Characterizing image quality in a scanning laser ophthalmoscope with differing pinholes and induced scattered light.

We quantify the effects on scanning laser ophthalmoscope image quality of controlled amounts of scattered light, confocal pinhole diameter, and age. Optical volumes through the optic nerve head were recorded for a range of pinhole sizes in 12 subjects (19-64 years). The usefulness of various overall metrics in quantifying the changes in fundus image quality is assessed. For registered and averaged images, we calculated signal-to-noise ratio, entropy, and acutance. Entropy was best able to distinguish differing image quality. The optimum confocal pinhole diameter was found to be 50 microm (on the retina), providing improved axial resolution and image quality under all conditions.

[1]  J. Pawley,et al.  Handbook of Biological Confocal Microscopy , 1990, Springer US.

[2]  A. Roorda,et al.  Theoretical modeling and evaluation of the axial resolution of the adaptive optics scanning laser ophthalmoscope. , 2004, Journal of biomedical optics.

[3]  P. Artal,et al.  Optical Aberrations and the Aging Eye , 2003, International ophthalmology clinics.

[4]  T. Wilson,et al.  The Role of the Pinhole in Confocal Imaging Systems , 1990 .

[5]  R N Weinreb,et al.  Effect of cataract and pupil size on image quality with confocal scanning laser ophthalmoscopy. , 1997, Archives of ophthalmology.

[6]  A. Roorda,et al.  MEMS-based adaptive optics scanning laser ophthalmoscopy. , 2006, Optics letters.

[7]  D. C. Howell.  Statistical Methods for Psychology , 1987 .

[8]  R. Webb,et al.  Flying spot TV ophthalmoscope. , 1980, Applied optics.

[9]  P Artal,et al.  Effects of aging in retinal image quality. , 1993, Journal of the Optical Society of America. A, Optics and image science.

[10]  Juan M. Bueno,et al.  Polarimetric high-resolution confocal scanning laser ophthalmoscope , 2005, Vision Research.

[11]  T Wilson,et al.  Size of the detector in confocal imaging systems. , 1987, Optics letters.

[12]  T. Wilson,et al.  Adaptive aberration correction in a confocal microscope , 2002, Proceedings of the National Academy of Sciences of the United States of America.

[13]  Rafael C. González,et al.  Digital image processing using MATLAB , 2006 .

[14]  P. Sharp,et al.  Performance measurements of an infrared digital scanning laser ophthalmoscope. , 1994, Physiological measurement.

[15]  T. J. T. P. van den Berg,et al.  The intraocular straylight function in 129 healthy volunteers; Dependence on angle, age and pigmentation , 1990, Vision Research.

[16]  Mahnaz Shahidi,et al.  Optical Section Retinal Imaging and Wavefront Sensing in Diabetes , 2004, Optometry and vision science : official publication of the American Academy of Optometry.

[17]  C. Hudson,et al.  The Impact of Artificial Light Scatter on Scanning Laser Tomography , 2006, Optometry and vision science : official publication of the American Academy of Optometry.

[18]  Maris Ozolinsh,et al.  Eye Cataract Simulation Using Polymer Dispersed Liquid Crystal Scattering Obstacles , 2004 .

[19]  G Westheimer,et al.  Optical performances of human eyes derived from double-pass measurements. , 1995, Journal of the Optical Society of America. A, Optics, image science, and vision.

[20]  Siddharth Poonja,et al.  MEMS-based adaptive optics scanning laser ophthalmoscopy , 2006 .

[21]  Takashi Fujikado,et al.  Effect of aging on ocular light scatter and higher order aberrations. , 2002, Journal of refractive surgery.

[22]  P T de Jong,et al.  Intraocular light scattering in age-related cataracts. , 1992, Investigative ophthalmology & visual science.

[23]  T. Wilson,et al.  Aberration correction for confocal imaging in refractive‐index‐mismatched media , 1998 .

[24]  R. Navarro,et al.  Monochromatic modulation transfer function of the human eye for different pupil diameters: an analytical expression. , 1994, Journal of the Optical Society of America. A, Optics, image science, and vision.

[25]  Theory of Dielectric and Optical Properties of Pdlc Films , 1998 .

[26]  Juan M Bueno,et al.  Confocal scanning laser ophthalmoscopy improvement by use of Mueller-matrix polarimetry. , 2002, Optics letters.

[27]  Benjamin A. Rockwell,et al.  A procedure for laser hazard classification under the Z136.1-2000 American National Standard for Safe Use of Lasers , 2002 .

[28]  G Westheimer,et al.  Evaluating diffusion of light in the eye by objective means. , 1994, Investigative ophthalmology & visual science.

[29]  Ann E Elsner,et al.  Improved contrast of subretinal structures using polarization analysis. , 2003, Investigative ophthalmology & visual science.

[30]  A. Bradley,et al.  Statistical variation of aberration structure and image quality in a normal population of healthy eyes. , 2002, Journal of the Optical Society of America. A, Optics, image science, and vision.

[31]  A. Roorda,et al.  Optimal pupil size in the human eye for axial resolution. , 2003, Journal of the Optical Society of America. A, Optics, image science, and vision.

[32]  Rangaraj M. Rangayyan,et al.  Measures of acutance and shape for classification of breast tumors , 1997, IEEE Transactions on Medical Imaging.

[33]  R V North,et al.  Acutance, an objective measure of retinal nerve fibre image clarity , 2003, The British journal of ophthalmology.

[34]  Claes Beckman.  The influence of increased interocular lightscatter on the contrast in a confocal scanning laserophthalmoscope image , 1995 .

[35]  F. Campbell,et al.  Optical quality of the human eye , 1966, The Journal of physiology.

[36]  B Lindblom,et al.  Confocal fundus imaging with a scanning laser ophthalmoscope in eyes with cataract. , 1995, The British journal of ophthalmology.

[37]  J. Goodman.  Statistical Properties of Laser Speckle Patterns , 1963 .

[38]  Robert H. Webb,et al.  Scanning Laser Ophthalmoscope , 1981, IEEE Transactions on Biomedical Engineering.

[39]  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.