Optical aberrations in the mouse eye

PURPOSE The mouse eye is a widely used model for retinal disease and has potential to become a model for myopia. Studies of retinal disease will benefit from imaging the fundus in vivo. Experimental models of myopia often rely on manipulation of the visual experience. In both cases, knowledge of the optical quality of the eye, and in particular, the retinal image quality degradation imposed by the ocular aberrations is essential. In this study, we measured the ocular aberrations in the wild type mouse. METHODS Twelve eyes from six four-week old black C57BL/6 wild type mice were studied. Measurements were done on awake animals, one being also measured under anesthesia for comparative purposes. Ocular aberrations were measured using a custom-built Hartmann-Shack system (using 680-nm illumination). Wave aberrations are reported up to fourth order Zernike polynomials. Spherical equivalent and astigmatism were obtained from the 2nd order Zernike terms. Modulation Transfer Functions (MTF) were estimated for the best focus, and through-focus, to estimate depth-of-focus. All reported data were for 1.5-mm pupils. RESULTS Hartmann-Shack refractions were consistently hyperopic (10.12+/-1.41 D, mean and standard deviation) and astigmatism was present in many of the eyes (3.64+/-3.70 D, on average). Spherical aberration was positive in all eyes (0.15+/-0.07 microm) and coma terms RMS were significantly high compared to other Zernike terms (0.10+/-0.03 microm). MTFs estimated from wave aberrations show a modulation of 0.4 at 2c/deg, for best focus (and 0.15 without cancelling the measured defocus). For that spatial frequency, depth-of-focus estimated from through-focus modulation data using the Rayleigh criterion was 6D. Aberrations in the eye of one anesthetized mouse were higher than in the same eye of the awake animal. CONCLUSIONS Hyperopic refractions in the mouse eye are consistent with previous retinoscopic data. The optics of the mouse eye is far from being diffraction-limited at 1.5-mm pupil, with significant amounts of spherical aberration and coma. However, estimates of MTFs from wave aberrations are higher than previously reported using a double-pass technique, resulting in smaller depth-of-field predictions. Despite the large degradation imposed by the aberrations these are lower than the amount of aberrations typically corrected by available correction techniques (i.e., adaptive optics). On the other hand, aberrations do not seem to be the limiting factor in the mouse spatial resolution. While the mouse optics are much more degraded than in other experimental models of myopia, its tolerance to large amounts of defocus does not seem to be determined entirely by the ocular aberrations.

[1]  M. T. Davisson,et al.  Retinal degeneration mutants in the mouse , 2002, Vision Research.

[2]  Robert N Weinreb,et al.  Elevated intraocular pressure and transgenic applications in the mouse. , 2005, Journal of glaucoma.

[3]  L. Maffei,et al.  The visual physiology of the wild type mouse determined with pattern VEPs , 1999, Vision Research.

[4]  Susana Marcos,et al.  The depth-of-field of the human eye from objective and subjective measurements , 1999, Vision Research.

[5]  D. Lara-Saucedo,et al.  Aberrations of the Human Eye in Visible and Near Infrared Illumination , 2003, Optometry and vision science : official publication of the American Academy of Optometry.

[6]  D. Mutti,et al.  The Artifact of Retinoscopy Revisited: Comparison of Refractive Error Measured by Retinoscopy and Visual Evoked Potential in the Rat , 1997, Optometry and Vision Science.

[7]  P. de la Villa,et al.  Refractive changes induced by form deprivation in the mouse eye. , 2003, Investigative ophthalmology & visual science.

[8]  F. Schaeffel,et al.  Contrast sensitivity of wildtype mice wearing diffusers or spectacle lenses, and the effect of atropine , 2006, Vision Research.

[9]  Eric P.H. Yap,et al.  Two models of experimental myopia in the mouse , 2008, Vision Research.

[10]  David Williams,et al.  Monochromatic ocular wavefront aberrations in the awake-behaving cat , 2004, Vision Research.

[11]  Susana Marcos,et al.  Ocular aberrations with ray tracing and Shack-Hartmann wave-front sensors: does polarization play a role? , 2002, Journal of the Optical Society of America. A, Optics, image science, and vision.

[12]  P. E. Hallett,et al.  A schematic eye for the mouse, and comparisons with the rat , 1985, Vision Research.

[13]  Sergio Barbero,et al.  Optical aberrations of intraocular lenses measured in vivo and in vitro. , 2003, Journal of the Optical Society of America. A, Optics, image science, and vision.

[14]  Susana Marcos,et al.  Contrast improvement of confocal retinal imaging by use of phase-correcting plates. , 2002, Optics letters.

[15]  R. Douglas,et al.  Rapid quantification of adult and developing mouse spatial vision using a virtual optomotor system. , 2004, Investigative ophthalmology & visual science.

[16]  A. Hughes,et al.  A schematic eye for the rat , 1979, Vision Research.

[17]  T. Kern,et al.  A mouse model of diabetic retinopathy. , 1996, Archives of ophthalmology.

[18]  Stephen A. Burns,et al.  Comparing Laser Ray Tracing, the Spatially Resolved Refractometer, and the Hartmann-Shack Sensor to Measure the Ocular Wave Aberration , 2001, Optometry and vision science : official publication of the American Academy of Optometry.

[19]  H. Wässle,et al.  An estimate of image quality in the rat eye. , 1979, Investigative ophthalmology & visual science.

[20]  Frank Schaeffel,et al.  In vivo biometry in the mouse eye with low coherence interferometry , 2004, Vision Research.

[21]  E. Irving,et al.  Refractive Error and Optical Image Quality in Three Strains of Albino Rats , 2005 .

[22]  Sergio Barbero,et al.  Optical quality and depth-of-field of eyes implanted with spherical and aspheric intraocular lenses. , 2005, Journal of refractive surgery.

[23]  Junzhong Liang,et al.  Aberrations and retinal image quality of the normal human eye. , 1997, Journal of the Optical Society of America. A, Optics, image science, and vision.

[24]  Spatially variant changes in lens power during ocular accommodation in a rhesus monkey eye. , 2004, Journal of vision.

[25]  Raymond A. Applegate,et al.  Customized corneal ablation : the quest for super vision , 2001 .

[26]  Frank Schaeffel,et al.  A paraxial schematic eye model for the growing C57BL/6 mouse , 2004, Vision Research.

[27]  P Artal,et al.  Retinal image quality in the rodent eye , 1998, Visual Neuroscience.

[28]  R. Fernald,et al.  Multifocal lenses compensate for chromatic defocus in vertebrate eyes , 1999, Journal of Comparative Physiology A.

[29]  ’ K.POWERS,et al.  DEPTH OF FOCUS, EYE SIZE AND VISUAL ACUITY , 2002 .

[30]  E. Aguilar,et al.  Three-dimensional in vivo imaging of the mouse intraocular vasculature during development and disease. , 2005, Investigative ophthalmology & visual science.

[31]  L. Thibos,et al.  Standards for reporting the optical aberrations of eyes. , 2002, Journal of refractive surgery.

[32]  Robert W. Williams,et al.  Measurement of Refractive State and Deprivation Myopia in Two Strains of Mice , 2004, Optometry and vision science : official publication of the American Academy of Optometry.

[33]  A. Guirao,et al.  A Method to Predict Refractive Errors from Wave Aberration Data , 2003, Optometry and vision science : official publication of the American Academy of Optometry.

[34]  M. Millodot,et al.  Retinoscopy and Eye Size , 1970, Science.

[35]  P Grimes,et al.  Acute reversible cataract induced by xylazine and by ketamine-xylazine anesthesia in rats and mice. , 1986, Experimental eye research.

[36]  Thomas G. Bifano,et al.  Retinal Imaging and Wavefront Sensing in Mice , 2004 .

[37]  E. G. D. L. Cera,et al.  Longitudinal changes of optical aberrations in normal and form-deprived myopic chick eyes , 2006, Vision Research.

[38]  Mark C. Pierce,et al.  Mouse Eye Parameters by Optical Coherence Tomography (OCT) , 2004 .

[39]  Andreas Wenzel,et al.  In vivo confocal imaging of the retina in animal models using scanning laser ophthalmoscopy , 2005, Vision Research.

[40]  S. Varma,et al.  Establishment of the Mouse as a Model Animal for the Study of Diabetic Cataracts , 2003, Ophthalmic Research.