Definition irregulær astigmatisme - optikerforeningen.dk Keratometri • Refleksen er skarp, men hurtig sløret, mistænk tørt øje • Refleksen er stabil, bølget eller sløret

SIM K

SIM 1 SIM 2 880 837 axe1234 334

Inferior-superior value (I-S)

bull 140Dgt Mistaelignk

bull 19Dgt Irregulaeligr

Forskel i dioptrier superior og inferior

Inferior-superior value (I-S)

bull gt140D Mistaelignk

bull gt19D Irregulaeligr

Forskel i dioptrier superior og inferior

Coma 90 abberationer og IS value som indikation i tidlig fase Optometry and Vision Sciense Vol 89 No 4 April 2012

Surface regularity index (SRI)

bull Analyserer central cornea

bull Normal cornea vaeligrdi lt08

Surface asymmetri index (SAI)

bull Beregner hele cornea

bull Normal vaeligrdi lt10

Hoslashjeste punkt

Hoslashjeste punkt

Elevation

Elevation

Kurvet Hoslashjt eller lavt

Tangential Elevation

Fiksering

Taringrefilm

bull Dryp oslashjet med comfortdraringber bull Indsaeligt bloslashd kontaktlinse +100 sf

IndstillingerFarveoploslashsning

IndstillingerFarveoploslashsning

Forward light scatter and contrast sensitivity in keratoconic patients

a b s t r a c t Purpose The aim of this study was to obtain intraocular forward light scatter (FLS) data in keratoconus patients and to explore possible relationships with contrast sensitivity Method Intraocular straylight was assessed in the right eye of 10 visually-normal subjects (31plusmn5 years) and 5 keratoconus patients (34plusmn9 years) using the van den Berg straylight meter Contrast sensitivity was also measured in both groups with and without a glare source provided by the Brightness Acuity Tester (BAT) using a PellindashRobson chart Inclusion criteria for the keratoconic patients were chosen to avoid natural causes of increased scatter and to limit the influence of factors that could affect the straylight measurements Results Intraocular light scatter was significantly greater in the keratoconic patients than in normal subjects for each of the three eccentricities tested (MannndashWhitney U test (2-tailed) Zleminus22 ple0027) Baseline PellindashRobson contrast sensitivity was also found to be lower in the keratoconus group than in the normal subjects (MannndashWhitney U test Z =minus22 p = 0023) Under glare conditions contrast loss was significantly greater in the keratoconic patients than in the normal subjects (MannndashWhitney U test Z =minus25 p = 0013) High levels of negative correlation were found between the magnitudes of intraocular straylight and baseline contrast sensitivity in the keratoconus group (Spearmanrsquos correlation coefficient (RS)leminus087 ple0027) Conclusion The high values of straylight measured in the keratoconic patients cannot be explained by age or scarring and could be related to the structural degradation of the cornea Further investigation of intraocular scatter in keratoconus is warranted to improve our current understanding of the visual deficits associated with this pathology copy 2011 British Contact Lens Association Published by Elsevier Ltd All rights reserved

Amit Jinabhai Clare OrsquoDonnell Hema Radhakrishnan Vincent Nourritlowast The University of Manchester England UK

Aberrations and topography in normal

keratoconus-suspect and keratoconic eyes

bull Department of Optometry and Vision Science Hadassah Academic College Jerusalem Israel arielaghadassahacil bull PURPOSE bull This study was designed to compare higher order aberrations of the cornea and of the eye with inferior-superior (I-S)

corneal topographic values in keratoconic eyes bull METHODS bull We studied 92 eyes from 78 subjects 21 eyes of 14 subjects with suspected keratoconus 23 eyes of 16 subjects with

manifest keratoconus and 48 eyes of 48 subjects without keratoconus using the L80 wave+ an instrument which can measure corneal topography and aberrations simultaneously with a large dynamic range making it possible to evaluate higher order aberrations to the seventh order of the Zernike polynomial function series

bull RESULTS bull All ocular and corneal higher order aberrations were found to be significantly higher for keratoconic than normal eyes but

for suspected keratoconus the results were mixed Corneal aberrations were higher than ocular aberrations due to compensation from the internal aberrations For manifest keratoconus the corneal and ocular vertical coma displayed the largest difference being 386 and 785 times higher respectively than normal eyes while the largest differences for suspected keratoconus were only 53 and 40 times higher respectively On the other hand inferior-superior dioptric asymmetry was 94 and 373 times higher for suspected keratoconus and keratoconic eyes respectively than normal eyes The separation of normality curves between suspected keratoconus and normal eyes was 286 for I-S and 143 for both corneal vertical coma and corneal total coma

bull CONCLUSIONS bull Although corneal vertical coma and to a lesser extent ocular vertical coma were found to be good indicators for the

detection of keratoconic eyes the traditional corneal topographic value such as the inferior-superior dioptric asymmetry remains an important predictor for identifying suspected keratoconus However ocular vertical coma and ocular higher order total root mean square also represent a good means of identifying suspected keratoconus

bull PMID 22311193 [PubMed - indexed for MEDLINE]

Department of Optometry and Vision Science Hadassah Academic College Jerusalem Israel arielaghadassahacil Gordon-Shaag A Millodot M Ifrah R Shneor E