Distribution and Change of Total Astigmatism, Corneal Astigmatism and Residual Astigmatism with Age in Patient with Emmetropia

PURPOSE: We evaluated the distribution and change of total, corneal and residual astigmatism with age in patients with emmetropia. METHODS: We examined the visual acuity, refraction, and corneal curvature in 263 persons aged from 3 to 83 years (mean, 38 years), with a spherical equivalent refraction of under +/-0.75 diopter (D). We analysed the distribution and change of the astigmatism. RESULTS: Total astigmatism was changed from with-the-rule (WTR) to against-the-rule (ATR) with aging based on WTR of 0.31 +/- 0.48 D in the 3-10 year-old group, ATR of 0.02 +/-0.52 D in the 31-40 year-old group and ATR of 0.65 +/- 0.66 D in the 71-83 year-old group. Corneal astigmatism showed a similar pattern to that of total astigmatism with WTR of 1.03 +/- 0.47 D, WTR of 0.37 +/- 0.78 D, ATR of 0.05 +/- 0.59 D and ATR of 0.31 +/- 0.64 D in the 3-10, 31-40, 61-70 and 71-83 year-old groups, respectively. Residual astigmatism showed ATR astigmatism in all age groups such as ATR of 0.71 +/- 0.48 D, ATR of 0.60 +/- 0.44 D and ATR of 0.35 +/- 0.71 D in the 3-10, 41-50 and 71-83 year-old groups, respectively. CONCLUSIONS: Total and corneal astigmatism showed the change from WTR to ATR, and residual astigmatism showed the pattern of decreasing ATR with aging in patients with emmetropia. The change of total astigmatism with aging seems to be influenced by that of corneal astigmatism rather than by that of residual astigmatism.

Change of Corneal Astigmatism with Aging in Koreans with Normal Visual Acuity

PURPOSE: To evaluate the distribution and change of corneal astigmatism with aging in persons with normal visual acuity. METHODS: We classified 504 subjects (504 eyes) showing good naked vision at least 1.0 from 3 to 83 years into 15 groups with 5 year interval and analyzed corneal astigmatism using refraction and keratometry. RESULTS: With-the-rule astigmatism (WTR) was shown in 98.5% between 3 and 25 years and progressively decreased with aging. In 61 to 65 years' group WTR was 34.1% and against-the-rule astigmatism (ATR) was 36.4%. After then ATR was more predominant. Mean corneal astigmatism was about 1 diopter under 20 years and progressively decreased to 0.5 D at 60 years with aging. CONCLUSIONS: 84.7% of persons with normal visual acuity have corneal astigmatism. WTR was predominant in the youth but progressively decreased with aging to equal balance with ATR in the mid sixties. After then corneal astigmatism would be inclined to against-the-rule. The amount of corneal astigmatism was decreased from about an 1 diopter in twenties to 0.5 diopter in sixties.

P100 Latency in Normal Persons by Pattern Reversal VEP and Flash VEP

The Flash Light Emitted Diode Flash Visual Evoked Potential(Flash VEP) is useful when patients are unable to cooperate sufficiently for a Pattern Reversal Visual Evoked Potential(RP-VEP). In order to evaluate the clinical utility of Flash VEP, we performed the PR-VEP and Flash VEP in 208 eyes of 104 normal persons. The average P100 latency(LaP100) was analyzed according to check size, age, sex, and the laterality of the eye. The LaP100 of PR-VEP stimulated with 8 X 8(120' X 96'), 16 X 16(60' X 48'), 32 X 32 (30' X 24') and 64 X 64(15' X 12') check size were 98.88 +/- 7.57msec(mean S.D msec) , 97.68 +/- 7.44msec, 96.31 +/- 7.21msec, 101.20 +/- 7.81msec, respectively. The LaP100 of PR-VEP stimulated with 32 X 32 check size at 3rd, 4th, 5th, 6th and 7th decades were 93.95 +/- 5.61msec, 94.70 +/- 7.71msec, 92.92 +/- 6.28msec, 97.78 +/- 6.24 msec, 102.79 +/- 5.27msec, respectively. The LaP100 of PR-VEP remained relatively stable until over 6th decade when it increased significantly (p0.05), and between male and female(p>0.05) in the LaP100 of both VEP. These results showed that LaP100 of PR-VEP changes according to the check size and patient's age. We should interprete the LaP100 of PR-VEP or Flash VEP after the processing of averaging its P100 according to the patient's.

Normal Aging Changes of The Scattering Intensity in The Human Lens

This report represents a quantitative analysis of the human lens changes in density correlated with aging using the Scheimpflug Camera(EAS-1000, Nidek) and image analysis technique. We measured the scattering light intensity(biometric; analysis) of the 13 points from the anterior capsule to the posterior capsule in 156 eyes. In generally, the scattering intensity of lens anterior part was greater than that of posterior part. The scattering light intensity of lens was increased with aging except in the posterior subcapsule and posterior capsule. This results will assist the classification and monitoring of human cataracts grade.

Aging Change of Pupil Size in Normal and Diabetic Patients

It is well recognized that diabetic patients have small pupil. The most likely cause of the abnormally small pupil in diabetics is decreased funcitor of the autonomic nerves. We measured pupil size in 141 control subjects and 53 diabetic patients (29 cases with symptomatic autonomic neuropathy, 24 cases without symptomatic autonomic neuropathy) with portable pupillometry, PUPILSCAN in darkness. Pupils become smaller in healthy and diabetic subjects with advancing age. (log pupil size = 2.05 - 0.066 X age, r: -0.47, p

DEVELOPMENT OF THE COCHLEAR AQUEDUCT AND ITS AGING CHANGE / 解剖学报

The development of the cochlear aqueduct and its aging change were investiga-ted in 234 temporal bones,ranging from 12-week-old embryo to adult by the lightmicroscope.The width of inner and outer opening,width and length of thecochlear aqueduct were parallel with the advance of fetal age.The length of thecochlear aqueduct at one year old was about the length of adult cochlear aqueduct.The diameter of the cochlear aqueduct at the child was wider than that of theadult.On the basis of morphology of the cochlear aqueduct and its characteristicof age,the developmental rule of the cochlear aqueduct,its function and clinicalsignificance were discussed.