The retinal image quality characterized by the modulation-transfer function of the eye was measured for two groups of subjects aged in the late twenties and mid sixties, respectively. In both groups, we obtained modulation transfer functions by using a double-pass method under the same experimental conditions: 4-mm artificial pupil, paralyzed accommodation, and objective control of the refractive state and centering. Results showed lower values of modulation in the retinal image for older subjects compared with the younger subjects. The modulation transfer function ratio is similar to that previously found for contrast-sensitivity measurements with subjects in the same age groups. These results suggest that a significant fraction of the loss in spatial vision with age has an optical origin. Apart from the well-known increase in intraocular scattering, there also appears to be an increment in ocular aberration that causes an additional reduction in the contrast of retinal images.

An experimental study of the retinal image quality in aged subjects after their eyes have been implanted with intraocular lenses (IOL's) has been performed. The method is based on recording in vivo the aerial image of a point test, after a double pass through the ocular media, and subsequent computation of the eye's modulation transfer function. The optical performance of three different types of bifocal IOL is compared with that of conventional monofocal IOL's. The results show that eyes implanted with bifocals exhibit a mean reduction in the modulation transfer function (contrast in the retinal image) of a factor of 2, while keeping a resolution similar to that of monofocal IOL's (which explains why visual acuities are also similar in these two cases). The mean retinal image modulation in eyes implanted with monofocal IOL's is ∼2.5 times lower than that obtained with young emmetropic subjects, but it seems to be similar to that corresponding to # of persons of the same age (∼60 years) normal eyes.

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A case of cutis marmorata telangiectatica congenita (CMTC) is described in association with congenital glaucoma. Approximately 68 cases of CMTC and only four cases associated with glaucoma have been reported. The type of glaucoma seems to be related to an abnormality of the filtration in the anterior angle, due to increased pressure in the episcleral vessels. The surgical treatment is trabeculectomy, and opening an alternative drainage pathway.

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