The effect of optic asphericity on visual rehabilitation of corneal ectasia with a prosthetic device.

OBJECTIVES: To study the effect of optic asphericity on visual rehabilitation of corneal ectasia with a prosthetic device. METHODS: Subjects with corneal ectasia treated with a fluid-ventilated gas-permeable prosthetic device of diameter 18.0-19.0 mm, who had subjective improvement of good Snellen vision with introduction of optic asphericity, were studied. Best corrected Snellen visual acuity (BCVA) under standard illumination, high contrast visual acuity (HCVA), low contrast visual acuity (LCVA), and wavefront aberrations were measured in a sequence of devices that varied per patient only in presence or amount of ellipsoidal front surface optical eccentricity (FSE). RESULTS: Five eyes of 5 subjects were studied. (M:F = 3:2; Age: 20-76). Mean steepest SimK was 57.72±8.30 D. BCVA was ≥20/30 in all eyes in all prosthetic devices, regardless of FSE. Although FSE improved BCVA, HCVA, and LCVA in each patient, no optimal amount could be identified in this small series. Asphericity in the form of 0.6 or 0.8 FSE improved HCVA, LCVA, or both in each patient. FSE was associated with a trend toward reduction of higher-order aberrations, particularly coma. CONCLUSIONS: Optic asphericity shows promise for optimization of vision in the rehabilitation of corneal ectasia with a prosthetic device.

Memory for the September 11, 2001, terrorist attacks one year later in patients with Alzheimer's disease, patients with mild cognitive impairment, and healthy older adults.

Although there are many opportunities to study memory in patients with Alzheimer's disease (AD) in the laboratory, there are few opportunities to study memory for real world events in these patients. The September 11, 2001 terrorist attacks provided one such opportunity. Patients with AD, patients with mild cognitive impairment (MCI), and healthy older adults were given a telephone questionnaire in the initial weeks after the event, again three to four months later, and finally one year afterwards to evaluate their memory for the September 11, 2001 terrorist attacks. We were particularly interested in using the attacks as an opportunity to examine the decline of episodic memory in patients with AD, patients with MCI, and older adult controls over a period of months. We found that compared to healthy older adults, patients with AD and MCI showed impaired memory at the initial time point, more rapid forgetting from the initial to the three-month time point, and very similar changes in memory from the three-month to the one-year time point. We speculated that these findings were consistent with patients with AD and MCI showing initial impaired encoding and a more rapid rate of forgetting compared with healthy older adults, but that once the memories had been consolidated, their decay rate became similar to that of healthy older adults. Lastly, although memory distortions were common among all groups, they were greatest in the patients with AD.