Biomedical subjects

W C Fan

Publications and source records attributed to W C Fan.

4 recordsLinked to original sources

PubMed1996

A new stereotest: the double two rod test.

A new stereoacuity test, the double two rod test, uses a two-alternative forced-choice (2AFC) paradigm. The subject's task is to state which pair of rods, the left or the right, contains depth information. The test gives repeatable results; comparison between the depth threshold measured binocularly and monocularly suggests that monocular cues, if present, provide only poor depth information, compared to the depth information arising from binocular disparity. As part of an investigation of stereoacuity and ageing, we tested stereoacuity as a function of viewing time and the number of comparisons made between the two pairs of rods. Stereoacuity was significantly reduced for viewing times less than 3 s while longer viewing times did not improve stereoacuity. The number of comparisons made between the two pairs of rods had no effect on stereoacuity.

Adult↗

PubMed1993

Decrease in stereoacuity in the seventh decade of life.

We measured stereoacuity in 41 subjects with normal Snellen acuity in each eye, and normal ocular health. Patients were measured in each of the age ranges 21-28, 41-49, 51-59 and 60-70 years. Stereoacuity was reduced from about 16 sec arc for the three younger groups to about 27 sec arc for the older subjects. Since stereopsis has a cortical neural substrate, these data suggest that there may be cortical changes affecting the interaction of information from the two eyes with advancing age, but whether these changes result from loss of contrast sensitivity, instability of ocular alignment or binocular stress, all of which have been reported in elderly subjects, is not known.

Adult↗

PubMed1990

[Use of intraspinal narcotics in obstetric anesthesia and analgesia].

The use of intraspinal narcotics has attracted great interest worldwide, particularly in the discipline of obstetric anesthesia. As the advent of spinal and epidural local anesthetics dramatically effected the anesthetic management of labor, delivery and obstetric surgery, likewise spinally administered opioids are emerging as safe and very effective methods of relieving post-cesarean section pain, improving labor and cesarean section analgesia in combination with local anesthetics, and injected alone in the subarachnoid space for the management of labor itself. Though intraspinal narcotic analgesia is associated with a number of side effects, with proper knowledge these adverse reactions are wither preventable or can be greatly reduced. Compared to the benefits of nearly complete pain relief in the intrapartum and postpartum periods, the price paid in terms of these side effects in minimal. The review was based on a computer-assisted search for articles published after 1975.

Analgesia↗

PubMed1976

Combined para-aminosalicylic acid and dietary therapy in long-term control of hypercholesterolemia and hypertriglyceridemia (Types IIa and IIb hyperlipoproteinemia).

The hypolipidemic effect of PAS-C-diet treatment was studied in 63 patients with Types IIa and IIb hyperlipoproteinemia for 6-36 months. Serum lipids and body weights of all patients were stabilized by a low cholesterol-saturated fat-refined carbohydrate diet before the initiation of an eight-week placebo-drug single-blind crossover study. During the placebo period the plasma lipids levels, mean +/- SD: cholesterol 355 +/- 63.5 mg%, triglyceride 141 +/- 68.7 mg%, and LDL-cholesterol 279 +/- 56.8 mg% were lowered to 274 +/- 53.1 mg+, 98 +/- 40.6 mg%, and 209 +/- 52.9 mg%, respectively (P less than 0.001 in each instance), with 7.5-11.0 grams of PAS-C/day given in one to three divided doses. In ten patients who have completed three years of treatment similar results were obtained. They showed no tendency to develop drug tolerance. Eight had watery diarrhea during the initial period which promptly subsided with interruption of drug therapy. Reintroduction of PAS-C in smaller dose (4.5 g/day) with gradual increment to effective dosage level was tolerated by all. No hematologic, hepatic, and ophthalmologic abnormalities were demonstrated by periodic monitoring. The hypoplipidemic effect of the drug was found to be diminished by alcohol and caloric excess.

Adolescent↗