Optical section retinal imaging and wavefront sensing in diabetes.

PURPOSE

To investigate differences in higher-order ocular aberrations and in optical section retinal image resolution between healthy normal and diabetic subjects.

METHODS

An optical imaging system was established for combined retinal optical section imaging and wavefront sensing. A laser beam was expanded and focused to a point on the retina by the optics of the eye. For optical section retinal imaging, a cylindrical lens was placed in the path of the incident laser beam to form a focused line on the retina. Because of the angle between the incident laser and imaging path, an optical section image of the retina was captured. For wavefront sensing, a Shack-Hartmann aberrometer was incorporated in the imaging system. Twenty-two subjects with diabetes (average age, 52 +/- 12 years) and 13 normal subjects (average age, 47 +/- 9 years) were imaged. Retinal depth resolution was determined from the width of the laser line on the retina. Higher-order ocular aberrations were determined from the root mean square of the third to seventh Zernike terms, characterizing the wavefront aberration function. The data were analyzed statistically using Student's t-test and linear regression.

RESULTS

Higher-order ocular aberrations in diabetic subjects were significantly higher than in normal subjects (p=0.03). The retinal image depth resolution in diabetic subjects was significantly lower than in normal subjects (p <0.001). The retinal image depth resolution was inversely correlated with higher-order aberrations (r=-0.5; p=0.007; N=35).

CONCLUSIONS

The results demonstrate disease-related increases in higher-order ocular aberrations that influence retinal image resolution in diabetic eyes. This information is useful for designing high-resolution retinal imaging systems applicable for eyes with retinal disease.