Using Life-Tech instrument(Visulab 5102 recorder, 7330 black and white visual pattern stimulator, 5402A averager, and 5874 P1 preamplifier), normal VEP was measured on 49 healthy person(98 eyes) aged from 23 to 27yrs with visual acuity better than 0.9. The frequency of stimulus was 2Hz, averaged 128 responses and analysis time was 250ms. The check size was 60min horizontally and 50min vertically. The mean P1 latency of 98 eyes was 96.81 +/- 7.51ms. The mean P1 latency of 49 right eyes was 96.78 +/- 7.98ms and that of left eyes was 96.88 +/- 7.20ms. The difference between right and left eye was not significant statistically(p>0.05). The amplitide of VEP was so variable that it was excluded from this analysis.
Visual Acuity

No abstract available.
Strabismus* ; Visual Acuity*

Sixteen normal subjects were tested with the Titmus stereotest varying the binocular Snellen's visual acuity from 1.0 to 0.2. From 15 possible combinations, a nomogram describing the relationship of binocular variations of Snellen's visual acuity and stereoacuity was constructed and the relationship of binocular isoacuities to Titmus stereotest performance was expressed as an S-shaped function.
Nomograms ; Telescopes ; Visual Acuity*

We performed coreoplasty on drawn pupils(17 eyes) by using Argon laser only or Argon laser combined with Q-switched Nd:YAG laser from June 1983 to May 1989. The results were as follows; 1. The causes were divided by 7 eyes(41.2%) with trauma and 10 eyes(58.8%) without trauma. 2. There were 15 eyes(88.2%) in up-drawn pupils and 2 eyes(11.8%) in downdrawn pupils. 3. The degree of preoperative drawn pupil was 1.42mm in average and enlargement of postoperative drawn pupil was 1.25mm in average. The corrected effect for preoperative drawn pupil and postoperative drawn pupil and postoperative drawn pupil was shown as 2.58mm in average. 4. Postoperative corrected visual acuity improved fairly. It was same as preoperative corrected visual acuity in 4 eyes(23.5%) and improved in 13 eyes(76.5%).
Argon ; Pupil ; Visual Acuity

PURPOSE: This study compares the outcomes of unilateral cataract surgery to those of bilateral cataract surgery in patients with cataract of both eyes. METHODS: Among a total of 153 patients, 61 underwent unilateral surgery and 92 bilateral surgery. RESULTS: The unilateral and bilateral surgeries were similar in demographic and ocular characteristics including visual acuity and visual function-14, except patient-reported factor, such as trouble with vision at baseline. The patient-reported factor was more serious in bilateral surgery than in unilateral surgery. The changes of three outcomes were associated not with unilateral eye or bilateral eye surgery, but with each baseline condition. CONCLUSION: The patient-reported factors such as symptom score, trouble with vision were the significant outcomes to decide unilateral or bilateral surgery in patients with cataract of both eyes. The result of unilateral or bilateral surgery did not affect the outcomes of cataract surgery after 12 months.
Cataract* ; Humans ; Visual Acuity

Prisms have been used as tools with which to treat and diagnose many diseases in strabismology. But, because of prismatic distortion and dispersion, the visual acuities are declined. The purpose of this study is to show the relationship between prismatic effect and visual acuity degradation. Visual acuities were measured through a series of prisms of CR-39 to quantify the blur induced by prism. The mean visual acuities of myopias and amblyopias(with or without correction), and emmetropias were reduced as prism diopters were increased. The declines were linear. There was no significant difference among the declines of visual acuities of each group. Whenever to prescribe prisms and to test with prisms, we should remind that prisms could reduce visual acuities.
Emmetropia ; Myopia ; Visual Acuity*

To evaluate the predictability of visual outcome in vaculopathy patients after treatment, we compared the difference between the pre-treatment visual acuity measured by hand-held laser interferometer and the posttreatment corrected visual acuity using Han`s visual acuity chart. Disease distribution was as follows; BRVO(18 cases), CRVO(11 cases), CSCR(9 cases), posterior uveitis(4 cases). The mean up period was 3.45 months. Among 42 cases, 28 eyes showed positive disparity and 13 eyes showed negative disparity. The range of disparity was from -0.2 to +0.3(mean 0.113). The post-treatment visual acuity was predictable within 2 lines in 38 eyes(90%) We concluded that the hand-held laser interferometer is one of the reliable methods to predict the post-treatment visual acuity in maculopathy patients.
Humans ; Visual Acuity*

We compared postoperative visual outcome and corneal refractive power depending on preoperative corneal topographic pattern and the predictibility of corneal topographic measurement compared with keratometric measurement after PRK. The subjects were 91 eyes divided into two goups composed of 44 eyes, symmetric bow tie type(SB) and 47 eyes, asymmetric bow tie type (aSB). The visual acuity, central power, and topographic pattern were measured before operation, postoperative 1 week, 1, 2 and 6 month in two groups, but no statistical difference(p>0.05). The averages of uncorrected visual acuity at 6 month were improved to 0.80(SB) and 0.85(aSB) from 0.09(SB) and 0.11(aSB) before operation. Topographic central refractive powers of +42.98D (SB), +43.32D(aSB) before operation were changed to +37.68D(SB), 37.56D(aSB) at 6month. The pattern of the region affected by the excimer laser was classified by key hole type 38%(SB) , 34%(aSB) , uniform roud type 41%(SB), 43%(aSB), semicircular type 21%(SB), 23%(aSB). The proportion of the difference less than one diopter between PRK setting and the change of the corneal refractive power at 6month was 36% and 76% in keratometric and topographic measurement. Above results show that the asymmetricity of bow tie type did not influence the visual outcome. The topographic measurement was better than keratometric measurement in evaluating the corneal refractory change after PRK.
Lasers, Excimer* ; Visual Acuity

One hundred and twenty-three cases of planned ECCE with biconvex posterior chamber lens implantation were performed in St. Mary's Hospital from April 1988 to February 1990, were followed up for more than 6 months. We also analyzed 123 cases of planned ECCE with convex-plano posterior chamber lens implantation during the same period. The results were as follows: 1. The difference of visual acuity between the two groups was not statistically significant. 2. Of the 123 eyes with biconvex lens, 106 eyes (86%) were within +/- 0.50 spherical equivalent diopter compared to 55 of 123 eyes (44.7%) with convex-plano lens. This difference is statistically signficant (p<.001). 3. Eight out of the 123 eyes with biconvex lens (6.5%) developed after-cataract and two of these eight eyes were of the central type: 36 out of the 123 eyes (29.3%) with convex-plano lens developed after-cataract and 31 of the these 36 eyes were of the central type. This difference is statistically significant(p<.001).
Cataract* ; Visual Acuity

No abstract available.
Child* ; Humans ; Visual Acuity*