Spherical aberration,contrast sensitivity and color discrimination after cataract surgery with the aspherical intraocular lens / 北京大学学报(医学版)

Objective:To determine whether implantation of an intraocular lens(IOL) with a modified prolate anterior surface results in reduced spherical aberration and improved contrast sensitivity after cataract surgery.Methods: Consecutively 72 eyes were selected from 53 senile cataract patients who had received phacoemulsification and IOL implantation in Peking University Eye Center.Each was randomly assigned to receive Tecnis Z9001 IOL or Sensar AR40e(both made by AMO).Three months after operation,the eyes underwent several tests including visual acuity,optometry and wavefront aberration examination.Mesopic contrast sensitivity test was measured with ROLAND BA-4 Contrastometer.Results: The eyes treated with Tecnis Z9001 had significantly less spherical aberration.The eyes treated with Tecnis IOL got lower C12 coefficient and RMS4 than those with Sensar AR40e(P value

Comparison of laser in situ keratomileusis and laser-assisted subepithelial keratectomy for myopia more than-10.00 diopters / 北京大学学报(医学版)

0.05).There were more complaints of postoperative pain and discomfort after LASEK procedure.No severe vision threatening complications in these two groups were found.Conclusion:Both LASIK and LASEK are safe and effective in treating eyes with severe myopia.

Clinical study of higher order wavefront aberrations with a Tscherning aberrometer / 北京大学学报(医学版)

Objective: To study the higher order aberrations of emmetropic and ametropic eyes with wavefront aberrometer. Methods: Forty of cases 77 emmetropic and ametropic eyes were measured with an aberrometer based on Tscherning's principle with the pupils dilated. The Zernike coefficients and root mean square values of wavefront aberrations up to the 6th order were recorded and statistically analyzed. Results: The C06,C07,C08,C12,C13,C14,C24,C26,and C27 were significantly different from zero under 7 mm pupil size and the C06,C10,C12,C23,and C24 were significantly different from zero under 4 mm pupil size. There was no significant difference of higher order wavefront aberrations between emmetropic and ametropic eyes. Comparing the age of 40 years or less with the age over 40 years, there were significant differences in RMS3 between the two under 7 mm pupil size, and statistical diffenences in RMS6 and RMSh between the two under 4 mm pupil size. Conclusion: There are certain higher order wavefront aberrations in the normal human eyes, especially with the pupis dilated. No differences are found in higher order aberrations between emmetropic and ametropic eyes. The higher order aberrations of the age over 40 years are more than those of the age of 40 years or younger.

The role of the posterior corneal parameters measured by Pentacam in subclinical keratoconus screening / 眼科

Objective To estimate the role of the posterior corneal parameters measured by Pentacam in screening subclinical keratoconus.Design Retrospective case-controlled study.Participants Forty five healthy subjects(73 eyes),14 keratoconus patients (20 eyes),43 subclinical keratoconus patients(58 eyes).Methods Based TOPOLYZER and biomicroscope signs,eyes were diagnosed as subclinical keratoconus and keratoconus to compare the differnces of related posterior corneal parameters provided by Pentacam in normal eyes and subclinical keratoconus or keratoconus eyes.Main Outcome Measures Back-Diff(6 mm) max,Back-Diff(6 mm )min, Back-Difference(6 mm),Back-Rmin,Back-Astig.Results The parameters which were statistically different between normal corneas and clinical keratoconus,normal corneas and subclinical keratoconus include Back-Diff(6 mm)max(P