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A System for Culturing Iris Pigment Epithelial Cells to Study Lens Regeneration in Newt
Published on: June 22, 2011
The role of the iris in chick accommodation
Lisa Anne Ostrin1, Yue Liu, Vivian Choh
1School of Optometry, University of California Berkeley, Berkeley, California 94720, USA. laostrin@gmail.com
Investigative Ophthalmology & Visual Science
|March 2, 2011
Summary
Iridectomy (ID) minimally impacted chicken eye growth and refraction, suggesting it does not affect emmetropization. In vitro studies showed ID significantly reduced accommodation, highlighting biomechanical factors in chick vision.
Area of Science:
- Ophthalmology
- Animal Models
- Vision Science
Background:
- Pupil size, higher-order aberrations, and accommodation influence retinal image quality and eye growth.
- Iridectomy (ID) creates a fixed, enlarged pupil and may alter accommodation.
- Previous in vitro studies suggested ID could reduce accommodation in chickens.
Purpose of the Study:
- To investigate the effects of iridectomy (ID) on accommodation, eye growth, and refractive development in chickens.
- To explore the role of biomechanical factors in chick accommodation.
- To assess the impact of ID on intraocular pressure (IOP) and aqueous humor dynamics.
Main Methods:
- Monocular ID was performed on White-Leghorn chickens.
- Refraction, biometry, and corneal curvature were measured before and after nicotine instillation.
- Intraocular pressure (IOP) and anterior segment imaging (OCT) were conducted during accommodation.
- In vitro lens-scanning instrument was used to assess accommodation responses.
Main Results:
- ID caused minor decreases in chamber depths and increased lens thickness, but IOP remained similar to controls.
- In vivo, nicotine-induced accommodation was comparable between iridectomized and control eyes.
- In vitro, iridectomized eyes exhibited significantly reduced accommodation responses to nicotine.
- OCT showed iris displacement during accommodation in control eyes, but not in ID eyes.
Conclusions:
- Iridectomy minimally affected refraction and eye growth in chickens, supporting its use in emmetropization and myopia research.
- Reduced in vitro accommodation in iridectomized eyes suggests significant biomechanical contributions to accommodation in chicks.
- ID did not affect IOP, indicating iris musculature is not critical for aqueous outflow.
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