Light-scattering characteristics of explanted opacified Aquasense intraocular lenses.

AIM: To study forward light-scattering characteristics of calcified explanted intraocular lenses (IOLs) (Aquasense, Ophthalmic Innovation International Ontario). METHODS: The amount of light scattered by the opacified IOLs was measured using a validated in vitro set-up for angles from 1.7 degrees to 22 degrees . This set-up gives results directly comparable with straylight values as valid for the in vivo situation. RESULTS: Straylight is highest at large angles and declines steeply approaching 0 degrees angle. This corresponds to the in vivo findings that opacified IOLs cause important visual complaints but have little effect on visual acuity. At 7.5 degrees , log (s) is around 1.8 and 2.9 for the two lenses respectively. This corresponds to 8 x and 100 x increases in straylight values compared with values in young, normal eyes. CONCLUSION: High straylight values caused by opacified IOLs can explain subjective complaints of reduced quality of vision in patients with opacified implants, despite good visual acuity.

Visual information processing in high-functioning individuals with autism spectrum disorders and their parents.

The authors assessed visual information processing in high-functioning individuals with pervasive developmental disorders (PDD) and their parents. The authors used tasks for contrast sensitivity, motion, and form perception to test visual processing occurring relatively early and late in the magnocellular-dorsal and parvocellular-ventral pathways. No deficits were found in contrast sensitivity for low or high spatial frequencies or for motion or form perception between individuals with PDD in comparison with a matched control group. Individuals with PDD performed equally with or better than controls on motion detection tasks. In addition, the authors did not find differences on any of the tasks between parents of the PDD group and matched control parents. These results indicate that high-functioning individuals with PDD and their parents are able to process visual stimuli that rely on early or late processing in the magnocellular-dorsal and parvocellular-ventral pathways as well as controls.

Measurement of stray light and glare: comparison of Nyktotest, Mesotest, stray light meter, and computer implemented stray light meter.

AIM: To evaluate the properties of devices for measuring stray light and glare: the Nyktotest, Mesotest, "conventional" stray light meter and a new, computer implemented version of the stray light meter. METHODS: 112 subjects, divided in three groups: (1) young subjects without any eye disease; (2) elderly subjects without any eye disease, and (3) subjects with (early) cataract in at least one eye. All subjects underwent a battery of glare and stray light tests, measurement of visual acuity, contrast sensitivity, refraction, and LOCS III cataract classification. Subjects answered a questionnaire on perceived disability during driving. RESULTS: Repeatability values were similar for all glare/stray light tests. Validity (correlation with LOCS III and questionnaire scores), discriminative ability (ability to discriminate between the three groups), and added value (to measurement of visual acuity and contrast sensitivity) were all superior for both stray light meters. Results of successive measurements are interrelated for the conventional but not the new stray light meter. This indicates a better resistance to fraud for the latter device. CONCLUSIONS: The new computer implemented stray light meter is the most promising device for future stray light measurements.