibit antagonistic effects on eye growth and anterior eye dimensions in response to specific visual stimuli.
- Findings suggest a role for choroidal blood flow, regulated by the pterygopalatine ganglion, in emmetropization.
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